add initial CODE PixiePro board support#2
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add initial CODE PixiePro board support#2code-ing wants to merge 1 commit intoFreescale:3.14-1.0.x-mx6from code-ing:3.14-1.0.x-mx6
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otavio
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…_BH() in preemptible context. [ Upstream commit 44f49dd ] Fixes the following kernel BUG : BUG: using __this_cpu_add() in preemptible [00000000] code: bash/2758 caller is __this_cpu_preempt_check+0x13/0x15 CPU: 0 PID: 2758 Comm: bash Tainted: P O 3.18.19 #2 ffffffff8170eaca ffff880110d1b788 ffffffff81482b2a 0000000000000000 0000000000000000 ffff880110d1b7b8 ffffffff812010ae ffff880007cab800 ffff88001a060800 ffff88013a899108 ffff880108b84240 ffff880110d1b7c8 Call Trace: [<ffffffff81482b2a>] dump_stack+0x52/0x80 [<ffffffff812010ae>] check_preemption_disabled+0xce/0xe1 [<ffffffff812010d4>] __this_cpu_preempt_check+0x13/0x15 [<ffffffff81419d60>] ipmr_queue_xmit+0x647/0x70c [<ffffffff8141a154>] ip_mr_forward+0x32f/0x34e [<ffffffff8141af76>] ip_mroute_setsockopt+0xe03/0x108c [<ffffffff810553fc>] ? get_parent_ip+0x11/0x42 [<ffffffff810e6974>] ? pollwake+0x4d/0x51 [<ffffffff81058ac0>] ? default_wake_function+0x0/0xf [<ffffffff810553fc>] ? get_parent_ip+0x11/0x42 [<ffffffff810613d9>] ? __wake_up_common+0x45/0x77 [<ffffffff81486ea9>] ? _raw_spin_unlock_irqrestore+0x1d/0x32 [<ffffffff810618bc>] ? __wake_up_sync_key+0x4a/0x53 [<ffffffff8139a519>] ? sock_def_readable+0x71/0x75 [<ffffffff813dd226>] do_ip_setsockopt+0x9d/0xb55 [<ffffffff81429818>] ? unix_seqpacket_sendmsg+0x3f/0x41 [<ffffffff813963fe>] ? sock_sendmsg+0x6d/0x86 [<ffffffff813959d4>] ? sockfd_lookup_light+0x12/0x5d [<ffffffff8139650a>] ? SyS_sendto+0xf3/0x11b [<ffffffff810d5738>] ? new_sync_read+0x82/0xaa [<ffffffff813ddd19>] compat_ip_setsockopt+0x3b/0x99 [<ffffffff813fb24a>] compat_raw_setsockopt+0x11/0x32 [<ffffffff81399052>] compat_sock_common_setsockopt+0x18/0x1f [<ffffffff813c4d05>] compat_SyS_setsockopt+0x1a9/0x1cf [<ffffffff813c4149>] compat_SyS_socketcall+0x180/0x1e3 [<ffffffff81488ea1>] cstar_dispatch+0x7/0x1e Signed-off-by: Ani Sinha <[email protected]> Acked-by: Eric Dumazet <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Dec 11, 2015
commit 1f9c6e1 upstream. There were several bugs here. 1) The done label was in the wrong place so we didn't copy any information out when there was no command given. 2) We were using PAGE_SIZE as the size of the buffer instead of "PAGE_SIZE - pos". 3) snprintf() returns the number of characters that would have been printed if there were enough space. If there was not enough space (and we had fixed the memory corruption bug #2) then it would result in an information leak when we do simple_read_from_buffer(). I've changed it to use scnprintf() instead. I also removed the initialization at the start of the function, because I thought it made the code a little more clear. Fixes: 5e6e3a9 ('wireless: mwifiex: initial commit for Marvell mwifiex driver') Signed-off-by: Dan Carpenter <[email protected]> Acked-by: Amitkumar Karwar <[email protected]> Signed-off-by: Kalle Valo <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Jan 13, 2016
When a43eec3 ("bpf: introduce bpf_perf_event_output() helper") added PERF_COUNT_SW_BPF_OUTPUT we ended up with a new entry in the event_symbols_sw array that wasn't initialized, thus set to NULL, fix print_symbol_events() to check for that case so that we don't crash if this happens again. (gdb) bt #0 __match_glob (ignore_space=false, pat=<optimized out>, str=<optimized out>) at util/string.c:198 #1 strglobmatch (str=<optimized out>, pat=pat@entry=0x7fffffffe61d "stall") at util/string.c:252 #2 0x00000000004993a5 in print_symbol_events (type=1, syms=0x872880 <event_symbols_sw+160>, max=11, name_only=false, event_glob=0x7fffffffe61d "stall") at util/parse-events.c:1615 #3 print_events (event_glob=event_glob@entry=0x7fffffffe61d "stall", name_only=false) at util/parse-events.c:1675 #4 0x000000000042c79e in cmd_list (argc=1, argv=0x7fffffffe390, prefix=<optimized out>) at builtin-list.c:68 #5 0x00000000004788a5 in run_builtin (p=p@entry=0x871758 <commands+120>, argc=argc@entry=2, argv=argv@entry=0x7fffffffe390) at perf.c:370 #6 0x0000000000420ab0 in handle_internal_command (argv=0x7fffffffe390, argc=2) at perf.c:429 #7 run_argv (argv=0x7fffffffe110, argcp=0x7fffffffe11c) at perf.c:473 #8 main (argc=2, argv=0x7fffffffe390) at perf.c:588 (gdb) p event_symbols_sw[PERF_COUNT_SW_BPF_OUTPUT] $4 = {symbol = 0x0, alias = 0x0} (gdb) A patch to robustify perf to not segfault when the next counter gets added in the kernel will follow this one. Reported-by: Ingo Molnar <[email protected]> Cc: Adrian Hunter <[email protected]> Cc: Alexei Starovoitov <[email protected]> Cc: David Ahern <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Wang Nan <[email protected]> Link: http://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
otavio
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Jan 13, 2016
When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel panic at t_show. general protection fault: 0000 [#1] PREEMPT SMP CPU: 0 PID: 2957 Comm: sh Tainted: G W O 3.14.55-x86_64-01062-gd4acdc7 #2 RIP: 0010:[<ffffffff811375b2>] [<ffffffff811375b2>] t_show+0x22/0xe0 RSP: 0000:ffff88002b4ebe80 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1 RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0 R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570 FS: 0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0 Call Trace: [<ffffffff811dc076>] seq_read+0x2f6/0x3e0 [<ffffffff811b749b>] vfs_read+0x9b/0x160 [<ffffffff811b7f69>] SyS_read+0x49/0xb0 [<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13 ---[ end trace 5bd9eb630614861e ]--- Kernel panic - not syncing: Fatal exception When the first time find_next calls find_next_mod_format, it should iterate the trace_bprintk_fmt_list to find the first print format of the module. However in current code, start_index is smaller than *pos at first, and code will not iterate the list. Latter container_of will get the wrong address with former v, which will cause mod_fmt be a meaningless object and so is the returned mod_fmt->fmt. This patch will fix it by correcting the start_index. After fixed, when the first time calls find_next_mod_format, start_index will be equal to *pos, and code will iterate the trace_bprintk_fmt_list to get the right module printk format, so is the returned mod_fmt->fmt. Link: http://lkml.kernel.org/r/[email protected] Cc: [email protected] # 3.12+ Fixes: 102c932 "tracing: Add __tracepoint_string() to export string pointers" Signed-off-by: Qiu Peiyang <[email protected]> Signed-off-by: Steven Rostedt <[email protected]>
otavio
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Feb 19, 2016
[ Upstream commit b4fe85f ] Drivers like vxlan use the recently introduced udp_tunnel_xmit_skb/udp_tunnel6_xmit_skb APIs. udp_tunnel6_xmit_skb makes use of ip6tunnel_xmit, and ip6tunnel_xmit, after sending the packet, updates the struct stats using the usual u64_stats_update_begin/end calls on this_cpu_ptr(dev->tstats). udp_tunnel_xmit_skb makes use of iptunnel_xmit, which doesn't touch tstats, so drivers like vxlan, immediately after, call iptunnel_xmit_stats, which does the same thing - calls u64_stats_update_begin/end on this_cpu_ptr(dev->tstats). While vxlan is probably fine (I don't know?), calling a similar function from, say, an unbound workqueue, on a fully preemptable kernel causes real issues: [ 188.434537] BUG: using smp_processor_id() in preemptible [00000000] code: kworker/u8:0/6 [ 188.435579] caller is debug_smp_processor_id+0x17/0x20 [ 188.435583] CPU: 0 PID: 6 Comm: kworker/u8:0 Not tainted 4.2.6 #2 [ 188.435607] Call Trace: [ 188.435611] [<ffffffff8234e936>] dump_stack+0x4f/0x7b [ 188.435615] [<ffffffff81915f3d>] check_preemption_disabled+0x19d/0x1c0 [ 188.435619] [<ffffffff81915f77>] debug_smp_processor_id+0x17/0x20 The solution would be to protect the whole this_cpu_ptr(dev->tstats)/u64_stats_update_begin/end blocks with disabling preemption and then reenabling it. Signed-off-by: Jason A. Donenfeld <[email protected]> Acked-by: Hannes Frederic Sowa <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Feb 19, 2016
[ Upstream commit 1b8e6a0 ] When a passive TCP is created, we eventually call tcp_md5_do_add() with sk pointing to the child. It is not owner by the user yet (we will add this socket into listener accept queue a bit later anyway) But we do own the spinlock, so amend the lockdep annotation to avoid following splat : [ 8451.090932] net/ipv4/tcp_ipv4.c:923 suspicious rcu_dereference_protected() usage! [ 8451.090932] [ 8451.090932] other info that might help us debug this: [ 8451.090932] [ 8451.090934] [ 8451.090934] rcu_scheduler_active = 1, debug_locks = 1 [ 8451.090936] 3 locks held by socket_sockopt_/214795: [ 8451.090936] #0: (rcu_read_lock){.+.+..}, at: [<ffffffff855c6ac1>] __netif_receive_skb_core+0x151/0xe90 [ 8451.090947] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff85618143>] ip_local_deliver_finish+0x43/0x2b0 [ 8451.090952] #2: (slock-AF_INET){+.-...}, at: [<ffffffff855acda5>] sk_clone_lock+0x1c5/0x500 [ 8451.090958] [ 8451.090958] stack backtrace: [ 8451.090960] CPU: 7 PID: 214795 Comm: socket_sockopt_ [ 8451.091215] Call Trace: [ 8451.091216] <IRQ> [<ffffffff856fb29c>] dump_stack+0x55/0x76 [ 8451.091229] [<ffffffff85123b5b>] lockdep_rcu_suspicious+0xeb/0x110 [ 8451.091235] [<ffffffff8564544f>] tcp_md5_do_add+0x1bf/0x1e0 [ 8451.091239] [<ffffffff85645751>] tcp_v4_syn_recv_sock+0x1f1/0x4c0 [ 8451.091242] [<ffffffff85642b27>] ? tcp_v4_md5_hash_skb+0x167/0x190 [ 8451.091246] [<ffffffff85647c78>] tcp_check_req+0x3c8/0x500 [ 8451.091249] [<ffffffff856451ae>] ? tcp_v4_inbound_md5_hash+0x11e/0x190 [ 8451.091253] [<ffffffff85647170>] tcp_v4_rcv+0x3c0/0x9f0 [ 8451.091256] [<ffffffff85618143>] ? ip_local_deliver_finish+0x43/0x2b0 [ 8451.091260] [<ffffffff856181b6>] ip_local_deliver_finish+0xb6/0x2b0 [ 8451.091263] [<ffffffff85618143>] ? ip_local_deliver_finish+0x43/0x2b0 [ 8451.091267] [<ffffffff85618d38>] ip_local_deliver+0x48/0x80 [ 8451.091270] [<ffffffff85618510>] ip_rcv_finish+0x160/0x700 [ 8451.091273] [<ffffffff8561900e>] ip_rcv+0x29e/0x3d0 [ 8451.091277] [<ffffffff855c74b7>] __netif_receive_skb_core+0xb47/0xe90 Fixes: a8afca0 ("tcp: md5: protects md5sig_info with RCU") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: Willem de Bruijn <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Feb 19, 2016
commit e46e31a upstream. When using the Promise TX2+ SATA controller on PA-RISC, the system often crashes with kernel panic, for example just writing data with the dd utility will make it crash. Kernel panic - not syncing: drivers/parisc/sba_iommu.c: I/O MMU @ 000000000000a000 is out of mapping resources CPU: 0 PID: 18442 Comm: mkspadfs Not tainted 4.4.0-rc2 #2 Backtrace: [<000000004021497c>] show_stack+0x14/0x20 [<0000000040410bf0>] dump_stack+0x88/0x100 [<000000004023978c>] panic+0x124/0x360 [<0000000040452c18>] sba_alloc_range+0x698/0x6a0 [<0000000040453150>] sba_map_sg+0x260/0x5b8 [<000000000c18dbb4>] ata_qc_issue+0x264/0x4a8 [libata] [<000000000c19535c>] ata_scsi_translate+0xe4/0x220 [libata] [<000000000c19a93c>] ata_scsi_queuecmd+0xbc/0x320 [libata] [<0000000040499bbc>] scsi_dispatch_cmd+0xfc/0x130 [<000000004049da34>] scsi_request_fn+0x6e4/0x970 [<00000000403e95a8>] __blk_run_queue+0x40/0x60 [<00000000403e9d8c>] blk_run_queue+0x3c/0x68 [<000000004049a534>] scsi_run_queue+0x2a4/0x360 [<000000004049be68>] scsi_end_request+0x1a8/0x238 [<000000004049de84>] scsi_io_completion+0xfc/0x688 [<0000000040493c74>] scsi_finish_command+0x17c/0x1d0 The cause of the crash is not exhaustion of the IOMMU space, there is plenty of free pages. The function sba_alloc_range is called with size 0x11000, thus the pages_needed variable is 0x11. The function sba_search_bitmap is called with bits_wanted 0x11 and boundary size is 0x10 (because dma_get_seg_boundary(dev) returns 0xffff). The function sba_search_bitmap attempts to allocate 17 pages that must not cross 16-page boundary - it can't satisfy this requirement (iommu_is_span_boundary always returns true) and fails even if there are many free entries in the IOMMU space. How did it happen that we try to allocate 17 pages that don't cross 16-page boundary? The cause is in the function iommu_coalesce_chunks. This function tries to coalesce adjacent entries in the scatterlist. The function does several checks if it may coalesce one entry with the next, one of those checks is this: if (startsg->length + dma_len > max_seg_size) break; When it finishes coalescing adjacent entries, it allocates the mapping: sg_dma_len(contig_sg) = dma_len; dma_len = ALIGN(dma_len + dma_offset, IOVP_SIZE); sg_dma_address(contig_sg) = PIDE_FLAG | (iommu_alloc_range(ioc, dev, dma_len) << IOVP_SHIFT) | dma_offset; It is possible that (startsg->length + dma_len > max_seg_size) is false (we are just near the 0x10000 max_seg_size boundary), so the funcion decides to coalesce this entry with the next entry. When the coalescing succeeds, the function performs dma_len = ALIGN(dma_len + dma_offset, IOVP_SIZE); And now, because of non-zero dma_offset, dma_len is greater than 0x10000. iommu_alloc_range (a pointer to sba_alloc_range) is called and it attempts to allocate 17 pages for a device that must not cross 16-page boundary. To fix the bug, we must make sure that dma_len after addition of dma_offset and alignment doesn't cross the segment boundary. I.e. change if (startsg->length + dma_len > max_seg_size) break; to if (ALIGN(dma_len + dma_offset + startsg->length, IOVP_SIZE) > max_seg_size) break; This patch makes this change (it precalculates max_seg_boundary at the beginning of the function iommu_coalesce_chunks). I also added a check that the mapping length doesn't exceed dma_get_seg_boundary(dev) (it is not needed for Promise TX2+ SATA, but it may be needed for other devices that have dma_get_seg_boundary lower than dma_get_max_seg_size). Signed-off-by: Mikulas Patocka <[email protected]> Signed-off-by: Helge Deller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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commit f36d1be upstream. When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel panic at t_show. general protection fault: 0000 [#1] PREEMPT SMP CPU: 0 PID: 2957 Comm: sh Tainted: G W O 3.14.55-x86_64-01062-gd4acdc7 #2 RIP: 0010:[<ffffffff811375b2>] [<ffffffff811375b2>] t_show+0x22/0xe0 RSP: 0000:ffff88002b4ebe80 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1 RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0 R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570 FS: 0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0 Call Trace: [<ffffffff811dc076>] seq_read+0x2f6/0x3e0 [<ffffffff811b749b>] vfs_read+0x9b/0x160 [<ffffffff811b7f69>] SyS_read+0x49/0xb0 [<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13 ---[ end trace 5bd9eb630614861e ]--- Kernel panic - not syncing: Fatal exception When the first time find_next calls find_next_mod_format, it should iterate the trace_bprintk_fmt_list to find the first print format of the module. However in current code, start_index is smaller than *pos at first, and code will not iterate the list. Latter container_of will get the wrong address with former v, which will cause mod_fmt be a meaningless object and so is the returned mod_fmt->fmt. This patch will fix it by correcting the start_index. After fixed, when the first time calls find_next_mod_format, start_index will be equal to *pos, and code will iterate the trace_bprintk_fmt_list to get the right module printk format, so is the returned mod_fmt->fmt. Link: http://lkml.kernel.org/r/[email protected] Fixes: 102c932 "tracing: Add __tracepoint_string() to export string pointers" Signed-off-by: Qiu Peiyang <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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[ Upstream commit cf0a254 ] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917 in_atomic(): 1, irqs_disabled(): 128, pid: 383, name: sh Preemption disabled at:[<ffff800000124c18>] kgdb_cpu_enter+0x158/0x6b8 CPU: 3 PID: 383 Comm: sh Tainted: G W 4.1.13-rt13 #2 Hardware name: Freescale Layerscape 2085a RDB Board (DT) Call trace: [<ffff8000000885e8>] dump_backtrace+0x0/0x128 [<ffff800000088734>] show_stack+0x24/0x30 [<ffff80000079a7c4>] dump_stack+0x80/0xa0 [<ffff8000000bd324>] ___might_sleep+0x18c/0x1a0 [<ffff8000007a20ac>] __rt_spin_lock+0x2c/0x40 [<ffff8000007a2268>] rt_read_lock+0x40/0x58 [<ffff800000085328>] single_step_handler+0x38/0xd8 [<ffff800000082368>] do_debug_exception+0x58/0xb8 Exception stack(0xffff80834a1e7c80 to 0xffff80834a1e7da0) 7c80: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7e4 ffff8083 001bfcc4 ffff8000 7ca0: f2000400 00000000 00000000 00000000 4a1e7d80 ffff8083 0049501c ffff8000 7cc0: 00005402 00000000 00aaa210 ffff8000 4a1e7ea0 ffff8083 000833f4 ffff8000 7ce0: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7ea0 ffff8083 001bfcc0 ffff8000 7d00: 4a0fc400 ffff8083 00005402 00000000 4a1e7d40 ffff8083 00490324 ffff8000 7d20: ffffff9c 00000000 92c23ba0 0000ffff 000a0000 00000000 00000000 00000000 7d40: 00000008 00000000 00080000 00000000 92c23b8b 0000ffff 92c23b8e 0000ffff 7d60: 00000038 00000000 00001cb2 00000000 00000005 00000000 92d7b498 0000ffff 7d80: 01010101 01010101 92be9000 0000ffff 00000000 00000000 00000030 00000000 [<ffff8000000833f4>] el1_dbg+0x18/0x6c This issue is similar with 62c6c61("arm64: replace read_lock to rcu lock in call_break_hook"), but comes to single_step_handler. This also solves kgdbts boot test silent hang issue on 4.4 -rt kernel. Signed-off-by: Yang Shi <[email protected]> Acked-by: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]> Signed-off-by: He Kuang <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Apr 20, 2016
… and subvolume roots [ Upstream commit f32e48e ] The following call trace is seen when btrfs/031 test is executed in a loop, [ 158.661848] ------------[ cut here ]------------ [ 158.662634] WARNING: CPU: 2 PID: 890 at /home/chandan/repos/linux/fs/btrfs/ioctl.c:558 create_subvol+0x3d1/0x6ea() [ 158.664102] BTRFS: Transaction aborted (error -2) [ 158.664774] Modules linked in: [ 158.665266] CPU: 2 PID: 890 Comm: btrfs Not tainted 4.4.0-rc6-g511711a #2 [ 158.666251] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 158.667392] ffffffff81c0a6b0 ffff8806c7c4f8e8 ffffffff81431fc8 ffff8806c7c4f930 [ 158.668515] ffff8806c7c4f920 ffffffff81051aa1 ffff880c85aff000 ffff8800bb44d000 [ 158.669647] ffff8808863b5c98 0000000000000000 00000000fffffffe ffff8806c7c4f980 [ 158.670769] Call Trace: [ 158.671153] [<ffffffff81431fc8>] dump_stack+0x44/0x5c [ 158.671884] [<ffffffff81051aa1>] warn_slowpath_common+0x81/0xc0 [ 158.672769] [<ffffffff81051b27>] warn_slowpath_fmt+0x47/0x50 [ 158.673620] [<ffffffff813bc98d>] create_subvol+0x3d1/0x6ea [ 158.674440] [<ffffffff813777c9>] btrfs_mksubvol.isra.30+0x369/0x520 [ 158.675376] [<ffffffff8108a4aa>] ? percpu_down_read+0x1a/0x50 [ 158.676235] [<ffffffff81377a81>] btrfs_ioctl_snap_create_transid+0x101/0x180 [ 158.677268] [<ffffffff81377b52>] btrfs_ioctl_snap_create+0x52/0x70 [ 158.678183] [<ffffffff8137afb4>] btrfs_ioctl+0x474/0x2f90 [ 158.678975] [<ffffffff81144b8e>] ? vma_merge+0xee/0x300 [ 158.679751] [<ffffffff8115be31>] ? alloc_pages_vma+0x91/0x170 [ 158.680599] [<ffffffff81123f62>] ? lru_cache_add_active_or_unevictable+0x22/0x70 [ 158.681686] [<ffffffff813d99cf>] ? selinux_file_ioctl+0xff/0x1d0 [ 158.682581] [<ffffffff8117b791>] do_vfs_ioctl+0x2c1/0x490 [ 158.683399] [<ffffffff813d3cde>] ? security_file_ioctl+0x3e/0x60 [ 158.684297] [<ffffffff8117b9d4>] SyS_ioctl+0x74/0x80 [ 158.685051] [<ffffffff819b2bd7>] entry_SYSCALL_64_fastpath+0x12/0x6a [ 158.685958] ---[ end trace 4b63312de5a2cb76 ]--- [ 158.686647] BTRFS: error (device loop0) in create_subvol:558: errno=-2 No such entry [ 158.709508] BTRFS info (device loop0): forced readonly [ 158.737113] BTRFS info (device loop0): disk space caching is enabled [ 158.738096] BTRFS error (device loop0): Remounting read-write after error is not allowed [ 158.851303] BTRFS error (device loop0): cleaner transaction attach returned -30 This occurs because, Mount filesystem Create subvol with ID 257 Unmount filesystem Mount filesystem Delete subvol with ID 257 btrfs_drop_snapshot() Add root corresponding to subvol 257 into btrfs_transaction->dropped_roots list Create new subvol (i.e. create_subvol()) 257 is returned as the next free objectid btrfs_read_fs_root_no_name() Finds the btrfs_root instance corresponding to the old subvol with ID 257 in btrfs_fs_info->fs_roots_radix. Returns error since btrfs_root_item->refs has the value of 0. To fix the issue the commit initializes tree root's and subvolume root's highest_objectid when loading the roots from disk. Signed-off-by: Chandan Rajendra <[email protected]> Signed-off-by: David Sterba <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 6acfe68 ] Request-based DM's blk-mq support (dm-mq) was reported to be 50% slower than if an underlying null_blk device were used directly. One of the reasons for this drop in performance is that blk_insert_clone_request() was calling blk_mq_insert_request() with @async=true. This forced the use of kblockd_schedule_delayed_work_on() to run the blk-mq hw queues which ushered in ping-ponging between process context (fio in this case) and kblockd's kworker to submit the cloned request. The ftrace function_graph tracer showed: kworker-2013 => fio-12190 fio-12190 => kworker-2013 ... kworker-2013 => fio-12190 fio-12190 => kworker-2013 ... Fixing blk_insert_clone_request()'s blk_mq_insert_request() call to _not_ use kblockd to submit the cloned requests isn't enough to eliminate the observed context switches. In addition to this dm-mq specific blk-core fix, there are 2 DM core fixes to dm-mq that (when paired with the blk-core fix) completely eliminate the observed context switching: 1) don't blk_mq_run_hw_queues in blk-mq request completion Motivated by desire to reduce overhead of dm-mq, punting to kblockd just increases context switches. In my testing against a really fast null_blk device there was no benefit to running blk_mq_run_hw_queues() on completion (and no other blk-mq driver does this). So hopefully this change doesn't induce the need for yet another revert like commit 621739b ! 2) use blk_mq_complete_request() in dm_complete_request() blk_complete_request() doesn't offer the traditional q->mq_ops vs .request_fn branching pattern that other historic block interfaces do (e.g. blk_get_request). Using blk_mq_complete_request() for blk-mq requests is important for performance. It should be noted that, like blk_complete_request(), blk_mq_complete_request() doesn't natively handle partial completions -- but the request-based DM-multipath target does provide the required partial completion support by dm.c:end_clone_bio() triggering requeueing of the request via dm-mpath.c:multipath_end_io()'s return of DM_ENDIO_REQUEUE. dm-mq fix #2 is _much_ more important than #1 for eliminating the context switches. Before: cpu : usr=15.10%, sys=59.39%, ctx=7905181, majf=0, minf=475 After: cpu : usr=20.60%, sys=79.35%, ctx=2008, majf=0, minf=472 With these changes multithreaded async read IOPs improved from ~950K to ~1350K for this dm-mq stacked on null_blk test-case. The raw read IOPs of the underlying null_blk device for the same workload is ~1950K. Fixes: 7fb4898 ("block: add blk-mq support to blk_insert_cloned_request()") Fixes: bfebd1c ("dm: add full blk-mq support to request-based DM") Cc: [email protected] # 4.1+ Reported-by: Sagi Grimberg <[email protected]> Signed-off-by: Mike Snitzer <[email protected]> Acked-by: Jens Axboe <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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May 5, 2016
[ Upstream commit ad6b1d9 ] The problem seems to be that if a new device is detected while we have already removed the shared HCD, then many of the xhci operations (e.g. xhci_alloc_dev(), xhci_setup_device()) hang as command never completes. I don't think XHCI can operate without the shared HCD as we've already called xhci_halt() in xhci_only_stop_hcd() when shared HCD goes away. We need to prevent new commands from being queued not only when HCD is dying but also when HCD is halted. The following lockup was detected while testing the otg state machine. [ 178.199951] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller [ 178.205799] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 1 [ 178.214458] xhci-hcd xhci-hcd.0.auto: hcc params 0x0220f04c hci version 0x100 quirks 0x00010010 [ 178.223619] xhci-hcd xhci-hcd.0.auto: irq 400, io mem 0x48890000 [ 178.230677] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002 [ 178.237796] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 178.245358] usb usb1: Product: xHCI Host Controller [ 178.250483] usb usb1: Manufacturer: Linux 4.0.0-rc1-00024-g6111320 xhci-hcd [ 178.257783] usb usb1: SerialNumber: xhci-hcd.0.auto [ 178.267014] hub 1-0:1.0: USB hub found [ 178.272108] hub 1-0:1.0: 1 port detected [ 178.278371] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller [ 178.284171] xhci-hcd xhci-hcd.0.auto: new USB bus registered, assigned bus number 2 [ 178.294038] usb usb2: New USB device found, idVendor=1d6b, idProduct=0003 [ 178.301183] usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 178.308776] usb usb2: Product: xHCI Host Controller [ 178.313902] usb usb2: Manufacturer: Linux 4.0.0-rc1-00024-g6111320 xhci-hcd [ 178.321222] usb usb2: SerialNumber: xhci-hcd.0.auto [ 178.329061] hub 2-0:1.0: USB hub found [ 178.333126] hub 2-0:1.0: 1 port detected [ 178.567585] dwc3 48890000.usb: usb_otg_start_host 0 [ 178.572707] xhci-hcd xhci-hcd.0.auto: remove, state 4 [ 178.578064] usb usb2: USB disconnect, device number 1 [ 178.586565] xhci-hcd xhci-hcd.0.auto: USB bus 2 deregistered [ 178.592585] xhci-hcd xhci-hcd.0.auto: remove, state 1 [ 178.597924] usb usb1: USB disconnect, device number 1 [ 178.603248] usb 1-1: new high-speed USB device number 2 using xhci-hcd [ 190.597337] INFO: task kworker/u4:0:6 blocked for more than 10 seconds. [ 190.604273] Not tainted 4.0.0-rc1-00024-g6111320 #1058 [ 190.610228] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 190.618443] kworker/u4:0 D c05c0ac0 0 6 2 0x00000000 [ 190.625120] Workqueue: usb_otg usb_otg_work [ 190.629533] [<c05c0ac0>] (__schedule) from [<c05c10ac>] (schedule+0x34/0x98) [ 190.636915] [<c05c10ac>] (schedule) from [<c05c1318>] (schedule_preempt_disabled+0xc/0x10) [ 190.645591] [<c05c1318>] (schedule_preempt_disabled) from [<c05c23d0>] (mutex_lock_nested+0x1ac/0x3fc) [ 190.655353] [<c05c23d0>] (mutex_lock_nested) from [<c046cf8c>] (usb_disconnect+0x3c/0x208) [ 190.664043] [<c046cf8c>] (usb_disconnect) from [<c0470cf0>] (_usb_remove_hcd+0x98/0x1d8) [ 190.672535] [<c0470cf0>] (_usb_remove_hcd) from [<c0485da8>] (usb_otg_start_host+0x50/0xf4) [ 190.681299] [<c0485da8>] (usb_otg_start_host) from [<c04849a4>] (otg_set_protocol+0x5c/0xd0) [ 190.690153] [<c04849a4>] (otg_set_protocol) from [<c0484b88>] (otg_set_state+0x170/0xbfc) [ 190.698735] [<c0484b88>] (otg_set_state) from [<c0485740>] (otg_statemachine+0x12c/0x470) [ 190.707326] [<c0485740>] (otg_statemachine) from [<c0053c84>] (process_one_work+0x1b4/0x4a0) [ 190.716162] [<c0053c84>] (process_one_work) from [<c00540f8>] (worker_thread+0x154/0x44c) [ 190.724742] [<c00540f8>] (worker_thread) from [<c0058f88>] (kthread+0xd4/0xf0) [ 190.732328] [<c0058f88>] (kthread) from [<c000e810>] (ret_from_fork+0x14/0x24) [ 190.739898] 5 locks held by kworker/u4:0/6: [ 190.744274] #0: ("%s""usb_otg"){.+.+.+}, at: [<c0053bf4>] process_one_work+0x124/0x4a0 [ 190.752799] #1: ((&otgd->work)){+.+.+.}, at: [<c0053bf4>] process_one_work+0x124/0x4a0 [ 190.761326] #2: (&otgd->fsm.lock){+.+.+.}, at: [<c048562c>] otg_statemachine+0x18/0x470 [ 190.769934] #3: (usb_bus_list_lock){+.+.+.}, at: [<c0470ce8>] _usb_remove_hcd+0x90/0x1d8 [ 190.778635] #4: (&dev->mutex){......}, at: [<c046cf8c>] usb_disconnect+0x3c/0x208 [ 190.786700] INFO: task kworker/1:0:14 blocked for more than 10 seconds. [ 190.793633] Not tainted 4.0.0-rc1-00024-g6111320 #1058 [ 190.799567] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 190.807783] kworker/1:0 D c05c0ac0 0 14 2 0x00000000 [ 190.814457] Workqueue: usb_hub_wq hub_event [ 190.818866] [<c05c0ac0>] (__schedule) from [<c05c10ac>] (schedule+0x34/0x98) [ 190.826252] [<c05c10ac>] (schedule) from [<c05c4e40>] (schedule_timeout+0x13c/0x1ec) [ 190.834377] [<c05c4e40>] (schedule_timeout) from [<c05c19f0>] (wait_for_common+0xbc/0x150) [ 190.843062] [<c05c19f0>] (wait_for_common) from [<bf068a3c>] (xhci_setup_device+0x164/0x5cc [xhci_hcd]) [ 190.852986] [<bf068a3c>] (xhci_setup_device [xhci_hcd]) from [<c046b7f4>] (hub_port_init+0x3f4/0xb10) [ 190.862667] [<c046b7f4>] (hub_port_init) from [<c046eb64>] (hub_event+0x704/0x1018) [ 190.870704] [<c046eb64>] (hub_event) from [<c0053c84>] (process_one_work+0x1b4/0x4a0) [ 190.878919] [<c0053c84>] (process_one_work) from [<c00540f8>] (worker_thread+0x154/0x44c) [ 190.887503] [<c00540f8>] (worker_thread) from [<c0058f88>] (kthread+0xd4/0xf0) [ 190.895076] [<c0058f88>] (kthread) from [<c000e810>] (ret_from_fork+0x14/0x24) [ 190.902650] 5 locks held by kworker/1:0/14: [ 190.907023] #0: ("usb_hub_wq"){.+.+.+}, at: [<c0053bf4>] process_one_work+0x124/0x4a0 [ 190.915454] #1: ((&hub->events)){+.+.+.}, at: [<c0053bf4>] process_one_work+0x124/0x4a0 [ 190.924070] #2: (&dev->mutex){......}, at: [<c046e490>] hub_event+0x30/0x1018 [ 190.931768] #3: (&port_dev->status_lock){+.+.+.}, at: [<c046eb50>] hub_event+0x6f0/0x1018 [ 190.940558] #4: (&bus->usb_address0_mutex){+.+.+.}, at: [<c046b458>] hub_port_init+0x58/0xb10 Signed-off-by: Roger Quadros <[email protected]> Signed-off-by: Mathias Nyman <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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commit 00cd29b upstream. The starting node for a klist iteration is often passed in from somewhere way above the klist infrastructure, meaning there's no guarantee the node is still on the list. We've seen this in SCSI where we use bus_find_device() to iterate through a list of devices. In the face of heavy hotplug activity, the last device returned by bus_find_device() can be removed before the next call. This leads to Dec 3 13:22:02 localhost kernel: WARNING: CPU: 2 PID: 28073 at include/linux/kref.h:47 klist_iter_init_node+0x3d/0x50() Dec 3 13:22:02 localhost kernel: Modules linked in: scsi_debug x86_pkg_temp_thermal kvm_intel kvm irqbypass crc32c_intel joydev iTCO_wdt dcdbas ipmi_devintf acpi_power_meter iTCO_vendor_support ipmi_si imsghandler pcspkr wmi acpi_cpufreq tpm_tis tpm shpchp lpc_ich mfd_core nfsd nfs_acl lockd grace sunrpc tg3 ptp pps_core Dec 3 13:22:02 localhost kernel: CPU: 2 PID: 28073 Comm: cat Not tainted 4.4.0-rc1+ #2 Dec 3 13:22:02 localhost kernel: Hardware name: Dell Inc. PowerEdge R320/08VT7V, BIOS 2.0.22 11/19/2013 Dec 3 13:22:02 localhost kernel: ffffffff81a20e77 ffff880613acfd18 ffffffff81321eef 0000000000000000 Dec 3 13:22:02 localhost kernel: ffff880613acfd50 ffffffff8107ca52 ffff88061176b198 0000000000000000 Dec 3 13:22:02 localhost kernel: ffffffff814542b0 ffff880610cfb100 ffff88061176b198 ffff880613acfd60 Dec 3 13:22:02 localhost kernel: Call Trace: Dec 3 13:22:02 localhost kernel: [<ffffffff81321eef>] dump_stack+0x44/0x55 Dec 3 13:22:02 localhost kernel: [<ffffffff8107ca52>] warn_slowpath_common+0x82/0xc0 Dec 3 13:22:02 localhost kernel: [<ffffffff814542b0>] ? proc_scsi_show+0x20/0x20 Dec 3 13:22:02 localhost kernel: [<ffffffff8107cb4a>] warn_slowpath_null+0x1a/0x20 Dec 3 13:22:02 localhost kernel: [<ffffffff8167225d>] klist_iter_init_node+0x3d/0x50 Dec 3 13:22:02 localhost kernel: [<ffffffff81421d41>] bus_find_device+0x51/0xb0 Dec 3 13:22:02 localhost kernel: [<ffffffff814545ad>] scsi_seq_next+0x2d/0x40 [...] And an eventual crash. It can actually occur in any hotplug system which has a device finder and a starting device. We can fix this globally by making sure the starting node for klist_iter_init_node() is actually a member of the list before using it (and by starting from the beginning if it isn't). Reported-by: Ewan D. Milne <[email protected]> Tested-by: Ewan D. Milne <[email protected]> Signed-off-by: James Bottomley <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 361cad3 upstream. We've seen this in a packet capture - I've intermixed what I think was going on. The fix here is to grab the so_lock sooner. 1964379 -> #1 open (for write) reply seqid=1 1964393 -> #2 open (for read) reply seqid=2 __nfs4_close(), state->n_wronly-- nfs4_state_set_mode_locked(), changes state->state = [R] state->flags is [RW] state->state is [R], state->n_wronly == 0, state->n_rdonly == 1 1964398 -> #3 open (for write) call -> because close is already running 1964399 -> downgrade (to read) call seqid=2 (close of #1) 1964402 -> #3 open (for write) reply seqid=3 __update_open_stateid() nfs_set_open_stateid_locked(), changes state->flags state->flags is [RW] state->state is [R], state->n_wronly == 0, state->n_rdonly == 1 new sequence number is exposed now via nfs4_stateid_copy() next step would be update_open_stateflags(), pending so_lock 1964403 -> downgrade reply seqid=2, fails with OLD_STATEID (close of #1) nfs4_close_prepare() gets so_lock and recalcs flags -> send close 1964405 -> downgrade (to read) call seqid=3 (close of #1 retry) __update_open_stateid() gets so_lock * update_open_stateflags() updates state->n_wronly. nfs4_state_set_mode_locked() updates state->state state->flags is [RW] state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1 * should have suppressed the preceding nfs4_close_prepare() from sending open_downgrade 1964406 -> write call 1964408 -> downgrade (to read) reply seqid=4 (close of #1 retry) nfs_clear_open_stateid_locked() state->flags is [R] state->state is [RW], state->n_wronly == 1, state->n_rdonly == 1 1964409 -> write reply (fails, openmode) Signed-off-by: Andrew Elble <[email protected]> Signed-off-by: Trond Myklebust <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit d144dfe upstream. If we use USB ID pin as wakeup source, and there is a USB block device on this USB OTG (ID) cable, the system will be deadlock after system resume. The root cause for this problem is: the workqueue ci_otg may try to remove hcd before the driver resume has finished, and hcd will disconnect the device on it, then, it will call device_release_driver, and holds the device lock "dev->mutex", but it is never unlocked since it waits workqueue writeback to run to flush the block information, but the workqueue writeback is freezable, it is not thawed before driver resume has finished. When the driver (device: sd 0:0:0:0:) resume goes to dpm_complete, it tries to get its device lock "dev->mutex", but it can't get it forever, then the deadlock occurs. Below call stacks show the situation. So, in order to fix this problem, we need to change workqueue ci_otg as freezable, then the work item in this workqueue will be run after driver's resume, this workqueue will not be blocked forever like above case since the workqueue writeback has been thawed too. Tested at: i.mx6qdl-sabresd and i.mx6sx-sdb. [ 555.178869] kworker/u2:13 D c07de74c 0 826 2 0x00000000 [ 555.185310] Workqueue: ci_otg ci_otg_work [ 555.189353] Backtrace: [ 555.191849] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0) [ 555.198912] r10:ee471ba0 r9:00000000 r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4 [ 555.206867] r4:ee470000 [ 555.209453] [<c07dec24>] (schedule) from [<c07e2fc4>] (schedule_timeout+0x15c/0x1e0) [ 555.217212] r4:7fffffff r3:edc2b000 [ 555.220862] [<c07e2e68>] (schedule_timeout) from [<c07df6c8>] (wait_for_common+0x94/0x144) [ 555.229140] r8:00000000 r7:00000002 r6:ee470000 r5:ee471ba4 r4:7fffffff [ 555.235980] [<c07df634>] (wait_for_common) from [<c07df790>] (wait_for_completion+0x18/0x1c) [ 555.244430] r10:00000001 r9:c0b5563c r8:c0042e48 r7:ef086000 r6:eea4372c r5:ef131b00 [ 555.252383] r4:00000000 [ 555.254970] [<c07df778>] (wait_for_completion) from [<c0043cb8>] (flush_work+0x19c/0x234) [ 555.263177] [<c0043b1c>] (flush_work) from [<c0043fac>] (flush_delayed_work+0x48/0x4c) [ 555.271106] r8:ed5b5000 r7:c0b38a3c r6:eea439cc r5:eea4372c r4:eea4372c [ 555.277958] [<c0043f64>] (flush_delayed_work) from [<c00eae18>] (bdi_unregister+0x84/0xec) [ 555.286236] r4:eea43520 r3:20000153 [ 555.289885] [<c00ead94>] (bdi_unregister) from [<c02c2154>] (blk_cleanup_queue+0x180/0x29c) [ 555.298250] r5:eea43808 r4:eea43400 [ 555.301909] [<c02c1fd4>] (blk_cleanup_queue) from [<c0417914>] (__scsi_remove_device+0x48/0xb8) [ 555.310623] r7:00000000 r6:20000153 r5:ededa950 r4:ededa800 [ 555.316403] [<c04178cc>] (__scsi_remove_device) from [<c0415e90>] (scsi_forget_host+0x64/0x68) [ 555.325028] r5:ededa800 r4:ed5b5000 [ 555.328689] [<c0415e2c>] (scsi_forget_host) from [<c0409828>] (scsi_remove_host+0x78/0x104) [ 555.337054] r5:ed5b5068 r4:ed5b5000 [ 555.340709] [<c04097b0>] (scsi_remove_host) from [<c04cdfcc>] (usb_stor_disconnect+0x50/0xb4) [ 555.349247] r6:ed5b56e4 r5:ed5b5818 r4:ed5b5690 r3:00000008 [ 555.355025] [<c04cdf7c>] (usb_stor_disconnect) from [<c04b3bc8>] (usb_unbind_interface+0x78/0x25c) [ 555.363997] r8:c13919b4 r7:edd3c000 r6:edd3c020 r5:ee551c68 r4:ee551c00 r3:c04cdf7c [ 555.371892] [<c04b3b50>] (usb_unbind_interface) from [<c03dc248>] (__device_release_driver+0x8c/0x118) [ 555.381213] r10:00000001 r9:edd90c00 r8:c13919b4 r7:ee551c68 r6:c0b546e0 r5:c0b5563c [ 555.389167] r4:edd3c020 [ 555.391752] [<c03dc1bc>] (__device_release_driver) from [<c03dc2fc>] (device_release_driver+0x28/0x34) [ 555.401071] r5:edd3c020 r4:edd3c054 [ 555.404721] [<c03dc2d4>] (device_release_driver) from [<c03db304>] (bus_remove_device+0xe0/0x110) [ 555.413607] r5:edd3c020 r4:ef17f04c [ 555.417253] [<c03db224>] (bus_remove_device) from [<c03d8128>] (device_del+0x114/0x21c) [ 555.425270] r6:edd3c028 r5:edd3c020 r4:ee551c00 r3:00000000 [ 555.431045] [<c03d8014>] (device_del) from [<c04b1560>] (usb_disable_device+0xa4/0x1e8) [ 555.439061] r8:edd3c000 r7:eded8000 r6:00000000 r5:00000001 r4:ee551c00 [ 555.445906] [<c04b14bc>] (usb_disable_device) from [<c04a8e54>] (usb_disconnect+0x74/0x224) [ 555.454271] r9:edd90c00 r8:ee551000 r7:ee551c68 r6:ee551c9c r5:ee551c00 r4:00000001 [ 555.462156] [<c04a8de0>] (usb_disconnect) from [<c04a8fb8>] (usb_disconnect+0x1d8/0x224) [ 555.470259] r10:00000001 r9:edd90000 r8:ee471e2c r7:ee551468 r6:ee55149c r5:ee551400 [ 555.478213] r4:00000001 [ 555.480797] [<c04a8de0>] (usb_disconnect) from [<c04ae5ec>] (usb_remove_hcd+0xa0/0x1ac) [ 555.488813] r10:00000001 r9:ee471eb0 r8:00000000 r7:ef3d9500 r6:eded810c r5:eded80b0 [ 555.496765] r4:eded8000 [ 555.499351] [<c04ae54c>] (usb_remove_hcd) from [<c04d4158>] (host_stop+0x28/0x64) [ 555.506847] r6:eeb50010 r5:eded8000 r4:eeb51010 [ 555.511563] [<c04d4130>] (host_stop) from [<c04d09b8>] (ci_otg_work+0xc4/0x124) [ 555.518885] r6:00000001 r5:eeb50010 r4:eeb502a0 r3:c04d4130 [ 555.524665] [<c04d08f4>] (ci_otg_work) from [<c00454f0>] (process_one_work+0x194/0x420) [ 555.532682] r6:ef086000 r5:eeb502a0 r4:edc44480 [ 555.537393] [<c004535c>] (process_one_work) from [<c00457b0>] (worker_thread+0x34/0x514) [ 555.545496] r10:edc44480 r9:ef086000 r8:c0b1a100 r7:ef086034 r6:00000088 r5:edc44498 [ 555.553450] r4:ef086000 [ 555.556032] [<c004577c>] (worker_thread) from [<c004bab4>] (kthread+0xdc/0xf8) [ 555.563268] r10:00000000 r9:00000000 r8:00000000 r7:c004577c r6:edc44480 r5:eddc15c0 [ 555.571221] r4:00000000 [ 555.573804] [<c004b9d8>] (kthread) from [<c000fef0>] (ret_from_fork+0x14/0x24) [ 555.581040] r7:00000000 r6:00000000 r5:c004b9d8 r4:eddc15c0 [ 553.429383] sh D c07de74c 0 694 691 0x00000000 [ 553.435801] Backtrace: [ 553.438295] [<c07de4fc>] (__schedule) from [<c07dec6c>] (schedule+0x48/0xa0) [ 553.445358] r10:edd3c054 r9:edd3c078 r8:edddbd50 r7:edcbbc00 r6:c1377c34 r5:60000153 [ 553.453313] r4:eddda000 [ 553.455896] [<c07dec24>] (schedule) from [<c07deff8>] (schedule_preempt_disabled+0x10/0x14) [ 553.464261] r4:edd3c058 r3:0000000a [ 553.467910] [<c07defe8>] (schedule_preempt_disabled) from [<c07e0bbc>] (mutex_lock_nested+0x1a0/0x3e8) [ 553.477254] [<c07e0a1c>] (mutex_lock_nested) from [<c03e927c>] (dpm_complete+0xc0/0x1b0) [ 553.485358] r10:00561408 r9:edd3c054 r8:c0b4863c r7:edddbd90 r6:c0b485d8 r5:edd3c020 [ 553.493313] r4:edd3c0d0 [ 553.495896] [<c03e91bc>] (dpm_complete) from [<c03e9388>] (dpm_resume_end+0x1c/0x20) [ 553.503652] r9:00000000 r8:c0b1a9d0 r7:c1334ec0 r6:c1334edc r5:00000003 r4:00000010 [ 553.511544] [<c03e936c>] (dpm_resume_end) from [<c0079894>] (suspend_devices_and_enter+0x158/0x504) [ 553.520604] r4:00000000 r3:c1334efc [ 553.524250] [<c007973c>] (suspend_devices_and_enter) from [<c0079e74>] (pm_suspend+0x234/0x2cc) [ 553.532961] r10:00561408 r9:ed6b7300 r8:00000004 r7:c1334eec r6:00000000 r5:c1334ee8 [ 553.540914] r4:00000003 [ 553.543493] [<c0079c40>] (pm_suspend) from [<c0078a6c>] (state_store+0x6c/0xc0) [ 555.703684] 7 locks held by kworker/u2:13/826: [ 555.708140] #0: ("%s""ci_otg"){++++.+}, at: [<c0045484>] process_one_work+0x128/0x420 [ 555.716277] #1: ((&ci->work)){+.+.+.}, at: [<c0045484>] process_one_work+0x128/0x420 [ 555.724317] #2: (usb_bus_list_lock){+.+.+.}, at: [<c04ae5e4>] usb_remove_hcd+0x98/0x1ac [ 555.732626] #3: (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224 [ 555.740403] #4: (&dev->mutex){......}, at: [<c04a8e28>] usb_disconnect+0x48/0x224 [ 555.748179] #5: (&dev->mutex){......}, at: [<c03dc2f4>] device_release_driver+0x20/0x34 [ 555.756487] #6: (&shost->scan_mutex){+.+.+.}, at: [<c04097d0>] scsi_remove_host+0x20/0x104 Cc: Jun Li <[email protected]> Signed-off-by: Peter Chen <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit b49b927 ] We shouldn't be calling clk_prepare_enable()/clk_prepare_disable() in an atomic context. Fixes the following issue: [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver [ 5.830974] driver_register 'ehci-omap' [ 5.895849] driver_register 'wl1271_sdio' [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002 [ 5.896876] 4 locks held by udevd/994: [ 5.896904] #0: (&dev->mutex){......}, at: [<c049597c>] __driver_attach+0x60/0xac [ 5.896923] #1: (&dev->mutex){......}, at: [<c049598c>] __driver_attach+0x70/0xac [ 5.896946] #2: (tll_lock){+.+...}, at: [<c04c2630>] omap_tll_enable+0x2c/0xd0 [ 5.896966] #3: (prepare_lock){+.+...}, at: [<c05ce9c8>] clk_prepare_lock+0x48/0xe0 [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine [ 5.897048] Preemption disabled at:[< (null)>] (null) [ 5.897051] [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233 [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree) [ 5.897076] [<c010e714>] (unwind_backtrace) from [<c010af34>] (show_stack+0x10/0x14) [ 5.897087] [<c010af34>] (show_stack) from [<c040aa7c>] (dump_stack+0x88/0xc0) [ 5.897099] [<c040aa7c>] (dump_stack) from [<c020c558>] (__schedule_bug+0xac/0xd0) [ 5.897111] [<c020c558>] (__schedule_bug) from [<c06f3d44>] (__schedule+0x88/0x7e4) [ 5.897120] [<c06f3d44>] (__schedule) from [<c06f46d8>] (schedule+0x9c/0xc0) [ 5.897129] [<c06f46d8>] (schedule) from [<c06f4904>] (schedule_preempt_disabled+0x14/0x20) [ 5.897140] [<c06f4904>] (schedule_preempt_disabled) from [<c06f64e4>] (mutex_lock_nested+0x258/0x43c) [ 5.897150] [<c06f64e4>] (mutex_lock_nested) from [<c05ce9c8>] (clk_prepare_lock+0x48/0xe0) [ 5.897160] [<c05ce9c8>] (clk_prepare_lock) from [<c05d0e7c>] (clk_prepare+0x10/0x28) [ 5.897169] [<c05d0e7c>] (clk_prepare) from [<c04c2668>] (omap_tll_enable+0x64/0xd0) [ 5.897180] [<c04c2668>] (omap_tll_enable) from [<c04c1728>] (usbhs_runtime_resume+0x18/0x17c) [ 5.897192] [<c04c1728>] (usbhs_runtime_resume) from [<c049d404>] (pm_generic_runtime_resume+0x2c/0x40) [ 5.897202] [<c049d404>] (pm_generic_runtime_resume) from [<c049f180>] (__rpm_callback+0x38/0x68) [ 5.897210] [<c049f180>] (__rpm_callback) from [<c049f220>] (rpm_callback+0x70/0x88) [ 5.897218] [<c049f220>] (rpm_callback) from [<c04a0a00>] (rpm_resume+0x4ec/0x7ec) [ 5.897227] [<c04a0a00>] (rpm_resume) from [<c04a0f48>] (__pm_runtime_resume+0x4c/0x64) [ 5.897236] [<c04a0f48>] (__pm_runtime_resume) from [<c04958dc>] (driver_probe_device+0x30/0x70) [ 5.897246] [<c04958dc>] (driver_probe_device) from [<c04959a4>] (__driver_attach+0x88/0xac) [ 5.897256] [<c04959a4>] (__driver_attach) from [<c04940f8>] (bus_for_each_dev+0x50/0x84) [ 5.897267] [<c04940f8>] (bus_for_each_dev) from [<c0494e40>] (bus_add_driver+0xcc/0x1e4) [ 5.897276] [<c0494e40>] (bus_add_driver) from [<c0496914>] (driver_register+0xac/0xf4) [ 5.897286] [<c0496914>] (driver_register) from [<c01018e0>] (do_one_initcall+0x100/0x1b8) [ 5.897296] [<c01018e0>] (do_one_initcall) from [<c01c7a54>] (do_init_module+0x58/0x1c0) [ 5.897304] [<c01c7a54>] (do_init_module) from [<c01c8a3c>] (SyS_finit_module+0x88/0x90) [ 5.897313] [<c01c8a3c>] (SyS_finit_module) from [<c0107120>] (ret_fast_syscall+0x0/0x1c) [ 5.912697] ------------[ cut here ]------------ [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58 [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count()) Cc: <[email protected]> Reported-by: H. Nikolaus Schaller <[email protected]> Tested-by: H. Nikolaus Schaller <[email protected]> Signed-off-by: Roger Quadros <[email protected]> Signed-off-by: Lee Jones <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 8e96a87 ] Userspace can quite legitimately perform an exec() syscall with a suspended transaction. exec() does not return to the old process, rather it load a new one and starts that, the expectation therefore is that the new process starts not in a transaction. Currently exec() is not treated any differently to any other syscall which creates problems. Firstly it could allow a new process to start with a suspended transaction for a binary that no longer exists. This means that the checkpointed state won't be valid and if the suspended transaction were ever to be resumed and subsequently aborted (a possibility which is exceedingly likely as exec()ing will likely doom the transaction) the new process will jump to invalid state. Secondly the incorrect attempt to keep the transactional state while still zeroing state for the new process creates at least two TM Bad Things. The first triggers on the rfid to return to userspace as start_thread() has given the new process a 'clean' MSR but the suspend will still be set in the hardware MSR. The second TM Bad Thing triggers in __switch_to() as the processor is still transactionally suspended but __switch_to() wants to zero the TM sprs for the new process. This is an example of the outcome of calling exec() with a suspended transaction. Note the first 700 is likely the first TM bad thing decsribed earlier only the kernel can't report it as we've loaded userspace registers. c000000000009980 is the rfid in fast_exception_return() Bad kernel stack pointer 3fffcfa1a370 at c000000000009980 Oops: Bad kernel stack pointer, sig: 6 [#1] CPU: 0 PID: 2006 Comm: tm-execed Not tainted NIP: c000000000009980 LR: 0000000000000000 CTR: 0000000000000000 REGS: c00000003ffefd40 TRAP: 0700 Not tainted MSR: 8000000300201031 <SF,ME,IR,DR,LE,TM[SE]> CR: 00000000 XER: 00000000 CFAR: c0000000000098b4 SOFTE: 0 PACATMSCRATCH: b00000010000d033 GPR00: 0000000000000000 00003fffcfa1a370 0000000000000000 0000000000000000 GPR04: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR12: 00003fff966611c0 0000000000000000 0000000000000000 0000000000000000 NIP [c000000000009980] fast_exception_return+0xb0/0xb8 LR [0000000000000000] (null) Call Trace: Instruction dump: f84d0278 e9a100d8 7c7b03a6 e84101a0 7c4ff120 e8410170 7c5a03a6 e8010070 e8410080 e8610088 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed023b Kernel BUG at c000000000043e80 [verbose debug info unavailable] Unexpected TM Bad Thing exception at c000000000043e80 (msr 0x201033) Oops: Unrecoverable exception, sig: 6 [#2] CPU: 0 PID: 2006 Comm: tm-execed Tainted: G D task: c0000000fbea6d80 ti: c00000003ffec000 task.ti: c0000000fb7ec000 NIP: c000000000043e80 LR: c000000000015a24 CTR: 0000000000000000 REGS: c00000003ffef7e0 TRAP: 0700 Tainted: G D MSR: 8000000300201033 <SF,ME,IR,DR,RI,LE,TM[SE]> CR: 28002828 XER: 00000000 CFAR: c000000000015a20 SOFTE: 0 PACATMSCRATCH: b00000010000d033 GPR00: 0000000000000000 c00000003ffefa60 c000000000db5500 c0000000fbead000 GPR04: 8000000300001033 2222222222222222 2222222222222222 00000000ff160000 GPR08: 0000000000000000 800000010000d033 c0000000fb7e3ea0 c00000000fe00004 GPR12: 0000000000002200 c00000000fe00000 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 c0000000fbea7410 00000000ff160000 GPR24: c0000000ffe1f600 c0000000fbea8700 c0000000fbea8700 c0000000fbead000 GPR28: c000000000e20198 c0000000fbea6d80 c0000000fbeab680 c0000000fbea6d80 NIP [c000000000043e80] tm_restore_sprs+0xc/0x1c LR [c000000000015a24] __switch_to+0x1f4/0x420 Call Trace: Instruction dump: 7c800164 4e800020 7c0022a6 f80304a8 7c0222a6 f80304b0 7c0122a6 f80304b8 4e800020 e80304a8 7c0023a e80304b0 <7c0223a6> e80304b8 7c0123a6 4e800020 This fixes CVE-2016-5828. Fixes: bc2a940 ("powerpc: Hook in new transactional memory code") Cc: [email protected] # v3.9+ Signed-off-by: Cyril Bur <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit ab2a4bf ] The USB core contains a bug that can show up when a USB-3 host controller is removed. If the primary (USB-2) hcd structure is released before the shared (USB-3) hcd, the core will try to do a double-free of the common bandwidth_mutex. The problem was described in graphical form by Chung-Geol Kim, who first reported it: ================================================= At *remove USB(3.0) Storage sequence <1> --> <5> ((Problem Case)) ================================================= VOLD ------------------------------------|------------ (uevent) ________|_________ |<1> | |dwc3_otg_sm_work | |usb_put_hcd | |peer_hcd(kref=2)| |__________________| ________|_________ |<2> | |New USB BUS #2 | | | |peer_hcd(kref=1) | | | --(Link)-bandXX_mutex| | |__________________| | ___________________ | |<3> | | |dwc3_otg_sm_work | | |usb_put_hcd | | |primary_hcd(kref=1)| | |___________________| | _________|_________ | |<4> | | |New USB BUS #1 | | |hcd_release | | |primary_hcd(kref=0)| | | | | |bandXX_mutex(free) |<- |___________________| (( VOLD )) ______|___________ |<5> | | SCSI | |usb_put_hcd | |peer_hcd(kref=0) | |*hcd_release | |bandXX_mutex(free*)|<- double free |__________________| ================================================= This happens because hcd_release() frees the bandwidth_mutex whenever it sees a primary hcd being released (which is not a very good idea in any case), but in the course of releasing the primary hcd, it changes the pointers in the shared hcd in such a way that the shared hcd will appear to be primary when it gets released. This patch fixes the problem by changing hcd_release() so that it deallocates the bandwidth_mutex only when the _last_ hcd structure referencing it is released. The patch also removes an unnecessary test, so that when an hcd is released, both the shared_hcd and primary_hcd pointers in the hcd's peer will be cleared. Signed-off-by: Alan Stern <[email protected]> Reported-by: Chung-Geol Kim <[email protected]> Tested-by: Chung-Geol Kim <[email protected]> CC: <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Backport of caaee62 ("ptrace: use fsuid, fsgid, effective creds for fs access checks") to v4.1 failed to update the mode parameter in the mm_access() call in pagemap_read() to have one of the new PTRACE_MODE_*CREDS flags. Attempting to read any other process' pagemap results in a WARN() WARNING: CPU: 0 PID: 883 at kernel/ptrace.c:229 __ptrace_may_access+0x14a/0x160() denying ptrace access check without PTRACE_MODE_*CREDS Modules linked in: loop sg e1000 i2c_piix4 ppdev virtio_balloon virtio_pci parport_pc i2c_core virtio_ring ata_generic serio_raw pata_acpi virtio parport pcspkr floppy acpi_cpufreq ip_tables ext3 mbcache jbd sd_mod ata_piix crc32c_intel libata CPU: 0 PID: 883 Comm: cat Tainted: G W 4.1.12-51.el7uek.x86_64 #2 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 0000000000000286 00000000619f225a ffff88003b6fbc18 ffffffff81717021 ffff88003b6fbc70 ffffffff819be870 ffff88003b6fbc58 ffffffff8108477a 000000003b6fbc58 0000000000000001 ffff88003d287000 0000000000000001 Call Trace: [<ffffffff81717021>] dump_stack+0x63/0x81 [<ffffffff8108477a>] warn_slowpath_common+0x8a/0xc0 [<ffffffff81084805>] warn_slowpath_fmt+0x55/0x70 [<ffffffff8108e57a>] __ptrace_may_access+0x14a/0x160 [<ffffffff8108f372>] ptrace_may_access+0x32/0x50 [<ffffffff81081bad>] mm_access+0x6d/0xb0 [<ffffffff81278c81>] pagemap_read+0xe1/0x360 [<ffffffff811a046b>] ? lru_cache_add_active_or_unevictable+0x2b/0xa0 [<ffffffff8120d2e7>] __vfs_read+0x37/0x100 [<ffffffff812b9ab4>] ? security_file_permission+0x84/0xa0 [<ffffffff8120d8b6>] ? rw_verify_area+0x56/0xe0 [<ffffffff8120d9c6>] vfs_read+0x86/0x140 [<ffffffff8120e945>] SyS_read+0x55/0xd0 [<ffffffff8171eb6e>] system_call_fastpath+0x12/0x71 Fixes: ab88ce5 (ptrace: use fsuid, fsgid, effective creds for fs access checks) Signed-off-by: Kenny Keslar <[email protected]> Cc: Roland McGrath <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: [email protected] Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit bd975d1 ] The secmech hmac(md5) structures are present in the TCP_Server_Info struct and can be shared among multiple CIFS sessions. However, the server mutex is not currently held when these structures are allocated and used, which can lead to a kernel crashes, as in the scenario below: mount.cifs(8) #1 mount.cifs(8) #2 Is secmech.sdeschmaccmd5 allocated? // false Is secmech.sdeschmaccmd5 allocated? // false secmech.hmacmd = crypto_alloc_shash.. secmech.sdeschmaccmd5 = kzalloc.. sdeschmaccmd5->shash.tfm = &secmec.hmacmd; secmech.sdeschmaccmd5 = kzalloc // sdeschmaccmd5->shash.tfm // not yet assigned crypto_shash_update() deref NULL sdeschmaccmd5->shash.tfm Unable to handle kernel paging request at virtual address 00000030 epc : 8027ba34 crypto_shash_update+0x38/0x158 ra : 8020f2e8 setup_ntlmv2_rsp+0x4bc/0xa84 Call Trace: crypto_shash_update+0x38/0x158 setup_ntlmv2_rsp+0x4bc/0xa84 build_ntlmssp_auth_blob+0xbc/0x34c sess_auth_rawntlmssp_authenticate+0xac/0x248 CIFS_SessSetup+0xf0/0x178 cifs_setup_session+0x4c/0x84 cifs_get_smb_ses+0x2c8/0x314 cifs_mount+0x38c/0x76c cifs_do_mount+0x98/0x440 mount_fs+0x20/0xc0 vfs_kern_mount+0x58/0x138 do_mount+0x1e8/0xccc SyS_mount+0x88/0xd4 syscall_common+0x30/0x54 Fix this by locking the srv_mutex around the code which uses these hmac(md5) structures. All the other secmech algos already have similar locking. Fixes: 95dc8dd ("Limit allocation of crypto mechanisms to dialect which requires") Signed-off-by: Rabin Vincent <[email protected]> Acked-by: Sachin Prabhu <[email protected]> CC: Stable <[email protected]> Signed-off-by: Steve French <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Sep 5, 2016
[ Upstream commit adc8a43 ] Done, because line6_stream_stop() locks and calls line6_unlink_audio_urbs(), which in turn invokes audio_out_callback(), which tries to lock 2nd time. Fixes: ============================================= [ INFO: possible recursive locking detected ] 4.4.15+ #15 Not tainted --------------------------------------------- mplayer/3591 is trying to acquire lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa27655>] audio_out_callback+0x70/0x110 [snd_usb_line6] but task is already holding lock: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&line6pcm->out.lock)->rlock); lock(&(&line6pcm->out.lock)->rlock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mplayer/3591: #0: (snd_pcm_link_rwlock){.-.-..}, at: [<bf8d49a7>] snd_pcm_stream_lock+0x1e/0x40 [snd_pcm] #1: (&(&substream->self_group.lock)->rlock){-.-...}, at: [<bf8d49af>] snd_pcm_stream_lock+0x26/0x40 [snd_pcm] #2: (&(&line6pcm->out.lock)->rlock){-.-...}, at: [<bfa26aad>] line6_stream_stop+0x24/0x5c [snd_usb_line6] stack backtrace: CPU: 0 PID: 3591 Comm: mplayer Not tainted 4.4.15+ #15 Hardware name: Generic AM33XX (Flattened Device Tree) [<c0015d85>] (unwind_backtrace) from [<c001253d>] (show_stack+0x11/0x14) [<c001253d>] (show_stack) from [<c02f1bdf>] (dump_stack+0x8b/0xac) [<c02f1bdf>] (dump_stack) from [<c0076f43>] (__lock_acquire+0xc8b/0x1780) [<c0076f43>] (__lock_acquire) from [<c007810d>] (lock_acquire+0x99/0x1c0) [<c007810d>] (lock_acquire) from [<c06171e7>] (_raw_spin_lock_irqsave+0x3f/0x4c) [<c06171e7>] (_raw_spin_lock_irqsave) from [<bfa27655>] (audio_out_callback+0x70/0x110 [snd_usb_line6]) [<bfa27655>] (audio_out_callback [snd_usb_line6]) from [<c04294db>] (__usb_hcd_giveback_urb+0x53/0xd0) [<c04294db>] (__usb_hcd_giveback_urb) from [<c046388d>] (musb_giveback+0x3d/0x98) [<c046388d>] (musb_giveback) from [<c04647f5>] (musb_urb_dequeue+0x6d/0x114) [<c04647f5>] (musb_urb_dequeue) from [<c042ac11>] (usb_hcd_unlink_urb+0x39/0x98) [<c042ac11>] (usb_hcd_unlink_urb) from [<bfa26a87>] (line6_unlink_audio_urbs+0x6a/0x6c [snd_usb_line6]) [<bfa26a87>] (line6_unlink_audio_urbs [snd_usb_line6]) from [<bfa26acb>] (line6_stream_stop+0x42/0x5c [snd_usb_line6]) [<bfa26acb>] (line6_stream_stop [snd_usb_line6]) from [<bfa26fe7>] (snd_line6_trigger+0xb6/0xf4 [snd_usb_line6]) [<bfa26fe7>] (snd_line6_trigger [snd_usb_line6]) from [<bf8d47b7>] (snd_pcm_do_stop+0x36/0x38 [snd_pcm]) [<bf8d47b7>] (snd_pcm_do_stop [snd_pcm]) from [<bf8d462f>] (snd_pcm_action_single+0x22/0x40 [snd_pcm]) [<bf8d462f>] (snd_pcm_action_single [snd_pcm]) from [<bf8d46f9>] (snd_pcm_action+0xac/0xb0 [snd_pcm]) [<bf8d46f9>] (snd_pcm_action [snd_pcm]) from [<bf8d4b61>] (snd_pcm_drop+0x38/0x64 [snd_pcm]) [<bf8d4b61>] (snd_pcm_drop [snd_pcm]) from [<bf8d6233>] (snd_pcm_common_ioctl1+0x7fe/0xbe8 [snd_pcm]) [<bf8d6233>] (snd_pcm_common_ioctl1 [snd_pcm]) from [<bf8d6779>] (snd_pcm_playback_ioctl1+0x15c/0x51c [snd_pcm]) [<bf8d6779>] (snd_pcm_playback_ioctl1 [snd_pcm]) from [<bf8d6b59>] (snd_pcm_playback_ioctl+0x20/0x28 [snd_pcm]) [<bf8d6b59>] (snd_pcm_playback_ioctl [snd_pcm]) from [<c016714b>] (do_vfs_ioctl+0x3af/0x5c8) Fixes: 63e20df ('ALSA: line6: Reorganize PCM stream handling') Cc: <[email protected]> # v4.0+ Reviewed-by: Stefan Hajnoczi <[email protected]> Signed-off-by: Andrej Krutak <[email protected]> Signed-off-by: Takashi Iwai <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
otavio
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Oct 25, 2016
commit 420902c upstream. If we hold the superblock lock while calling reiserfs_quota_on_mount(), we can deadlock our own worker - mount blocks kworker/3:2, sleeps forever more. crash> ps|grep UN 715 2 3 ffff880220734d30 UN 0.0 0 0 [kworker/3:2] 9369 9341 2 ffff88021ffb7560 UN 1.3 493404 123184 Xorg 9665 9664 3 ffff880225b92ab0 UN 0.0 47368 812 udisks-daemon 10635 10403 3 ffff880222f22c70 UN 0.0 14904 936 mount crash> bt ffff880220734d30 PID: 715 TASK: ffff880220734d30 CPU: 3 COMMAND: "kworker/3:2" #0 [ffff8802244c3c20] schedule at ffffffff8144584b #1 [ffff8802244c3cc8] __rt_mutex_slowlock at ffffffff814472b3 #2 [ffff8802244c3d28] rt_mutex_slowlock at ffffffff814473f5 #3 [ffff8802244c3dc8] reiserfs_write_lock at ffffffffa05f28fd [reiserfs] #4 [ffff8802244c3de8] flush_async_commits at ffffffffa05ec91d [reiserfs] #5 [ffff8802244c3e08] process_one_work at ffffffff81073726 #6 [ffff8802244c3e68] worker_thread at ffffffff81073eba #7 [ffff8802244c3ec8] kthread at ffffffff810782e0 #8 [ffff8802244c3f48] kernel_thread_helper at ffffffff81450064 crash> rd ffff8802244c3cc8 10 ffff8802244c3cc8: ffffffff814472b3 ffff880222f23250 .rD.....P2.".... ffff8802244c3cd8: 0000000000000000 0000000000000286 ................ ffff8802244c3ce8: ffff8802244c3d30 ffff880220734d80 0=L$.....Ms .... ffff8802244c3cf8: ffff880222e8f628 0000000000000000 (.."............ ffff8802244c3d08: 0000000000000000 0000000000000002 ................ crash> struct rt_mutex ffff880222e8f628 struct rt_mutex { wait_lock = { raw_lock = { slock = 65537 } }, wait_list = { node_list = { next = 0xffff8802244c3d48, prev = 0xffff8802244c3d48 } }, owner = 0xffff880222f22c71, save_state = 0 } crash> bt 0xffff880222f22c70 PID: 10635 TASK: ffff880222f22c70 CPU: 3 COMMAND: "mount" #0 [ffff8802216a9868] schedule at ffffffff8144584b #1 [ffff8802216a9910] schedule_timeout at ffffffff81446865 #2 [ffff8802216a99a0] wait_for_common at ffffffff81445f74 #3 [ffff8802216a9a30] flush_work at ffffffff810712d3 #4 [ffff8802216a9ab0] schedule_on_each_cpu at ffffffff81074463 #5 [ffff8802216a9ae0] invalidate_bdev at ffffffff81178aba #6 [ffff8802216a9af0] vfs_load_quota_inode at ffffffff811a3632 #7 [ffff8802216a9b50] dquot_quota_on_mount at ffffffff811a375c #8 [ffff8802216a9b80] finish_unfinished at ffffffffa05dd8b0 [reiserfs] #9 [ffff8802216a9cc0] reiserfs_fill_super at ffffffffa05de825 [reiserfs] RIP: 00007f7b9303997a RSP: 00007ffff443c7a8 RFLAGS: 00010202 RAX: 00000000000000a5 RBX: ffffffff8144ef12 RCX: 00007f7b932e9ee0 RDX: 00007f7b93d9a400 RSI: 00007f7b93d9a3e0 RDI: 00007f7b93d9a3c0 RBP: 00007f7b93d9a2c0 R8: 00007f7b93d9a550 R9: 0000000000000001 R10: ffffffffc0ed040e R11: 0000000000000202 R12: 000000000000040e R13: 0000000000000000 R14: 00000000c0ed040e R15: 00007ffff443ca20 ORIG_RAX: 00000000000000a5 CS: 0033 SS: 002b Signed-off-by: Mike Galbraith <[email protected]> Acked-by: Frederic Weisbecker <[email protected]> Acked-by: Mike Galbraith <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Oct 25, 2016
commit a818101 upstream. An NULL-pointer dereference happens in cachefiles_mark_object_inactive() when it tries to read i_blocks so that it can tell the cachefilesd daemon how much space it's making available. The problem is that cachefiles_drop_object() calls cachefiles_mark_object_inactive() after calling cachefiles_delete_object() because the object being marked active staves off attempts to (re-)use the file at that filename until after it has been deleted. This means that d_inode is NULL by the time we come to try to access it. To fix the problem, have the caller of cachefiles_mark_object_inactive() supply the number of blocks freed up. Without this, the following oops may occur: BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 IP: [<ffffffffa06c5cc1>] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles] ... CPU: 11 PID: 527 Comm: kworker/u64:4 Tainted: G I ------------ 3.10.0-470.el7.x86_64 #1 Hardware name: Hewlett-Packard HP Z600 Workstation/0B54h, BIOS 786G4 v03.19 03/11/2011 Workqueue: fscache_object fscache_object_work_func [fscache] task: ffff880035edaf10 ti: ffff8800b77c0000 task.ti: ffff8800b77c0000 RIP: 0010:[<ffffffffa06c5cc1>] cachefiles_mark_object_inactive+0x61/0xb0 [cachefiles] RSP: 0018:ffff8800b77c3d70 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff8800bf6cc400 RCX: 0000000000000034 RDX: 0000000000000000 RSI: ffff880090ffc710 RDI: ffff8800bf761ef8 RBP: ffff8800b77c3d88 R08: 2000000000000000 R09: 0090ffc710000000 R10: ff51005d2ff1c400 R11: 0000000000000000 R12: ffff880090ffc600 R13: ffff8800bf6cc520 R14: ffff8800bf6cc400 R15: ffff8800bf6cc498 FS: 0000000000000000(0000) GS:ffff8800bb8c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000098 CR3: 00000000019ba000 CR4: 00000000000007e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Stack: ffff880090ffc600 ffff8800bf6cc400 ffff8800867df140 ffff8800b77c3db0 ffffffffa06c48cb ffff880090ffc600 ffff880090ffc180 ffff880090ffc658 ffff8800b77c3df0 ffffffffa085d846 ffff8800a96b8150 ffff880090ffc600 Call Trace: [<ffffffffa06c48cb>] cachefiles_drop_object+0x6b/0xf0 [cachefiles] [<ffffffffa085d846>] fscache_drop_object+0xd6/0x1e0 [fscache] [<ffffffffa085d615>] fscache_object_work_func+0xa5/0x200 [fscache] [<ffffffff810a605b>] process_one_work+0x17b/0x470 [<ffffffff810a6e96>] worker_thread+0x126/0x410 [<ffffffff810a6d70>] ? rescuer_thread+0x460/0x460 [<ffffffff810ae64f>] kthread+0xcf/0xe0 [<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140 [<ffffffff81695418>] ret_from_fork+0x58/0x90 [<ffffffff810ae580>] ? kthread_create_on_node+0x140/0x140 The oopsing code shows: callq 0xffffffff810af6a0 <wake_up_bit> mov 0xf8(%r12),%rax mov 0x30(%rax),%rax mov 0x98(%rax),%rax <---- oops here lock add %rax,0x130(%rbx) where this is: d_backing_inode(object->dentry)->i_blocks Fixes: a5b3a80 (CacheFiles: Provide read-and-reset release counters for cachefilesd) Reported-by: Jianhong Yin <[email protected]> Signed-off-by: David Howells <[email protected]> Reviewed-by: Jeff Layton <[email protected]> Reviewed-by: Steve Dickson <[email protected]> Signed-off-by: Al Viro <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Oct 26, 2016
[ Upstream commit 7e95630 ] In the mipsr2_decoder() function, used to emulate pre-MIPSr6 instructions that were removed in MIPSr6, the init_fpu() function is called if a removed pre-MIPSr6 floating point instruction is the first floating point instruction used by the task. However, init_fpu() performs varous actions that rely upon not being migrated. For example in the most basic case it sets the coprocessor 0 Status.CU1 bit to enable the FPU & then loads FP register context into the FPU registers. If the task were to migrate during this time, it may end up attempting to load FP register context on a different CPU where it hasn't set the CU1 bit, leading to errors such as: do_cpu invoked from kernel context![#2]: CPU: 2 PID: 7338 Comm: fp-prctl Tainted: G D 4.7.0-00424-g49b0c82 #2 task: 838e4000 ti: 88d38000 task.ti: 88d38000 $ 0 : 00000000 00000001 ffffffff 88d3fef8 $ 4 : 838e4000 88d38004 00000000 00000001 $ 8 : 3400fc01 801f8020 808e9100 24000000 $12 : dbffffff 807b69d8 807b0000 00000000 $16 : 00000000 80786150 00400fc4 809c0398 $20 : 809c0338 0040273c 88d3ff28 808e9d30 $24 : 808e9d30 00400fb4 $28 : 88d38000 88d3fe88 00000000 8011a2ac Hi : 0040273c Lo : 88d3ff28 epc : 80114178 _restore_fp+0x10/0xa0 ra : 8011a2ac mipsr2_decoder+0xd5c/0x1660 Status: 1400fc03 KERNEL EXL IE Cause : 1080002c (ExcCode 0b) PrId : 0001a920 (MIPS I6400) Modules linked in: Process fp-prctl (pid: 7338, threadinfo=88d38000, task=838e4000, tls=766527d0) Stack : 00000000 00000000 00000000 88d3fe98 00000000 00000000 809c0398 809c0338 808e9100 00000000 88d3ff28 00400fc4 00400fc4 0040273c 7fb69e18 004a0000 004a0000 004a0000 7664add 8010de18 00000000 00000000 88d3fef8 88d3ff28 808e9100 00000000 766527d0 8010e534 000c0000 85755000 8181d580 00000000 00000000 00000000 004a0000 00000000 766527d0 7fb69e18 004a0000 80105c20 ... Call Trace: [<80114178>] _restore_fp+0x10/0xa0 [<8011a2ac>] mipsr2_decoder+0xd5c/0x1660 [<8010de18>] do_ri+0x90/0x6b8 [<80105c20>] ret_from_exception+0x0/0x10 Fix this by disabling preemption around the call to init_fpu(), ensuring that it starts & completes on one CPU. Signed-off-by: Paul Burton <[email protected]> Fixes: b0a668f ("MIPS: kernel: mips-r2-to-r6-emul: Add R2 emulator for MIPS R6") Cc: [email protected] Cc: [email protected] # v4.0+ Patchwork: https://patchwork.linux-mips.org/patch/14305/ Signed-off-by: Ralf Baechle <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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Oct 31, 2016
commit b6bc1c7 upstream. Function ib_create_qp() was failing to return an error when rdma_rw_init_mrs() fails, causing a crash further down in ib_create_qp() when trying to dereferece the qp pointer which was actually a negative errno. The crash: crash> log|grep BUG [ 136.458121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000098 crash> bt PID: 3736 TASK: ffff8808543215c0 CPU: 2 COMMAND: "kworker/u64:2" #0 [ffff88084d323340] machine_kexec at ffffffff8105fbb0 #1 [ffff88084d3233b0] __crash_kexec at ffffffff81116758 #2 [ffff88084d323480] crash_kexec at ffffffff8111682d #3 [ffff88084d3234b0] oops_end at ffffffff81032bd6 #4 [ffff88084d3234e0] no_context at ffffffff8106e431 #5 [ffff88084d323530] __bad_area_nosemaphore at ffffffff8106e610 #6 [ffff88084d323590] bad_area_nosemaphore at ffffffff8106e6f4 #7 [ffff88084d3235a0] __do_page_fault at ffffffff8106ebdc #8 [ffff88084d323620] do_page_fault at ffffffff8106f057 #9 [ffff88084d323660] page_fault at ffffffff816e3148 [exception RIP: ib_create_qp+427] RIP: ffffffffa02554fb RSP: ffff88084d323718 RFLAGS: 00010246 RAX: 0000000000000004 RBX: fffffffffffffff4 RCX: 000000018020001f RDX: ffff880830997fc0 RSI: 0000000000000001 RDI: ffff88085f407200 RBP: ffff88084d323778 R8: 0000000000000001 R9: ffffea0020bae210 R10: ffffea0020bae218 R11: 0000000000000001 R12: ffff88084d3237c8 R13: 00000000fffffff4 R14: ffff880859fa5000 R15: ffff88082eb89800 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #10 [ffff88084d323780] rdma_create_qp at ffffffffa0782681 [rdma_cm] #11 [ffff88084d3237b0] nvmet_rdma_create_queue_ib at ffffffffa07c43f3 [nvmet_rdma] #12 [ffff88084d323860] nvmet_rdma_alloc_queue at ffffffffa07c5ba9 [nvmet_rdma] #13 [ffff88084d323900] nvmet_rdma_queue_connect at ffffffffa07c5c96 [nvmet_rdma] #14 [ffff88084d323980] nvmet_rdma_cm_handler at ffffffffa07c6450 [nvmet_rdma] #15 [ffff88084d3239b0] iw_conn_req_handler at ffffffffa0787480 [rdma_cm] #16 [ffff88084d323a60] cm_conn_req_handler at ffffffffa0775f06 [iw_cm] #17 [ffff88084d323ab0] process_event at ffffffffa0776019 [iw_cm] #18 [ffff88084d323af0] cm_work_handler at ffffffffa0776170 [iw_cm] #19 [ffff88084d323cb0] process_one_work at ffffffff810a1483 #20 [ffff88084d323d90] worker_thread at ffffffff810a211d #21 [ffff88084d323ec0] kthread at ffffffff810a6c5c #22 [ffff88084d323f50] ret_from_fork at ffffffff816e1ebf Fixes: 632bc3f ("IB/core, RDMA RW API: Do not exceed QP SGE send limit") Signed-off-by: Steve Wise <[email protected]> Reviewed-by: Bart Van Assche <[email protected]> Signed-off-by: Doug Ledford <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Oct 31, 2016
commit 341d7eb upstream. AP queue is properly released, but P2P queue isn't. Fixes: commit 4c96513 ("iwlwifi: mvm: support p2p device frames tx on dqa queue #2") Signed-off-by: Sara Sharon <[email protected]> Signed-off-by: Luca Coelho <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
redbrain17
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Mar 28, 2017
[ Upstream commit d5afb6f ] The code where sk_clone() came from created a new socket and locked it, but then, on the error path didn't unlock it. This problem stayed there for a long while, till b0691c8 ("net: Unlock sock before calling sk_free()") fixed it, but unfortunately the callers of sk_clone() (now sk_clone_locked()) were not audited and the one in dccp_create_openreq_child() remained. Now in the age of the syskaller fuzzer, this was finally uncovered, as reported by Dmitry: ---- 8< ---- I've got the following report while running syzkaller fuzzer on 86292b3 ("Merge branch 'akpm' (patches from Andrew)") [ BUG: held lock freed! ] 4.10.0+ Freescale#234 Not tainted ------------------------- syz-executor6/6898 is freeing memory ffff88006286cac0-ffff88006286d3b7, with a lock still held there! (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 5 locks held by syz-executor6/6898: #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681 Freescale#1: (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>] inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126 Freescale#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink include/linux/skbuff.h:1767 [inline] Freescale#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue include/linux/skbuff.h:1783 [inline] Freescale#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] process_backlog+0x264/0x730 net/core/dev.c:4835 Freescale#3: (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>] ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59 Freescale#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock include/linux/spinlock.h:299 [inline] Freescale#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 Fix it just like was done by b0691c8 ("net: Unlock sock before calling sk_free()"). Reported-by: Dmitry Vyukov <[email protected]> Cc: Cong Wang <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Gerrit Renker <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Apr 10, 2017
…e_pmd() commit c9d398f upstream. I found the race condition which triggers the following bug when move_pages() and soft offline are called on a single hugetlb page concurrently. Soft offlining page 0x119400 at 0x700000000000 BUG: unable to handle kernel paging request at ffffea0011943820 IP: follow_huge_pmd+0x143/0x190 PGD 7ffd2067 PUD 7ffd1067 PMD 0 [61163.582052] Oops: 0000 [#1] SMP Modules linked in: binfmt_misc ppdev virtio_balloon parport_pc pcspkr i2c_piix4 parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi virtio_blk 8139too crc32c_intel ata_piix serio_raw libata virtio_pci 8139cp virtio_ring virtio mii floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: cap_check] CPU: 0 PID: 22573 Comm: iterate_numa_mo Tainted: P OE 4.11.0-rc2-mm1+ #2 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:follow_huge_pmd+0x143/0x190 RSP: 0018:ffffc90004bdbcd0 EFLAGS: 00010202 RAX: 0000000465003e80 RBX: ffffea0004e34d30 RCX: 00003ffffffff000 RDX: 0000000011943800 RSI: 0000000000080001 RDI: 0000000465003e80 RBP: ffffc90004bdbd18 R08: 0000000000000000 R09: ffff880138d34000 R10: ffffea0004650000 R11: 0000000000c363b0 R12: ffffea0011943800 R13: ffff8801b8d34000 R14: ffffea0000000000 R15: 000077ff80000000 FS: 00007fc977710740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffea0011943820 CR3: 000000007a746000 CR4: 00000000001406f0 Call Trace: follow_page_mask+0x270/0x550 SYSC_move_pages+0x4ea/0x8f0 SyS_move_pages+0xe/0x10 do_syscall_64+0x67/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7fc976e03949 RSP: 002b:00007ffe72221d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000117 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc976e03949 RDX: 0000000000c22390 RSI: 0000000000001400 RDI: 0000000000005827 RBP: 00007ffe72221e00 R08: 0000000000c2c3a0 R09: 0000000000000004 R10: 0000000000c363b0 R11: 0000000000000246 R12: 0000000000400650 R13: 00007ffe72221ee0 R14: 0000000000000000 R15: 0000000000000000 Code: 81 e4 ff ff 1f 00 48 21 c2 49 c1 ec 0c 48 c1 ea 0c 4c 01 e2 49 bc 00 00 00 00 00 ea ff ff 48 c1 e2 06 49 01 d4 f6 45 bc 04 74 90 <49> 8b 7c 24 20 40 f6 c7 01 75 2b 4c 89 e7 8b 47 1c 85 c0 7e 2a RIP: follow_huge_pmd+0x143/0x190 RSP: ffffc90004bdbcd0 CR2: ffffea0011943820 ---[ end trace e4f81353a2d23232 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled This bug is triggered when pmd_present() returns true for non-present hugetlb, so fixing the present check in follow_huge_pmd() prevents it. Using pmd_present() to determine present/non-present for hugetlb is not correct, because pmd_present() checks multiple bits (not only _PAGE_PRESENT) for historical reason and it can misjudge hugetlb state. Fixes: e66f17f ("mm/hugetlb: take page table lock in follow_huge_pmd()") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Naoya Horiguchi <[email protected]> Acked-by: Hillf Danton <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Michal Hocko <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Gerald Schaefer <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Apr 10, 2017
…e_pmd() commit c9d398f upstream. I found the race condition which triggers the following bug when move_pages() and soft offline are called on a single hugetlb page concurrently. Soft offlining page 0x119400 at 0x700000000000 BUG: unable to handle kernel paging request at ffffea0011943820 IP: follow_huge_pmd+0x143/0x190 PGD 7ffd2067 PUD 7ffd1067 PMD 0 [61163.582052] Oops: 0000 [#1] SMP Modules linked in: binfmt_misc ppdev virtio_balloon parport_pc pcspkr i2c_piix4 parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi virtio_blk 8139too crc32c_intel ata_piix serio_raw libata virtio_pci 8139cp virtio_ring virtio mii floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: cap_check] CPU: 0 PID: 22573 Comm: iterate_numa_mo Tainted: P OE 4.11.0-rc2-mm1+ #2 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:follow_huge_pmd+0x143/0x190 RSP: 0018:ffffc90004bdbcd0 EFLAGS: 00010202 RAX: 0000000465003e80 RBX: ffffea0004e34d30 RCX: 00003ffffffff000 RDX: 0000000011943800 RSI: 0000000000080001 RDI: 0000000465003e80 RBP: ffffc90004bdbd18 R08: 0000000000000000 R09: ffff880138d34000 R10: ffffea0004650000 R11: 0000000000c363b0 R12: ffffea0011943800 R13: ffff8801b8d34000 R14: ffffea0000000000 R15: 000077ff80000000 FS: 00007fc977710740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffea0011943820 CR3: 000000007a746000 CR4: 00000000001406f0 Call Trace: follow_page_mask+0x270/0x550 SYSC_move_pages+0x4ea/0x8f0 SyS_move_pages+0xe/0x10 do_syscall_64+0x67/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7fc976e03949 RSP: 002b:00007ffe72221d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000117 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc976e03949 RDX: 0000000000c22390 RSI: 0000000000001400 RDI: 0000000000005827 RBP: 00007ffe72221e00 R08: 0000000000c2c3a0 R09: 0000000000000004 R10: 0000000000c363b0 R11: 0000000000000246 R12: 0000000000400650 R13: 00007ffe72221ee0 R14: 0000000000000000 R15: 0000000000000000 Code: 81 e4 ff ff 1f 00 48 21 c2 49 c1 ec 0c 48 c1 ea 0c 4c 01 e2 49 bc 00 00 00 00 00 ea ff ff 48 c1 e2 06 49 01 d4 f6 45 bc 04 74 90 <49> 8b 7c 24 20 40 f6 c7 01 75 2b 4c 89 e7 8b 47 1c 85 c0 7e 2a RIP: follow_huge_pmd+0x143/0x190 RSP: ffffc90004bdbcd0 CR2: ffffea0011943820 ---[ end trace e4f81353a2d23232 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled This bug is triggered when pmd_present() returns true for non-present hugetlb, so fixing the present check in follow_huge_pmd() prevents it. Using pmd_present() to determine present/non-present for hugetlb is not correct, because pmd_present() checks multiple bits (not only _PAGE_PRESENT) for historical reason and it can misjudge hugetlb state. Fixes: e66f17f ("mm/hugetlb: take page table lock in follow_huge_pmd()") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Naoya Horiguchi <[email protected]> Acked-by: Hillf Danton <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Michal Hocko <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Gerald Schaefer <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Apr 20, 2017
commit 3d3d18f upstream. The rcu_barrier() takes the cpu_hotplug mutex which itself is not reclaim-safe, and so rcu_barrier() is illegal from inside the shrinker. [ 309.661373] ========================================================= [ 309.661376] [ INFO: possible irq lock inversion dependency detected ] [ 309.661380] 4.11.0-rc1-CI-CI_DRM_2333+ #1 Tainted: G W [ 309.661383] --------------------------------------------------------- [ 309.661386] gem_exec_gttfil/6435 just changed the state of lock: [ 309.661389] (rcu_preempt_state.barrier_mutex){+.+.-.}, at: [<ffffffff81100731>] _rcu_barrier+0x31/0x160 [ 309.661399] but this lock took another, RECLAIM_FS-unsafe lock in the past: [ 309.661402] (cpu_hotplug.lock){+.+.+.} [ 309.661404] and interrupts could create inverse lock ordering between them. [ 309.661410] other info that might help us debug this: [ 309.661414] Possible interrupt unsafe locking scenario: [ 309.661417] CPU0 CPU1 [ 309.661419] ---- ---- [ 309.661421] lock(cpu_hotplug.lock); [ 309.661425] local_irq_disable(); [ 309.661432] lock(rcu_preempt_state.barrier_mutex); [ 309.661441] lock(cpu_hotplug.lock); [ 309.661446] <Interrupt> [ 309.661448] lock(rcu_preempt_state.barrier_mutex); [ 309.661453] *** DEADLOCK *** [ 309.661460] 4 locks held by gem_exec_gttfil/6435: [ 309.661464] #0: (sb_writers#10){.+.+.+}, at: [<ffffffff8120d83d>] vfs_write+0x17d/0x1f0 [ 309.661475] #1: (debugfs_srcu){......}, at: [<ffffffff81320491>] debugfs_use_file_start+0x41/0xa0 [ 309.661486] #2: (&attr->mutex){+.+.+.}, at: [<ffffffff8123a3e7>] simple_attr_write+0x37/0xe0 [ 309.661495] #3: (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0091b4a>] i915_drop_caches_set+0x3a/0x150 [i915] [ 309.661540] the shortest dependencies between 2nd lock and 1st lock: [ 309.661547] -> (cpu_hotplug.lock){+.+.+.} ops: 829 { [ 309.661553] HARDIRQ-ON-W at: [ 309.661560] __lock_acquire+0x5e5/0x1b50 [ 309.661565] lock_acquire+0xc9/0x220 [ 309.661572] __mutex_lock+0x6e/0x990 [ 309.661576] mutex_lock_nested+0x16/0x20 [ 309.661583] get_online_cpus+0x61/0x80 [ 309.661590] kmem_cache_create+0x25/0x1d0 [ 309.661596] debug_objects_mem_init+0x30/0x249 [ 309.661602] start_kernel+0x341/0x3fe [ 309.661607] x86_64_start_reservations+0x2a/0x2c [ 309.661612] x86_64_start_kernel+0x173/0x186 [ 309.661619] verify_cpu+0x0/0xfc [ 309.661622] SOFTIRQ-ON-W at: [ 309.661627] __lock_acquire+0x611/0x1b50 [ 309.661632] lock_acquire+0xc9/0x220 [ 309.661636] __mutex_lock+0x6e/0x990 [ 309.661641] mutex_lock_nested+0x16/0x20 [ 309.661646] get_online_cpus+0x61/0x80 [ 309.661650] kmem_cache_create+0x25/0x1d0 [ 309.661655] debug_objects_mem_init+0x30/0x249 [ 309.661660] start_kernel+0x341/0x3fe [ 309.661664] x86_64_start_reservations+0x2a/0x2c [ 309.661669] x86_64_start_kernel+0x173/0x186 [ 309.661674] verify_cpu+0x0/0xfc [ 309.661677] RECLAIM_FS-ON-W at: [ 309.661682] mark_held_locks+0x6f/0xa0 [ 309.661687] lockdep_trace_alloc+0xb3/0x100 [ 309.661693] kmem_cache_alloc_trace+0x31/0x2e0 [ 309.661699] __smpboot_create_thread.part.1+0x27/0xe0 [ 309.661704] smpboot_create_threads+0x61/0x90 [ 309.661709] cpuhp_invoke_callback+0x9c/0x8a0 [ 309.661713] cpuhp_up_callbacks+0x31/0xb0 [ 309.661718] _cpu_up+0x7a/0xc0 [ 309.661723] do_cpu_up+0x5f/0x80 [ 309.661727] cpu_up+0xe/0x10 [ 309.661734] smp_init+0x71/0xb3 [ 309.661738] kernel_init_freeable+0x94/0x19e [ 309.661743] kernel_init+0x9/0xf0 [ 309.661748] ret_from_fork+0x2e/0x40 [ 309.661752] INITIAL USE at: [ 309.661757] __lock_acquire+0x234/0x1b50 [ 309.661761] lock_acquire+0xc9/0x220 [ 309.661766] __mutex_lock+0x6e/0x990 [ 309.661771] mutex_lock_nested+0x16/0x20 [ 309.661775] get_online_cpus+0x61/0x80 [ 309.661780] __cpuhp_setup_state+0x44/0x170 [ 309.661785] page_alloc_init+0x23/0x3a [ 309.661790] start_kernel+0x124/0x3fe [ 309.661794] x86_64_start_reservations+0x2a/0x2c [ 309.661799] x86_64_start_kernel+0x173/0x186 [ 309.661804] verify_cpu+0x0/0xfc [ 309.661807] } [ 309.661813] ... key at: [<ffffffff81e37690>] cpu_hotplug+0xb0/0x100 [ 309.661817] ... acquired at: [ 309.661821] lock_acquire+0xc9/0x220 [ 309.661825] __mutex_lock+0x6e/0x990 [ 309.661829] mutex_lock_nested+0x16/0x20 [ 309.661833] get_online_cpus+0x61/0x80 [ 309.661837] _rcu_barrier+0x9f/0x160 [ 309.661841] rcu_barrier+0x10/0x20 [ 309.661847] netdev_run_todo+0x5f/0x310 [ 309.661852] rtnl_unlock+0x9/0x10 [ 309.661856] default_device_exit_batch+0x133/0x150 [ 309.661862] ops_exit_list.isra.0+0x4d/0x60 [ 309.661866] cleanup_net+0x1d8/0x2c0 [ 309.661872] process_one_work+0x1f4/0x6d0 [ 309.661876] worker_thread+0x49/0x4a0 [ 309.661881] kthread+0x107/0x140 [ 309.661884] ret_from_fork+0x2e/0x40 [ 309.661890] -> (rcu_preempt_state.barrier_mutex){+.+.-.} ops: 179 { [ 309.661896] HARDIRQ-ON-W at: [ 309.661901] __lock_acquire+0x5e5/0x1b50 [ 309.661905] lock_acquire+0xc9/0x220 [ 309.661910] __mutex_lock+0x6e/0x990 [ 309.661914] mutex_lock_nested+0x16/0x20 [ 309.661919] _rcu_barrier+0x31/0x160 [ 309.661923] rcu_barrier+0x10/0x20 [ 309.661928] netdev_run_todo+0x5f/0x310 [ 309.661932] rtnl_unlock+0x9/0x10 [ 309.661936] default_device_exit_batch+0x133/0x150 [ 309.661941] ops_exit_list.isra.0+0x4d/0x60 [ 309.661946] cleanup_net+0x1d8/0x2c0 [ 309.661951] process_one_work+0x1f4/0x6d0 [ 309.661955] worker_thread+0x49/0x4a0 [ 309.661960] kthread+0x107/0x140 [ 309.661964] ret_from_fork+0x2e/0x40 [ 309.661968] SOFTIRQ-ON-W at: [ 309.661972] __lock_acquire+0x611/0x1b50 [ 309.661977] lock_acquire+0xc9/0x220 [ 309.661981] __mutex_lock+0x6e/0x990 [ 309.661986] mutex_lock_nested+0x16/0x20 [ 309.661990] _rcu_barrier+0x31/0x160 [ 309.661995] rcu_barrier+0x10/0x20 [ 309.661999] netdev_run_todo+0x5f/0x310 [ 309.662003] rtnl_unlock+0x9/0x10 [ 309.662008] default_device_exit_batch+0x133/0x150 [ 309.662013] ops_exit_list.isra.0+0x4d/0x60 [ 309.662017] cleanup_net+0x1d8/0x2c0 [ 309.662022] process_one_work+0x1f4/0x6d0 [ 309.662027] worker_thread+0x49/0x4a0 [ 309.662031] kthread+0x107/0x140 [ 309.662035] ret_from_fork+0x2e/0x40 [ 309.662039] IN-RECLAIM_FS-W at: [ 309.662043] __lock_acquire+0x638/0x1b50 [ 309.662048] lock_acquire+0xc9/0x220 [ 309.662053] __mutex_lock+0x6e/0x990 [ 309.662058] mutex_lock_nested+0x16/0x20 [ 309.662062] _rcu_barrier+0x31/0x160 [ 309.662067] rcu_barrier+0x10/0x20 [ 309.662089] i915_gem_shrink_all+0x33/0x40 [i915] [ 309.662109] i915_drop_caches_set+0x141/0x150 [i915] [ 309.662114] simple_attr_write+0xc7/0xe0 [ 309.662119] full_proxy_write+0x4f/0x70 [ 309.662124] __vfs_write+0x23/0x120 [ 309.662128] vfs_write+0xc6/0x1f0 [ 309.662133] SyS_write+0x44/0xb0 [ 309.662138] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 309.662142] INITIAL USE at: [ 309.662147] __lock_acquire+0x234/0x1b50 [ 309.662151] lock_acquire+0xc9/0x220 [ 309.662156] __mutex_lock+0x6e/0x990 [ 309.662160] mutex_lock_nested+0x16/0x20 [ 309.662165] _rcu_barrier+0x31/0x160 [ 309.662169] rcu_barrier+0x10/0x20 [ 309.662174] netdev_run_todo+0x5f/0x310 [ 309.662178] rtnl_unlock+0x9/0x10 [ 309.662183] default_device_exit_batch+0x133/0x150 [ 309.662188] ops_exit_list.isra.0+0x4d/0x60 [ 309.662192] cleanup_net+0x1d8/0x2c0 [ 309.662197] process_one_work+0x1f4/0x6d0 [ 309.662202] worker_thread+0x49/0x4a0 [ 309.662206] kthread+0x107/0x140 [ 309.662210] ret_from_fork+0x2e/0x40 [ 309.662214] } [ 309.662220] ... key at: [<ffffffff81e4e1c8>] rcu_preempt_state+0x508/0x780 [ 309.662225] ... acquired at: [ 309.662229] check_usage_forwards+0x12b/0x130 [ 309.662233] mark_lock+0x360/0x6f0 [ 309.662237] __lock_acquire+0x638/0x1b50 [ 309.662241] lock_acquire+0xc9/0x220 [ 309.662245] __mutex_lock+0x6e/0x990 [ 309.662249] mutex_lock_nested+0x16/0x20 [ 309.662253] _rcu_barrier+0x31/0x160 [ 309.662257] rcu_barrier+0x10/0x20 [ 309.662279] i915_gem_shrink_all+0x33/0x40 [i915] [ 309.662298] i915_drop_caches_set+0x141/0x150 [i915] [ 309.662303] simple_attr_write+0xc7/0xe0 [ 309.662307] full_proxy_write+0x4f/0x70 [ 309.662311] __vfs_write+0x23/0x120 [ 309.662315] vfs_write+0xc6/0x1f0 [ 309.662319] SyS_write+0x44/0xb0 [ 309.662323] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 309.662329] stack backtrace: [ 309.662335] CPU: 1 PID: 6435 Comm: gem_exec_gttfil Tainted: G W 4.11.0-rc1-CI-CI_DRM_2333+ #1 [ 309.662342] Hardware name: Hewlett-Packard HP Compaq 8100 Elite SFF PC/304Ah, BIOS 786H1 v01.13 07/14/2011 [ 309.662348] Call Trace: [ 309.662354] dump_stack+0x67/0x92 [ 309.662359] print_irq_inversion_bug.part.19+0x1a4/0x1b0 [ 309.662365] check_usage_forwards+0x12b/0x130 [ 309.662369] mark_lock+0x360/0x6f0 [ 309.662374] ? print_shortest_lock_dependencies+0x1a0/0x1a0 [ 309.662379] __lock_acquire+0x638/0x1b50 [ 309.662383] ? __mutex_unlock_slowpath+0x3e/0x2e0 [ 309.662388] ? trace_hardirqs_on+0xd/0x10 [ 309.662392] ? _rcu_barrier+0x31/0x160 [ 309.662396] lock_acquire+0xc9/0x220 [ 309.662400] ? _rcu_barrier+0x31/0x160 [ 309.662404] ? _rcu_barrier+0x31/0x160 [ 309.662409] __mutex_lock+0x6e/0x990 [ 309.662412] ? _rcu_barrier+0x31/0x160 [ 309.662416] ? _rcu_barrier+0x31/0x160 [ 309.662421] ? synchronize_rcu_expedited+0x35/0xb0 [ 309.662426] ? _raw_spin_unlock_irqrestore+0x52/0x60 [ 309.662434] mutex_lock_nested+0x16/0x20 [ 309.662438] _rcu_barrier+0x31/0x160 [ 309.662442] rcu_barrier+0x10/0x20 [ 309.662464] i915_gem_shrink_all+0x33/0x40 [i915] [ 309.662484] i915_drop_caches_set+0x141/0x150 [i915] [ 309.662489] simple_attr_write+0xc7/0xe0 [ 309.662494] full_proxy_write+0x4f/0x70 [ 309.662498] __vfs_write+0x23/0x120 [ 309.662503] ? rcu_read_lock_sched_held+0x75/0x80 [ 309.662507] ? rcu_sync_lockdep_assert+0x2a/0x50 [ 309.662512] ? __sb_start_write+0x102/0x210 [ 309.662516] ? vfs_write+0x17d/0x1f0 [ 309.662520] vfs_write+0xc6/0x1f0 [ 309.662524] ? trace_hardirqs_on_caller+0xe7/0x200 [ 309.662529] SyS_write+0x44/0xb0 [ 309.662533] entry_SYSCALL_64_fastpath+0x1c/0xb1 [ 309.662537] RIP: 0033:0x7f507eac24a0 [ 309.662541] RSP: 002b:00007fffda8720e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 [ 309.662548] RAX: ffffffffffffffda RBX: ffffffff81482bd3 RCX: 00007f507eac24a0 [ 309.662552] RDX: 0000000000000005 RSI: 00007fffda8720f0 RDI: 0000000000000005 [ 309.662557] RBP: ffffc9000048bf88 R08: 0000000000000000 R09: 000000000000002c [ 309.662561] R10: 0000000000000014 R11: 0000000000000246 R12: 00007fffda872230 [ 309.662566] R13: 00007fffda872228 R14: 0000000000000201 R15: 00007fffda8720f0 [ 309.662572] ? __this_cpu_preempt_check+0x13/0x20 Fixes: 0eafec6 ("drm/i915: Enable lockless lookup of request tracking via RCU") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=100192 Signed-off-by: Chris Wilson <[email protected]> Cc: Daniel Vetter <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected] Reviewed-by: Daniel Vetter <[email protected]> (cherry picked from commit bd784b7) Signed-off-by: Jani Nikula <[email protected]> Link: http://patchwork.freedesktop.org/patch/msgid/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Jun 13, 2017
mipsxx_pmu_handle_shared_irq() calls irq_work_run() while holding the pmuint_rwlock for read. irq_work_run() can, via perf_pending_event(), call try_to_wake_up() which can try to take rq->lock. However, perf can also call perf_pmu_enable() (and thus take the pmuint_rwlock for write) while holding the rq->lock, from finish_task_switch() via perf_event_context_sched_in(). This leads to an ABBA deadlock: PID: 3855 TASK: 8f7ce288 CPU: 2 COMMAND: "process" #0 [89c39ac8] __delay at 803b5be4 #1 [89c39ac8] do_raw_spin_lock at 8008fdcc #2 [89c39af8] try_to_wake_up at 8006e47c #3 [89c39b38] pollwake at 8018eab0 #4 [89c39b68] __wake_up_common at 800879f4 #5 [89c39b98] __wake_up at 800880e4 #6 [89c39bc8] perf_event_wakeup at 8012109 #7 [89c39be8] perf_pending_event at 80121184 #8 [89c39c08] irq_work_run_list at 801151f0 #9 [89c39c38] irq_work_run at 80115274 #10 [89c39c50] mipsxx_pmu_handle_shared_irq at 8002cc7c PID: 1481 TASK: 8eaac6a8 CPU: 3 COMMAND: "process" #0 [8de7f90] do_raw_write_lock at 800900e0 #1 [8de7f918] perf_event_context_sched_in at 80122310 #2 [8de7f938] __perf_event_task_sched_in at 80122608 #3 [8de7f958] finish_task_switch at 8006b8a4 #4 [8de7f998] __schedule at 805e4dc4 #5 [8de7f9f8] schedule at 805e5558 #6 [8de7fa10] schedule_hrtimeout_range_clock at 805e9984 #7 [8de7fa70] poll_schedule_timeout at 8018e8f8 #8 [8de7fa88] do_select at 8018f338 #9 [8de7fd88] core_sys_select at 8018f5cc #10 [8de7fee0] sys_select at 8018f854 #11 [8de7ff28] syscall_common at 80028fc8 The lock seems to be there to protect the hardware counters so there is no need to hold it across irq_work_run(). Signed-off-by: Rabin Vincent <[email protected]> Signed-off-by: Ralf Baechle <[email protected]>
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Holding the reconfig_mutex over a potential userspace fault sets up a
lockdep dependency chain between filesystem-DAX and the libnvdimm ioctl
path. Move the user access outside of the lock.
[ INFO: possible circular locking dependency detected ]
4.11.0-rc3+ #13 Tainted: G W O
-------------------------------------------------------
fallocate/16656 is trying to acquire lock:
(&nvdimm_bus->reconfig_mutex){+.+.+.}, at: [<ffffffffa00080b1>] nvdimm_bus_lock+0x21/0x30 [libnvdimm]
but task is already holding lock:
(jbd2_handle){++++..}, at: [<ffffffff813b4944>] start_this_handle+0x104/0x460
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (jbd2_handle){++++..}:
lock_acquire+0xbd/0x200
start_this_handle+0x16a/0x460
jbd2__journal_start+0xe9/0x2d0
__ext4_journal_start_sb+0x89/0x1c0
ext4_dirty_inode+0x32/0x70
__mark_inode_dirty+0x235/0x670
generic_update_time+0x87/0xd0
touch_atime+0xa9/0xd0
ext4_file_mmap+0x90/0xb0
mmap_region+0x370/0x5b0
do_mmap+0x415/0x4f0
vm_mmap_pgoff+0xd7/0x120
SyS_mmap_pgoff+0x1c5/0x290
SyS_mmap+0x22/0x30
entry_SYSCALL_64_fastpath+0x1f/0xc2
-> #1 (&mm->mmap_sem){++++++}:
lock_acquire+0xbd/0x200
__might_fault+0x70/0xa0
__nd_ioctl+0x683/0x720 [libnvdimm]
nvdimm_ioctl+0x8b/0xe0 [libnvdimm]
do_vfs_ioctl+0xa8/0x740
SyS_ioctl+0x79/0x90
do_syscall_64+0x6c/0x200
return_from_SYSCALL_64+0x0/0x7a
-> #0 (&nvdimm_bus->reconfig_mutex){+.+.+.}:
__lock_acquire+0x16b6/0x1730
lock_acquire+0xbd/0x200
__mutex_lock+0x88/0x9b0
mutex_lock_nested+0x1b/0x20
nvdimm_bus_lock+0x21/0x30 [libnvdimm]
nvdimm_forget_poison+0x25/0x50 [libnvdimm]
nvdimm_clear_poison+0x106/0x140 [libnvdimm]
pmem_do_bvec+0x1c2/0x2b0 [nd_pmem]
pmem_make_request+0xf9/0x270 [nd_pmem]
generic_make_request+0x118/0x3b0
submit_bio+0x75/0x150
Cc: <[email protected]>
Fixes: 62232e4 ("libnvdimm: control (ioctl) messages for nvdimm_bus and nvdimm devices")
Cc: Dave Jiang <[email protected]>
Reported-by: Vishal Verma <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
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[ Upstream commit ddc665a ] When the instruction right before the branch destination is a 64 bit load immediate, we currently calculate the wrong jump offset in the ctx->offset[] array as we only account one instruction slot for the 64 bit load immediate although it uses two BPF instructions. Fix it up by setting the offset into the right slot after we incremented the index. Before (ldimm64 test 1): [...] 00000020: 52800007 mov w7, #0x0 // #0 00000024: d2800060 mov x0, #0x3 // #3 00000028: d2800041 mov x1, #0x2 // #2 0000002c: eb01001f cmp x0, x1 00000030: 54ffff82 b.cs 0x00000020 00000034: d29fffe7 mov x7, #0xffff // #65535 00000038: f2bfffe7 movk x7, #0xffff, lsl #16 0000003c: f2dfffe7 movk x7, #0xffff, lsl #32 00000040: f2ffffe7 movk x7, #0xffff, lsl #48 00000044: d29dddc7 mov x7, #0xeeee // #61166 00000048: f2bdddc7 movk x7, #0xeeee, lsl #16 0000004c: f2ddddc7 movk x7, #0xeeee, lsl #32 00000050: f2fdddc7 movk x7, #0xeeee, lsl #48 [...] After (ldimm64 test 1): [...] 00000020: 52800007 mov w7, #0x0 // #0 00000024: d2800060 mov x0, #0x3 // #3 00000028: d2800041 mov x1, #0x2 // #2 0000002c: eb01001f cmp x0, x1 00000030: 540000a2 b.cs 0x00000044 00000034: d29fffe7 mov x7, #0xffff // #65535 00000038: f2bfffe7 movk x7, #0xffff, lsl #16 0000003c: f2dfffe7 movk x7, #0xffff, lsl #32 00000040: f2ffffe7 movk x7, #0xffff, lsl #48 00000044: d29dddc7 mov x7, #0xeeee // #61166 00000048: f2bdddc7 movk x7, #0xeeee, lsl #16 0000004c: f2ddddc7 movk x7, #0xeeee, lsl #32 00000050: f2fdddc7 movk x7, #0xeeee, lsl #48 [...] Also, add a couple of test cases to make sure JITs pass this test. Tested on Cavium ThunderX ARMv8. The added test cases all pass after the fix. Fixes: 8eee539 ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()") Reported-by: David S. Miller <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Alexei Starovoitov <[email protected]> Cc: Xi Wang <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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…e_pmd() [ Upstream commit c9d398f ] I found the race condition which triggers the following bug when move_pages() and soft offline are called on a single hugetlb page concurrently. Soft offlining page 0x119400 at 0x700000000000 BUG: unable to handle kernel paging request at ffffea0011943820 IP: follow_huge_pmd+0x143/0x190 PGD 7ffd2067 PUD 7ffd1067 PMD 0 [61163.582052] Oops: 0000 [#1] SMP Modules linked in: binfmt_misc ppdev virtio_balloon parport_pc pcspkr i2c_piix4 parport i2c_core acpi_cpufreq ip_tables xfs libcrc32c ata_generic pata_acpi virtio_blk 8139too crc32c_intel ata_piix serio_raw libata virtio_pci 8139cp virtio_ring virtio mii floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: cap_check] CPU: 0 PID: 22573 Comm: iterate_numa_mo Tainted: P OE 4.11.0-rc2-mm1+ #2 Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 RIP: 0010:follow_huge_pmd+0x143/0x190 RSP: 0018:ffffc90004bdbcd0 EFLAGS: 00010202 RAX: 0000000465003e80 RBX: ffffea0004e34d30 RCX: 00003ffffffff000 RDX: 0000000011943800 RSI: 0000000000080001 RDI: 0000000465003e80 RBP: ffffc90004bdbd18 R08: 0000000000000000 R09: ffff880138d34000 R10: ffffea0004650000 R11: 0000000000c363b0 R12: ffffea0011943800 R13: ffff8801b8d34000 R14: ffffea0000000000 R15: 000077ff80000000 FS: 00007fc977710740(0000) GS:ffff88007dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffea0011943820 CR3: 000000007a746000 CR4: 00000000001406f0 Call Trace: follow_page_mask+0x270/0x550 SYSC_move_pages+0x4ea/0x8f0 SyS_move_pages+0xe/0x10 do_syscall_64+0x67/0x180 entry_SYSCALL64_slow_path+0x25/0x25 RIP: 0033:0x7fc976e03949 RSP: 002b:00007ffe72221d88 EFLAGS: 00000246 ORIG_RAX: 0000000000000117 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc976e03949 RDX: 0000000000c22390 RSI: 0000000000001400 RDI: 0000000000005827 RBP: 00007ffe72221e00 R08: 0000000000c2c3a0 R09: 0000000000000004 R10: 0000000000c363b0 R11: 0000000000000246 R12: 0000000000400650 R13: 00007ffe72221ee0 R14: 0000000000000000 R15: 0000000000000000 Code: 81 e4 ff ff 1f 00 48 21 c2 49 c1 ec 0c 48 c1 ea 0c 4c 01 e2 49 bc 00 00 00 00 00 ea ff ff 48 c1 e2 06 49 01 d4 f6 45 bc 04 74 90 <49> 8b 7c 24 20 40 f6 c7 01 75 2b 4c 89 e7 8b 47 1c 85 c0 7e 2a RIP: follow_huge_pmd+0x143/0x190 RSP: ffffc90004bdbcd0 CR2: ffffea0011943820 ---[ end trace e4f81353a2d23232 ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled This bug is triggered when pmd_present() returns true for non-present hugetlb, so fixing the present check in follow_huge_pmd() prevents it. Using pmd_present() to determine present/non-present for hugetlb is not correct, because pmd_present() checks multiple bits (not only _PAGE_PRESENT) for historical reason and it can misjudge hugetlb state. Fixes: e66f17f ("mm/hugetlb: take page table lock in follow_huge_pmd()") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Naoya Horiguchi <[email protected]> Acked-by: Hillf Danton <[email protected]> Cc: Hugh Dickins <[email protected]> Cc: Michal Hocko <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Mike Kravetz <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Gerald Schaefer <[email protected]> Cc: <[email protected]> [4.0+] Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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…nt() commit 4eecbe8 upstream. In case oldtrig == trig == NULL (which happens when we set none trigger, when there is already none set) there is a NULL pointer dereference during iio_trigger_put(trig). Below is kernel output when this occurs: [ 26.741790] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 26.750179] pgd = cacc0000 [ 26.752936] [00000000] *pgd=8adc6835, *pte=00000000, *ppte=00000000 [ 26.759531] Internal error: Oops: 17 [#1] SMP ARM [ 26.764261] Modules linked in: usb_f_ncm u_ether usb_f_acm u_serial usb_f_fs libcomposite configfs evbug [ 26.773844] CPU: 0 PID: 152 Comm: synchro Not tainted 4.12.0-rc1 #2 [ 26.780128] Hardware name: Freescale i.MX6 Ultralite (Device Tree) [ 26.786329] task: cb1de200 task.stack: cac92000 [ 26.790892] PC is at iio_trigger_write_current+0x188/0x1f4 [ 26.796403] LR is at lock_release+0xf8/0x20c [ 26.800696] pc : [<c0736f34>] lr : [<c016efb0>] psr: 600d0013 [ 26.800696] sp : cac93e30 ip : cac93db0 fp : cac93e5c [ 26.812193] r10: c0e64fe8 r9 : 00000000 r8 : 00000001 [ 26.817436] r7 : cb190810 r6 : 00000010 r5 : 00000001 r4 : 00000000 [ 26.823982] r3 : 00000000 r2 : 00000000 r1 : cb1de200 r0 : 00000000 [ 26.830528] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [ 26.837683] Control: 10c5387d Table: 8acc006a DAC: 00000051 [ 26.843448] Process synchro (pid: 152, stack limit = 0xcac92210) [ 26.849475] Stack: (0xcac93e30 to 0xcac94000) [ 26.853857] 3e20: 00000001 c0736dac c054033c cae6b680 [ 26.862060] 3e40: cae6b680 00000000 00000001 cb3f861 cac93e74 cac93e60 c054035c c0736db8 [ 26.870264] 3e60: 00000001 c054033c cac93e94 cac93e78 c029bf34 c0540348 00000000 00000000 [ 26.878469] 3e80: cb3f8600 cae6b680 cac93ed4 cac93e98 c029b320 c029bef0 00000000 00000000 [ 26.886672] 3ea0: 00000000 cac93f78 cb2d41fc caed3280 c029b214 cac93f78 00000001 000e20f8 [ 26.894874] 3ec0: 00000001 00000000 cac93f44 cac93ed8 c0221dcc c029b220 c0e1ca39 cb2d41fc [ 26.903079] 3ee0: cac93f04 cac93ef0 c0183ef0 c0183ab0 cb2d41fc 00000000 cac93f44 cac93f08 [ 26.911282] 3f00: c0225eec c0183ebc 00000001 00000000 c0223728 00000000 c024545 00000001 [ 26.919485] 3f20: 00000001 caed3280 000e20f8 cac93f78 000e20f8 00000001 cac93f74 cac93f48 [ 26.927690] 3f40: c0223680 c0221da4 c0246520 c0245460 caed3283 caed3280 00000000 00000000 [ 26.935893] 3f60: 000e20f8 00000001 cac93fa4 cac93f78 c0224520 c02235e4 00000000 00000000 [ 26.944096] 3f80: 00000001 000e20f8 00000001 00000004 c0107f84 cac92000 00000000 cac93fa8 [ 26.952299] 3fa0: c0107de0 c02244e8 00000001 000e20f8 0000000 000e20f8 00000001 fbad2484 [ 26.960502] 3fc0: 00000001 000e20f8 00000001 00000004 beb6b698 00064260 0006421c beb6b4b4 [ 26.968705] 3fe0: 00000000 beb6b450 b6f219a0 b6e2f268 800d0010 0000000 cac93ff4 cac93ffc [ 26.976896] Backtrace: [ 26.979388] [<c0736dac>] (iio_trigger_write_current) from [<c054035c>] (dev_attr_store+0x20/0x2c) [ 26.988289] r10:cb3f8610 r9:00000001 r8:00000000 r7:cae6b680 r6:cae6b680 r5:c054033c [ 26.996138] r4:c0736dac r3:00000001 [ 26.999747] [<c054033c>] (dev_attr_store) from [<c029bf34>] (sysfs_kf_write+0x50/0x54) [ 27.007686] r5:c054033c r4:00000001 [ 27.011290] [<c029bee4>] (sysfs_kf_write) from [<c029b320>] (kernfs_fop_write+0x10c/0x224) [ 27.019579] r7:cae6b680 r6:cb3f8600 r5:00000000 r4:00000000 [ 27.025271] [<c029b214>] (kernfs_fop_write) from [<c0221dcc>] (__vfs_write+0x34/0x120) [ 27.033214] r10:00000000 r9:00000001 r8:000e20f8 r7:00000001 r6:cac93f78 r5:c029b214 [ 27.041059] r4:caed3280 [ 27.043622] [<c0221d98>] (__vfs_write) from [<c0223680>] (vfs_write+0xa8/0x170) [ 27.050959] r9:00000001 r8:000e20f8 r7:cac93f78 r6:000e20f8 r5:caed3280 r4:00000001 [ 27.058731] [<c02235d8>] (vfs_write) from [<c0224520>] (SyS_write+0x44/0x98) [ 27.065806] r9:00000001 r8:000e20f8 r7:00000000 r6:00000000 r5:caed3280 r4:caed3283 [ 27.073582] [<c02244dc>] (SyS_write) from [<c0107de0>] (ret_fast_syscall+0x0/0x1c) [ 27.081179] r9:cac92000 r8:c0107f84 r7:00000004 r6:00000001 r5:000e20f8 r4:00000001 [ 27.088947] Code: 1a000009 e1a04009 e3a06010 e1a05008 (e5943000) [ 27.095244] ---[ end trace 06d1dab86d6e6bab ]--- To fix that problem call iio_trigger_put(trig) only when trig is not NULL. Fixes: d5d24bc ("iio: trigger: close race condition in acquiring trigger reference") Signed-off-by: Marcin Niestroj <[email protected]> Signed-off-by: Jonathan Cameron <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit b425e50 upstream. Since the introduction of .init_rq_fn() and .exit_rq_fn() it is essential that the memory allocated for struct request_queue stays around until all blk_exit_rl() calls have finished. Hence make blk_init_rl() take a reference on struct request_queue. This patch fixes the following crash: general protection fault: 0000 [#2] SMP CPU: 3 PID: 28 Comm: ksoftirqd/3 Tainted: G D 4.12.0-rc2-dbg+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 task: ffff88013a108040 task.stack: ffffc9000071c000 RIP: 0010:free_request_size+0x1a/0x30 RSP: 0018:ffffc9000071fd38 EFLAGS: 00010202 RAX: 6b6b6b6b6b6b6b6b RBX: ffff880067362a88 RCX: 0000000000000003 RDX: ffff880067464178 RSI: ffff880067362a88 RDI: ffff880135ea4418 RBP: ffffc9000071fd40 R08: 0000000000000000 R09: 0000000100180009 R10: ffffc9000071fd38 R11: ffffffff81110800 R12: ffff88006752d3d8 R13: ffff88006752d3d8 R14: ffff88013a108040 R15: 000000000000000a FS: 0000000000000000(0000) GS:ffff88013fd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa8ec1edb00 CR3: 0000000138ee8000 CR4: 00000000001406e0 Call Trace: mempool_destroy.part.10+0x21/0x40 mempool_destroy+0xe/0x10 blk_exit_rl+0x12/0x20 blkg_free+0x4d/0xa0 __blkg_release_rcu+0x59/0x170 rcu_process_callbacks+0x260/0x4e0 __do_softirq+0x116/0x250 smpboot_thread_fn+0x123/0x1e0 kthread+0x109/0x140 ret_from_fork+0x31/0x40 Fixes: commit e9c787e ("scsi: allocate scsi_cmnd structures as part of struct request") Signed-off-by: Bart Van Assche <[email protected]> Acked-by: Tejun Heo <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Cc: Jan Kara <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit cdea465 upstream. A vendor with a system having more than 128 CPUs occasionally encounters the following crash during shutdown. This is not an easily reproduceable event, but the vendor was able to provide the following analysis of the crash, which exhibits the same footprint each time. crash> bt PID: 0 TASK: ffff88017c70ce70 CPU: 5 COMMAND: "swapper/5" #0 [ffff88085c143ac8] machine_kexec at ffffffff81059c8b #1 [ffff88085c143b28] __crash_kexec at ffffffff811052e2 #2 [ffff88085c143bf8] crash_kexec at ffffffff811053d0 #3 [ffff88085c143c10] oops_end at ffffffff8168ef88 #4 [ffff88085c143c38] no_context at ffffffff8167ebb3 #5 [ffff88085c143c88] __bad_area_nosemaphore at ffffffff8167ec49 #6 [ffff88085c143cd0] bad_area_nosemaphore at ffffffff8167edb3 #7 [ffff88085c143ce0] __do_page_fault at ffffffff81691d1e #8 [ffff88085c143d40] do_page_fault at ffffffff81691ec5 #9 [ffff88085c143d70] page_fault at ffffffff8168e188 [exception RIP: unknown or invalid address] RIP: ffffffffa053c800 RSP: ffff88085c143e28 RFLAGS: 00010206 RAX: ffff88017c72bfd8 RBX: ffff88017a8dc000 RCX: ffff8810588b5ac8 RDX: ffff8810588b5a00 RSI: ffffffffa053c800 RDI: ffff8810588b5a00 RBP: ffff88085c143e58 R8: ffff88017c70d408 R9: ffff88017a8dc000 R10: 0000000000000002 R11: ffff88085c143da0 R12: ffff8810588b5ac8 R13: 0000000000000100 R14: ffffffffa053c800 R15: ffff8810588b5a00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 <IRQ stack> [exception RIP: cpuidle_enter_state+82] RIP: ffffffff81514192 RSP: ffff88017c72be50 RFLAGS: 00000202 RAX: 0000001e4c3c6f16 RBX: 000000000000f8a0 RCX: 0000000000000018 RDX: 0000000225c17d03 RSI: ffff88017c72bfd8 RDI: 0000001e4c3c6f16 RBP: ffff88017c72be78 R8: 000000000000237e R9: 0000000000000018 R10: 0000000000002494 R11: 0000000000000001 R12: ffff88017c72be20 R13: ffff88085c14f8e0 R14: 0000000000000082 R15: 0000001e4c3bb400 ORIG_RAX: ffffffffffffff10 CS: 0010 SS: 0018 This is the corresponding stack trace It has crashed because the area pointed with RIP extracted from timer element is already removed during a shutdown process. The function is smi_timeout(). And we think ffff8810588b5a00 in RDX is a parameter struct smi_info crash> rd ffff8810588b5a00 20 ffff8810588b5a00: ffff8810588b6000 0000000000000000 .`.X............ ffff8810588b5a10: ffff880853264400 ffffffffa05417e0 .D&S......T..... ffff8810588b5a20: 24a024a000000000 0000000000000000 .....$.$........ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a40: ffffffffa053a040 ffffffffa053a060 @.S.....`.S..... ffff8810588b5a50: 0000000000000000 0000000100000001 ................ ffff8810588b5a60: 0000000000000000 0000000000000e00 ................ ffff8810588b5a70: ffffffffa053a580 ffffffffa053a6e0 ..S.......S..... ffff8810588b5a80: ffffffffa053a4a0 ffffffffa053a250 ..S.....P.S..... ffff8810588b5a90: 0000000500000002 0000000000000000 ................ Unfortunately the top of this area is already detroyed by someone. But because of two reasonns we think this is struct smi_info 1) The address included in between ffff8810588b5a70 and ffff8810588b5a80: are inside of ipmi_si_intf.c see crash> module ffff88085779d2c0 2) We've found the area which point this. It is offset 0x68 of ffff880859df4000 crash> rd ffff880859df4000 100 ffff880859df4000: 0000000000000000 0000000000000001 ................ ffff880859df4010: ffffffffa0535290 dead000000000200 .RS............. ffff880859df4020: ffff880859df4020 ffff880859df4020 @.Y.... @.Y.... ffff880859df4030: 0000000000000002 0000000000100010 ................ ffff880859df4040: ffff880859df4040 ffff880859df4040 @@.Y....@@.Y.... ffff880859df4050: 0000000000000000 0000000000000000 ................ ffff880859df4060: 0000000000000000 ffff8810588b5a00 .........Z.X.... ffff880859df4070: 0000000000000001 ffff880859df4078 [email protected].... If we regards it as struct ipmi_smi in shutdown process it looks consistent. The remedy for this apparent race is affixed below. Signed-off-by: Tony Camuso <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> This was first introduced in 7ea0ed2 ipmi: Make the message handler easier to use for SMI interfaces where some code was moved outside of the rcu_read_lock() and the lock was not added. Signed-off-by: Corey Minyard <[email protected]>
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Aug 14, 2017
[ Upstream commit 253fd0f ] Syzkaller fuzzer managed to trigger this: BUG: sleeping function called from invalid context at mm/shmem.c:852 in_atomic(): 1, irqs_disabled(): 0, pid: 529, name: khugepaged 3 locks held by khugepaged/529: #0: (shrinker_rwsem){++++..}, at: [<ffffffff818d7ef1>] shrink_slab.part.59+0x121/0xd30 mm/vmscan.c:451 Freescale#1: (&type->s_umount_key#29){++++..}, at: [<ffffffff81a63630>] trylock_super+0x20/0x100 fs/super.c:392 Freescale#2: (&(&sbinfo->shrinklist_lock)->rlock){+.+.-.}, at: [<ffffffff818fd83e>] spin_lock include/linux/spinlock.h:302 [inline] Freescale#2: (&(&sbinfo->shrinklist_lock)->rlock){+.+.-.}, at: [<ffffffff818fd83e>] shmem_unused_huge_shrink+0x28e/0x1490 mm/shmem.c:427 CPU: 2 PID: 529 Comm: khugepaged Not tainted 4.10.0-rc5+ Freescale#201 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: shmem_undo_range+0xb20/0x2710 mm/shmem.c:852 shmem_truncate_range+0x27/0xa0 mm/shmem.c:939 shmem_evict_inode+0x35f/0xca0 mm/shmem.c:1030 evict+0x46e/0x980 fs/inode.c:553 iput_final fs/inode.c:1515 [inline] iput+0x589/0xb20 fs/inode.c:1542 shmem_unused_huge_shrink+0xbad/0x1490 mm/shmem.c:446 shmem_unused_huge_scan+0x10c/0x170 mm/shmem.c:512 super_cache_scan+0x376/0x450 fs/super.c:106 do_shrink_slab mm/vmscan.c:378 [inline] shrink_slab.part.59+0x543/0xd30 mm/vmscan.c:481 shrink_slab mm/vmscan.c:2592 [inline] shrink_node+0x2c7/0x870 mm/vmscan.c:2592 shrink_zones mm/vmscan.c:2734 [inline] do_try_to_free_pages+0x369/0xc80 mm/vmscan.c:2776 try_to_free_pages+0x3c6/0x900 mm/vmscan.c:2982 __perform_reclaim mm/page_alloc.c:3301 [inline] __alloc_pages_direct_reclaim mm/page_alloc.c:3322 [inline] __alloc_pages_slowpath+0xa24/0x1c30 mm/page_alloc.c:3683 __alloc_pages_nodemask+0x544/0xae0 mm/page_alloc.c:3848 __alloc_pages include/linux/gfp.h:426 [inline] __alloc_pages_node include/linux/gfp.h:439 [inline] khugepaged_alloc_page+0xc2/0x1b0 mm/khugepaged.c:750 collapse_huge_page+0x182/0x1fe0 mm/khugepaged.c:955 khugepaged_scan_pmd+0xfdf/0x12a0 mm/khugepaged.c:1208 khugepaged_scan_mm_slot mm/khugepaged.c:1727 [inline] khugepaged_do_scan mm/khugepaged.c:1808 [inline] khugepaged+0xe9b/0x1590 mm/khugepaged.c:1853 kthread+0x326/0x3f0 kernel/kthread.c:227 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 The iput() from atomic context was a bad idea: if after igrab() somebody else calls iput() and we left with the last inode reference, our iput() would lead to inode eviction and therefore sleeping. This patch should fix the situation. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Kirill A. Shutemov <[email protected]> Reported-by: Dmitry Vyukov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit cdea465 upstream. A vendor with a system having more than 128 CPUs occasionally encounters the following crash during shutdown. This is not an easily reproduceable event, but the vendor was able to provide the following analysis of the crash, which exhibits the same footprint each time. crash> bt PID: 0 TASK: ffff88017c70ce70 CPU: 5 COMMAND: "swapper/5" #0 [ffff88085c143ac8] machine_kexec at ffffffff81059c8b Freescale#1 [ffff88085c143b28] __crash_kexec at ffffffff811052e2 Freescale#2 [ffff88085c143bf8] crash_kexec at ffffffff811053d0 Freescale#3 [ffff88085c143c10] oops_end at ffffffff8168ef88 Freescale#4 [ffff88085c143c38] no_context at ffffffff8167ebb3 Freescale#5 [ffff88085c143c88] __bad_area_nosemaphore at ffffffff8167ec49 Freescale#6 [ffff88085c143cd0] bad_area_nosemaphore at ffffffff8167edb3 Freescale#7 [ffff88085c143ce0] __do_page_fault at ffffffff81691d1e Freescale#8 [ffff88085c143d40] do_page_fault at ffffffff81691ec5 Freescale#9 [ffff88085c143d70] page_fault at ffffffff8168e188 [exception RIP: unknown or invalid address] RIP: ffffffffa053c800 RSP: ffff88085c143e28 RFLAGS: 00010206 RAX: ffff88017c72bfd8 RBX: ffff88017a8dc000 RCX: ffff8810588b5ac8 RDX: ffff8810588b5a00 RSI: ffffffffa053c800 RDI: ffff8810588b5a00 RBP: ffff88085c143e58 R8: ffff88017c70d408 R9: ffff88017a8dc000 R10: 0000000000000002 R11: ffff88085c143da0 R12: ffff8810588b5ac8 R13: 0000000000000100 R14: ffffffffa053c800 R15: ffff8810588b5a00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 <IRQ stack> [exception RIP: cpuidle_enter_state+82] RIP: ffffffff81514192 RSP: ffff88017c72be50 RFLAGS: 00000202 RAX: 0000001e4c3c6f16 RBX: 000000000000f8a0 RCX: 0000000000000018 RDX: 0000000225c17d03 RSI: ffff88017c72bfd8 RDI: 0000001e4c3c6f16 RBP: ffff88017c72be78 R8: 000000000000237e R9: 0000000000000018 R10: 0000000000002494 R11: 0000000000000001 R12: ffff88017c72be20 R13: ffff88085c14f8e0 R14: 0000000000000082 R15: 0000001e4c3bb400 ORIG_RAX: ffffffffffffff10 CS: 0010 SS: 0018 This is the corresponding stack trace It has crashed because the area pointed with RIP extracted from timer element is already removed during a shutdown process. The function is smi_timeout(). And we think ffff8810588b5a00 in RDX is a parameter struct smi_info crash> rd ffff8810588b5a00 20 ffff8810588b5a00: ffff8810588b6000 0000000000000000 .`.X............ ffff8810588b5a10: ffff880853264400 ffffffffa05417e0 .D&S......T..... ffff8810588b5a20: 24a024a000000000 0000000000000000 .....$.$........ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a40: ffffffffa053a040 ffffffffa053a060 @.S.....`.S..... ffff8810588b5a50: 0000000000000000 0000000100000001 ................ ffff8810588b5a60: 0000000000000000 0000000000000e00 ................ ffff8810588b5a70: ffffffffa053a580 ffffffffa053a6e0 ..S.......S..... ffff8810588b5a80: ffffffffa053a4a0 ffffffffa053a250 ..S.....P.S..... ffff8810588b5a90: 0000000500000002 0000000000000000 ................ Unfortunately the top of this area is already detroyed by someone. But because of two reasonns we think this is struct smi_info 1) The address included in between ffff8810588b5a70 and ffff8810588b5a80: are inside of ipmi_si_intf.c see crash> module ffff88085779d2c0 2) We've found the area which point this. It is offset 0x68 of ffff880859df4000 crash> rd ffff880859df4000 100 ffff880859df4000: 0000000000000000 0000000000000001 ................ ffff880859df4010: ffffffffa0535290 dead000000000200 .RS............. ffff880859df4020: ffff880859df4020 ffff880859df4020 @.Y.... @.Y.... ffff880859df4030: 0000000000000002 0000000000100010 ................ ffff880859df4040: ffff880859df4040 ffff880859df4040 @@.Y....@@.Y.... ffff880859df4050: 0000000000000000 0000000000000000 ................ ffff880859df4060: 0000000000000000 ffff8810588b5a00 .........Z.X.... ffff880859df4070: 0000000000000001 ffff880859df4078 [email protected].... If we regards it as struct ipmi_smi in shutdown process it looks consistent. The remedy for this apparent race is affixed below. Signed-off-by: Tony Camuso <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> This was first introduced in 7ea0ed2 ipmi: Make the message handler easier to use for SMI interfaces where some code was moved outside of the rcu_read_lock() and the lock was not added. Signed-off-by: Corey Minyard <[email protected]>
otavio
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Aug 24, 2017
commit 6104672 upstream. Subsystem migration methods shouldn't be called for empty migrations. cgroup_migrate_execute() implements this guarantee by bailing early if there are no source css_sets. This used to be correct before a79a908 ("cgroup: introduce cgroup namespaces"), but no longer since the commit because css_sets can stay pinned without tasks in them. This caused cgroup_migrate_execute() call into cpuset migration methods with an empty cgroup_taskset. cpuset migration methods correctly assume that cgroup_taskset_first() never returns NULL; however, due to the bug, it can, leading to the following oops. Unable to handle kernel paging request for data at address 0x00000960 Faulting instruction address: 0xc0000000001d6868 Oops: Kernel access of bad area, sig: 11 [#1] ... CPU: 14 PID: 16947 Comm: kworker/14:0 Tainted: G W 4.12.0-rc4-next-20170609 #2 Workqueue: events cpuset_hotplug_workfn task: c00000000ca60580 task.stack: c00000000c728000 NIP: c0000000001d6868 LR: c0000000001d6858 CTR: c0000000001d6810 REGS: c00000000c72b720 TRAP: 0300 Tainted: GW (4.12.0-rc4-next-20170609) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 44722422 XER: 20000000 CFAR: c000000000008710 DAR: 0000000000000960 DSISR: 40000000 SOFTE: 1 GPR00: c0000000001d6858 c00000000c72b9a0 c000000001536e00 0000000000000000 GPR04: c00000000c72b9c0 0000000000000000 c00000000c72bad0 c000000766367678 GPR08: c000000766366d10 c00000000c72b958 c000000001736e00 0000000000000000 GPR12: c0000000001d6810 c00000000e749300 c000000000123ef8 c000000775af4180 GPR16: 0000000000000000 0000000000000000 c00000075480e9c0 c00000075480e9e0 GPR20: c00000075480e8c0 0000000000000001 0000000000000000 c00000000c72ba20 GPR24: c00000000c72baa0 c00000000c72bac0 c000000001407248 c00000000c72ba20 GPR28: c00000000141fc80 c00000000c72bac0 c00000000c6bc790 0000000000000000 NIP [c0000000001d6868] cpuset_can_attach+0x58/0x1b0 LR [c0000000001d6858] cpuset_can_attach+0x48/0x1b0 Call Trace: [c00000000c72b9a0] [c0000000001d6858] cpuset_can_attach+0x48/0x1b0 (unreliable) [c00000000c72ba00] [c0000000001cbe80] cgroup_migrate_execute+0xb0/0x450 [c00000000c72ba80] [c0000000001d3754] cgroup_transfer_tasks+0x1c4/0x360 [c00000000c72bba0] [c0000000001d923c] cpuset_hotplug_workfn+0x86c/0xa20 [c00000000c72bca0] [c00000000011aa44] process_one_work+0x1e4/0x580 [c00000000c72bd30] [c00000000011ae78] worker_thread+0x98/0x5c0 [c00000000c72bdc0] [c000000000124058] kthread+0x168/0x1b0 [c00000000c72be30] [c00000000000b2e8] ret_from_kernel_thread+0x5c/0x74 Instruction dump: f821ffa1 7c7d1b78 60000000 60000000 38810020 7fa3eb78 3f42ffed 4bff4c25 60000000 3b5a0448 3d420020 eb610020 <e9230960> 7f43d378 e9290000 f92af200 ---[ end trace dcaaf98fb36d9e64 ]--- This patch fixes the bug by adding an explicit nr_tasks counter to cgroup_taskset and skipping calling the migration methods if the counter is zero. While at it, remove the now spurious check on no source css_sets. Signed-off-by: Tejun Heo <[email protected]> Reported-and-tested-by: Abdul Haleem <[email protected]> Cc: Roman Gushchin <[email protected]> Fixes: a79a908 ("cgroup: introduce cgroup namespaces") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Aug 24, 2017
commit 978d13d upstream. This patch fixes a bug associated with iscsit_reset_np_thread() that can occur during parallel configfs rmdir of a single iscsi_np used across multiple iscsi-target instances, that would result in hung task(s) similar to below where configfs rmdir process context was blocked indefinately waiting for iscsi_np->np_restart_comp to finish: [ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds. [ 6726.119440] Tainted: G W O 4.1.26-3321 #2 [ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88 0 15550 1 0x00000000 [ 6726.140058] ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08 [ 6726.147593] ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0 [ 6726.155132] ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8 [ 6726.162667] Call Trace: [ 6726.165150] [<ffffffff8168ced2>] schedule+0x32/0x80 [ 6726.170156] [<ffffffff8168f5b4>] schedule_timeout+0x214/0x290 [ 6726.176030] [<ffffffff810caef2>] ? __send_signal+0x52/0x4a0 [ 6726.181728] [<ffffffff8168d7d6>] wait_for_completion+0x96/0x100 [ 6726.187774] [<ffffffff810e7c80>] ? wake_up_state+0x10/0x10 [ 6726.193395] [<ffffffffa035d6e2>] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod] [ 6726.201278] [<ffffffffa0355d86>] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod] [ 6726.210033] [<ffffffffa0363f7f>] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod] [ 6726.218351] [<ffffffff81260c5a>] configfs_write_file+0xaa/0x110 [ 6726.224392] [<ffffffff811ea364>] vfs_write+0xa4/0x1b0 [ 6726.229576] [<ffffffff811eb111>] SyS_write+0x41/0xb0 [ 6726.234659] [<ffffffff8169042e>] system_call_fastpath+0x12/0x71 It would happen because each iscsit_reset_np_thread() sets state to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting for completion on iscsi_np->np_restart_comp. However, if iscsi_np was active processing a login request and more than a single iscsit_reset_np_thread() caller to the same iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np kthread process context in __iscsi_target_login_thread() would flush pending signals and only perform a single completion of np->np_restart_comp before going back to sleep within transport specific iscsit_transport->iscsi_accept_np code. To address this bug, add a iscsi_np->np_reset_count and update __iscsi_target_login_thread() to keep completing np->np_restart_comp until ->np_reset_count has reached zero. Reported-by: Gary Guo <[email protected]> Tested-by: Gary Guo <[email protected]> Cc: Mike Christie <[email protected]> Cc: Hannes Reinecke <[email protected]> Signed-off-by: Nicholas Bellinger <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 978d13d upstream. This patch fixes a bug associated with iscsit_reset_np_thread() that can occur during parallel configfs rmdir of a single iscsi_np used across multiple iscsi-target instances, that would result in hung task(s) similar to below where configfs rmdir process context was blocked indefinately waiting for iscsi_np->np_restart_comp to finish: [ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds. [ 6726.119440] Tainted: G W O 4.1.26-3321 #2 [ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88 0 15550 1 0x00000000 [ 6726.140058] ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08 [ 6726.147593] ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0 [ 6726.155132] ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8 [ 6726.162667] Call Trace: [ 6726.165150] [<ffffffff8168ced2>] schedule+0x32/0x80 [ 6726.170156] [<ffffffff8168f5b4>] schedule_timeout+0x214/0x290 [ 6726.176030] [<ffffffff810caef2>] ? __send_signal+0x52/0x4a0 [ 6726.181728] [<ffffffff8168d7d6>] wait_for_completion+0x96/0x100 [ 6726.187774] [<ffffffff810e7c80>] ? wake_up_state+0x10/0x10 [ 6726.193395] [<ffffffffa035d6e2>] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod] [ 6726.201278] [<ffffffffa0355d86>] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod] [ 6726.210033] [<ffffffffa0363f7f>] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod] [ 6726.218351] [<ffffffff81260c5a>] configfs_write_file+0xaa/0x110 [ 6726.224392] [<ffffffff811ea364>] vfs_write+0xa4/0x1b0 [ 6726.229576] [<ffffffff811eb111>] SyS_write+0x41/0xb0 [ 6726.234659] [<ffffffff8169042e>] system_call_fastpath+0x12/0x71 It would happen because each iscsit_reset_np_thread() sets state to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting for completion on iscsi_np->np_restart_comp. However, if iscsi_np was active processing a login request and more than a single iscsit_reset_np_thread() caller to the same iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np kthread process context in __iscsi_target_login_thread() would flush pending signals and only perform a single completion of np->np_restart_comp before going back to sleep within transport specific iscsit_transport->iscsi_accept_np code. To address this bug, add a iscsi_np->np_reset_count and update __iscsi_target_login_thread() to keep completing np->np_restart_comp until ->np_reset_count has reached zero. Reported-by: Gary Guo <[email protected]> Tested-by: Gary Guo <[email protected]> Cc: Mike Christie <[email protected]> Cc: Hannes Reinecke <[email protected]> Signed-off-by: Nicholas Bellinger <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
otavio
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Aug 28, 2017
The following commit: 39a0526 ("x86/mm: Factor out LDT init from context init") renamed init_new_context() to init_new_context_ldt() and added a new init_new_context() which calls init_new_context_ldt(). However, the error code of init_new_context_ldt() was ignored. Consequently, if a memory allocation in alloc_ldt_struct() failed during a fork(), the ->context.ldt of the new task remained the same as that of the old task (due to the memcpy() in dup_mm()). ldt_struct's are not intended to be shared, so a use-after-free occurred after one task exited. Fix the bug by making init_new_context() pass through the error code of init_new_context_ldt(). This bug was found by syzkaller, which encountered the following splat: BUG: KASAN: use-after-free in free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116 Read of size 4 at addr ffff88006d2cb7c8 by task kworker/u9:0/3710 CPU: 1 PID: 3710 Comm: kworker/u9:0 Not tainted 4.13.0-rc4-next-20170811 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116 free_ldt_struct arch/x86/kernel/ldt.c:173 [inline] destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171 destroy_context arch/x86/include/asm/mmu_context.h:157 [inline] __mmdrop+0xe9/0x530 kernel/fork.c:889 mmdrop include/linux/sched/mm.h:42 [inline] exec_mmap fs/exec.c:1061 [inline] flush_old_exec+0x173c/0x1ff0 fs/exec.c:1291 load_elf_binary+0x81f/0x4ba0 fs/binfmt_elf.c:855 search_binary_handler+0x142/0x6b0 fs/exec.c:1652 exec_binprm fs/exec.c:1694 [inline] do_execveat_common.isra.33+0x1746/0x22e0 fs/exec.c:1816 do_execve+0x31/0x40 fs/exec.c:1860 call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Allocated by task 3700: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627 kmalloc include/linux/slab.h:493 [inline] alloc_ldt_struct+0x52/0x140 arch/x86/kernel/ldt.c:67 write_ldt+0x7b7/0xab0 arch/x86/kernel/ldt.c:277 sys_modify_ldt+0x1ef/0x240 arch/x86/kernel/ldt.c:307 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 3700: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 free_ldt_struct.part.2+0xdd/0x150 arch/x86/kernel/ldt.c:121 free_ldt_struct arch/x86/kernel/ldt.c:173 [inline] destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171 destroy_context arch/x86/include/asm/mmu_context.h:157 [inline] __mmdrop+0xe9/0x530 kernel/fork.c:889 mmdrop include/linux/sched/mm.h:42 [inline] __mmput kernel/fork.c:916 [inline] mmput+0x541/0x6e0 kernel/fork.c:927 copy_process.part.36+0x22e1/0x4af0 kernel/fork.c:1931 copy_process kernel/fork.c:1546 [inline] _do_fork+0x1ef/0xfb0 kernel/fork.c:2025 SYSC_clone kernel/fork.c:2135 [inline] SyS_clone+0x37/0x50 kernel/fork.c:2129 do_syscall_64+0x26c/0x8c0 arch/x86/entry/common.c:287 return_from_SYSCALL_64+0x0/0x7a Here is a C reproducer: #include <asm/ldt.h> #include <pthread.h> #include <signal.h> #include <stdlib.h> #include <sys/syscall.h> #include <sys/wait.h> #include <unistd.h> static void *fork_thread(void *_arg) { fork(); } int main(void) { struct user_desc desc = { .entry_number = 8191 }; syscall(__NR_modify_ldt, 1, &desc, sizeof(desc)); for (;;) { if (fork() == 0) { pthread_t t; srand(getpid()); pthread_create(&t, NULL, fork_thread, NULL); usleep(rand() % 10000); syscall(__NR_exit_group, 0); } wait(NULL); } } Note: the reproducer takes advantage of the fact that alloc_ldt_struct() may use vmalloc() to allocate a large ->entries array, and after commit: 5d17a73 ("vmalloc: back off when the current task is killed") it is possible for userspace to fail a task's vmalloc() by sending a fatal signal, e.g. via exit_group(). It would be more difficult to reproduce this bug on kernels without that commit. This bug only affected kernels with CONFIG_MODIFY_LDT_SYSCALL=y. Signed-off-by: Eric Biggers <[email protected]> Acked-by: Dave Hansen <[email protected]> Cc: <[email protected]> [v4.6+] Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Fixes: 39a0526 ("x86/mm: Factor out LDT init from context init") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
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[ Upstream commit cdea465 ] A vendor with a system having more than 128 CPUs occasionally encounters the following crash during shutdown. This is not an easily reproduceable event, but the vendor was able to provide the following analysis of the crash, which exhibits the same footprint each time. crash> bt PID: 0 TASK: ffff88017c70ce70 CPU: 5 COMMAND: "swapper/5" #0 [ffff88085c143ac8] machine_kexec at ffffffff81059c8b #1 [ffff88085c143b28] __crash_kexec at ffffffff811052e2 #2 [ffff88085c143bf8] crash_kexec at ffffffff811053d0 #3 [ffff88085c143c10] oops_end at ffffffff8168ef88 #4 [ffff88085c143c38] no_context at ffffffff8167ebb3 #5 [ffff88085c143c88] __bad_area_nosemaphore at ffffffff8167ec49 #6 [ffff88085c143cd0] bad_area_nosemaphore at ffffffff8167edb3 #7 [ffff88085c143ce0] __do_page_fault at ffffffff81691d1e #8 [ffff88085c143d40] do_page_fault at ffffffff81691ec5 #9 [ffff88085c143d70] page_fault at ffffffff8168e188 [exception RIP: unknown or invalid address] RIP: ffffffffa053c800 RSP: ffff88085c143e28 RFLAGS: 00010206 RAX: ffff88017c72bfd8 RBX: ffff88017a8dc000 RCX: ffff8810588b5ac8 RDX: ffff8810588b5a00 RSI: ffffffffa053c800 RDI: ffff8810588b5a00 RBP: ffff88085c143e58 R8: ffff88017c70d408 R9: ffff88017a8dc000 R10: 0000000000000002 R11: ffff88085c143da0 R12: ffff8810588b5ac8 R13: 0000000000000100 R14: ffffffffa053c800 R15: ffff8810588b5a00 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 <IRQ stack> [exception RIP: cpuidle_enter_state+82] RIP: ffffffff81514192 RSP: ffff88017c72be50 RFLAGS: 00000202 RAX: 0000001e4c3c6f16 RBX: 000000000000f8a0 RCX: 0000000000000018 RDX: 0000000225c17d03 RSI: ffff88017c72bfd8 RDI: 0000001e4c3c6f16 RBP: ffff88017c72be78 R8: 000000000000237e R9: 0000000000000018 R10: 0000000000002494 R11: 0000000000000001 R12: ffff88017c72be20 R13: ffff88085c14f8e0 R14: 0000000000000082 R15: 0000001e4c3bb400 ORIG_RAX: ffffffffffffff10 CS: 0010 SS: 0018 This is the corresponding stack trace It has crashed because the area pointed with RIP extracted from timer element is already removed during a shutdown process. The function is smi_timeout(). And we think ffff8810588b5a00 in RDX is a parameter struct smi_info crash> rd ffff8810588b5a00 20 ffff8810588b5a00: ffff8810588b6000 0000000000000000 .`.X............ ffff8810588b5a10: ffff880853264400 ffffffffa05417e0 .D&S......T..... ffff8810588b5a20: 24a024a000000000 0000000000000000 .....$.$........ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a30: 0000000000000000 0000000000000000 ................ ffff8810588b5a40: ffffffffa053a040 ffffffffa053a060 @.S.....`.S..... ffff8810588b5a50: 0000000000000000 0000000100000001 ................ ffff8810588b5a60: 0000000000000000 0000000000000e00 ................ ffff8810588b5a70: ffffffffa053a580 ffffffffa053a6e0 ..S.......S..... ffff8810588b5a80: ffffffffa053a4a0 ffffffffa053a250 ..S.....P.S..... ffff8810588b5a90: 0000000500000002 0000000000000000 ................ Unfortunately the top of this area is already detroyed by someone. But because of two reasonns we think this is struct smi_info 1) The address included in between ffff8810588b5a70 and ffff8810588b5a80: are inside of ipmi_si_intf.c see crash> module ffff88085779d2c0 2) We've found the area which point this. It is offset 0x68 of ffff880859df4000 crash> rd ffff880859df4000 100 ffff880859df4000: 0000000000000000 0000000000000001 ................ ffff880859df4010: ffffffffa0535290 dead000000000200 .RS............. ffff880859df4020: ffff880859df4020 ffff880859df4020 @.Y.... @.Y.... ffff880859df4030: 0000000000000002 0000000000100010 ................ ffff880859df4040: ffff880859df4040 ffff880859df4040 @@.Y....@@.Y.... ffff880859df4050: 0000000000000000 0000000000000000 ................ ffff880859df4060: 0000000000000000 ffff8810588b5a00 .........Z.X.... ffff880859df4070: 0000000000000001 ffff880859df4078 [email protected].... If we regards it as struct ipmi_smi in shutdown process it looks consistent. The remedy for this apparent race is affixed below. Signed-off-by: Tony Camuso <[email protected]> Cc: [email protected] # 3.19 This was first introduced in 7ea0ed2 ipmi: Make the message handler easier to use for SMI interfaces where some code was moved outside of the rcu_read_lock() and the lock was not added. Signed-off-by: Corey Minyard <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 978d13d ] This patch fixes a bug associated with iscsit_reset_np_thread() that can occur during parallel configfs rmdir of a single iscsi_np used across multiple iscsi-target instances, that would result in hung task(s) similar to below where configfs rmdir process context was blocked indefinately waiting for iscsi_np->np_restart_comp to finish: [ 6726.112076] INFO: task dcp_proxy_node_:15550 blocked for more than 120 seconds. [ 6726.119440] Tainted: G W O 4.1.26-3321 #2 [ 6726.125045] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 6726.132927] dcp_proxy_node_ D ffff8803f202bc88 0 15550 1 0x00000000 [ 6726.140058] ffff8803f202bc88 ffff88085c64d960 ffff88083b3b1ad0 ffff88087fffeb08 [ 6726.147593] ffff8803f202c000 7fffffffffffffff ffff88083f459c28 ffff88083b3b1ad0 [ 6726.155132] ffff88035373c100 ffff8803f202bca8 ffffffff8168ced2 ffff8803f202bcb8 [ 6726.162667] Call Trace: [ 6726.165150] [<ffffffff8168ced2>] schedule+0x32/0x80 [ 6726.170156] [<ffffffff8168f5b4>] schedule_timeout+0x214/0x290 [ 6726.176030] [<ffffffff810caef2>] ? __send_signal+0x52/0x4a0 [ 6726.181728] [<ffffffff8168d7d6>] wait_for_completion+0x96/0x100 [ 6726.187774] [<ffffffff810e7c80>] ? wake_up_state+0x10/0x10 [ 6726.193395] [<ffffffffa035d6e2>] iscsit_reset_np_thread+0x62/0xe0 [iscsi_target_mod] [ 6726.201278] [<ffffffffa0355d86>] iscsit_tpg_disable_portal_group+0x96/0x190 [iscsi_target_mod] [ 6726.210033] [<ffffffffa0363f7f>] lio_target_tpg_store_enable+0x4f/0xc0 [iscsi_target_mod] [ 6726.218351] [<ffffffff81260c5a>] configfs_write_file+0xaa/0x110 [ 6726.224392] [<ffffffff811ea364>] vfs_write+0xa4/0x1b0 [ 6726.229576] [<ffffffff811eb111>] SyS_write+0x41/0xb0 [ 6726.234659] [<ffffffff8169042e>] system_call_fastpath+0x12/0x71 It would happen because each iscsit_reset_np_thread() sets state to ISCSI_NP_THREAD_RESET, sends SIGINT, and then blocks waiting for completion on iscsi_np->np_restart_comp. However, if iscsi_np was active processing a login request and more than a single iscsit_reset_np_thread() caller to the same iscsi_np was blocked on iscsi_np->np_restart_comp, iscsi_np kthread process context in __iscsi_target_login_thread() would flush pending signals and only perform a single completion of np->np_restart_comp before going back to sleep within transport specific iscsit_transport->iscsi_accept_np code. To address this bug, add a iscsi_np->np_reset_count and update __iscsi_target_login_thread() to keep completing np->np_restart_comp until ->np_reset_count has reached zero. Reported-by: Gary Guo <[email protected]> Tested-by: Gary Guo <[email protected]> Cc: Mike Christie <[email protected]> Cc: Hannes Reinecke <[email protected]> Cc: [email protected] # 3.10+ Signed-off-by: Nicholas Bellinger <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
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[ Upstream commit 36f41f8 ] pfkey_broadcast() might be called from non process contexts, we can not use GFP_KERNEL in these cases [1]. This patch partially reverts commit ba51b6b ("net: Fix RCU splat in af_key"), only keeping the GFP_ATOMIC forcing under rcu_read_lock() section. [1] : syzkaller reported : in_atomic(): 1, irqs_disabled(): 0, pid: 2932, name: syzkaller183439 3 locks held by syzkaller183439/2932: #0: (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [<ffffffff83b43888>] pfkey_sendmsg+0x4c8/0x9f0 net/key/af_key.c:3649 #1: (&pfk->dump_lock){+.+.+.}, at: [<ffffffff83b467f6>] pfkey_do_dump+0x76/0x3f0 net/key/af_key.c:293 #2: (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] spin_lock_bh include/linux/spinlock.h:304 [inline] #2: (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] xfrm_policy_walk+0x192/0xa30 net/xfrm/xfrm_policy.c:1028 CPU: 0 PID: 2932 Comm: syzkaller183439 Not tainted 4.13.0-rc4+ #24 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:5994 __might_sleep+0x95/0x190 kernel/sched/core.c:5947 slab_pre_alloc_hook mm/slab.h:416 [inline] slab_alloc mm/slab.c:3383 [inline] kmem_cache_alloc+0x24b/0x6e0 mm/slab.c:3559 skb_clone+0x1a0/0x400 net/core/skbuff.c:1037 pfkey_broadcast_one+0x4b2/0x6f0 net/key/af_key.c:207 pfkey_broadcast+0x4ba/0x770 net/key/af_key.c:281 dump_sp+0x3d6/0x500 net/key/af_key.c:2685 xfrm_policy_walk+0x2f1/0xa30 net/xfrm/xfrm_policy.c:1042 pfkey_dump_sp+0x42/0x50 net/key/af_key.c:2695 pfkey_do_dump+0xaa/0x3f0 net/key/af_key.c:299 pfkey_spddump+0x1a0/0x210 net/key/af_key.c:2722 pfkey_process+0x606/0x710 net/key/af_key.c:2814 pfkey_sendmsg+0x4d6/0x9f0 net/key/af_key.c:3650 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 ___sys_sendmsg+0x755/0x890 net/socket.c:2035 __sys_sendmsg+0xe5/0x210 net/socket.c:2069 SYSC_sendmsg net/socket.c:2080 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2076 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x445d79 RSP: 002b:00007f32447c1dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445d79 RDX: 0000000000000000 RSI: 000000002023dfc8 RDI: 0000000000000008 RBP: 0000000000000086 R08: 00007f32447c2700 R09: 00007f32447c2700 R10: 00007f32447c2700 R11: 0000000000000202 R12: 0000000000000000 R13: 00007ffe33edec4f R14: 00007f32447c29c0 R15: 0000000000000000 Fixes: ba51b6b ("net: Fix RCU splat in af_key") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: Dmitry Vyukov <[email protected]> Cc: David Ahern <[email protected]> Acked-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit 7749d4f ] syzkaller reported that DCCP could have a non empty write queue at dismantle time. WARNING: CPU: 1 PID: 2953 at net/core/stream.c:199 sk_stream_kill_queues+0x3ce/0x520 net/core/stream.c:199 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2953 Comm: syz-executor0 Not tainted 4.13.0-rc4+ #2 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 panic+0x1e4/0x417 kernel/panic.c:180 __warn+0x1c4/0x1d9 kernel/panic.c:541 report_bug+0x211/0x2d0 lib/bug.c:183 fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:273 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:846 RIP: 0010:sk_stream_kill_queues+0x3ce/0x520 net/core/stream.c:199 RSP: 0018:ffff8801d182f108 EFLAGS: 00010297 RAX: ffff8801d1144140 RBX: ffff8801d13cb280 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff85137b00 RDI: ffff8801d13cb280 RBP: ffff8801d182f148 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d13cb4d0 R13: ffff8801d13cb3b8 R14: ffff8801d13cb300 R15: ffff8801d13cb3b8 inet_csk_destroy_sock+0x175/0x3f0 net/ipv4/inet_connection_sock.c:835 dccp_close+0x84d/0xc10 net/dccp/proto.c:1067 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 sock_release+0x8d/0x1e0 net/socket.c:597 sock_close+0x16/0x20 net/socket.c:1126 __fput+0x327/0x7e0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:246 task_work_run+0x18a/0x260 kernel/task_work.c:116 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0xa32/0x1b10 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:969 get_signal+0x7e8/0x17e0 kernel/signal.c:2330 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808 exit_to_usermode_loop+0x21c/0x2d0 arch/x86/entry/common.c:157 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath+0x3a7/0x450 arch/x86/entry/common.c:263 Signed-off-by: Eric Dumazet <[email protected]> Reported-by: Dmitry Vyukov <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Sep 22, 2017
commit ccd5b32 upstream. The following commit: 39a0526 ("x86/mm: Factor out LDT init from context init") renamed init_new_context() to init_new_context_ldt() and added a new init_new_context() which calls init_new_context_ldt(). However, the error code of init_new_context_ldt() was ignored. Consequently, if a memory allocation in alloc_ldt_struct() failed during a fork(), the ->context.ldt of the new task remained the same as that of the old task (due to the memcpy() in dup_mm()). ldt_struct's are not intended to be shared, so a use-after-free occurred after one task exited. Fix the bug by making init_new_context() pass through the error code of init_new_context_ldt(). This bug was found by syzkaller, which encountered the following splat: BUG: KASAN: use-after-free in free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116 Read of size 4 at addr ffff88006d2cb7c8 by task kworker/u9:0/3710 CPU: 1 PID: 3710 Comm: kworker/u9:0 Not tainted 4.13.0-rc4-next-20170811 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429 free_ldt_struct.part.2+0x10a/0x150 arch/x86/kernel/ldt.c:116 free_ldt_struct arch/x86/kernel/ldt.c:173 [inline] destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171 destroy_context arch/x86/include/asm/mmu_context.h:157 [inline] __mmdrop+0xe9/0x530 kernel/fork.c:889 mmdrop include/linux/sched/mm.h:42 [inline] exec_mmap fs/exec.c:1061 [inline] flush_old_exec+0x173c/0x1ff0 fs/exec.c:1291 load_elf_binary+0x81f/0x4ba0 fs/binfmt_elf.c:855 search_binary_handler+0x142/0x6b0 fs/exec.c:1652 exec_binprm fs/exec.c:1694 [inline] do_execveat_common.isra.33+0x1746/0x22e0 fs/exec.c:1816 do_execve+0x31/0x40 fs/exec.c:1860 call_usermodehelper_exec_async+0x457/0x8f0 kernel/umh.c:100 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 Allocated by task 3700: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627 kmalloc include/linux/slab.h:493 [inline] alloc_ldt_struct+0x52/0x140 arch/x86/kernel/ldt.c:67 write_ldt+0x7b7/0xab0 arch/x86/kernel/ldt.c:277 sys_modify_ldt+0x1ef/0x240 arch/x86/kernel/ldt.c:307 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 3700: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 free_ldt_struct.part.2+0xdd/0x150 arch/x86/kernel/ldt.c:121 free_ldt_struct arch/x86/kernel/ldt.c:173 [inline] destroy_context_ldt+0x60/0x80 arch/x86/kernel/ldt.c:171 destroy_context arch/x86/include/asm/mmu_context.h:157 [inline] __mmdrop+0xe9/0x530 kernel/fork.c:889 mmdrop include/linux/sched/mm.h:42 [inline] __mmput kernel/fork.c:916 [inline] mmput+0x541/0x6e0 kernel/fork.c:927 copy_process.part.36+0x22e1/0x4af0 kernel/fork.c:1931 copy_process kernel/fork.c:1546 [inline] _do_fork+0x1ef/0xfb0 kernel/fork.c:2025 SYSC_clone kernel/fork.c:2135 [inline] SyS_clone+0x37/0x50 kernel/fork.c:2129 do_syscall_64+0x26c/0x8c0 arch/x86/entry/common.c:287 return_from_SYSCALL_64+0x0/0x7a Here is a C reproducer: #include <asm/ldt.h> #include <pthread.h> #include <signal.h> #include <stdlib.h> #include <sys/syscall.h> #include <sys/wait.h> #include <unistd.h> static void *fork_thread(void *_arg) { fork(); } int main(void) { struct user_desc desc = { .entry_number = 8191 }; syscall(__NR_modify_ldt, 1, &desc, sizeof(desc)); for (;;) { if (fork() == 0) { pthread_t t; srand(getpid()); pthread_create(&t, NULL, fork_thread, NULL); usleep(rand() % 10000); syscall(__NR_exit_group, 0); } wait(NULL); } } Note: the reproducer takes advantage of the fact that alloc_ldt_struct() may use vmalloc() to allocate a large ->entries array, and after commit: 5d17a73 ("vmalloc: back off when the current task is killed") it is possible for userspace to fail a task's vmalloc() by sending a fatal signal, e.g. via exit_group(). It would be more difficult to reproduce this bug on kernels without that commit. This bug only affected kernels with CONFIG_MODIFY_LDT_SYSCALL=y. Signed-off-by: Eric Biggers <[email protected]> Acked-by: Dave Hansen <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Rik van Riel <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Fixes: 39a0526 ("x86/mm: Factor out LDT init from context init") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit a47f68d upstream. IDR only supports non-negative IDs. There used to be a 'WARN_ON_ONCE(id < 0)' in idr_replace(), but it was intentionally removed by commit 2e1c9b2 ("idr: remove WARN_ON_ONCE() on negative IDs"). Then it was added back by commit 0a835c4 ("Reimplement IDR and IDA using the radix tree"). However it seems that adding it back was a mistake, given that some users such as drm_gem_handle_delete() (DRM_IOCTL_GEM_CLOSE) pass in a value from userspace to idr_replace(), allowing the WARN_ON_ONCE to be triggered. drm_gem_handle_delete() actually just wants idr_replace() to return an error code if the ID is not allocated, including in the case where the ID is invalid (negative). So once again remove the bogus WARN_ON_ONCE(). This bug was found by syzkaller, which encountered the following warning: WARNING: CPU: 3 PID: 3008 at lib/idr.c:157 idr_replace+0x1d8/0x240 lib/idr.c:157 Kernel panic - not syncing: panic_on_warn set ... CPU: 3 PID: 3008 Comm: syzkaller218828 Not tainted 4.13.0-rc4-next-20170811 #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190 do_trap_no_signal arch/x86/kernel/traps.c:224 [inline] do_trap+0x260/0x390 arch/x86/kernel/traps.c:273 do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323 invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:930 RIP: 0010:idr_replace+0x1d8/0x240 lib/idr.c:157 RSP: 0018:ffff8800394bf9f8 EFLAGS: 00010297 RAX: ffff88003c6c60c0 RBX: 1ffff10007297f43 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800394bfa78 RBP: ffff8800394bfae0 R08: ffffffff82856487 R09: 0000000000000000 R10: ffff8800394bf9a8 R11: ffff88006c8bae28 R12: ffffffffffffffff R13: ffff8800394bfab8 R14: dffffc0000000000 R15: ffff8800394bfbc8 drm_gem_handle_delete+0x33/0xa0 drivers/gpu/drm/drm_gem.c:297 drm_gem_close_ioctl+0xa1/0xe0 drivers/gpu/drm/drm_gem.c:671 drm_ioctl_kernel+0x1e7/0x2e0 drivers/gpu/drm/drm_ioctl.c:729 drm_ioctl+0x72e/0xa50 drivers/gpu/drm/drm_ioctl.c:825 vfs_ioctl fs/ioctl.c:45 [inline] do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685 SYSC_ioctl fs/ioctl.c:700 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691 entry_SYSCALL_64_fastpath+0x1f/0xbe Here is a C reproducer: #include <fcntl.h> #include <stddef.h> #include <stdint.h> #include <sys/ioctl.h> #include <drm/drm.h> int main(void) { int cardfd = open("/dev/dri/card0", O_RDONLY); ioctl(cardfd, DRM_IOCTL_GEM_CLOSE, &(struct drm_gem_close) { .handle = -1 } ); } Link: http://lkml.kernel.org/r/[email protected] Fixes: 0a835c4 ("Reimplement IDR and IDA using the radix tree") Signed-off-by: Eric Biggers <[email protected]> Acked-by: Tejun Heo <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Matthew Wilcox <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 656d61c upstream. printk_ratelimit() invokes ___ratelimit() which may invoke a normal printk() (pr_warn() in this particular case) to warn about suppressed output. Given that printk_ratelimit() may be called from anywhere, that pr_warn() is dangerous - it may end up deadlocking the system. Fix ___ratelimit() by using deferred printk(). Sasha reported the following lockdep error: : Unregister pv shared memory for cpu 8 : select_fallback_rq: 3 callbacks suppressed : process 8583 (trinity-c78) no longer affine to cpu8 : : ====================================================== : WARNING: possible circular locking dependency detected : 4.14.0-rc2-next-20170927+ #252 Not tainted : ------------------------------------------------------ : migration/8/62 is trying to acquire lock: : (&port_lock_key){-.-.}, at: serial8250_console_write() : : but task is already holding lock: : (&rq->lock){-.-.}, at: sched_cpu_dying() : : which lock already depends on the new lock. : : : the existing dependency chain (in reverse order) is: : : -> #3 (&rq->lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock() : task_fork_fair() : sched_fork() : copy_process.part.31() : _do_fork() : kernel_thread() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #2 (&p->pi_lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : try_to_wake_up() : default_wake_function() : woken_wake_function() : __wake_up_common() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #1 (&tty->write_wait){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #0 (&port_lock_key){-.-.}: : check_prev_add() : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : serial8250_console_write() : univ8250_console_write() : console_unlock() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : cpuhp_invoke_callback() : take_cpu_down() : multi_cpu_stop() : cpu_stopper_thread() : smpboot_thread_fn() : kthread() : ret_from_fork() : : other info that might help us debug this: : : Chain exists of: : &port_lock_key --> &p->pi_lock --> &rq->lock : : Possible unsafe locking scenario: : : CPU0 CPU1 : ---- ---- : lock(&rq->lock); : lock(&p->pi_lock); : lock(&rq->lock); : lock(&port_lock_key); : : *** DEADLOCK *** : : 4 locks held by migration/8/62: : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying() : #1: (&rq->lock){-.-.}, at: sched_cpu_dying() : #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit() : #3: (console_lock){+.+.}, at: vprintk_emit() : : stack backtrace: : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252 : Call Trace: : dump_stack() : print_circular_bug() : check_prev_add() : ? add_lock_to_list.isra.26() : ? check_usage() : ? kvm_clock_read() : ? kvm_sched_clock_read() : ? sched_clock() : ? check_preemption_disabled() : __lock_acquire() : ? __lock_acquire() : ? add_lock_to_list.isra.26() : ? debug_check_no_locks_freed() : ? memcpy() : lock_acquire() : ? serial8250_console_write() : _raw_spin_lock_irqsave() : ? serial8250_console_write() : serial8250_console_write() : ? serial8250_start_tx() : ? lock_acquire() : ? memcpy() : univ8250_console_write() : console_unlock() : ? __down_trylock_console_sem() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ? show_regs_print_info() : ? lock_acquire() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : ? sched_cpu_starting() : ? rcutree_dying_cpu() : ? sched_cpu_starting() : cpuhp_invoke_callback() : ? cpu_disable_common() : take_cpu_down() : ? trace_hardirqs_off_caller() : ? cpuhp_invoke_callback() : multi_cpu_stop() : ? __this_cpu_preempt_check() : ? cpu_stop_queue_work() : cpu_stopper_thread() : ? cpu_stop_create() : smpboot_thread_fn() : ? sort_range() : ? schedule() : ? __kthread_parkme() : kthread() : ? sort_range() : ? kthread_create_on_node() : ret_from_fork() : process 9121 (trinity-c78) no longer affine to cpu8 : smpboot: CPU 8 is now offline Link: http://lkml.kernel.org/r/[email protected] Fixes: 6b1d174 ("ratelimit: extend to print suppressed messages on release") Signed-off-by: Sergey Senozhatsky <[email protected]> Reported-by: Sasha Levin <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Steven Rostedt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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[ Upstream commit 12d656a ] While destroying a network namespace that contains a L2TP tunnel a "BUG: scheduling while atomic" can be observed. Enabling lockdep shows that this is happening because l2tp_exit_net() is calling l2tp_tunnel_closeall() (via l2tp_tunnel_delete()) from within an RCU critical section. l2tp_exit_net() takes rcu_read_lock_bh() << list_for_each_entry_rcu() >> l2tp_tunnel_delete() l2tp_tunnel_closeall() __l2tp_session_unhash() synchronize_rcu() << Illegal inside RCU critical section >> BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 0, pid: 86, name: kworker/u16:2 INFO: lockdep is turned off. CPU: 2 PID: 86 Comm: kworker/u16:2 Tainted: G W O 4.4.6-at1 #2 Hardware name: Xen HVM domU, BIOS 4.6.1-xs125300 05/09/2016 Workqueue: netns cleanup_net 0000000000000000 ffff880202417b90 ffffffff812b0013 ffff880202410ac0 ffffffff81870de8 ffff880202417bb8 ffffffff8107aee8 ffffffff81870de8 0000000000000c51 0000000000000000 ffff880202417be0 ffffffff8107b024 Call Trace: [<ffffffff812b0013>] dump_stack+0x85/0xc2 [<ffffffff8107aee8>] ___might_sleep+0x148/0x240 [<ffffffff8107b024>] __might_sleep+0x44/0x80 [<ffffffff810b21bd>] synchronize_sched+0x2d/0xe0 [<ffffffff8109be6d>] ? trace_hardirqs_on+0xd/0x10 [<ffffffff8105c7bb>] ? __local_bh_enable_ip+0x6b/0xc0 [<ffffffff816a1b00>] ? _raw_spin_unlock_bh+0x30/0x40 [<ffffffff81667482>] __l2tp_session_unhash+0x172/0x220 [<ffffffff81667397>] ? __l2tp_session_unhash+0x87/0x220 [<ffffffff8166888b>] l2tp_tunnel_closeall+0x9b/0x140 [<ffffffff81668c74>] l2tp_tunnel_delete+0x14/0x60 [<ffffffff81668dd0>] l2tp_exit_net+0x110/0x270 [<ffffffff81668d5c>] ? l2tp_exit_net+0x9c/0x270 [<ffffffff815001c3>] ops_exit_list.isra.6+0x33/0x60 [<ffffffff81501166>] cleanup_net+0x1b6/0x280 ... This bug can easily be reproduced with a few steps: $ sudo unshare -n bash # Create a shell in a new namespace # ip link set lo up # ip addr add 127.0.0.1 dev lo # ip l2tp add tunnel remote 127.0.0.1 local 127.0.0.1 tunnel_id 1 \ peer_tunnel_id 1 udp_sport 50000 udp_dport 50000 # ip l2tp add session name foo tunnel_id 1 session_id 1 \ peer_session_id 1 # ip link set foo up # exit # Exit the shell, in turn exiting the namespace $ dmesg ... [942121.089216] BUG: scheduling while atomic: kworker/u16:3/13872/0x00000200 ... To fix this, move the call to l2tp_tunnel_closeall() out of the RCU critical section, and instead call it from l2tp_tunnel_del_work(), which is running from the l2tp_wq workqueue. Fixes: 2b551c6 ("l2tp: close sessions before initiating tunnel delete") Signed-off-by: Ridge Kennedy <[email protected]> Acked-by: Guillaume Nault <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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commit 67f8a8c upstream. Aneesh Kumar reported seeing host crashes when running recent kernels on POWER8. The symptom was an oops like this: Unable to handle kernel paging request for data at address 0xf00000000786c620 Faulting instruction address: 0xc00000000030e1e4 Oops: Kernel access of bad area, sig: 11 [#1] LE SMP NR_CPUS=2048 NUMA PowerNV Modules linked in: powernv_op_panel CPU: 24 PID: 6663 Comm: qemu-system-ppc Tainted: G W 4.13.0-rc7-43932-gfc36c59 #2 task: c000000fdeadfe80 task.stack: c000000fdeb68000 NIP: c00000000030e1e4 LR: c00000000030de6c CTR: c000000000103620 REGS: c000000fdeb6b450 TRAP: 0300 Tainted: G W (4.13.0-rc7-43932-gfc36c59) MSR: 9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE> CR: 24044428 XER: 20000000 CFAR: c00000000030e134 DAR: f00000000786c620 DSISR: 40000000 SOFTE: 0 GPR00: 0000000000000000 c000000fdeb6b6d0 c0000000010bd000 000000000000e1b0 GPR04: c00000000115e168 c000001fffa6e4b0 c00000000115d000 c000001e1b180386 GPR08: f000000000000000 c000000f9a8913e0 f00000000786c600 00007fff587d0000 GPR12: c000000fdeb68000 c00000000fb0f000 0000000000000001 00007fff587cffff GPR16: 0000000000000000 c000000000000000 00000000003fffff c000000fdebfe1f8 GPR20: 0000000000000004 c000000fdeb6b8a8 0000000000000001 0008000000000040 GPR24: 07000000000000c0 00007fff587cffff c000000fdec20bf8 00007fff587d0000 GPR28: c000000fdeca9ac0 00007fff587d0000 00007fff587c0000 00007fff587d0000 NIP [c00000000030e1e4] __get_user_pages_fast+0x434/0x1070 LR [c00000000030de6c] __get_user_pages_fast+0xbc/0x1070 Call Trace: [c000000fdeb6b6d0] [c00000000139dab8] lock_classes+0x0/0x35fe50 (unreliable) [c000000fdeb6b7e0] [c00000000030ef38] get_user_pages_fast+0xf8/0x120 [c000000fdeb6b830] [c000000000112318] kvmppc_book3s_hv_page_fault+0x308/0xf30 [c000000fdeb6b960] [c00000000010e10c] kvmppc_vcpu_run_hv+0xfdc/0x1f00 [c000000fdeb6bb20] [c0000000000e915c] kvmppc_vcpu_run+0x2c/0x40 [c000000fdeb6bb40] [c0000000000e5650] kvm_arch_vcpu_ioctl_run+0x110/0x300 [c000000fdeb6bbe0] [c0000000000d6468] kvm_vcpu_ioctl+0x528/0x900 [c000000fdeb6bd40] [c0000000003bc04c] do_vfs_ioctl+0xcc/0x950 [c000000fdeb6bde0] [c0000000003bc930] SyS_ioctl+0x60/0x100 [c000000fdeb6be30] [c00000000000b96c] system_call+0x58/0x6c Instruction dump: 7ca81a14 2fa50000 41de0010 7cc8182a 68c60002 78c6ffe2 0b060000 3cc2000a 794a3664 390610d8 e9080000 7d485214 <e90a0020> 7d435378 790507e1 408202f0 ---[ end trace fad4a342d0414aa2 ]--- It turns out that what has happened is that the SLB entry for the vmmemap region hasn't been reloaded on exit from a guest, and it has the wrong page size. Then, when the host next accesses the vmemmap region, it gets a page fault. Commit a25bd72 ("powerpc/mm/radix: Workaround prefetch issue with KVM", 2017-07-24) modified the guest exit code so that it now only clears out the SLB for hash guest. The code tests the radix flag and puts the result in a non-volatile CR field, CR2, and later branches based on CR2. Unfortunately, the kvmppc_save_tm function, which gets called between those two points, modifies all the user-visible registers in the case where the guest was in transactional or suspended state, except for a few which it restores (namely r1, r2, r9 and r13). Thus the hash/radix indication in CR2 gets corrupted. This fixes the problem by re-doing the comparison just before the result is needed. For good measure, this also adds comments next to the call sites of kvmppc_save_tm and kvmppc_restore_tm pointing out that non-volatile register state will be lost. Fixes: a25bd72 ("powerpc/mm/radix: Workaround prefetch issue with KVM") Tested-by: Aneesh Kumar K.V <[email protected]> Signed-off-by: Paul Mackerras <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Oct 12, 2017
commit 656d61c upstream. printk_ratelimit() invokes ___ratelimit() which may invoke a normal printk() (pr_warn() in this particular case) to warn about suppressed output. Given that printk_ratelimit() may be called from anywhere, that pr_warn() is dangerous - it may end up deadlocking the system. Fix ___ratelimit() by using deferred printk(). Sasha reported the following lockdep error: : Unregister pv shared memory for cpu 8 : select_fallback_rq: 3 callbacks suppressed : process 8583 (trinity-c78) no longer affine to cpu8 : : ====================================================== : WARNING: possible circular locking dependency detected : 4.14.0-rc2-next-20170927+ #252 Not tainted : ------------------------------------------------------ : migration/8/62 is trying to acquire lock: : (&port_lock_key){-.-.}, at: serial8250_console_write() : : but task is already holding lock: : (&rq->lock){-.-.}, at: sched_cpu_dying() : : which lock already depends on the new lock. : : : the existing dependency chain (in reverse order) is: : : -> #3 (&rq->lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock() : task_fork_fair() : sched_fork() : copy_process.part.31() : _do_fork() : kernel_thread() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #2 (&p->pi_lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : try_to_wake_up() : default_wake_function() : woken_wake_function() : __wake_up_common() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #1 (&tty->write_wait){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #0 (&port_lock_key){-.-.}: : check_prev_add() : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : serial8250_console_write() : univ8250_console_write() : console_unlock() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : cpuhp_invoke_callback() : take_cpu_down() : multi_cpu_stop() : cpu_stopper_thread() : smpboot_thread_fn() : kthread() : ret_from_fork() : : other info that might help us debug this: : : Chain exists of: : &port_lock_key --> &p->pi_lock --> &rq->lock : : Possible unsafe locking scenario: : : CPU0 CPU1 : ---- ---- : lock(&rq->lock); : lock(&p->pi_lock); : lock(&rq->lock); : lock(&port_lock_key); : : *** DEADLOCK *** : : 4 locks held by migration/8/62: : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying() : #1: (&rq->lock){-.-.}, at: sched_cpu_dying() : #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit() : #3: (console_lock){+.+.}, at: vprintk_emit() : : stack backtrace: : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252 : Call Trace: : dump_stack() : print_circular_bug() : check_prev_add() : ? add_lock_to_list.isra.26() : ? check_usage() : ? kvm_clock_read() : ? kvm_sched_clock_read() : ? sched_clock() : ? check_preemption_disabled() : __lock_acquire() : ? __lock_acquire() : ? add_lock_to_list.isra.26() : ? debug_check_no_locks_freed() : ? memcpy() : lock_acquire() : ? serial8250_console_write() : _raw_spin_lock_irqsave() : ? serial8250_console_write() : serial8250_console_write() : ? serial8250_start_tx() : ? lock_acquire() : ? memcpy() : univ8250_console_write() : console_unlock() : ? __down_trylock_console_sem() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ? show_regs_print_info() : ? lock_acquire() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : ? sched_cpu_starting() : ? rcutree_dying_cpu() : ? sched_cpu_starting() : cpuhp_invoke_callback() : ? cpu_disable_common() : take_cpu_down() : ? trace_hardirqs_off_caller() : ? cpuhp_invoke_callback() : multi_cpu_stop() : ? __this_cpu_preempt_check() : ? cpu_stop_queue_work() : cpu_stopper_thread() : ? cpu_stop_create() : smpboot_thread_fn() : ? sort_range() : ? schedule() : ? __kthread_parkme() : kthread() : ? sort_range() : ? kthread_create_on_node() : ret_from_fork() : process 9121 (trinity-c78) no longer affine to cpu8 : smpboot: CPU 8 is now offline Link: http://lkml.kernel.org/r/[email protected] Fixes: 6b1d174 ("ratelimit: extend to print suppressed messages on release") Signed-off-by: Sergey Senozhatsky <[email protected]> Reported-by: Sasha Levin <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Steven Rostedt <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Guillaume Nault says: ==================== l2tp: fix some races in session deletion L2TP provides several interfaces for deleting sessions. Using two of them concurrently can lead to use-after-free bugs. Patch #2 uses a flag to prevent double removal of L2TP sessions. Patch #1 fixes a bug found in the way. Fixing this bug is also necessary for patch #2 to handle all cases. This issue is similar to the tunnel deletion bug being worked on by Sabrina: https://patchwork.ozlabs.org/patch/814173/ ==================== Signed-off-by: David S. Miller <[email protected]>
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The following lockdep splat has been noticed during LTP testing ====================================================== WARNING: possible circular locking dependency detected 4.13.0-rc3-next-20170807 #12 Not tainted ------------------------------------------------------ a.out/4771 is trying to acquire lock: (cpu_hotplug_lock.rw_sem){++++++}, at: [<ffffffff812b4668>] drain_all_stock.part.35+0x18/0x140 but task is already holding lock: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&mm->mmap_sem){++++++}: lock_acquire+0xc9/0x230 __might_fault+0x70/0xa0 _copy_to_user+0x23/0x70 filldir+0xa7/0x110 xfs_dir2_sf_getdents.isra.10+0x20c/0x2c0 [xfs] xfs_readdir+0x1fa/0x2c0 [xfs] xfs_file_readdir+0x30/0x40 [xfs] iterate_dir+0x17a/0x1a0 SyS_getdents+0xb0/0x160 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #2 (&type->i_mutex_dir_key#3){++++++}: lock_acquire+0xc9/0x230 down_read+0x51/0xb0 lookup_slow+0xde/0x210 walk_component+0x160/0x250 link_path_walk+0x1a6/0x610 path_openat+0xe4/0xd50 do_filp_open+0x91/0x100 file_open_name+0xf5/0x130 filp_open+0x33/0x50 kernel_read_file_from_path+0x39/0x80 _request_firmware+0x39f/0x880 request_firmware_direct+0x37/0x50 request_microcode_fw+0x64/0xe0 reload_store+0xf7/0x180 dev_attr_store+0x18/0x30 sysfs_kf_write+0x44/0x60 kernfs_fop_write+0x113/0x1a0 __vfs_write+0x37/0x170 vfs_write+0xc7/0x1c0 SyS_write+0x58/0xc0 do_syscall_64+0x6c/0x1f0 return_from_SYSCALL_64+0x0/0x7a -> #1 (microcode_mutex){+.+.+.}: lock_acquire+0xc9/0x230 __mutex_lock+0x88/0x960 mutex_lock_nested+0x1b/0x20 microcode_init+0xbb/0x208 do_one_initcall+0x51/0x1a9 kernel_init_freeable+0x208/0x2a7 kernel_init+0xe/0x104 ret_from_fork+0x2a/0x40 -> #0 (cpu_hotplug_lock.rw_sem){++++++}: __lock_acquire+0x153c/0x1550 lock_acquire+0xc9/0x230 cpus_read_lock+0x4b/0x90 drain_all_stock.part.35+0x18/0x140 try_charge+0x3ab/0x6e0 mem_cgroup_try_charge+0x7f/0x2c0 shmem_getpage_gfp+0x25f/0x1050 shmem_fault+0x96/0x200 __do_fault+0x1e/0xa0 __handle_mm_fault+0x9c3/0xe00 handle_mm_fault+0x16e/0x380 __do_page_fault+0x24a/0x530 do_page_fault+0x30/0x80 page_fault+0x28/0x30 other info that might help us debug this: Chain exists of: cpu_hotplug_lock.rw_sem --> &type->i_mutex_dir_key#3 --> &mm->mmap_sem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_sem); lock(&type->i_mutex_dir_key#3); lock(&mm->mmap_sem); lock(cpu_hotplug_lock.rw_sem); *** DEADLOCK *** 2 locks held by a.out/4771: #0: (&mm->mmap_sem){++++++}, at: [<ffffffff8106eb35>] __do_page_fault+0x175/0x530 #1: (percpu_charge_mutex){+.+...}, at: [<ffffffff812b4c97>] try_charge+0x397/0x6e0 The problem is very similar to the one fixed by commit a459eeb ("mm, page_alloc: do not depend on cpu hotplug locks inside the allocator"). We are taking hotplug locks while we can be sitting on top of basically arbitrary locks. This just calls for problems. We can get rid of {get,put}_online_cpus, fortunately. We do not have to be worried about races with memory hotplug because drain_local_stock, which is called from both the WQ draining and the memory hotplug contexts, is always operating on the local cpu stock with IRQs disabled. The only thing to be careful about is that the target memcg doesn't vanish while we are still in drain_all_stock so take a reference on it. Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Michal Hocko <[email protected]> Reported-by: Artem Savkov <[email protected]> Tested-by: Artem Savkov <[email protected]> Cc: Johannes Weiner <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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printk_ratelimit() invokes ___ratelimit() which may invoke a normal printk() (pr_warn() in this particular case) to warn about suppressed output. Given that printk_ratelimit() may be called from anywhere, that pr_warn() is dangerous - it may end up deadlocking the system. Fix ___ratelimit() by using deferred printk(). Sasha reported the following lockdep error: : Unregister pv shared memory for cpu 8 : select_fallback_rq: 3 callbacks suppressed : process 8583 (trinity-c78) no longer affine to cpu8 : : ====================================================== : WARNING: possible circular locking dependency detected : 4.14.0-rc2-next-20170927+ #252 Not tainted : ------------------------------------------------------ : migration/8/62 is trying to acquire lock: : (&port_lock_key){-.-.}, at: serial8250_console_write() : : but task is already holding lock: : (&rq->lock){-.-.}, at: sched_cpu_dying() : : which lock already depends on the new lock. : : : the existing dependency chain (in reverse order) is: : : -> #3 (&rq->lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock() : task_fork_fair() : sched_fork() : copy_process.part.31() : _do_fork() : kernel_thread() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #2 (&p->pi_lock){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : try_to_wake_up() : default_wake_function() : woken_wake_function() : __wake_up_common() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #1 (&tty->write_wait){-.-.}: : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : __wake_up_common_lock() : __wake_up() : tty_wakeup() : tty_port_default_wakeup() : tty_port_tty_wakeup() : uart_write_wakeup() : serial8250_tx_chars() : serial8250_handle_irq.part.25() : serial8250_default_handle_irq() : serial8250_interrupt() : __handle_irq_event_percpu() : handle_irq_event_percpu() : handle_irq_event() : handle_level_irq() : handle_irq() : do_IRQ() : ret_from_intr() : native_safe_halt() : default_idle() : arch_cpu_idle() : default_idle_call() : do_idle() : cpu_startup_entry() : rest_init() : start_kernel() : x86_64_start_reservations() : x86_64_start_kernel() : verify_cpu() : : -> #0 (&port_lock_key){-.-.}: : check_prev_add() : __lock_acquire() : lock_acquire() : _raw_spin_lock_irqsave() : serial8250_console_write() : univ8250_console_write() : console_unlock() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : cpuhp_invoke_callback() : take_cpu_down() : multi_cpu_stop() : cpu_stopper_thread() : smpboot_thread_fn() : kthread() : ret_from_fork() : : other info that might help us debug this: : : Chain exists of: : &port_lock_key --> &p->pi_lock --> &rq->lock : : Possible unsafe locking scenario: : : CPU0 CPU1 : ---- ---- : lock(&rq->lock); : lock(&p->pi_lock); : lock(&rq->lock); : lock(&port_lock_key); : : *** DEADLOCK *** : : 4 locks held by migration/8/62: : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying() : #1: (&rq->lock){-.-.}, at: sched_cpu_dying() : #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit() : #3: (console_lock){+.+.}, at: vprintk_emit() : : stack backtrace: : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252 : Call Trace: : dump_stack() : print_circular_bug() : check_prev_add() : ? add_lock_to_list.isra.26() : ? check_usage() : ? kvm_clock_read() : ? kvm_sched_clock_read() : ? sched_clock() : ? check_preemption_disabled() : __lock_acquire() : ? __lock_acquire() : ? add_lock_to_list.isra.26() : ? debug_check_no_locks_freed() : ? memcpy() : lock_acquire() : ? serial8250_console_write() : _raw_spin_lock_irqsave() : ? serial8250_console_write() : serial8250_console_write() : ? serial8250_start_tx() : ? lock_acquire() : ? memcpy() : univ8250_console_write() : console_unlock() : ? __down_trylock_console_sem() : vprintk_emit() : vprintk_default() : vprintk_func() : printk() : ? show_regs_print_info() : ? lock_acquire() : ___ratelimit() : __printk_ratelimit() : select_fallback_rq() : sched_cpu_dying() : ? sched_cpu_starting() : ? rcutree_dying_cpu() : ? sched_cpu_starting() : cpuhp_invoke_callback() : ? cpu_disable_common() : take_cpu_down() : ? trace_hardirqs_off_caller() : ? cpuhp_invoke_callback() : multi_cpu_stop() : ? __this_cpu_preempt_check() : ? cpu_stop_queue_work() : cpu_stopper_thread() : ? cpu_stop_create() : smpboot_thread_fn() : ? sort_range() : ? schedule() : ? __kthread_parkme() : kthread() : ? sort_range() : ? kthread_create_on_node() : ret_from_fork() : process 9121 (trinity-c78) no longer affine to cpu8 : smpboot: CPU 8 is now offline Link: http://lkml.kernel.org/r/[email protected] Fixes: 6b1d174 ("ratelimit: extend to print suppressed messages on release") Signed-off-by: Sergey Senozhatsky <[email protected]> Reported-by: Sasha Levin <[email protected]> Reviewed-by: Petr Mladek <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
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