INFO: trying to register non-static key in l2cap_chan_del

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 31acccdc Linux 4.19.157
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=17bb85e6500000
kernel config: https://syzkaller.appspot.com/x/.config?x=1f604e014c43fe09
dashboard link: https://syzkaller.appspot.com/bug?extid=206885707c6c6d3e137c
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+206885...@syzkaller.appspotmail.com

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 13895 Comm: kworker/0:1 Not tainted 4.19.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
assign_lock_key kernel/locking/lockdep.c:727 [inline]
register_lock_class+0xe76/0x11c0 kernel/locking/lockdep.c:753
__lock_acquire+0x17d/0x3ff0 kernel/locking/lockdep.c:3303
lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:334 [inline]
lock_sock_nested+0x3b/0x110 net/core/sock.c:2864
l2cap_sock_teardown_cb+0xa0/0x6d0 net/bluetooth/l2cap_sock.c:1340
l2cap_chan_del+0xbc/0xa50 net/bluetooth/l2cap_core.c:599
l2cap_chan_close+0x1b5/0x950 net/bluetooth/l2cap_core.c:757
l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:430
process_one_work+0x864/0x1570 kernel/workqueue.c:2155
worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD af11c067 P4D af11c067 PUD 579a2067 PMD 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 13895 Comm: kworker/0:1 Not tainted 4.19.157-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
RIP: 0010: (null)
Code: Bad RIP value.
RSP: 0018:ffff888030a8fbb0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff876246f5
RDX: 1ffff1100ae206e9 RSI: ffffffff87624ae4 RDI: ffff888057103340
RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000009
R10: 0000000000000001 R11: ffffffff8c65b01b R12: ffff888057102adc
R13: ffff888057103340 R14: ffff888057102ac0 R15: 0000000000000005
FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000093459000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
l2cap_sock_teardown_cb+0x4f0/0x6d0 net/bluetooth/l2cap_sock.c:1365
l2cap_chan_del+0xbc/0xa50 net/bluetooth/l2cap_core.c:599
l2cap_chan_close+0x1b5/0x950 net/bluetooth/l2cap_core.c:757
l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:430
process_one_work+0x864/0x1570 kernel/workqueue.c:2155
worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Modules linked in:
CR2: 0000000000000000
---[ end trace 69274ba9deb10d0a ]---
RIP: 0010: (null)
Code: Bad RIP value.
RSP: 0018:ffff888030a8fbb0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff876246f5
RDX: 1ffff1100ae206e9 RSI: ffffffff87624ae4 RDI: ffff888057103340
RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000009
R10: 0000000000000001 R11: ffffffff8c65b01b R12: ffff888057102adc
R13: ffff888057103340 R14: ffff888057102ac0 R15: 0000000000000005
FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000093459000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

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