INFO: trying to register non-static key in l2cap_sock_teardown_cb

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 811218ec Linux 4.19.172
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1387f2f4d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=c1cb1d27398c8808
dashboard link: https://syzkaller.appspot.com/bug?extid=34e50fe1cd107030371e

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+34e50f...@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: 14 Comm: kworker/0:1 Not tainted 4.19.172-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 syzkaller/managers/linux-4-19/kernel/lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef syzkaller/managers/linux-4-19/kernel/lib/dump_stack.c:118
assign_lock_key syzkaller/managers/linux-4-19/kernel/kernel/locking/lockdep.c:727 [inline]
register_lock_class+0xe76/0x11c0 syzkaller/managers/linux-4-19/kernel/kernel/locking/lockdep.c:753
__lock_acquire+0x17d/0x3ff0 syzkaller/managers/linux-4-19/kernel/kernel/locking/lockdep.c:3303
lock_acquire+0x170/0x3c0 syzkaller/managers/linux-4-19/kernel/kernel/locking/lockdep.c:3907
__raw_spin_lock_bh syzkaller/managers/linux-4-19/kernel/./include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 syzkaller/managers/linux-4-19/kernel/kernel/locking/spinlock.c:168
spin_lock_bh syzkaller/managers/linux-4-19/kernel/./include/linux/spinlock.h:334 [inline]
lock_sock_nested+0x3b/0x110 syzkaller/managers/linux-4-19/kernel/net/core/sock.c:2864
l2cap_sock_teardown_cb+0xa0/0x6d0 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_sock.c:1340
l2cap_chan_del+0xbc/0xa50 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_core.c:599
l2cap_chan_close+0x1b5/0x950 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_core.c:757
l2cap_chan_timeout+0x17e/0x2f0 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_core.c:430
process_one_work+0x864/0x1570 syzkaller/managers/linux-4-19/kernel/kernel/workqueue.c:2155
worker_thread+0x64c/0x1130 syzkaller/managers/linux-4-19/kernel/kernel/workqueue.c:2298
kthread+0x33f/0x460 syzkaller/managers/linux-4-19/kernel/kernel/kthread.c:259
ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-19/kernel/arch/x86/entry/entry_64.S:415
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD 0 P4D 0
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 14 Comm: kworker/0:1 Not tainted 4.19.172-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:ffff8880b5aa7bb0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8740dbd5
RDX: 1ffff1100a70dcf1 RSI: ffffffff8740dfc4 RDI: ffff88805386e380
RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000009
R10: 0000000000000001 R11: ffffffff8c65d01b R12: ffff88804eb3529c
R13: ffff88805386e380 R14: ffff88804eb35280 R15: 0000000000000005
FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000000a13ae000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
l2cap_sock_teardown_cb+0x4f0/0x6d0 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_sock.c:1365
l2cap_chan_del+0xbc/0xa50 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_core.c:599
l2cap_chan_close+0x1b5/0x950 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_core.c:757
l2cap_chan_timeout+0x17e/0x2f0 syzkaller/managers/linux-4-19/kernel/net/bluetooth/l2cap_core.c:430
process_one_work+0x864/0x1570 syzkaller/managers/linux-4-19/kernel/kernel/workqueue.c:2155
worker_thread+0x64c/0x1130 syzkaller/managers/linux-4-19/kernel/kernel/workqueue.c:2298
kthread+0x33f/0x460 syzkaller/managers/linux-4-19/kernel/kernel/kthread.c:259
ret_from_fork+0x24/0x30 syzkaller/managers/linux-4-19/kernel/arch/x86/entry/entry_64.S:415
Modules linked in:
CR2: 0000000000000000
---[ end trace 939b420d6addb45d ]---
RIP: 0010: (null)
Code: Bad RIP value.
RSP: 0018:ffff8880b5aa7bb0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8740dbd5
RDX: 1ffff1100a70dcf1 RSI: ffffffff8740dfc4 RDI: ffff88805386e380
RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000009
R10: 0000000000000001 R11: ffffffff8c65d01b R12: ffff88804eb3529c
R13: ffff88805386e380 R14: ffff88804eb35280 R15: 0000000000000005
FS: 0000000000000000(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000000a13ae000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

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