[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 56.938963][ T26] audit: type=1800 audit(1570244270.675:25): pid=8645 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 56.979861][ T26] audit: type=1800 audit(1570244270.685:26): pid=8645 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 57.000330][ T26] audit: type=1800 audit(1570244270.685:27): pid=8645 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.28' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 72.872249][ T1523] block nbd0: Receive control failed (result -22) [ 72.909163][ T2496] block nbd0: Send control failed (result -89) [ 72.915625][ T2496] block nbd0: Request send failed, requeueing [ 72.922741][ T1523] block nbd0: Receive control failed (result -32) [ 72.922817][ T2496] block nbd0: Dead connection, failed to find a fallback [ 72.936413][ T2496] block nbd0: shutting down sockets [ 72.937636][ T8804] block nbd0: Device being setup by another task [ 72.941957][ T2496] blk_update_request: I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 2 prio class 0 [ 72.948731][ T8805] block nbd0: Device being setup by another task [ 72.959650][ T2496] Buffer I/O error on dev nbd0, logical block 2, async page read [ 72.973354][ T2496] Buffer I/O error on dev nbd0, logical block 3, async page read [ 72.981475][ T2496] ------------[ cut here ]------------ [ 72.987035][ T2496] WARNING: CPU: 0 PID: 2496 at include/linux/cpumask.h:137 __blk_mq_delay_run_hw_queue+0x498/0x600 [ 72.997699][ T2496] Kernel panic - not syncing: panic_on_warn set ... [ 73.004268][ T2496] CPU: 0 PID: 2496 Comm: kworker/0:1H Not tainted 5.4.0-rc1+ #0 [ 73.011879][ T2496] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 73.021969][ T2496] Workqueue: kblockd blk_mq_requeue_work [ 73.027576][ T2496] Call Trace: [ 73.030851][ T2496] dump_stack+0x172/0x1f0 [ 73.035166][ T2496] ? __blk_mq_delay_run_hw_queue+0x400/0x600 [ 73.041161][ T2496] panic+0x2dc/0x755 [ 73.045033][ T2496] ? add_taint.cold+0x16/0x16 [ 73.049730][ T2496] ? printk+0xba/0xed [ 73.053797][ T2496] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 73.059253][ T2496] ? __warn.cold+0x14/0x3c [ 73.063652][ T2496] ? __warn+0xd9/0x1d0 [ 73.067708][ T2496] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 73.073722][ T2496] __warn.cold+0x2f/0x3c [ 73.077956][ T2496] ? report_bug.cold+0x63/0xad [ 73.082751][ T2496] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 73.088710][ T2496] report_bug+0x289/0x300 [ 73.093020][ T2496] do_error_trap+0x11b/0x200 [ 73.097624][ T2496] do_invalid_op+0x37/0x50 [ 73.102154][ T2496] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 73.108154][ T2496] invalid_op+0x23/0x30 [ 73.112305][ T2496] RIP: 0010:__blk_mq_delay_run_hw_queue+0x498/0x600 [ 73.118882][ T2496] Code: 01 00 00 41 c7 84 24 24 01 00 00 01 00 00 00 41 bd 40 00 00 00 e9 ab fe ff ff 41 bd 40 00 00 00 e9 a0 fe ff ff e8 48 68 41 fe <0f> 0b e9 50 fd ff ff e8 3c 68 41 fe 48 c7 c2 40 b9 c5 89 4c 89 fe [ 73.138490][ T2496] RSP: 0018:ffff8880a3287b18 EFLAGS: 00010293 [ 73.144531][ T2496] RAX: ffff8880a32720c0 RBX: 0000000000000040 RCX: ffffffff8331a7e6 [ 73.152479][ T2496] RDX: 0000000000000000 RSI: ffffffff8331aa98 RDI: 0000000000000005 [ 73.160425][ T2496] RBP: ffff8880a3287b58 R08: ffff8880a32720c0 R09: ffffed101141a05a [ 73.168385][ T2496] R10: ffffed101141a059 R11: ffff88808a0d02cf R12: ffff88808a0d0280 [ 73.176345][ T2496] R13: 0000000000000040 R14: ffff88808a0d03a4 R15: 0000000000000000 [ 73.184306][ T2496] ? __blk_mq_delay_run_hw_queue+0x1e6/0x600 [ 73.190264][ T2496] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 73.196221][ T2496] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 73.202219][ T2496] blk_mq_run_hw_queue+0x19d/0x350 [ 73.207353][ T2496] ? blk_mq_delay_run_hw_queue+0x30/0x30 [ 73.212964][ T2496] ? blk_mq_sched_insert_request+0x214/0x720 [ 73.218922][ T2496] blk_mq_run_hw_queues+0x112/0x1a0 [ 73.224101][ T2496] blk_mq_requeue_work+0x502/0x780 [ 73.229190][ T2496] ? blk_mq_make_request+0x2280/0x2280 [ 73.234626][ T2496] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 73.240146][ T2496] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 73.246110][ T2496] ? trace_hardirqs_on+0x67/0x240 [ 73.251152][ T2496] process_one_work+0x9af/0x1740 [ 73.256072][ T2496] ? pwq_dec_nr_in_flight+0x320/0x320 [ 73.261430][ T2496] ? lock_acquire+0x190/0x410 [ 73.266091][ T2496] worker_thread+0x98/0xe40 [ 73.270569][ T2496] ? trace_hardirqs_on+0x67/0x240 [ 73.275579][ T2496] kthread+0x361/0x430 [ 73.279661][ T2496] ? process_one_work+0x1740/0x1740 [ 73.284837][ T2496] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 73.291057][ T2496] ret_from_fork+0x24/0x30 [ 73.296985][ T2496] Kernel Offset: disabled [ 73.301373][ T2496] Rebooting in 86400 seconds..