[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 57.755718][ T26] audit: type=1800 audit(1571211317.286:25): pid=8516 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 57.776931][ T26] audit: type=1800 audit(1571211317.286:26): pid=8516 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 57.825016][ T26] audit: type=1800 audit(1571211317.286:27): pid=8516 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 '10.128.0.253' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 83.077367][ T1527] block nbd0: Receive control failed (result -22) [ 83.127477][ T2500] block nbd0: Send control failed (result -89) [ 83.134074][ T2500] block nbd0: Request send failed, requeueing [ 83.140685][ T1527] block nbd0: Receive control failed (result -32) [ 83.140775][ T2500] block nbd0: Dead connection, failed to find a fallback [ 83.154257][ T2500] block nbd0: shutting down sockets [ 83.159717][ T2500] blk_update_request: I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 2 prio class 0 [ 83.167485][ T8674] block nbd0: Device being setup by another task [ 83.170776][ T2500] Buffer I/O error on dev nbd0, logical block 2, async page read [ 83.178341][ T8676] block nbd0: Device being setup by another task [ 83.184903][ T2500] Buffer I/O error on dev nbd0, logical block 3, async page read [ 83.199228][ T2500] ------------[ cut here ]------------ [ 83.204772][ T2500] WARNING: CPU: 0 PID: 2500 at include/linux/cpumask.h:137 __blk_mq_delay_run_hw_queue+0x498/0x600 [ 83.215418][ T2500] Kernel panic - not syncing: panic_on_warn set ... [ 83.221984][ T2500] CPU: 0 PID: 2500 Comm: kworker/0:1H Not tainted 5.4.0-rc3+ #0 [ 83.229585][ T2500] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 83.239634][ T2500] Workqueue: kblockd blk_mq_requeue_work [ 83.245244][ T2500] Call Trace: [ 83.248535][ T2500] dump_stack+0x172/0x1f0 [ 83.252856][ T2500] ? __blk_mq_delay_run_hw_queue+0x420/0x600 [ 83.258870][ T2500] panic+0x2e3/0x75c [ 83.262752][ T2500] ? add_taint.cold+0x16/0x16 [ 83.267416][ T2500] ? printk+0xba/0xed [ 83.271374][ T2500] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 83.276823][ T2500] ? __warn.cold+0x14/0x35 [ 83.281216][ T2500] ? __warn+0xd9/0x1d0 [ 83.285267][ T2500] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 83.291221][ T2500] __warn.cold+0x2f/0x35 [ 83.295443][ T2500] ? report_bug.cold+0x63/0xad [ 83.300269][ T2500] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 83.306232][ T2500] report_bug+0x289/0x300 [ 83.310547][ T2500] do_error_trap+0x11b/0x200 [ 83.315112][ T2500] do_invalid_op+0x37/0x50 [ 83.319503][ T2500] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 83.325458][ T2500] invalid_op+0x23/0x30 [ 83.329591][ T2500] RIP: 0010:__blk_mq_delay_run_hw_queue+0x498/0x600 [ 83.336154][ T2500] 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 98 1d 40 fe <0f> 0b e9 50 fd ff ff e8 8c 1d 40 fe 48 c7 c2 80 73 c6 89 4c 89 fe [ 83.355749][ T2500] RSP: 0018:ffff8880a33dfb18 EFLAGS: 00010293 [ 83.361791][ T2500] RAX: ffff8880a33d61c0 RBX: 0000000000000040 RCX: ffffffff8332f4c6 [ 83.369751][ T2500] RDX: 0000000000000000 RSI: ffffffff8332f778 RDI: 0000000000000005 [ 83.377699][ T2500] RBP: ffff8880a33dfb58 R08: ffff8880a33d61c0 R09: ffffed10121bd40a [ 83.385648][ T2500] R10: ffffed10121bd409 R11: ffff888090dea04f R12: ffff888090dea000 [ 83.393877][ T2500] R13: 0000000000000040 R14: ffff888090dea124 R15: 0000000000000000 [ 83.401836][ T2500] ? __blk_mq_delay_run_hw_queue+0x1e6/0x600 [ 83.407805][ T2500] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 83.413776][ T2500] ? __blk_mq_delay_run_hw_queue+0x498/0x600 [ 83.419734][ T2500] blk_mq_run_hw_queue+0x19d/0x350 [ 83.424820][ T2500] ? blk_mq_delay_run_hw_queue+0x30/0x30 [ 83.430431][ T2500] ? blk_mq_sched_insert_request+0x214/0x720 [ 83.436389][ T2500] blk_mq_run_hw_queues+0x112/0x1a0 [ 83.441566][ T2500] blk_mq_requeue_work+0x502/0x780 [ 83.446654][ T2500] ? blk_mq_make_request+0x2280/0x2280 [ 83.452089][ T2500] ? rcu_read_lock_sched_held+0x9c/0xd0 [ 83.457613][ T2500] ? rcu_read_lock_any_held.part.0+0x50/0x50 [ 83.463580][ T2500] ? trace_hardirqs_on+0x67/0x240 [ 83.468590][ T2500] process_one_work+0x9af/0x1740 [ 83.473600][ T2500] ? pwq_dec_nr_in_flight+0x320/0x320 [ 83.478965][ T2500] ? lock_acquire+0x190/0x410 [ 83.483628][ T2500] worker_thread+0x98/0xe40 [ 83.488113][ T2500] ? trace_hardirqs_on+0x67/0x240 [ 83.493215][ T2500] kthread+0x361/0x430 [ 83.497268][ T2500] ? process_one_work+0x1740/0x1740 [ 83.502448][ T2500] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 83.508668][ T2500] ret_from_fork+0x24/0x30 [ 83.514656][ T2500] Kernel Offset: disabled [ 83.519041][ T2500] Rebooting in 86400 seconds..