syzbot

Bluetooth: hci6 sending frame failed (-49)
Bluetooth: hci6 command 0x1001 tx timeout
Bluetooth: hci6 sending frame failed (-49)
DEBUG_LOCKS_WARN_ON(class_idx > MAX_LOCKDEP_KEYS)
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WARNING: CPU: 1 PID: 23 at kernel/locking/lockdep.c:3468 __lock_acquire.cold+0x7c0/0x97c kernel/locking/lockdep.c:3468
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 23 Comm: kworker/1:1 Not tainted 4.14.231-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:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 __warn.cold+0x20/0x44 kernel/panic.c:547
 report_bug+0x208/0x250 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:__lock_acquire.cold+0x7c0/0x97c kernel/locking/lockdep.c:3468
RSP: 0018:ffff8880b56079a8 EFLAGS: 00010086
RAX: 0000000000000031 RBX: 0000000000000007 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffed1016ac0f2b
RBP: ffff8880b55eef4a R08: 0000000000000031 R09: 0000000000000000
R10: 0000000000000001 R11: 000000c5765d65ba R12: ffff8880b55eef40
R13: 0000000000000000 R14: 00000000ab428751 R15: ffffffff8bebbd40
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:176
 spin_lock_bh include/linux/spinlock.h:322 [inline]
 lock_sock_nested+0x39/0x100 net/core/sock.c:2788
 l2cap_sock_teardown_cb+0x93/0x650 net/bluetooth/l2cap_sock.c:1341
 l2cap_chan_del+0xaf/0x950 net/bluetooth/l2cap_core.c:599
 l2cap_chan_close+0x103/0x870 net/bluetooth/l2cap_core.c:757
 l2cap_chan_timeout+0x143/0x2a0 net/bluetooth/l2cap_core.c:430
 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
Kernel Offset: disabled
Rebooting in 86400 seconds..