general protection fault in l2cap_chan_timeout

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7f2c5eb4 Linux 4.14.191
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14e1da42900000
kernel config: https://syzkaller.appspot.com/x/.config?x=881f1aee9620bf9f
dashboard link: https://syzkaller.appspot.com/bug?extid=fc88c1331f789387ff53
compiler: gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fc88c1...@syzkaller.appspotmail.com

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 3347 Comm: kworker/0:2 Not tainted 4.14.191-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
task: ffff88809b6de400 task.stack: ffff88809b698000
RIP: 0010:trace_event_get_offsets_lock_acquire include/trace/events/lock.h:13 [inline]
RIP: 0010:perf_trace_lock_acquire+0xb2/0x510 include/trace/events/lock.h:13
RSP: 0018:ffff88809b69faa0 EFLAGS: 00010002
RAX: dffffc0000000000 RBX: ffff88809b787428 RCX: 0000000000000000
RDX: 0000000000000057 RSI: 00000000000002a0 RDI: ffffffff87d6f2c0
RBP: ffff88809b69fb68 R08: 0000000000000000 R09: 0000000000000001
R10: 000000000011dff3 R11: ffff88809b6de400 R12: ffffffff87d6f240
R13: 00000000000002a0 R14: 0000000000000000 R15: ffff88809b69fb40
FS: 0000000000000000(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa51edacdb8 CR3: 000000005b8ec000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x2b8/0x3f0 kernel/locking/lockdep.c:3997
__mutex_lock_common kernel/locking/mutex.c:756 [inline]
__mutex_lock+0xc4/0x1310 kernel/locking/mutex.c:893
l2cap_chan_timeout+0x4a/0x1e0 net/bluetooth/l2cap_core.c:416
process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Code: 00 0f 85 45 03 00 00 49 8d 45 18 4d 8b b4 24 80 00 00 00 48 89 c2 48 89 85 60 ff ff ff 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 2b 03 00 00 49 8b 7d 18 48 c7 c0 60 43 aa 86
RIP: trace_event_get_offsets_lock_acquire include/trace/events/lock.h:13 [inline] RSP: ffff88809b69faa0
RIP: perf_trace_lock_acquire+0xb2/0x510 include/trace/events/lock.h:13 RSP: ffff88809b69faa0
---[ end trace 07c6753d6be77e44 ]---


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.