tun: limit printing rate when illegal packet received by tun dev

Lei Chen · gregkh · commit 68459b8e3ee5 · 2024-05-02T16:17:09.000+02:00
[ Upstream commit f8bbc07 ] vhost_worker will call tun call backs to receive packets. If too many illegal packets arrives, tun_do_read will keep dumping packet contents. When console is enabled, it will costs much more cpu time to dump packet and soft lockup will be detected. net_ratelimit mechanism can be used to limit the dumping rate. PID: 33036 TASK: ffff949da6f20000 CPU: 23 COMMAND: "vhost-32980" #0 [fffffe00003fce50] crash_nmi_callback at ffffffff89249253 #1 [fffffe00003fce58] nmi_handle at ffffffff89225fa3 #2 [fffffe00003fceb0] default_do_nmi at ffffffff8922642e #3 [fffffe00003fced0] do_nmi at ffffffff8922660d #4 [fffffe00003fcef0] end_repeat_nmi at ffffffff89c01663 [exception RIP: io_serial_in+20] RIP: ffffffff89792594 RSP: ffffa655314979e8 RFLAGS: 00000002 RAX: ffffffff89792500 RBX: ffffffff8af428a0 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000005 RDI: ffffffff8af428a0 RBP: 0000000000002710 R8: 0000000000000004 R9: 000000000000000f R10: 0000000000000000 R11: ffffffff8acbf64f R12: 0000000000000020 R13: ffffffff8acbf698 R14: 0000000000000058 R15: 0000000000000000 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #5 [ffffa655314979e8] io_serial_in at ffffffff89792594 gregkh#6 [ffffa655314979e8] wait_for_xmitr at ffffffff89793470 gregkh#7 [ffffa65531497a08] serial8250_console_putchar at ffffffff897934f6 gregkh#8 [ffffa65531497a20] uart_console_write at ffffffff8978b605 gregkh#9 [ffffa65531497a48] serial8250_console_write at ffffffff89796558 gregkh#10 [ffffa65531497ac8] console_unlock at ffffffff89316124 gregkh#11 [ffffa65531497b10] vprintk_emit at ffffffff89317c07 gregkh#12 [ffffa65531497b68] printk at ffffffff89318306 gregkh#13 [ffffa65531497bc8] print_hex_dump at ffffffff89650765 gregkh#14 [ffffa65531497ca8] tun_do_read at ffffffffc0b06c27 [tun] gregkh#15 [ffffa65531497d38] tun_recvmsg at ffffffffc0b06e34 [tun] gregkh#16 [ffffa65531497d68] handle_rx at ffffffffc0c5d682 [vhost_net] gregkh#17 [ffffa65531497ed0] vhost_worker at ffffffffc0c644dc [vhost] gregkh#18 [ffffa65531497f10] kthread at ffffffff892d2e72 gregkh#19 [ffffa65531497f50] ret_from_fork at ffffffff89c0022f Fixes: ef3db4a ("tun: avoid BUG, dump packet on GSO errors") Signed-off-by: Lei Chen <lei.chen@smartx.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/20240415020247.2207781-1-lei.chen@smartx.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
@@ -2168,14 +2168,16 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 					    tun_is_little_endian(tun), true,
 					    vlan_hlen)) {
 			struct skb_shared_info *sinfo = skb_shinfo(skb);
-			pr_err("unexpected GSO type: "
-			       "0x%x, gso_size %d, hdr_len %d\n",
-			       sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
-			       tun16_to_cpu(tun, gso.hdr_len));
-			print_hex_dump(KERN_ERR, "tun: ",
-				       DUMP_PREFIX_NONE,
-				       16, 1, skb->head,
-				       min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
+
+			if (net_ratelimit()) {
+				netdev_err(tun->dev, "unexpected GSO type: 0x%x, gso_size %d, hdr_len %d\n",
+					   sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
+					   tun16_to_cpu(tun, gso.hdr_len));
+				print_hex_dump(KERN_ERR, "tun: ",
+					       DUMP_PREFIX_NONE,
+					       16, 1, skb->head,
+					       min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
+			}
 			WARN_ON_ONCE(1);
 			return -EINVAL;
 		}
