[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Update UTMP about System Runlevel Changes. [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.87' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 31.573524] IPVS: ftp: loaded support on port[0] = 21 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 48.647098] block nbd0: NBD_DISCONNECT [ 48.651148] kasan: CONFIG_KASAN_INLINE enabled [ 48.655722] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 48.663165] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 48.669560] Modules linked in: [ 48.672748] CPU: 1 PID: 10297 Comm: systemd-udevd Not tainted 4.14.236-syzkaller #0 [ 48.680605] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.689937] task: ffff888092852440 task.stack: ffff8880905b0000 [ 48.696008] RIP: 0010:__lock_acquire+0x1cc/0x3f20 [ 48.701157] RSP: 0018:ffff8880905b7938 EFLAGS: 00010006 [ 48.706499] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 48.713936] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000110 [ 48.721207] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 48.728483] R10: 0000000000000001 R11: ffff888092852440 R12: 0000000000000110 [ 48.735839] R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8bebcd40 [ 48.743298] FS: 00007f1f5ea628c0(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 [ 48.751502] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 48.757360] CR2: 00007ffc4cf53558 CR3: 00000000a5fc7000 CR4: 00000000001406e0 [ 48.764610] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 48.771858] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 48.779104] Call Trace: [ 48.781686] ? vprintk_emit+0x170/0x620 [ 48.785649] ? dev_vprintk_emit+0x1da/0x440 [ 48.790011] ? trace_hardirqs_on+0x10/0x10 [ 48.794236] ? dev_driver_string+0x160/0x160 [ 48.798639] ? __lock_acquire+0x5fc/0x3f20 [ 48.802857] ? trace_hardirqs_on+0x10/0x10 [ 48.807102] lock_acquire+0x170/0x3f0 [ 48.810893] ? flush_workqueue+0xcb/0x1310 [ 48.815115] flush_workqueue+0xfa/0x1310 [ 48.819166] ? flush_workqueue+0xcb/0x1310 [ 48.823390] ? nbd_disconnect_and_put+0x99/0x140 [ 48.828126] ? lock_downgrade+0x740/0x740 [ 48.832280] ? check_flush_dependency+0x2a0/0x2a0 [ 48.837125] nbd_disconnect_and_put+0xc3/0x140 [ 48.841695] nbd_release+0x123/0x150 [ 48.845393] ? nbd_queue_rq+0xc50/0xc50 [ 48.849385] __blkdev_put+0x5aa/0x800 [ 48.853201] ? revalidate_disk+0x1f0/0x1f0 [ 48.857524] ? locks_remove_file+0x2cd/0x420 [ 48.861929] ? blkdev_put+0x75/0x4c0 [ 48.865628] ? blkdev_put+0x4c0/0x4c0 [ 48.869415] blkdev_close+0x86/0xb0 [ 48.873087] __fput+0x25f/0x7a0 [ 48.876372] task_work_run+0x11f/0x190 [ 48.880412] exit_to_usermode_loop+0x1ad/0x200 [ 48.884982] do_syscall_64+0x4a3/0x640 [ 48.888858] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 48.894036] RIP: 0033:0x7f1f5dba8270 [ 48.897730] RSP: 002b:00007ffdc9359508 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 48.905423] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007f1f5dba8270 [ 48.912961] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 48.920229] RBP: 00007f1f5ea62710 R08: 0000561aa1fb4fe0 R09: 0000000000000018 [ 48.927500] R10: 0000561aa1fa0e38 R11: 0000000000000246 R12: 0000000000000000 [ 48.934775] R13: 0000561aa1fb2880 R14: 0000000000000003 R15: 000000000000000e [ 48.942028] 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 a0 87 2e 8b 0f 84 5f [ 48.961103] RIP: __lock_acquire+0x1cc/0x3f20 RSP: ffff8880905b7938 [ 48.967421] ---[ end trace 7e9d892959b3c1e4 ]--- [ 48.972259] Kernel panic - not syncing: Fatal exception [ 48.978430] Kernel Offset: disabled [ 48.982052] Rebooting in 86400 seconds..