block nbd0: NBD_DISCONNECT 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: 19817 Comm: systemd-udevd Not tainted 4.14.307-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 task: ffff888087a5c080 task.stack: ffff888097bd0000 RIP: 0010:__lock_acquire+0x1cc/0x3f20 kernel/locking/lockdep.c:3369 RSP: 0018:ffff888097bd7938 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000110 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffff888087a5c080 R12: 0000000000000110 R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8bed1e40 FS: 00007f93ccc4f8c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa18d975ff8 CR3: 000000008f651000 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_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: 0033:0x7f93cbd95270 RSP: 002b:00007ffca4572f58 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f93cbd95270 RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007f93ccc4f710 R08: 0000000000000045 R09: 0000000000000018 R10: 000055bf8b0c61b8 R11: 0000000000000246 R12: 0000000000000000 R13: 000055bf8b0c1860 R14: 0000000000000003 R15: 000000000000000e Code: 18 00 00 00 00 48 81 c4 80 01 00 00 44 89 e8 5b 5d 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: ffff888097bd7938 ---[ end trace aa05e53db7c5824c ]--- ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 48 81 c4 80 01 00 00 add $0x180,%rsp b: 44 89 e8 mov %r13d,%eax e: 5b pop %rbx f: 5d pop %rbp 10: 41 5c pop %r12 12: 41 5d pop %r13 14: 41 5e pop %r14 16: 41 5f pop %r15 18: c3 retq 19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 20: fc ff df 23: 4c 89 e2 mov %r12,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx * 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 67 2a 00 00 jne 0x2a9b 34: 49 81 3c 24 60 d8 2f cmpq $0xffffffff8b2fd860,(%r12) 3b: 8b 3c: 0f .byte 0xf 3d: 84 .byte 0x84 3e: 5f pop %rdi