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Issue #, if available:
vewe-richard#1

Description of changes:
Do not call generic_file_buffered_read() directly, call generic_file_read_iter() which will check number of iov to read, and return immediately when the number of iov is zero.

Else, generic_file_buffered_read() will fall into an infinite loop, eat up all cpu resources, cause system lockup.

Baolin Wang and others added 30 commits August 18, 2023 22:38
The huge_ptep_set_access_flags() can not make the huge pte old according
to the discussion [1], that means we will always mornitor the young state
of the hugetlb though we stopped accessing the hugetlb, as a result DAMON
will get inaccurate accessing statistics.

So changing to use set_huge_pte_at() to make the huge pte old to fix this
issue.

[1] https://lore.kernel.org/all/[email protected]/

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 49f4203 ("mm/damon: add access checking for hugetlb pages")
Signed-off-by: Baolin Wang <[email protected]>
Reviewed-by: SeongJae Park <[email protected]>
Acked-by: Mike Kravetz <[email protected]>
Reviewed-by: Muchun Song <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
damon_reclaim_init() allocates a memory chunk for ctx with
damon_new_ctx().  When damon_select_ops() fails, ctx is not released,
which will lead to a memory leak.

We should release the ctx with damon_destroy_ctx() when damon_select_ops()
fails to fix the memory leak.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 4d69c34 ("mm/damon/reclaim: use damon_select_ops() instead of damon_{v,p}a_set_operations()")
Signed-off-by: Jianglei Nie <[email protected]>
Reviewed-by: SeongJae Park <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
When user tries to create a DAMON context via the DAMON debugfs interface
with a name of an already existing context, the context directory creation
fails but a new context is created and added in the internal data
structure, due to absence of the directory creation success check.  As a
result, memory could leak and DAMON cannot be turned on.  An example test
case is as below:

    # cd /sys/kernel/debug/damon/
    # echo "off" >  monitor_on
    # echo paddr > target_ids
    # echo "abc" > mk_context
    # echo "abc" > mk_context
    # echo $$ > abc/target_ids
    # echo "on" > monitor_on  <<< fails

Return value of 'debugfs_create_dir()' is expected to be ignored in
general, but this is an exceptional case as DAMON feature is depending
on the debugfs functionality and it has the potential duplicate name
issue.  This commit therefore fixes the issue by checking the directory
creation failure and immediately return the error in the case.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 75c1c2b ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: Badari Pulavarty <[email protected]>
Signed-off-by: SeongJae Park <[email protected]>
Cc: <[email protected]>	[ 5.15.x]
Signed-off-by: Andrew Morton <[email protected]>
This reverts commit 509c2c9.

Commit "1a072f13b2dc Mitigate unbalanced RETs on vmexit via serialising wrmsr"
addresses this with less performance impact.

[ Hailmo: Resolved conflicts when rebasing onto 5.10.190 and adding SRSO
and GDS support ]

Signed-off-by: Suraj Jitindar Singh <[email protected]>
…-rwx-segments"

This reverts commit 8f4f2c9.

This causes arm64 debug builds to fail with:
*** ERROR: No build ID note found in /builddir/build/BUILDROOT/kernel-5.15.63-32.131.amzn2.aarch64/usr/lib/debug/lib/modules/5.15.63-32.131.amzn2.aarch64/vmlinux

This is due to the notes section which contains the build id being
missing from the linux elf.

Revert this commit until this can be remedied.

Signed-off-by: Suraj Jitindar Singh <[email protected]>
Source: https://github.com/amzn/amzn-drivers/

Change Log:

## r2.8.0 release notes
**Notes**
* The driver is now dependent on the ptp module for loading
  See README for more details.

**New Features**
* Add support for PTP HW clock
* Add support for SRD metrics
  Feature's enablement and documentation would be in future release

**Bug Fixes**
* Fix potential sign extension issue
* Reduce memory footprint of some structs
* Fix updating rx_copybreak issue
* Fix xdp drops handling due to multibuf packets
* Handle ena_calc_io_queue_size() possible errors
* Destroy correct amount of xdp queues upon failure

**Minor Changes**
* Remove wide LLQ comment on supported versions
* Backport uapi/bpf.h inclusion
* Add a counter for driver's reset failures
* Take xdp packets stats into account in ena_get_stats64()
* Make queue stats code cleaner by removing if block
* Remove redundant empty line
* Remove confusing comment
* Remove flag reading code duplication
* Replace ENA local ENA_NAPI_BUDGET to global NAPI_POLL_WEIGHT
* Change default print level for netif_ prints
* Relocate skb_tx_timestamp() to improve time stamping accuracy
* Backport bpf_warn_invalid_xdp_action() change
* Fix incorrect indentation using spaces
* Driver now compiles with Linux kernel 5.19

Signed-off-by: Suraj Jitindar Singh <[email protected]>
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time.  Fix this up by properly calling
dput().

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 75c1c2b ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: SeongJae Park <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
When damon_sysfs_add_target couldn't find proper task, New allocated
damon_target structure isn't registered yet, So, it's impossible to free
new allocated one by damon_sysfs_destroy_targets.

By calling damon_add_target as soon as allocating new target, Fix this
possible memory leak.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: a61ea56 ("mm/damon/sysfs: link DAMON for virtual address spaces monitoring")
Signed-off-by: Levi Yun <[email protected]>
Signed-off-by: SeongJae Park <[email protected]>
Reviewed-by: SeongJae Park <[email protected]>
Cc: <[email protected]>	[5.17.x]
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: SeongJae Park <[email protected]>
commit 9e7a4d9 upstream.

Usage of spin locks was not allowed for tracing programs due to
insufficient preemption checks. The verifier does not currently prevent
LSM programs from using spin locks, but the helpers are not exposed
via bpf_lsm_func_proto.

Based on the discussion in [1], non-sleepable LSM programs should be
able to use bpf_spin_{lock, unlock}.

Sleepable LSM programs can be preempted which means that allowng spin
locks will need more work (disabling preemption and the verifier
ensuring that no sleepable helpers are called when a spin lock is held).

[1]: https://lore.kernel.org/bpf/[email protected]/T/#md601a053229287659071600d3483523f752cd2fb

Signed-off-by: KP Singh <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Song Liu <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Kuniyuki Iwashima <[email protected]>
commit 4cf1bc1 upstream.

Similar to bpf_local_storage for sockets and inodes add local storage
for task_struct.

The life-cycle of storage is managed with the life-cycle of the
task_struct.  i.e. the storage is destroyed along with the owning task
with a callback to the bpf_task_storage_free from the task_free LSM
hook.

The BPF LSM allocates an __rcu pointer to the bpf_local_storage in
the security blob which are now stackable and can co-exist with other
LSMs.

The userspace map operations can be done by using a pid fd as a key
passed to the lookup, update and delete operations.

Signed-off-by: KP Singh <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Acked-by: Song Liu <[email protected]>
Acked-by: Martin KaFai Lau <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]
Signed-off-by: Kuniyuki Iwashima <[email protected]>
Instead of putting io_uring's registered files in unix_gc() we want it
to be done by io_uring itself. The trick here is to consider io_uring
registered files for cycle detection but not actually putting them down.
Because io_uring can't register other ring instances, this will remove
all refs to the ring file triggering the ->release path and clean up
with io_ring_ctx_free().

Cc: [email protected]
Fixes: 6b06314 ("io_uring: add file set registration")
Reported-and-tested-by: David Bouman <[email protected]>
Signed-off-by: Pavel Begunkov <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
[axboe: add kerneldoc comment to skb, fold in skb leak fix]
Signed-off-by: Jens Axboe <[email protected]>
Since commit 0f91d13 ("mm/damon: simplify stop mechanism") delete
kdamond_stop and change to use kthread stop mechanism, these obsolete
comments should be removed accordingly.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Chengming Zhou <[email protected]>
Reviewed-by: SeongJae Park <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
The kernel is in lockdown mode when secureboot is enabled and hence
debugfs cannot be used. Add support for this and other general cases
where debugfs cannot be read and communicate the same to the user before
running tests.

Signed-off-by: Gautam <[email protected]>
Reviewed-by: SeongJae Park <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
… due to online tuning support

Patch series "mm/damon: trivial cleanups".

This patchset contains trivial cleansups for DAMON code.

This patch (of 6):

Commit 81a8418 ("Docs/admin-guide/mm/damon/reclaim: document
'commit_inputs' parameter") has documented the 'commit_inputs' parameter
which allows online parameter update, but it didn't remove a paragraph
saying the online parameter update is impossible.  This commit removes the
obsolete paragraph.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 81a8418 ("Docs/admin-guide/mm/damon/reclaim: document 'commit_inputs' parameter")
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
The function for knowing if given monitoring context's targets will have
pid or not is defined and used in dbgfs only.  However, the logic is also
needed for sysfs.  This commit moves the code to damon.h and makes both
dbgfs and sysfs to use it.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
DAMON_RECLAIM's handling of 'commit_inputs' parameter is duplicated in
'after_aggregation()' and 'after_wmarks_check()' callbacks.  This commit
deduplicates the code for better maintenance.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
DAMON sysfs interface's DAMON context building and its online parameter
update have duplicated code.  This commit removes the duplicate.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
DAMON_RECLAIM's 'enabled' parameter store callback ('enabled_store()')
schedules the parameter check timer ('damon_reclaim_timer') if the
parameter is set as 'Y'.  Then, the timer schedules itself to check if
user has set the parameter as 'N'.  It's unnecessarily complex.

This commit makes it simpler by making the parameter store callback to
schedule the timer regardless of the parameter value and disabling the
timer's self scheduling.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
This commit adds 'damon_reclaim_' prefix to 'enabled_store()', so that we
can distinguish it easily from the stack trace using 'faddr2line.sh' like
tools.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
…and 'damos_action' values

Patch series "Extend DAMOS for Proactive LRU-lists Sorting".

Introduction
============

In short, this patchset 1) extends DAMON-based Operation Schemes (DAMOS)
for low overhead data access pattern based LRU-lists sorting, and 2)
implements a static kernel module for easy use of conservatively-tuned
version of that using the extended DAMOS capability.

Background
----------

As page-granularity access checking overhead could be significant on huge
systems, LRU lists are normally not proactively sorted but partially and
reactively sorted for special events including specific user requests,
system calls and memory pressure.  As a result, LRU lists are sometimes
not so perfectly prepared to be used as a trustworthy access pattern
source for some situations including reclamation target pages selection
under sudden memory pressure.

DAMON-based Proactive LRU-lists Sorting
---------------------------------------

Because DAMON can identify access patterns of best-effort accuracy while
inducing only user-specified range of overhead, using DAMON for Proactive
LRU-lists Sorting (PLRUS) could be helpful for this situation.  The idea
is quite simple.  Find hot pages and cold pages using DAMON, and
prioritize hot pages while deprioritizing cold pages on their LRU-lists.

This patchset extends DAMON to support such schemes by introducing a
couple of new DAMOS actions for prioritizing and deprioritizing memory
regions of specific access patterns on their LRU-lists.  In detail, this
patchset simply uses 'mark_page_accessed()' and 'deactivate_page()'
functions for prioritization and deprioritization of pages on their LRU
lists, respectively.

To make the scheme easy to use without complex tuning for common
situations, this patchset further implements a static kernel module called
'DAMON_LRU_SORT' using the extended DAMOS functionality.  It proactively
sorts LRU-lists using DAMON with conservatively chosen default
hotness/coldness thresholds and small CPU usage quota limit.  That is, the
module under its default parameters will make no harm for common situation
but provide some level of benefit for systems having clear hot/cold access
pattern under only memory pressure while consuming only limited small
portion of CPU time.

Related Works
-------------

Proactive reclamation is well known to be helpful for reducing non-optimal
reclamation target selection caused performance drops.  However, proactive
reclamation is not a best option for some cases, because it could incur
additional I/O.  For an example, it could be prohitive for systems using
storage devices that total number of writes is limited, or cloud block
storages that charges every I/O.

Some proactive reclamation approaches[1,2] induce a level of memory
pressure using memcg files or swappiness while monitoring PSI.  As
reclamation target selection is still relying on the original LRU-lists
mechanism, using DAMON-based proactive reclamation before inducing the
proactive reclamation could allow more memory saving with same level of
performance overhead, or less performance overhead with same level of
memory saving.

[1] https://blogs.oracle.com/linux/post/anticipating-your-memory-needs
[2] https://www.pdl.cmu.edu/ftp/NVM/tmo_asplos22.pdf

Evaluation
==========

In short, PLRUS achieves 10% memory PSI (some) reduction, 14% major page
faults reduction, and 3.74% speedup under memory pressure.

Setup
-----

To show the effect of PLRUS, I run PARSEC3 and SPLASH-2X benchmarks under
below variant systems and measure a few metrics including the runtime of
each workload, number of system-wide major page faults, and system-wide
memory PSI (some).

- orig: v5.18-rc4 based mm-unstable kernel + this patchset, but no DAMON scheme
        applied.
- mprs: Same to 'orig' but artificial memory pressure is induced.
- plrus: Same to 'mprs' but a radically tuned PLRUS scheme is applied to the
         entire physical address space of the system.

For the artificial memory pressure, I set 'memory.limit_in_bytes' to 75%
of the running workload's peak RSS, wait 1 second, remove the pressure by
setting it to 200% of the peak RSS, wait 10 seconds, and repeat the
procedure until the workload finishes[1].  I use zram based swap device.
The tests are automated[2].

[1] https://github.com/awslabs/damon-tests/blob/next/perf/runners/back/0009_memcg_pressure.sh
[2] https://github.com/awslabs/damon-tests/blob/next/perf/full_once_config.sh

Radically Tuned PLRUS
---------------------

To show effect of PLRUS on the PARSEC3/SPLASH-2X workloads which runs for
no long time, we use radically tuned version of PLRUS.  The version asks
DAMON to do the proactive LRU-lists sorting as below.

1. Find any memory regions shown some accesses (approximately >=20 accesses per
   100 sampling) and prioritize pages of the regions on their LRU lists using
   up to 2% CPU time.  Under the CPU time limit, prioritize regions having
   higher access frequency and kept the access frequency longer first.

2. Find any memory regions shown no access for at least >=5 seconds and
   deprioritize pages of the rgions on their LRU lists using up to 2% CPU time.
   Under the CPU time limit, deprioritize regions that not accessed for longer
   time first.

Results
-------

I repeat the tests 25 times and calculate average of the measured numbers.
The results are as below:

    metric               orig        mprs         plrus        plrus/mprs
    runtime_seconds      190.06      292.83       281.87       0.96
    pgmajfaults          852.55      8769420.00   7525040.00   0.86
    memory_psi_some_us   106911.00   6943420.00   6220920.00   0.90

The first row is for legend.  The first cell shows the metric that the
following cells of the row shows.  Second, third, and fourth cells show
the metrics under the configs shown at the first row of the cell, and the
fifth cell shows the metric under 'plrus' divided by the metric under
'mprs'.  Second row shows the averaged runtime of the workloads in
seconds.  Third row shows the number of system-wide major page faults
while the test was ongoing.  Fourth row shows the system-wide memory
pressure stall for some processes in microseconds while the test was
ongoing.

In short, PLRUS achieves 10% memory PSI (some) reduction, 14% major page
faults reduction, and 3.74% speedup under memory pressure.  We also
confirmed the CPU usage of kdamond was 2.61% of single CPU, which is below
4% as expected.

Sequence of Patches
===================

The first and second patch cleans up DAMON debugfs interface and
DAMOS_PAGEOUT handling code of physical address space monitoring
operations implementation for easier extension of the code.

The thrid and fourth patches implement a new DAMOS action called
'lru_prio', which prioritizes pages under memory regions which have a
user-specified access pattern, and document it, respectively.  The fifth
and sixth patches implement yet another new DAMOS action called
'lru_deprio', which deprioritizes pages under memory regions which have a
user-specified access pattern, and document it, respectively.

The seventh patch implements a static kernel module called
'damon_lru_sort', which utilizes the DAMON-based proactive LRU-lists
sorting under conservatively chosen default parameter.  Finally, the
eighth patch documents 'damon_lru_sort'.

This patch (of 8):

DAMON debugfs interface assumes users will write 'damos_action' value
directly to the 'schemes' file.  This makes adding new 'damos_action' in
the middle of its definition breaks the backward compatibility of DAMON
debugfs interface, as values of some 'damos_action' could be changed.  To
mitigate the situation, this commit adds mappings between the user inputs
and 'damos_action' value and makes DAMON debugfs code uses those.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
This commit moves code for 'DAMOS_PAGEOUT' handling of the physical
address space monitoring operations set to a separate function so that its
caller, 'damon_pa_apply_scheme()', can be more easily extended for
additional DAMOS actions later.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
This commit adds a new DAMOS action called 'LRU_PRIO' for the physical
address space.  The action prioritizes pages in the memory regions of the
user-specified target access pattern on their LRU lists.  This is hence
supposed to be used for frequently accessed (hot) memory regions so that
hot pages could be more likely protected under memory pressure.
Internally, it simply calls 'mark_page_accessed()'.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
This commit documents the 'lru_prio' scheme action for DAMON sysfs
interface.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
This commit adds a new DAMON-based operation scheme action called
'LRU_DEPRIO' for physical address space.  The action deprioritizes pages
in the memory area of the target access pattern on their LRU lists.  This
is hence supposed to be used for rarely accessed (cold) memory regions so
that cold pages could be more likely reclaimed first under memory
pressure.  Internally, it simply calls 'lru_deactivate()'.

Using this with 'LRU_PRIO' action for hot pages, users can proactively
sort LRU lists based on the access pattern.  That is, it can make the LRU
lists somewhat more trustworthy source of access temperature.  As a
result, efficiency of LRU-lists based mechanisms including the reclamation
target selection could be improved.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
This commit documents the 'LRU_DEPRIO' scheme action for DAMON sysfs
interface.`

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Users can do data access-aware LRU-lists sorting using 'LRU_PRIO' and
'LRU_DEPRIO' DAMOS actions.  However, finding best parameters including
the hotness/coldness thresholds, CPU quota, and watermarks could be
challenging for some users.  To make the scheme easy to be used without
complex tuning for common situations, this commit implements a static
kernel module called 'DAMON_LRU_SORT' using the 'LRU_PRIO' and
'LRU_DEPRIO' DAMOS actions.

It proactively sorts LRU-lists using DAMON with conservatively chosen
default values of the parameters.  That is, the module under its default
parameters will make no harm for common situations but provide some level
of efficiency improvements for systems having clear hot/cold access
pattern under a level of memory pressure while consuming only a limited
small portion of CPU time.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
This commit documents the usage of DAMON_LRU_SORT for admins.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: SeongJae Park <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
damon_lru_sort_init() returns an error when damon_select_ops() fails
without freeing 'ctx' which allocated before.  This commit fixes the
potential memory leak by freeing 'ctx' under the situation.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 40e983c ("mm/damon: introduce DAMON-based LRU-lists Sorting")
Signed-off-by: SeongJae Park <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
The workflow example code is not working since it got the file names
wrong. So fix this.

Fixes: b184027 ("Docs/admin-guide/mm/damon/usage: document DAMON sysfs interface")
Reviewed-by: SeongJae Park <[email protected]>
Signed-off-by: Kairui Song <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Corbet <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 10, 2025
[ Upstream commit 9afb4b2 ]

To clear the flow table on flow table free, the following sequence
normally happens in order:

  1) gc_step work is stopped to disable any further stats/del requests.
  2) All flow table entries are set to teardown state.
  3) Run gc_step which will queue HW del work for each flow table entry.
  4) Waiting for the above del work to finish (flush).
  5) Run gc_step again, deleting all entries from the flow table.
  6) Flow table is freed.

But if a flow table entry already has pending HW stats or HW add work
step 3 will not queue HW del work (it will be skipped), step 4 will wait
for the pending add/stats to finish, and step 5 will queue HW del work
which might execute after freeing of the flow table.

To fix the above, this patch flushes the pending work, then it sets the
teardown flag to all flows in the flowtable and it forces a garbage
collector run to queue work to remove the flows from hardware, then it
flushes this new pending work and (finally) it forces another garbage
collector run to remove the entry from the software flowtable.

Stack trace:
[47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460
[47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704
[47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2
[47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
[47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table]
[47773.889727] Call Trace:
[47773.890214]  dump_stack+0xbb/0x107
[47773.890818]  print_address_description.constprop.0+0x18/0x140
[47773.892990]  kasan_report.cold+0x7c/0xd8
[47773.894459]  kasan_check_range+0x145/0x1a0
[47773.895174]  down_read+0x99/0x460
[47773.899706]  nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table]
[47773.907137]  flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table]
[47773.913372]  process_one_work+0x8ac/0x14e0
[47773.921325]
[47773.921325] Allocated by task 592159:
[47773.922031]  kasan_save_stack+0x1b/0x40
[47773.922730]  __kasan_kmalloc+0x7a/0x90
[47773.923411]  tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct]
[47773.924363]  tcf_ct_init+0x71c/0x1156 [act_ct]
[47773.925207]  tcf_action_init_1+0x45b/0x700
[47773.925987]  tcf_action_init+0x453/0x6b0
[47773.926692]  tcf_exts_validate+0x3d0/0x600
[47773.927419]  fl_change+0x757/0x4a51 [cls_flower]
[47773.928227]  tc_new_tfilter+0x89a/0x2070
[47773.936652]
[47773.936652] Freed by task 543704:
[47773.937303]  kasan_save_stack+0x1b/0x40
[47773.938039]  kasan_set_track+0x1c/0x30
[47773.938731]  kasan_set_free_info+0x20/0x30
[47773.939467]  __kasan_slab_free+0xe7/0x120
[47773.940194]  slab_free_freelist_hook+0x86/0x190
[47773.941038]  kfree+0xce/0x3a0
[47773.941644]  tcf_ct_flow_table_cleanup_work

Original patch description and stack trace by Paul Blakey.

Fixes: c29f74e ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <[email protected]>
Tested-by: Paul Blakey <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Nathan Gao <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 10, 2025
commit c886d70 upstream.

Dipanjan reported a syzbot splat at close time:

WARNING: CPU: 1 PID: 10818 at net/ipv4/af_inet.c:153
inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Modules linked in: uio_ivshmem(OE) uio(E)
CPU: 1 PID: 10818 Comm: kworker/1:16 Tainted: G           OE
5.19.0-rc6-g2eae0556bb9d #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Code: 21 02 00 00 41 8b 9c 24 28 02 00 00 e9 07 ff ff ff e8 34 4d 91
f9 89 ee 4c 89 e7 e8 4a 47 60 ff e9 a6 fc ff ff e8 20 4d 91 f9 <0f> 0b
e9 84 fe ff ff e8 14 4d 91 f9 0f 0b e9 d4 fd ff ff e8 08 4d
RSP: 0018:ffffc9001b35fa78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000002879d0 RCX: ffff8881326f3b00
RDX: 0000000000000000 RSI: ffff8881326f3b00 RDI: 0000000000000002
RBP: ffff888179662674 R08: ffffffff87e983a0 R09: 0000000000000000
R10: 0000000000000005 R11: 00000000000004ea R12: ffff888179662400
R13: ffff888179662428 R14: 0000000000000001 R15: ffff88817e38e258
FS:  0000000000000000(0000) GS:ffff8881f5f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020007bc0 CR3: 0000000179592000 CR4: 0000000000150ee0
Call Trace:
 <TASK>
 __sk_destruct+0x4f/0x8e0 net/core/sock.c:2067
 sk_destruct+0xbd/0xe0 net/core/sock.c:2112
 __sk_free+0xef/0x3d0 net/core/sock.c:2123
 sk_free+0x78/0xa0 net/core/sock.c:2134
 sock_put include/net/sock.h:1927 [inline]
 __mptcp_close_ssk+0x50f/0x780 net/mptcp/protocol.c:2351
 __mptcp_destroy_sock+0x332/0x760 net/mptcp/protocol.c:2828
 mptcp_worker+0x5d2/0xc90 net/mptcp/protocol.c:2586
 process_one_work+0x9cc/0x1650 kernel/workqueue.c:2289
 worker_thread+0x623/0x1070 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

The root cause of the problem is that an mptcp-level (re)transmit can
race with mptcp_close() and the packet scheduler checks the subflow
state before acquiring the socket lock: we can try to (re)transmit on
an already closed ssk.

Fix the issue checking again the subflow socket status under the
subflow socket lock protection. Additionally add the missing check
for the fallback-to-tcp case.

Fixes: d5f4919 ("mptcp: allow picking different xmit subflows")
Reported-by: Dipanjan Das <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Mat Martineau <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
[mheyne@: Fixed a couple of conflicts due to some missing commit:
 - Commit d9ca1de ("mptcp: move page frag allocation in
   mptcp_sendmsg()") reworked a couple of functions. Before this commit
   there used to be a check for EAGAIN after mptcp_sendmsg_frag. This is
   equivalent to the "continue" from this backport and therefore is
   dropped.
 Other commits that affected the context:
 - 5cf92bb ("mptcp: re-enable sndbuf autotune")
 - b713d00 ("mptcp: really share subflow snd_wnd")
 - f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")]
Signed-off-by: Maximilian Heyne <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 10, 2025
[ Upstream commit 711741f ]

Fix cifs_signal_cifsd_for_reconnect() to take the correct lock order
and prevent the following deadlock from happening

======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc3-build2+ #1301 Tainted: G S      W
------------------------------------------------------
cifsd/6055 is trying to acquire lock:
ffff88810ad56038 (&tcp_ses->srv_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x134/0x200

but task is already holding lock:
ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&ret_buf->chan_lock){+.+.}-{3:3}:
       validate_chain+0x1cf/0x270
       __lock_acquire+0x60e/0x780
       lock_acquire.part.0+0xb4/0x1f0
       _raw_spin_lock+0x2f/0x40
       cifs_setup_session+0x81/0x4b0
       cifs_get_smb_ses+0x771/0x900
       cifs_mount_get_session+0x7e/0x170
       cifs_mount+0x92/0x2d0
       cifs_smb3_do_mount+0x161/0x460
       smb3_get_tree+0x55/0x90
       vfs_get_tree+0x46/0x180
       do_new_mount+0x1b0/0x2e0
       path_mount+0x6ee/0x740
       do_mount+0x98/0xe0
       __do_sys_mount+0x148/0x180
       do_syscall_64+0xa4/0x260
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> #1 (&ret_buf->ses_lock){+.+.}-{3:3}:
       validate_chain+0x1cf/0x270
       __lock_acquire+0x60e/0x780
       lock_acquire.part.0+0xb4/0x1f0
       _raw_spin_lock+0x2f/0x40
       cifs_match_super+0x101/0x320
       sget+0xab/0x270
       cifs_smb3_do_mount+0x1e0/0x460
       smb3_get_tree+0x55/0x90
       vfs_get_tree+0x46/0x180
       do_new_mount+0x1b0/0x2e0
       path_mount+0x6ee/0x740
       do_mount+0x98/0xe0
       __do_sys_mount+0x148/0x180
       do_syscall_64+0xa4/0x260
       entry_SYSCALL_64_after_hwframe+0x76/0x7e

-> #0 (&tcp_ses->srv_lock){+.+.}-{3:3}:
       check_noncircular+0x95/0xc0
       check_prev_add+0x115/0x2f0
       validate_chain+0x1cf/0x270
       __lock_acquire+0x60e/0x780
       lock_acquire.part.0+0xb4/0x1f0
       _raw_spin_lock+0x2f/0x40
       cifs_signal_cifsd_for_reconnect+0x134/0x200
       __cifs_reconnect+0x8f/0x500
       cifs_handle_standard+0x112/0x280
       cifs_demultiplex_thread+0x64d/0xbc0
       kthread+0x2f7/0x310
       ret_from_fork+0x2a/0x230
       ret_from_fork_asm+0x1a/0x30

other info that might help us debug this:

Chain exists of:
  &tcp_ses->srv_lock --> &ret_buf->ses_lock --> &ret_buf->chan_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ret_buf->chan_lock);
                               lock(&ret_buf->ses_lock);
                               lock(&ret_buf->chan_lock);
  lock(&tcp_ses->srv_lock);

 *** DEADLOCK ***

3 locks held by cifsd/6055:
 #0: ffffffff857de398 (&cifs_tcp_ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x7b/0x200
 #1: ffff888119c64060 (&ret_buf->ses_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0x9c/0x200
 #2: ffff888119c64330 (&ret_buf->chan_lock){+.+.}-{3:3}, at: cifs_signal_cifsd_for_reconnect+0xcf/0x200

Cc: [email protected]
Reported-by: David Howells <[email protected]>
Fixes: d7d7a66 ("cifs: avoid use of global locks for high contention data")
Reviewed-by: David Howells <[email protected]>
Tested-by: David Howells <[email protected]>
Signed-off-by: Paulo Alcantara (Red Hat) <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Steve French <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
[v6.1: replaced SERVER_IS_CHAN with CIFS_SERVER_IS_CHAN; resolved
contextual conflicts in cifs_signal_cifsd_for_reconnect()]
Signed-off-by: Shaoying Xu <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
As reported by syzbot and experienced by Pavel, using cpus_read_lock()
in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem
and possibly others).

Instead, shrink the preempt disable region by iterating all CPUs and
checking the online status for each individual CPU while having
preemption disabled.

Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()")
Reported-by: [email protected]
Reported-by: Pavel Machek <[email protected]>
Reported-by: Qian Cai <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Qian Cai <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
commit f79a609 upstream.

log_max_qp in driver's default profile #2 was set to 18, but FW actually
supports 17 at the most - a situation that led to the concerning print
when the driver is loaded:
"log_max_qp value in current profile is 18, changing to HCA capabaility
limit (17)"

The expected behavior from mlx5_profile #2 is to match the maximum FW
capability in regards to log_max_qp. Thus, log_max_qp in profile #2 is
initialized to a defined static value (0xff) - which basically means that
when loading this profile, log_max_qp value  will be what the currently
installed FW supports at most.

Signed-off-by: Maher Sanalla <[email protected]>
Reviewed-by: Maor Gottlieb <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
[v5.10: replaced prof->log_max_qp with profile[prof_sel].log_max_qp]
Signed-off-by: Shaoying Xu <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
[ Upstream commit 9afb4b2 ]

To clear the flow table on flow table free, the following sequence
normally happens in order:

  1) gc_step work is stopped to disable any further stats/del requests.
  2) All flow table entries are set to teardown state.
  3) Run gc_step which will queue HW del work for each flow table entry.
  4) Waiting for the above del work to finish (flush).
  5) Run gc_step again, deleting all entries from the flow table.
  6) Flow table is freed.

But if a flow table entry already has pending HW stats or HW add work
step 3 will not queue HW del work (it will be skipped), step 4 will wait
for the pending add/stats to finish, and step 5 will queue HW del work
which might execute after freeing of the flow table.

To fix the above, this patch flushes the pending work, then it sets the
teardown flag to all flows in the flowtable and it forces a garbage
collector run to queue work to remove the flows from hardware, then it
flushes this new pending work and (finally) it forces another garbage
collector run to remove the entry from the software flowtable.

Stack trace:
[47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460
[47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704
[47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2
[47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
[47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table]
[47773.889727] Call Trace:
[47773.890214]  dump_stack+0xbb/0x107
[47773.890818]  print_address_description.constprop.0+0x18/0x140
[47773.892990]  kasan_report.cold+0x7c/0xd8
[47773.894459]  kasan_check_range+0x145/0x1a0
[47773.895174]  down_read+0x99/0x460
[47773.899706]  nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table]
[47773.907137]  flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table]
[47773.913372]  process_one_work+0x8ac/0x14e0
[47773.921325]
[47773.921325] Allocated by task 592159:
[47773.922031]  kasan_save_stack+0x1b/0x40
[47773.922730]  __kasan_kmalloc+0x7a/0x90
[47773.923411]  tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct]
[47773.924363]  tcf_ct_init+0x71c/0x1156 [act_ct]
[47773.925207]  tcf_action_init_1+0x45b/0x700
[47773.925987]  tcf_action_init+0x453/0x6b0
[47773.926692]  tcf_exts_validate+0x3d0/0x600
[47773.927419]  fl_change+0x757/0x4a51 [cls_flower]
[47773.928227]  tc_new_tfilter+0x89a/0x2070
[47773.936652]
[47773.936652] Freed by task 543704:
[47773.937303]  kasan_save_stack+0x1b/0x40
[47773.938039]  kasan_set_track+0x1c/0x30
[47773.938731]  kasan_set_free_info+0x20/0x30
[47773.939467]  __kasan_slab_free+0xe7/0x120
[47773.940194]  slab_free_freelist_hook+0x86/0x190
[47773.941038]  kfree+0xce/0x3a0
[47773.941644]  tcf_ct_flow_table_cleanup_work

Original patch description and stack trace by Paul Blakey.

Fixes: c29f74e ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <[email protected]>
Tested-by: Paul Blakey <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Nathan Gao <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
commit c886d70 upstream.

Dipanjan reported a syzbot splat at close time:

WARNING: CPU: 1 PID: 10818 at net/ipv4/af_inet.c:153
inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Modules linked in: uio_ivshmem(OE) uio(E)
CPU: 1 PID: 10818 Comm: kworker/1:16 Tainted: G           OE
5.19.0-rc6-g2eae0556bb9d #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Code: 21 02 00 00 41 8b 9c 24 28 02 00 00 e9 07 ff ff ff e8 34 4d 91
f9 89 ee 4c 89 e7 e8 4a 47 60 ff e9 a6 fc ff ff e8 20 4d 91 f9 <0f> 0b
e9 84 fe ff ff e8 14 4d 91 f9 0f 0b e9 d4 fd ff ff e8 08 4d
RSP: 0018:ffffc9001b35fa78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000002879d0 RCX: ffff8881326f3b00
RDX: 0000000000000000 RSI: ffff8881326f3b00 RDI: 0000000000000002
RBP: ffff888179662674 R08: ffffffff87e983a0 R09: 0000000000000000
R10: 0000000000000005 R11: 00000000000004ea R12: ffff888179662400
R13: ffff888179662428 R14: 0000000000000001 R15: ffff88817e38e258
FS:  0000000000000000(0000) GS:ffff8881f5f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020007bc0 CR3: 0000000179592000 CR4: 0000000000150ee0
Call Trace:
 <TASK>
 __sk_destruct+0x4f/0x8e0 net/core/sock.c:2067
 sk_destruct+0xbd/0xe0 net/core/sock.c:2112
 __sk_free+0xef/0x3d0 net/core/sock.c:2123
 sk_free+0x78/0xa0 net/core/sock.c:2134
 sock_put include/net/sock.h:1927 [inline]
 __mptcp_close_ssk+0x50f/0x780 net/mptcp/protocol.c:2351
 __mptcp_destroy_sock+0x332/0x760 net/mptcp/protocol.c:2828
 mptcp_worker+0x5d2/0xc90 net/mptcp/protocol.c:2586
 process_one_work+0x9cc/0x1650 kernel/workqueue.c:2289
 worker_thread+0x623/0x1070 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

The root cause of the problem is that an mptcp-level (re)transmit can
race with mptcp_close() and the packet scheduler checks the subflow
state before acquiring the socket lock: we can try to (re)transmit on
an already closed ssk.

Fix the issue checking again the subflow socket status under the
subflow socket lock protection. Additionally add the missing check
for the fallback-to-tcp case.

Fixes: d5f4919 ("mptcp: allow picking different xmit subflows")
Reported-by: Dipanjan Das <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Mat Martineau <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
[mheyne@: Fixed a couple of conflicts due to some missing commit:
 - Commit d9ca1de ("mptcp: move page frag allocation in
   mptcp_sendmsg()") reworked a couple of functions. Before this commit
   there used to be a check for EAGAIN after mptcp_sendmsg_frag. This is
   equivalent to the "continue" from this backport and therefore is
   dropped.
 Other commits that affected the context:
 - 5cf92bb ("mptcp: re-enable sndbuf autotune")
 - b713d00 ("mptcp: really share subflow snd_wnd")
 - f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")]
Signed-off-by: Maximilian Heyne <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
As reported by syzbot and experienced by Pavel, using cpus_read_lock()
in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem
and possibly others).

Instead, shrink the preempt disable region by iterating all CPUs and
checking the online status for each individual CPU while having
preemption disabled.

Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()")
Reported-by: [email protected]
Reported-by: Pavel Machek <[email protected]>
Reported-by: Qian Cai <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Qian Cai <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
commit f79a609 upstream.

log_max_qp in driver's default profile #2 was set to 18, but FW actually
supports 17 at the most - a situation that led to the concerning print
when the driver is loaded:
"log_max_qp value in current profile is 18, changing to HCA capabaility
limit (17)"

The expected behavior from mlx5_profile #2 is to match the maximum FW
capability in regards to log_max_qp. Thus, log_max_qp in profile #2 is
initialized to a defined static value (0xff) - which basically means that
when loading this profile, log_max_qp value  will be what the currently
installed FW supports at most.

Signed-off-by: Maher Sanalla <[email protected]>
Reviewed-by: Maor Gottlieb <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
[v5.10: replaced prof->log_max_qp with profile[prof_sel].log_max_qp]
Signed-off-by: Shaoying Xu <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
[ Upstream commit 9afb4b2 ]

To clear the flow table on flow table free, the following sequence
normally happens in order:

  1) gc_step work is stopped to disable any further stats/del requests.
  2) All flow table entries are set to teardown state.
  3) Run gc_step which will queue HW del work for each flow table entry.
  4) Waiting for the above del work to finish (flush).
  5) Run gc_step again, deleting all entries from the flow table.
  6) Flow table is freed.

But if a flow table entry already has pending HW stats or HW add work
step 3 will not queue HW del work (it will be skipped), step 4 will wait
for the pending add/stats to finish, and step 5 will queue HW del work
which might execute after freeing of the flow table.

To fix the above, this patch flushes the pending work, then it sets the
teardown flag to all flows in the flowtable and it forces a garbage
collector run to queue work to remove the flows from hardware, then it
flushes this new pending work and (finally) it forces another garbage
collector run to remove the entry from the software flowtable.

Stack trace:
[47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460
[47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704
[47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2
[47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
[47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table]
[47773.889727] Call Trace:
[47773.890214]  dump_stack+0xbb/0x107
[47773.890818]  print_address_description.constprop.0+0x18/0x140
[47773.892990]  kasan_report.cold+0x7c/0xd8
[47773.894459]  kasan_check_range+0x145/0x1a0
[47773.895174]  down_read+0x99/0x460
[47773.899706]  nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table]
[47773.907137]  flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table]
[47773.913372]  process_one_work+0x8ac/0x14e0
[47773.921325]
[47773.921325] Allocated by task 592159:
[47773.922031]  kasan_save_stack+0x1b/0x40
[47773.922730]  __kasan_kmalloc+0x7a/0x90
[47773.923411]  tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct]
[47773.924363]  tcf_ct_init+0x71c/0x1156 [act_ct]
[47773.925207]  tcf_action_init_1+0x45b/0x700
[47773.925987]  tcf_action_init+0x453/0x6b0
[47773.926692]  tcf_exts_validate+0x3d0/0x600
[47773.927419]  fl_change+0x757/0x4a51 [cls_flower]
[47773.928227]  tc_new_tfilter+0x89a/0x2070
[47773.936652]
[47773.936652] Freed by task 543704:
[47773.937303]  kasan_save_stack+0x1b/0x40
[47773.938039]  kasan_set_track+0x1c/0x30
[47773.938731]  kasan_set_free_info+0x20/0x30
[47773.939467]  __kasan_slab_free+0xe7/0x120
[47773.940194]  slab_free_freelist_hook+0x86/0x190
[47773.941038]  kfree+0xce/0x3a0
[47773.941644]  tcf_ct_flow_table_cleanup_work

Original patch description and stack trace by Paul Blakey.

Fixes: c29f74e ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <[email protected]>
Tested-by: Paul Blakey <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Nathan Gao <[email protected]>
mngyadam pushed a commit that referenced this pull request Dec 10, 2025
commit c886d70 upstream.

Dipanjan reported a syzbot splat at close time:

WARNING: CPU: 1 PID: 10818 at net/ipv4/af_inet.c:153
inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Modules linked in: uio_ivshmem(OE) uio(E)
CPU: 1 PID: 10818 Comm: kworker/1:16 Tainted: G           OE
5.19.0-rc6-g2eae0556bb9d #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Code: 21 02 00 00 41 8b 9c 24 28 02 00 00 e9 07 ff ff ff e8 34 4d 91
f9 89 ee 4c 89 e7 e8 4a 47 60 ff e9 a6 fc ff ff e8 20 4d 91 f9 <0f> 0b
e9 84 fe ff ff e8 14 4d 91 f9 0f 0b e9 d4 fd ff ff e8 08 4d
RSP: 0018:ffffc9001b35fa78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000002879d0 RCX: ffff8881326f3b00
RDX: 0000000000000000 RSI: ffff8881326f3b00 RDI: 0000000000000002
RBP: ffff888179662674 R08: ffffffff87e983a0 R09: 0000000000000000
R10: 0000000000000005 R11: 00000000000004ea R12: ffff888179662400
R13: ffff888179662428 R14: 0000000000000001 R15: ffff88817e38e258
FS:  0000000000000000(0000) GS:ffff8881f5f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020007bc0 CR3: 0000000179592000 CR4: 0000000000150ee0
Call Trace:
 <TASK>
 __sk_destruct+0x4f/0x8e0 net/core/sock.c:2067
 sk_destruct+0xbd/0xe0 net/core/sock.c:2112
 __sk_free+0xef/0x3d0 net/core/sock.c:2123
 sk_free+0x78/0xa0 net/core/sock.c:2134
 sock_put include/net/sock.h:1927 [inline]
 __mptcp_close_ssk+0x50f/0x780 net/mptcp/protocol.c:2351
 __mptcp_destroy_sock+0x332/0x760 net/mptcp/protocol.c:2828
 mptcp_worker+0x5d2/0xc90 net/mptcp/protocol.c:2586
 process_one_work+0x9cc/0x1650 kernel/workqueue.c:2289
 worker_thread+0x623/0x1070 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

The root cause of the problem is that an mptcp-level (re)transmit can
race with mptcp_close() and the packet scheduler checks the subflow
state before acquiring the socket lock: we can try to (re)transmit on
an already closed ssk.

Fix the issue checking again the subflow socket status under the
subflow socket lock protection. Additionally add the missing check
for the fallback-to-tcp case.

Fixes: d5f4919 ("mptcp: allow picking different xmit subflows")
Reported-by: Dipanjan Das <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Mat Martineau <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
[mheyne@: Fixed a couple of conflicts due to some missing commit:
 - Commit d9ca1de ("mptcp: move page frag allocation in
   mptcp_sendmsg()") reworked a couple of functions. Before this commit
   there used to be a check for EAGAIN after mptcp_sendmsg_frag. This is
   equivalent to the "continue" from this backport and therefore is
   dropped.
 Other commits that affected the context:
 - 5cf92bb ("mptcp: re-enable sndbuf autotune")
 - b713d00 ("mptcp: really share subflow snd_wnd")
 - f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")]
Signed-off-by: Maximilian Heyne <[email protected]>
yifei-aws pushed a commit that referenced this pull request Dec 10, 2025
As reported by syzbot and experienced by Pavel, using cpus_read_lock()
in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem
and possibly others).

Instead, shrink the preempt disable region by iterating all CPUs and
checking the online status for each individual CPU while having
preemption disabled.

Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()")
Reported-by: [email protected]
Reported-by: Pavel Machek <[email protected]>
Reported-by: Qian Cai <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Qian Cai <[email protected]>
yifei-aws pushed a commit that referenced this pull request Dec 10, 2025
commit f79a609 upstream.

log_max_qp in driver's default profile #2 was set to 18, but FW actually
supports 17 at the most - a situation that led to the concerning print
when the driver is loaded:
"log_max_qp value in current profile is 18, changing to HCA capabaility
limit (17)"

The expected behavior from mlx5_profile #2 is to match the maximum FW
capability in regards to log_max_qp. Thus, log_max_qp in profile #2 is
initialized to a defined static value (0xff) - which basically means that
when loading this profile, log_max_qp value  will be what the currently
installed FW supports at most.

Signed-off-by: Maher Sanalla <[email protected]>
Reviewed-by: Maor Gottlieb <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
[v5.10: replaced prof->log_max_qp with profile[prof_sel].log_max_qp]
Signed-off-by: Shaoying Xu <[email protected]>
yifei-aws pushed a commit that referenced this pull request Dec 10, 2025
[ Upstream commit 9afb4b2 ]

To clear the flow table on flow table free, the following sequence
normally happens in order:

  1) gc_step work is stopped to disable any further stats/del requests.
  2) All flow table entries are set to teardown state.
  3) Run gc_step which will queue HW del work for each flow table entry.
  4) Waiting for the above del work to finish (flush).
  5) Run gc_step again, deleting all entries from the flow table.
  6) Flow table is freed.

But if a flow table entry already has pending HW stats or HW add work
step 3 will not queue HW del work (it will be skipped), step 4 will wait
for the pending add/stats to finish, and step 5 will queue HW del work
which might execute after freeing of the flow table.

To fix the above, this patch flushes the pending work, then it sets the
teardown flag to all flows in the flowtable and it forces a garbage
collector run to queue work to remove the flows from hardware, then it
flushes this new pending work and (finally) it forces another garbage
collector run to remove the entry from the software flowtable.

Stack trace:
[47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460
[47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704
[47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2
[47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
[47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table]
[47773.889727] Call Trace:
[47773.890214]  dump_stack+0xbb/0x107
[47773.890818]  print_address_description.constprop.0+0x18/0x140
[47773.892990]  kasan_report.cold+0x7c/0xd8
[47773.894459]  kasan_check_range+0x145/0x1a0
[47773.895174]  down_read+0x99/0x460
[47773.899706]  nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table]
[47773.907137]  flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table]
[47773.913372]  process_one_work+0x8ac/0x14e0
[47773.921325]
[47773.921325] Allocated by task 592159:
[47773.922031]  kasan_save_stack+0x1b/0x40
[47773.922730]  __kasan_kmalloc+0x7a/0x90
[47773.923411]  tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct]
[47773.924363]  tcf_ct_init+0x71c/0x1156 [act_ct]
[47773.925207]  tcf_action_init_1+0x45b/0x700
[47773.925987]  tcf_action_init+0x453/0x6b0
[47773.926692]  tcf_exts_validate+0x3d0/0x600
[47773.927419]  fl_change+0x757/0x4a51 [cls_flower]
[47773.928227]  tc_new_tfilter+0x89a/0x2070
[47773.936652]
[47773.936652] Freed by task 543704:
[47773.937303]  kasan_save_stack+0x1b/0x40
[47773.938039]  kasan_set_track+0x1c/0x30
[47773.938731]  kasan_set_free_info+0x20/0x30
[47773.939467]  __kasan_slab_free+0xe7/0x120
[47773.940194]  slab_free_freelist_hook+0x86/0x190
[47773.941038]  kfree+0xce/0x3a0
[47773.941644]  tcf_ct_flow_table_cleanup_work

Original patch description and stack trace by Paul Blakey.

Fixes: c29f74e ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <[email protected]>
Tested-by: Paul Blakey <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Signed-off-by: Nathan Gao <[email protected]>
yifei-aws pushed a commit that referenced this pull request Dec 10, 2025
commit c886d70 upstream.

Dipanjan reported a syzbot splat at close time:

WARNING: CPU: 1 PID: 10818 at net/ipv4/af_inet.c:153
inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Modules linked in: uio_ivshmem(OE) uio(E)
CPU: 1 PID: 10818 Comm: kworker/1:16 Tainted: G           OE
5.19.0-rc6-g2eae0556bb9d #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.13.0-1ubuntu1.1 04/01/2014
Workqueue: events mptcp_worker
RIP: 0010:inet_sock_destruct+0x6d0/0x8e0 net/ipv4/af_inet.c:153
Code: 21 02 00 00 41 8b 9c 24 28 02 00 00 e9 07 ff ff ff e8 34 4d 91
f9 89 ee 4c 89 e7 e8 4a 47 60 ff e9 a6 fc ff ff e8 20 4d 91 f9 <0f> 0b
e9 84 fe ff ff e8 14 4d 91 f9 0f 0b e9 d4 fd ff ff e8 08 4d
RSP: 0018:ffffc9001b35fa78 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 00000000002879d0 RCX: ffff8881326f3b00
RDX: 0000000000000000 RSI: ffff8881326f3b00 RDI: 0000000000000002
RBP: ffff888179662674 R08: ffffffff87e983a0 R09: 0000000000000000
R10: 0000000000000005 R11: 00000000000004ea R12: ffff888179662400
R13: ffff888179662428 R14: 0000000000000001 R15: ffff88817e38e258
FS:  0000000000000000(0000) GS:ffff8881f5f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020007bc0 CR3: 0000000179592000 CR4: 0000000000150ee0
Call Trace:
 <TASK>
 __sk_destruct+0x4f/0x8e0 net/core/sock.c:2067
 sk_destruct+0xbd/0xe0 net/core/sock.c:2112
 __sk_free+0xef/0x3d0 net/core/sock.c:2123
 sk_free+0x78/0xa0 net/core/sock.c:2134
 sock_put include/net/sock.h:1927 [inline]
 __mptcp_close_ssk+0x50f/0x780 net/mptcp/protocol.c:2351
 __mptcp_destroy_sock+0x332/0x760 net/mptcp/protocol.c:2828
 mptcp_worker+0x5d2/0xc90 net/mptcp/protocol.c:2586
 process_one_work+0x9cc/0x1650 kernel/workqueue.c:2289
 worker_thread+0x623/0x1070 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302
 </TASK>

The root cause of the problem is that an mptcp-level (re)transmit can
race with mptcp_close() and the packet scheduler checks the subflow
state before acquiring the socket lock: we can try to (re)transmit on
an already closed ssk.

Fix the issue checking again the subflow socket status under the
subflow socket lock protection. Additionally add the missing check
for the fallback-to-tcp case.

Fixes: d5f4919 ("mptcp: allow picking different xmit subflows")
Reported-by: Dipanjan Das <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Signed-off-by: Mat Martineau <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
[mheyne@: Fixed a couple of conflicts due to some missing commit:
 - Commit d9ca1de ("mptcp: move page frag allocation in
   mptcp_sendmsg()") reworked a couple of functions. Before this commit
   there used to be a check for EAGAIN after mptcp_sendmsg_frag. This is
   equivalent to the "continue" from this backport and therefore is
   dropped.
 Other commits that affected the context:
 - 5cf92bb ("mptcp: re-enable sndbuf autotune")
 - b713d00 ("mptcp: really share subflow snd_wnd")
 - f70cad1 ("mptcp: stop relying on tcp_tx_skb_cache")]
Signed-off-by: Maximilian Heyne <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 11, 2025
Commit 1d2da79 ("pinctrl: renesas: rzg2l: Avoid configuring ISEL in
gpio_irq_{en,dis}able*()") dropped the configuration of ISEL from
struct irq_chip::{irq_enable, irq_disable} APIs and moved it to
struct gpio_chip::irq::{child_to_parent_hwirq,
child_irq_domain_ops::free} APIs to fix spurious IRQs.

After commit 1d2da79 ("pinctrl: renesas: rzg2l: Avoid configuring ISEL
in gpio_irq_{en,dis}able*()"), ISEL was no longer configured properly on
resume. This is because the pinctrl resume code used
struct irq_chip::irq_enable  (called from rzg2l_gpio_irq_restore()) to
reconfigure the wakeup interrupts. Some drivers (e.g. Ethernet) may also
reconfigure non-wakeup interrupts on resume through their own code,
eventually calling struct irq_chip::irq_enable.

Fix this by adding ISEL configuration back into the
struct irq_chip::irq_enable API and on resume path for wakeup interrupts.

As struct irq_chip::irq_enable needs now to lock to update the ISEL,
convert the struct rzg2l_pinctrl::lock to a raw spinlock and replace the
locking API calls with the raw variants. Otherwise the lockdep reports
invalid wait context when probing the adv7511 module on RZ/G2L:

 [ BUG: Invalid wait context ]
 6.17.0-rc5-next-20250911-00001-gfcfac22533c9 gregkh#18 Not tainted
 -----------------------------
 (udev-worker)/165 is trying to lock:
 ffff00000e3664a8 (&pctrl->lock){....}-{3:3}, at: rzg2l_gpio_irq_enable+0x38/0x78
 other info that might help us debug this:
 context-{5:5}
 3 locks held by (udev-worker)/165:
 #0: ffff00000e890108 (&dev->mutex){....}-{4:4}, at: __driver_attach+0x90/0x1ac
 #1: ffff000011c07240 (request_class){+.+.}-{4:4}, at: __setup_irq+0xb4/0x6dc
 #2: ffff000011c070c8 (lock_class){....}-{2:2}, at: __setup_irq+0xdc/0x6dc
 stack backtrace:
 CPU: 1 UID: 0 PID: 165 Comm: (udev-worker) Not tainted 6.17.0-rc5-next-20250911-00001-gfcfac22533c9 gregkh#18 PREEMPT
 Hardware name: Renesas SMARC EVK based on r9a07g044l2 (DT)
 Call trace:
 show_stack+0x18/0x24 (C)
 dump_stack_lvl+0x90/0xd0
 dump_stack+0x18/0x24
 __lock_acquire+0xa14/0x20b4
 lock_acquire+0x1c8/0x354
 _raw_spin_lock_irqsave+0x60/0x88
 rzg2l_gpio_irq_enable+0x38/0x78
 irq_enable+0x40/0x8c
 __irq_startup+0x78/0xa4
 irq_startup+0x108/0x16c
 __setup_irq+0x3c0/0x6dc
 request_threaded_irq+0xec/0x1ac
 devm_request_threaded_irq+0x80/0x134
 adv7511_probe+0x928/0x9a4 [adv7511]
 i2c_device_probe+0x22c/0x3dc
 really_probe+0xbc/0x2a0
 __driver_probe_device+0x78/0x12c
 driver_probe_device+0x40/0x164
 __driver_attach+0x9c/0x1ac
 bus_for_each_dev+0x74/0xd0
 driver_attach+0x24/0x30
 bus_add_driver+0xe4/0x208
 driver_register+0x60/0x128
 i2c_register_driver+0x48/0xd0
 adv7511_init+0x5c/0x1000 [adv7511]
 do_one_initcall+0x64/0x30c
 do_init_module+0x58/0x23c
 load_module+0x1bcc/0x1d40
 init_module_from_file+0x88/0xc4
 idempotent_init_module+0x188/0x27c
 __arm64_sys_finit_module+0x68/0xac
 invoke_syscall+0x48/0x110
 el0_svc_common.constprop.0+0xc0/0xe0
 do_el0_svc+0x1c/0x28
 el0_svc+0x4c/0x160
 el0t_64_sync_handler+0xa0/0xe4
 el0t_64_sync+0x198/0x19c

Having ISEL configuration back into the struct irq_chip::irq_enable API
should be safe with respect to spurious IRQs, as in the probe case IRQs
are enabled anyway in struct gpio_chip::irq::child_to_parent_hwirq. No
spurious IRQs were detected on suspend/resume, boot, ethernet link
insert/remove tests (executed on RZ/G3S). Boot, ethernet link
insert/remove tests were also executed successfully on RZ/G2L.

Fixes: 1d2da79 ("pinctrl: renesas: rzg2l: Avoid configuring ISEL in gpio_irq_{en,dis}able*(")
Cc: [email protected]
Signed-off-by: Claudiu Beznea <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Geert Uytterhoeven <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 11, 2025
The pic64gx has a second pinmux "downstream" of the iomux0 pinmux. The
documentation for the SoC provides no name for this device, but it is
used to swap pins between either GPIO controller #2 or select other
functions, hence the "gpio2" name. Currently there is no documentation
about what each bit actually does that is publicly available, nor (I
believe) what pins are affected. That info is as follows:

pin     role (1/0)
---     ----------
E14	MAC_0_MDC/GPIO_2_0
E15	MAC_0_MDIO/GPIO_2_1
F16	MAC_1_MDC/GPIO_2_2
F17	MAC_1_MDIO/GPIO_2_3
D19	SPI_0_CLK/GPIO_2_4
B18	SPI_0_SS0/GPIO_2_5
B10	CAN_0_RXBUS/GPIO_2_6
C14	PCIE_PERST_2#/GPIO_2_7
E18	PCIE_WAKE#/GPIO_2_8
D18	PCIE_PERST_1#/GPIO_2_9
E19	SPI_0_DO/GPIO_2_10
C7	SPI_0_DI/GPIO_2_11
D6	QSPI_SS0/GPIO_2_12
D7	QSPI_CLK (B)/GPIO_2_13
C9	QSPI_DATA0/GPIO_2_14
C10	QSPI_DATA1/GPIO_2_15
A5	QSPI_DATA2/GPIO_2_16
A6	QSPI_DATA3/GPIO_2_17
D8	MMUART_3_RXD/GPIO_2_18
D9	MMUART_3_TXD/GPIO_2_19
B8	MMUART_4_RXD/GPIO_2_20
A8	MMUART_4_TXD/GPIO_2_21
C12	CAN_1_TXBUS/GPIO_2_22
B12	CAN_1_RXBUS/GPIO_2_23
A11	CAN_0_TX_EBL_N/GPIO_2_24
A10	CAN_1_TX_EBL_N/GPIO_2_25
D11	MMUART_2_RXD/GPIO_2_26
C11	MMUART_2_TXD/GPIO_2_27
B9	CAN_0_TXBUS/GPIO_2_28

Reviewed-by: Rob Herring (Arm) <[email protected]>
Signed-off-by: Conor Dooley <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 11, 2025
The pic64gx has a second pinmux "downstream" of the iomux0 pinmux. The
documentation for the SoC provides no name for this device, but it is
used to swap pins between either GPIO controller #2 or select other
functions, hence the "gpio2" name. Add a driver for it.

Signed-off-by: Conor Dooley <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 11, 2025
As Jiaming Zhang and syzbot reported, there is potential deadlock in
f2fs as below:

Chain exists of:
  &sbi->cp_rwsem --> fs_reclaim --> sb_internal#2

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(sb_internal#2);
                               lock(fs_reclaim);
                               lock(sb_internal#2);
  rlock(&sbi->cp_rwsem);

 *** DEADLOCK ***

3 locks held by kswapd0/73:
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat mm/vmscan.c:7015 [inline]
 #0: ffffffff8e247a40 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x951/0x2800 mm/vmscan.c:7389
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_trylock_shared fs/super.c:562 [inline]
 #1: ffff8880118400e0 (&type->s_umount_key#50){.+.+}-{4:4}, at: super_cache_scan+0x91/0x4b0 fs/super.c:197
 #2: ffff888011840610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x8d9/0x1b60 fs/f2fs/inode.c:890

stack backtrace:
CPU: 0 UID: 0 PID: 73 Comm: kswapd0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
 check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 down_read+0x46/0x2e0 kernel/locking/rwsem.c:1537
 f2fs_down_read fs/f2fs/f2fs.h:2278 [inline]
 f2fs_lock_op fs/f2fs/f2fs.h:2357 [inline]
 f2fs_do_truncate_blocks+0x21c/0x10c0 fs/f2fs/file.c:791
 f2fs_truncate_blocks+0x10a/0x300 fs/f2fs/file.c:867
 f2fs_truncate+0x489/0x7c0 fs/f2fs/file.c:925
 f2fs_evict_inode+0x9f2/0x1b60 fs/f2fs/inode.c:897
 evict+0x504/0x9c0 fs/inode.c:810
 f2fs_evict_inode+0x1dc/0x1b60 fs/f2fs/inode.c:853
 evict+0x504/0x9c0 fs/inode.c:810
 dispose_list fs/inode.c:852 [inline]
 prune_icache_sb+0x21b/0x2c0 fs/inode.c:1000
 super_cache_scan+0x39b/0x4b0 fs/super.c:224
 do_shrink_slab+0x6ef/0x1110 mm/shrinker.c:437
 shrink_slab_memcg mm/shrinker.c:550 [inline]
 shrink_slab+0x7ef/0x10d0 mm/shrinker.c:628
 shrink_one+0x28a/0x7c0 mm/vmscan.c:4955
 shrink_many mm/vmscan.c:5016 [inline]
 lru_gen_shrink_node mm/vmscan.c:5094 [inline]
 shrink_node+0x315d/0x3780 mm/vmscan.c:6081
 kswapd_shrink_node mm/vmscan.c:6941 [inline]
 balance_pgdat mm/vmscan.c:7124 [inline]
 kswapd+0x147c/0x2800 mm/vmscan.c:7389
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The root cause is deadlock among four locks as below:

kswapd
- fs_reclaim				--- Lock A
 - shrink_one
  - evict
   - f2fs_evict_inode
    - sb_start_intwrite			--- Lock B

- iput
 - evict
  - f2fs_evict_inode
   - sb_start_intwrite			--- Lock B
   - f2fs_truncate
    - f2fs_truncate_blocks
     - f2fs_do_truncate_blocks
      - f2fs_lock_op			--- Lock C

ioctl
- f2fs_ioc_commit_atomic_write
 - f2fs_lock_op				--- Lock C
  - __f2fs_commit_atomic_write
   - __replace_atomic_write_block
    - f2fs_get_dnode_of_data
     - __get_node_folio
      - f2fs_check_nid_range
       - f2fs_handle_error
        - f2fs_record_errors
         - f2fs_down_write		--- Lock D

open
- do_open
 - do_truncate
  - security_inode_need_killpriv
   - f2fs_getxattr
    - lookup_all_xattrs
     - f2fs_handle_error
      - f2fs_record_errors
       - f2fs_down_write		--- Lock D
        - f2fs_commit_super
         - read_mapping_folio
          - filemap_alloc_folio_noprof
           - prepare_alloc_pages
            - fs_reclaim_acquire	--- Lock A

In order to avoid such deadlock, we need to avoid grabbing sb_lock in
f2fs_handle_error(), so, let's use asynchronous method instead:
- remove f2fs_handle_error() implementation
- rename f2fs_handle_error_async() to f2fs_handle_error()
- spread f2fs_handle_error()

Fixes: 95fa90c ("f2fs: support recording errors into superblock")
Cc: [email protected]
Reported-by: [email protected]
Closes: https://lore.kernel.org/linux-f2fs-devel/[email protected]
Reported-by: Jiaming Zhang <[email protected]>
Closes: https://lore.kernel.org/lkml/CANypQFa-Gy9sD-N35o3PC+FystOWkNuN8pv6S75HLT0ga-Tzgw@mail.gmail.com
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
simonliebold pushed a commit that referenced this pull request Dec 12, 2025
Aishwarya reports that warnings are sometimes seen when running the
ftrace kselftests, e.g.

| WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0
| Modules linked in:
| CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x4a0/0x4c0
| lr : arch_stack_walk+0x248/0x4c0
| sp : ffff800083643d20
| x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928
| x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80
| x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0
| x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000
| x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000
| x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001
| x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0
| x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000
| x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690
| x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8
| Call trace:
|  arch_stack_walk+0x4a0/0x4c0 (P)
|  arch_stack_walk+0x248/0x4c0 (L)
|  profile_pc+0x44/0x80
|  profile_tick+0x50/0x80 (F)
|  tick_nohz_handler+0xcc/0x160 (F)
|  __hrtimer_run_queues+0x2ac/0x340 (F)
|  hrtimer_interrupt+0xf4/0x268 (F)
|  arch_timer_handler_virt+0x34/0x60 (F)
|  handle_percpu_devid_irq+0x88/0x220 (F)
|  generic_handle_domain_irq+0x34/0x60 (F)
|  gic_handle_irq+0x54/0x140 (F)
|  call_on_irq_stack+0x24/0x58 (F)
|  do_interrupt_handler+0x88/0x98
|  el1_interrupt+0x34/0x68 (F)
|  el1h_64_irq_handler+0x18/0x28
|  el1h_64_irq+0x6c/0x70
|  queued_spin_lock_slowpath+0x78/0x460 (P)

The warning in question is:

  WARN_ON_ONCE(state->common.pc == orig_pc))

... in kunwind_recover_return_address(), which is triggered when
return_to_handler() is encountered in the trace, but
ftrace_graph_ret_addr() cannot find a corresponding original return
address on the fgraph return stack.

This happens because the stacktrace code encounters an exception
boundary where the LR was not live at the time of the exception, but the
LR happens to contain return_to_handler(); either because the task
recently returned there, or due to unfortunate usage of the LR at a
scratch register. In such cases attempts to recover the return address
via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE()
above and aborting the unwind (hence the stacktrace terminating after
reporting the PC at the time of the exception).

Handling unreliable LR values in these cases is likely to require some
larger rework, so for the moment avoid this problem by restoring the old
behaviour of skipping the LR at exception boundaries, which the
stacktrace code did prior to commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

This commit is effectively a partial revert, keeping the structures and
logic to explicitly identify exception boundaries while still skipping
reporting of the LR. The logic to explicitly identify exception
boundaries is still useful for general robustness and as a building
block for future support for RELIABLE_STACKTRACE.

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Signed-off-by: Mark Rutland <[email protected]>
Reported-by: Aishwarya TCV <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
simonliebold pushed a commit that referenced this pull request Dec 12, 2025
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.

To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.

Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:

  42a20f8 ("sched: Add wrapper for get_wchan() to keep task blocked")

... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:

  f8a00ce ("proc: restrict kernel stack dumps to root")

... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):

| for n in $(seq 1 10); do
|     while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
|  arch_stack_walk+0x1c8/0x370 (P)
|  stack_trace_save_tsk+0x8c/0x108
|  proc_pid_stack+0xb0/0x134
|  proc_single_show+0x60/0x120
|  seq_read_iter+0x104/0x438
|  seq_read+0xf8/0x140
|  vfs_read+0xc4/0x31c
|  ksys_read+0x70/0x108
|  __arm64_sys_read+0x1c/0x28
|  invoke_syscall+0x48/0x104
|  el0_svc_common.constprop.0+0x40/0xe0
|  do_el0_svc+0x1c/0x28
|  el0_svc+0x30/0xcc
|  el0t_64_sync_handler+0x10c/0x138
|  el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---

Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.

The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:

  9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <[email protected]>
Reported-by: Kent Overstreet <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
gyokhan-aws pushed a commit that referenced this pull request Dec 12, 2025
Aishwarya reports that warnings are sometimes seen when running the
ftrace kselftests, e.g.

| WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0
| Modules linked in:
| CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x4a0/0x4c0
| lr : arch_stack_walk+0x248/0x4c0
| sp : ffff800083643d20
| x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928
| x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80
| x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0
| x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000
| x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000
| x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001
| x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0
| x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000
| x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690
| x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8
| Call trace:
|  arch_stack_walk+0x4a0/0x4c0 (P)
|  arch_stack_walk+0x248/0x4c0 (L)
|  profile_pc+0x44/0x80
|  profile_tick+0x50/0x80 (F)
|  tick_nohz_handler+0xcc/0x160 (F)
|  __hrtimer_run_queues+0x2ac/0x340 (F)
|  hrtimer_interrupt+0xf4/0x268 (F)
|  arch_timer_handler_virt+0x34/0x60 (F)
|  handle_percpu_devid_irq+0x88/0x220 (F)
|  generic_handle_domain_irq+0x34/0x60 (F)
|  gic_handle_irq+0x54/0x140 (F)
|  call_on_irq_stack+0x24/0x58 (F)
|  do_interrupt_handler+0x88/0x98
|  el1_interrupt+0x34/0x68 (F)
|  el1h_64_irq_handler+0x18/0x28
|  el1h_64_irq+0x6c/0x70
|  queued_spin_lock_slowpath+0x78/0x460 (P)

The warning in question is:

  WARN_ON_ONCE(state->common.pc == orig_pc))

... in kunwind_recover_return_address(), which is triggered when
return_to_handler() is encountered in the trace, but
ftrace_graph_ret_addr() cannot find a corresponding original return
address on the fgraph return stack.

This happens because the stacktrace code encounters an exception
boundary where the LR was not live at the time of the exception, but the
LR happens to contain return_to_handler(); either because the task
recently returned there, or due to unfortunate usage of the LR at a
scratch register. In such cases attempts to recover the return address
via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE()
above and aborting the unwind (hence the stacktrace terminating after
reporting the PC at the time of the exception).

Handling unreliable LR values in these cases is likely to require some
larger rework, so for the moment avoid this problem by restoring the old
behaviour of skipping the LR at exception boundaries, which the
stacktrace code did prior to commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

This commit is effectively a partial revert, keeping the structures and
logic to explicitly identify exception boundaries while still skipping
reporting of the LR. The logic to explicitly identify exception
boundaries is still useful for general robustness and as a building
block for future support for RELIABLE_STACKTRACE.

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Signed-off-by: Mark Rutland <[email protected]>
Reported-by: Aishwarya TCV <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
gyokhan-aws pushed a commit that referenced this pull request Dec 12, 2025
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.

To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.

Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:

  42a20f8 ("sched: Add wrapper for get_wchan() to keep task blocked")

... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:

  f8a00ce ("proc: restrict kernel stack dumps to root")

... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):

| for n in $(seq 1 10); do
|     while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
|  arch_stack_walk+0x1c8/0x370 (P)
|  stack_trace_save_tsk+0x8c/0x108
|  proc_pid_stack+0xb0/0x134
|  proc_single_show+0x60/0x120
|  seq_read_iter+0x104/0x438
|  seq_read+0xf8/0x140
|  vfs_read+0xc4/0x31c
|  ksys_read+0x70/0x108
|  __arm64_sys_read+0x1c/0x28
|  invoke_syscall+0x48/0x104
|  el0_svc_common.constprop.0+0x40/0xe0
|  do_el0_svc+0x1c/0x28
|  el0_svc+0x30/0xcc
|  el0t_64_sync_handler+0x10c/0x138
|  el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---

Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.

The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:

  9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <[email protected]>
Reported-by: Kent Overstreet <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 16, 2025
Aishwarya reports that warnings are sometimes seen when running the
ftrace kselftests, e.g.

| WARNING: CPU: 5 PID: 2066 at arch/arm64/kernel/stacktrace.c:141 arch_stack_walk+0x4a0/0x4c0
| Modules linked in:
| CPU: 5 UID: 0 PID: 2066 Comm: ftracetest Not tainted 6.13.0-rc2 #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x4a0/0x4c0
| lr : arch_stack_walk+0x248/0x4c0
| sp : ffff800083643d20
| x29: ffff800083643dd0 x28: ffff00007b891400 x27: ffff00007b891928
| x26: 0000000000000001 x25: 00000000000000c0 x24: ffff800082f39d80
| x23: ffff80008003ee8c x22: ffff80008004baa8 x21: ffff8000800533e0
| x20: ffff800083643e10 x19: ffff80008003eec8 x18: 0000000000000000
| x17: 0000000000000000 x16: ffff800083640000 x15: 0000000000000000
| x14: 02a37a802bbb8a92 x13: 00000000000001a9 x12: 0000000000000001
| x11: ffff800082ffad60 x10: ffff800083643d20 x9 : ffff80008003eed0
| x8 : ffff80008004baa8 x7 : ffff800086f2be80 x6 : ffff0000057cf000
| x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800086f2b690
| x2 : ffff80008004baa8 x1 : ffff80008004baa8 x0 : ffff80008004baa8
| Call trace:
|  arch_stack_walk+0x4a0/0x4c0 (P)
|  arch_stack_walk+0x248/0x4c0 (L)
|  profile_pc+0x44/0x80
|  profile_tick+0x50/0x80 (F)
|  tick_nohz_handler+0xcc/0x160 (F)
|  __hrtimer_run_queues+0x2ac/0x340 (F)
|  hrtimer_interrupt+0xf4/0x268 (F)
|  arch_timer_handler_virt+0x34/0x60 (F)
|  handle_percpu_devid_irq+0x88/0x220 (F)
|  generic_handle_domain_irq+0x34/0x60 (F)
|  gic_handle_irq+0x54/0x140 (F)
|  call_on_irq_stack+0x24/0x58 (F)
|  do_interrupt_handler+0x88/0x98
|  el1_interrupt+0x34/0x68 (F)
|  el1h_64_irq_handler+0x18/0x28
|  el1h_64_irq+0x6c/0x70
|  queued_spin_lock_slowpath+0x78/0x460 (P)

The warning in question is:

  WARN_ON_ONCE(state->common.pc == orig_pc))

... in kunwind_recover_return_address(), which is triggered when
return_to_handler() is encountered in the trace, but
ftrace_graph_ret_addr() cannot find a corresponding original return
address on the fgraph return stack.

This happens because the stacktrace code encounters an exception
boundary where the LR was not live at the time of the exception, but the
LR happens to contain return_to_handler(); either because the task
recently returned there, or due to unfortunate usage of the LR at a
scratch register. In such cases attempts to recover the return address
via ftrace_graph_ret_addr() may fail, triggering the WARN_ON_ONCE()
above and aborting the unwind (hence the stacktrace terminating after
reporting the PC at the time of the exception).

Handling unreliable LR values in these cases is likely to require some
larger rework, so for the moment avoid this problem by restoring the old
behaviour of skipping the LR at exception boundaries, which the
stacktrace code did prior to commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

This commit is effectively a partial revert, keeping the structures and
logic to explicitly identify exception boundaries while still skipping
reporting of the LR. The logic to explicitly identify exception
boundaries is still useful for general robustness and as a building
block for future support for RELIABLE_STACKTRACE.

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Signed-off-by: Mark Rutland <[email protected]>
Reported-by: Aishwarya TCV <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 16, 2025
The arm64 stacktrace code has a few error conditions where a
WARN_ON_ONCE() is triggered before the stacktrace is terminated and an
error is returned to the caller. The conditions shouldn't be triggered
when unwinding the current task, but it is possible to trigger these
when unwinding another task which is not blocked, as the stack of that
task is concurrently modified. Kent reports that these warnings can be
triggered while running filesystem tests on bcachefs, which calls the
stacktrace code directly.

To produce a meaningful stacktrace of another task, the task in question
should be blocked, but the stacktrace code is expected to be robust to
cases where it is not blocked. Note that this is purely about not
unuduly scaring the user and/or crashing the kernel; stacktraces in such
cases are meaningless and may leak kernel secrets from the stack of the
task being unwound.

Ideally we'd pin the task in a blocked state during the unwind, as we do
for /proc/${PID}/wchan since commit:

  42a20f8 ("sched: Add wrapper for get_wchan() to keep task blocked")

... but a bunch of places don't do that, notably /proc/${PID}/stack,
where we don't pin the task in a blocked state, but do restrict the
output to privileged users since commit:

  f8a00ce ("proc: restrict kernel stack dumps to root")

... and so it's possible to trigger these warnings accidentally, e.g. by
reading /proc/*/stack (as root):

| for n in $(seq 1 10); do
|     while true; do cat /proc/*/stack > /dev/null 2>&1; done &
| done
| ------------[ cut here ]------------
| WARNING: CPU: 3 PID: 166 at arch/arm64/kernel/stacktrace.c:207 arch_stack_walk+0x1c8/0x370
| Modules linked in:
| CPU: 3 UID: 0 PID: 166 Comm: cat Not tainted 6.13.0-rc2-00003-g3dafa7a7925d #2
| Hardware name: linux,dummy-virt (DT)
| pstate: 81400005 (Nzcv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
| pc : arch_stack_walk+0x1c8/0x370
| lr : arch_stack_walk+0x1b0/0x370
| sp : ffff800080773890
| x29: ffff800080773930 x28: fff0000005c44500 x27: fff00000058fa038
| x26: 000000007ffff000 x25: 0000000000000000 x24: 0000000000000000
| x23: ffffa35a8d9600ec x22: 0000000000000000 x21: fff00000043a33c0
| x20: ffff800080773970 x19: ffffa35a8d960168 x18: 0000000000000000
| x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000
| x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
| x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
| x8 : ffff8000807738e0 x7 : ffff8000806e3800 x6 : ffff8000806e3818
| x5 : ffff800080773920 x4 : ffff8000806e4000 x3 : ffff8000807738e0
| x2 : 0000000000000018 x1 : ffff8000806e3800 x0 : 0000000000000000
| Call trace:
|  arch_stack_walk+0x1c8/0x370 (P)
|  stack_trace_save_tsk+0x8c/0x108
|  proc_pid_stack+0xb0/0x134
|  proc_single_show+0x60/0x120
|  seq_read_iter+0x104/0x438
|  seq_read+0xf8/0x140
|  vfs_read+0xc4/0x31c
|  ksys_read+0x70/0x108
|  __arm64_sys_read+0x1c/0x28
|  invoke_syscall+0x48/0x104
|  el0_svc_common.constprop.0+0x40/0xe0
|  do_el0_svc+0x1c/0x28
|  el0_svc+0x30/0xcc
|  el0t_64_sync_handler+0x10c/0x138
|  el0t_64_sync+0x198/0x19c
| ---[ end trace 0000000000000000 ]---

Fix this by only warning when unwinding the current task. When unwinding
another task the error conditions will be handled by returning an error
without producing a warning.

The two warnings in kunwind_next_frame_record_meta() were added recently
as part of commit:

  c2c6b27 ("arm64: stacktrace: unwind exception boundaries")

The warning when recovering the fgraph return address has changed form
many times, but was originally introduced back in commit:

  9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")

Fixes: c2c6b27 ("arm64: stacktrace: unwind exception boundaries")
Fixes: 9f41631 ("arm64: fix unwind_frame() for filtered out fn for function graph tracing")
Signed-off-by: Mark Rutland <[email protected]>
Reported-by: Kent Overstreet <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
surajjs95 pushed a commit that referenced this pull request Dec 17, 2025
commit 96611c2 upstream.

As reported by syzbot and experienced by Pavel, using cpus_read_lock()
in wake_up_all_idle_cpus() generates lock inversion (against mmap_sem
and possibly others).

Instead, shrink the preempt disable region by iterating all CPUs and
checking the online status for each individual CPU while having
preemption disabled.

Fixes: 8850cb6 ("sched: Simplify wake_up_*idle*()")
Reported-by: [email protected]
Reported-by: Pavel Machek <[email protected]>
Reported-by: Qian Cai <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Qian Cai <[email protected]>
(cherry picked from commit 96611c2)
paniakin-aws pushed a commit that referenced this pull request Dec 18, 2025
[ Upstream commit 163e5f2 ]

When using perf record with the `--overwrite` option, a segmentation fault
occurs if an event fails to open. For example:

  perf record -e cycles-ct -F 1000 -a --overwrite
  Error:
  cycles-ct:H: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
  perf: Segmentation fault
      #0 0x6466b6 in dump_stack debug.c:366
      #1 0x646729 in sighandler_dump_stack debug.c:378
      #2 0x453fd1 in sigsegv_handler builtin-record.c:722
      #3 0x7f8454e65090 in __restore_rt libc-2.32.so[54090]
      #4 0x6c5671 in __perf_event__synthesize_id_index synthetic-events.c:1862
      #5 0x6c5ac0 in perf_event__synthesize_id_index synthetic-events.c:1943
      gregkh#6 0x458090 in record__synthesize builtin-record.c:2075
      gregkh#7 0x45a85a in __cmd_record builtin-record.c:2888
      gregkh#8 0x45deb6 in cmd_record builtin-record.c:4374
      gregkh#9 0x4e5e33 in run_builtin perf.c:349
      gregkh#10 0x4e60bf in handle_internal_command perf.c:401
      gregkh#11 0x4e6215 in run_argv perf.c:448
      gregkh#12 0x4e653a in main perf.c:555
      gregkh#13 0x7f8454e4fa72 in __libc_start_main libc-2.32.so[3ea72]
      gregkh#14 0x43a3ee in _start ??:0

The --overwrite option implies --tail-synthesize, which collects non-sample
events reflecting the system status when recording finishes. However, when
evsel opening fails (e.g., unsupported event 'cycles-ct'), session->evlist
is not initialized and remains NULL. The code unconditionally calls
record__synthesize() in the error path, which iterates through the NULL
evlist pointer and causes a segfault.

To fix it, move the record__synthesize() call inside the error check block, so
it's only called when there was no error during recording, ensuring that evlist
is properly initialized.

Fixes: 4ea648a ("perf record: Add --tail-synthesize option")
Signed-off-by: Shuai Xue <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 18, 2025
[ Upstream commit a907f3a ]

1. fadvise(fd1, POSIX_FADV_NOREUSE, {0,3});
2. fadvise(fd2, POSIX_FADV_NOREUSE, {1,2});
3. fadvise(fd3, POSIX_FADV_NOREUSE, {3,1});
4. echo 1024 > /sys/fs/f2fs/tuning/reclaim_caches_kb

This gives a way to reclaim file-backed pages by iterating all f2fs mounts until
reclaiming 1MB page cache ranges, registered by #1, #2, and #3.

5. cat /sys/fs/f2fs/tuning/reclaim_caches_kb
-> gives total number of registered file ranges.

Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
Stable-dep-of: e462fc4 ("f2fs: maintain one time GC mode is enabled during whole zoned GC cycle")
Signed-off-by: Sasha Levin <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 18, 2025
[ Upstream commit 163e5f2 ]

When using perf record with the `--overwrite` option, a segmentation fault
occurs if an event fails to open. For example:

  perf record -e cycles-ct -F 1000 -a --overwrite
  Error:
  cycles-ct:H: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
  perf: Segmentation fault
      #0 0x6466b6 in dump_stack debug.c:366
      #1 0x646729 in sighandler_dump_stack debug.c:378
      #2 0x453fd1 in sigsegv_handler builtin-record.c:722
      #3 0x7f8454e65090 in __restore_rt libc-2.32.so[54090]
      #4 0x6c5671 in __perf_event__synthesize_id_index synthetic-events.c:1862
      #5 0x6c5ac0 in perf_event__synthesize_id_index synthetic-events.c:1943
      gregkh#6 0x458090 in record__synthesize builtin-record.c:2075
      gregkh#7 0x45a85a in __cmd_record builtin-record.c:2888
      gregkh#8 0x45deb6 in cmd_record builtin-record.c:4374
      gregkh#9 0x4e5e33 in run_builtin perf.c:349
      gregkh#10 0x4e60bf in handle_internal_command perf.c:401
      gregkh#11 0x4e6215 in run_argv perf.c:448
      gregkh#12 0x4e653a in main perf.c:555
      gregkh#13 0x7f8454e4fa72 in __libc_start_main libc-2.32.so[3ea72]
      gregkh#14 0x43a3ee in _start ??:0

The --overwrite option implies --tail-synthesize, which collects non-sample
events reflecting the system status when recording finishes. However, when
evsel opening fails (e.g., unsupported event 'cycles-ct'), session->evlist
is not initialized and remains NULL. The code unconditionally calls
record__synthesize() in the error path, which iterates through the NULL
evlist pointer and causes a segfault.

To fix it, move the record__synthesize() call inside the error check block, so
it's only called when there was no error during recording, ensuring that evlist
is properly initialized.

Fixes: 4ea648a ("perf record: Add --tail-synthesize option")
Signed-off-by: Shuai Xue <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
paniakin-aws pushed a commit that referenced this pull request Dec 18, 2025
[ Upstream commit 163e5f2 ]

When using perf record with the `--overwrite` option, a segmentation fault
occurs if an event fails to open. For example:

  perf record -e cycles-ct -F 1000 -a --overwrite
  Error:
  cycles-ct:H: PMU Hardware doesn't support sampling/overflow-interrupts. Try 'perf stat'
  perf: Segmentation fault
      #0 0x6466b6 in dump_stack debug.c:366
      #1 0x646729 in sighandler_dump_stack debug.c:378
      #2 0x453fd1 in sigsegv_handler builtin-record.c:722
      #3 0x7f8454e65090 in __restore_rt libc-2.32.so[54090]
      #4 0x6c5671 in __perf_event__synthesize_id_index synthetic-events.c:1862
      #5 0x6c5ac0 in perf_event__synthesize_id_index synthetic-events.c:1943
      gregkh#6 0x458090 in record__synthesize builtin-record.c:2075
      gregkh#7 0x45a85a in __cmd_record builtin-record.c:2888
      gregkh#8 0x45deb6 in cmd_record builtin-record.c:4374
      gregkh#9 0x4e5e33 in run_builtin perf.c:349
      gregkh#10 0x4e60bf in handle_internal_command perf.c:401
      gregkh#11 0x4e6215 in run_argv perf.c:448
      gregkh#12 0x4e653a in main perf.c:555
      gregkh#13 0x7f8454e4fa72 in __libc_start_main libc-2.32.so[3ea72]
      gregkh#14 0x43a3ee in _start ??:0

The --overwrite option implies --tail-synthesize, which collects non-sample
events reflecting the system status when recording finishes. However, when
evsel opening fails (e.g., unsupported event 'cycles-ct'), session->evlist
is not initialized and remains NULL. The code unconditionally calls
record__synthesize() in the error path, which iterates through the NULL
evlist pointer and causes a segfault.

To fix it, move the record__synthesize() call inside the error check block, so
it's only called when there was no error during recording, ensuring that evlist
is properly initialized.

Fixes: 4ea648a ("perf record: Add --tail-synthesize option")
Signed-off-by: Shuai Xue <[email protected]>
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
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