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: 1 PID: 4263 Comm: systemd-udevd Not tainted 4.14.307-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
nbd: must specify an index to disconnect
task: ffff88808953a680 task.stack: ffff8880b4f78000
RIP: 0010:__lock_acquire+0x1cc/0x3f20 kernel/locking/lockdep.c:3369
RSP: 0018:ffff8880b4f7f938 EFLAGS: 00010006
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000110
nbd: nbd5 already in use
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88808953a680 R12: 0000000000000110
R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8bed1e40
FS:  00007facf7adf8c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffe2048918 CR3: 000000009cc6e000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998
 flush_workqueue+0xfa/0x1310 kernel/workqueue.c:2625
 nbd_disconnect_and_put+0xc3/0x140 drivers/block/nbd.c:1919
nbd: must specify at least one socket
 nbd_release+0x123/0x150 drivers/block/nbd.c:1450
 __blkdev_put+0x5aa/0x800 fs/block_dev.c:1803
 blkdev_close+0x86/0xb0 fs/block_dev.c:1875
 __fput+0x25f/0x7a0 fs/file_table.c:210
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164
 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:270 [inline]
 do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x5e/0xd3
RIP: 0033:0x7facf6c25270
RSP: 002b:00007fffe204c7a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007facf6c25270
RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007facf7adf710 R08: 0000000000000045 R09: 0000000000000018
R10: 00005590205bf838 R11: 0000000000000246 R12: 0000000000000000
R13: 00005590205b7420 R14: 0000000000000003 R15: 000000000000000e
Code: 18 00 00 00 00 48 81 c4 80 01 00 00 44 89 e8 5b 5d 
nbd: must specify an index to disconnect
41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 2a 00 00 49 81 3c 24 60 d8 2f 8b 0f 84 5f 
RIP: __lock_acquire+0x1cc/0x3f20 kernel/locking/lockdep.c:3369 RSP: ffff8880b4f7f938
---[ end trace 4f247ffcffd351e5 ]---