[ OK ] Started Getty on tty2. [ OK ] Reached target Login Prompts. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.6' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 40.273544] block nbd0: NBD_DISCONNECT [ 40.277954] kasan: CONFIG_KASAN_INLINE enabled [ 40.282553] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 40.289915] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 40.296231] CPU: 1 PID: 9313 Comm: systemd-udevd Not tainted 4.19.193-syzkaller #0 [ 40.303917] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.313262] RIP: 0010:__lock_acquire+0x1eb/0x3ff0 [ 40.318082] Code: 2b 29 00 00 48 81 c4 98 01 00 00 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 b3 2a 00 00 49 81 3e 20 b2 66 8c 0f 84 65 ff ff [ 40.336966] RSP: 0018:ffff88809f8ff910 EFLAGS: 00010006 [ 40.342309] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 40.349565] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000001 [ 40.356812] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 40.364095] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 40.371369] R13: ffff88809e08a0c0 R14: 0000000000000110 R15: 0000000000000001 [ 40.378636] FS: 00007fd0b64f48c0(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 [ 40.386841] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 40.392701] CR2: 00007ffeb35c09c0 CR3: 00000000b2ccb000 CR4: 00000000001406e0 [ 40.399974] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 40.407239] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 40.414574] Call Trace: [ 40.417151] ? __lock_acquire+0x6de/0x3ff0 [ 40.421368] ? mark_held_locks+0xf0/0xf0 [ 40.425409] ? __lock_acquire+0x6de/0x3ff0 [ 40.429627] ? mark_held_locks+0xf0/0xf0 [ 40.433670] ? __free_object+0xdd/0x1e0 [ 40.437631] ? mark_held_locks+0xf0/0xf0 [ 40.441674] ? mark_held_locks+0xa6/0xf0 [ 40.445720] lock_acquire+0x170/0x3c0 [ 40.449502] ? flush_workqueue+0xe8/0x13e0 [ 40.453748] flush_workqueue+0x117/0x13e0 [ 40.457875] ? flush_workqueue+0xe8/0x13e0 [ 40.462088] ? lock_downgrade+0x720/0x720 [ 40.466229] ? hctx_unlock+0x83/0x140 [ 40.470030] ? check_flush_dependency+0x400/0x400 [ 40.474860] nbd_disconnect_and_put+0x100/0x190 [ 40.479512] nbd_release+0x144/0x170 [ 40.483219] ? nbd_queue_rq+0xe60/0xe60 [ 40.487190] __blkdev_put+0x636/0x870 [ 40.490974] ? fsync_bdev+0xc0/0xc0 [ 40.495542] ? locks_remove_file+0x2cd/0x450 [ 40.500095] ? blkdev_put+0x85/0x520 [ 40.503802] ? blkdev_put+0x520/0x520 [ 40.507591] blkdev_close+0x86/0xb0 [ 40.511205] __fput+0x2ce/0x890 [ 40.514471] task_work_run+0x148/0x1c0 [ 40.518576] exit_to_usermode_loop+0x251/0x2a0 [ 40.523264] do_syscall_64+0x538/0x620 [ 40.527181] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 40.532403] RIP: 0033:0x7fd0b563a270 [ 40.536161] Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 [ 40.555052] RSP: 002b:00007ffeb349d9b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 40.562741] RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fd0b563a270 [ 40.569993] RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 [ 40.577245] RBP: 00007fd0b64f4710 R08: 0000000000000045 R09: 0000000000000018 [ 40.584498] R10: 0000563dbdd91c48 R11: 0000000000000246 R12: 0000000000000000 [ 40.591909] R13: 0000563dbdd91cd0 R14: 0000000000000003 R15: 000000000000000e [ 40.599392] Modules linked in: [ 40.602629] ---[ end trace cba41573a5097b0a ]--- [ 40.607518] RIP: 0010:__lock_acquire+0x1eb/0x3ff0 [ 40.612363] Code: 2b 29 00 00 48 81 c4 98 01 00 00 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 b3 2a 00 00 49 81 3e 20 b2 66 8c 0f 84 65 ff ff [ 40.631368] RSP: 0018:ffff88809f8ff910 EFLAGS: 00010006 [ 40.636714] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 40.643977] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000001 [ 40.651230] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 40.658500] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 40.665758] R13: ffff88809e08a0c0 R14: 0000000000000110 R15: 0000000000000001 [ 40.673094] FS: 00007fd0b64f48c0(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 [ 40.681364] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 40.687241] CR2: 00007ffeb35c09c0 CR3: 00000000b2ccb000 CR4: 00000000001406e0 [ 40.694640] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 40.701913] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 40.709340] Kernel panic - not syncing: Fatal exception [ 40.715380] Kernel Offset: disabled [ 40.719005] Rebooting in 86400 seconds..