This is a note to let you know that I've just added the patch titled
netdevsim: avoid potential loop in nsim_dev_trap_report_work()
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netdevsim-avoid-potential-loop-in-nsim_dev_trap_repo.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7e6e22ed83f461df7df03ba72924a4c2a43d21f5
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Thu Feb 1 17:53:24 2024 +0000
netdevsim: avoid potential loop in nsim_dev_trap_report_work()
[ Upstream commit ba5e1272142d051dcc57ca1d3225ad8a089f9858 ]
Many syzbot reports include the following trace [1]
If nsim_dev_trap_report_work() can not grab the mutex,
it should rearm itself at least one jiffie later.
[1]
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 32383 Comm: kworker/0:2 Not tainted 6.8.0-rc2-syzkaller-00031-g861c0981648f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:89 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x101/0x190 mm/kasan/generic.c:189
Code: 07 49 39 d1 75 0a 45 3a 11 b8 01 00 00 00 7c 0b 44 89 c2 e8 21 ed ff ff 83 f0 01 5b 5d 41 5c c3 48 85 d2 74 4f 48 01 ea eb 09 <48> 83 c0 01 48 39 d0 74 41 80 38 00 74 f2 eb b6 41 bc 08 00 00 00
RSP: 0018:ffffc90012dcf998 EFLAGS: 00000046
RAX: fffffbfff258af1e RBX: fffffbfff258af1f RCX: ffffffff8168eda3
RDX: fffffbfff258af1f RSI: 0000000000000004 RDI: ffffffff92c578f0
RBP: fffffbfff258af1e R08: 0000000000000000 R09: fffffbfff258af1e
R10: ffffffff92c578f3 R11: ffffffff8acbcbc0 R12: 0000000000000002
R13: ffff88806db38400 R14: 1ffff920025b9f42 R15: ffffffff92c578e8
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c00994e078 CR3: 000000002c250000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
instrument_atomic_read include/linux/instrumented.h:68 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline]
debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline]
do_raw_spin_unlock+0x53/0x230 kernel/locking/spinlock_debug.c:141
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
_raw_spin_unlock_irqrestore+0x22/0x70 kernel/locking/spinlock.c:194
debug_object_activate+0x349/0x540 lib/debugobjects.c:726
debug_work_activate kernel/workqueue.c:578 [inline]
insert_work+0x30/0x230 kernel/workqueue.c:1650
__queue_work+0x62e/0x11d0 kernel/workqueue.c:1802
__queue_delayed_work+0x1bf/0x270 kernel/workqueue.c:1953
queue_delayed_work_on+0x106/0x130 kernel/workqueue.c:1989
queue_delayed_work include/linux/workqueue.h:563 [inline]
schedule_delayed_work include/linux/workqueue.h:677 [inline]
nsim_dev_trap_report_work+0x9c0/0xc80 drivers/net/netdevsim/dev.c:842
process_one_work+0x886/0x15d0 kernel/workqueue.c:2633
process_scheduled_works kernel/workqueue.c:2706 [inline]
worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787
kthread+0x2c6/0x3a0 kernel/kthread.c:388
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
Fixes: 012ec02ae441 ("netdevsim: convert driver to use unlocked devlink API during init/fini")
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Jiri Pirko <jiri@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240201175324.3752746-1-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index c3fbdd6b68ba..f3fa4bd12116 100644
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -835,14 +835,14 @@ static void nsim_dev_trap_report_work(struct work_struct *work)
trap_report_dw.work);
nsim_dev = nsim_trap_data->nsim_dev;
- /* For each running port and enabled packet trap, generate a UDP
- * packet with a random 5-tuple and report it.
- */
if (!devl_trylock(priv_to_devlink(nsim_dev))) {
- schedule_delayed_work(&nsim_dev->trap_data->trap_report_dw, 0);
+ schedule_delayed_work(&nsim_dev->trap_data->trap_report_dw, 1);
return;
}
+ /* For each running port and enabled packet trap, generate a UDP
+ * packet with a random 5-tuple and report it.
+ */
list_for_each_entry(nsim_dev_port, &nsim_dev->port_list, list) {
if (!netif_running(nsim_dev_port->ns->netdev))
continue;
