INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 12976 Comm: kworker/0:42 Not tainted 5.12.0-rc4-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:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 assign_lock_key kernel/locking/lockdep.c:935 [inline] register_lock_class+0x106b/0x1170 kernel/locking/lockdep.c:1247 __lock_acquire+0x106/0x54c0 kernel/locking/lockdep.c:4779 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5475 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x40/0x120 net/core/sock.c:3063 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 2993d067 P4D 2993d067 PUD 619d2067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 12976 Comm: kworker/0:42 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc9001879fb70 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff888061296000 RCX: 0000000000000000 RDX: 1ffff1100c252c8c RSI: ffffffff87fcb31b RDI: ffff888061296000 RBP: 0000000000000000 R08: ffffffff8a7c11c0 R09: ffffffff87fcaf86 R10: 0000000000000004 R11: 0000000000000005 R12: 000000000000006f R13: ffff88801fd22000 R14: ffff88801fd22020 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000002993c000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: l2cap_sock_teardown_cb+0x496/0x660 net/bluetooth/l2cap_sock.c:1545 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Modules linked in: CR2: 0000000000000000 ---[ end trace 15d664eabaf00885 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc9001879fb70 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff888061296000 RCX: 0000000000000000 RDX: 1ffff1100c252c8c RSI: ffffffff87fcb31b RDI: ffff888061296000 RBP: 0000000000000000 R08: ffffffff8a7c11c0 R09: ffffffff87fcaf86 R10: 0000000000000004 R11: 0000000000000005 R12: 000000000000006f R13: ffff88801fd22000 R14: ffff88801fd22020 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 000000002993c000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400