[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 57.365570][ T27] audit: type=1800 audit(1562053671.764:25): pid=8413 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 57.414862][ T27] audit: type=1800 audit(1562053671.764:26): pid=8413 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 57.449485][ T27] audit: type=1800 audit(1562053671.764:27): pid=8413 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 '10.128.10.58' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 719.266573][ T8567] block nbd0: shutting down sockets [ 872.206912][ T1043] INFO: task syz-executor485:8568 blocked for more than 143 seconds. [ 872.215137][ T1043] Not tainted 5.2.0-rc7 #46 [ 872.220274][ T1043] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 872.228998][ T1043] syz-executor485 D28528 8568 8564 0x00004004 [ 872.235315][ T1043] Call Trace: [ 872.238648][ T1043] __schedule+0x7cb/0x1560 [ 872.243090][ T1043] ? __sched_text_start+0x8/0x8 [ 872.247997][ T1043] ? generic_make_request+0x321/0xb40 [ 872.253368][ T1043] schedule+0xa8/0x260 [ 872.257488][ T1043] schedule_timeout+0x717/0xc50 [ 872.262345][ T1043] ? usleep_range+0x170/0x170 [ 872.267056][ T1043] ? find_held_lock+0x35/0x130 [ 872.271878][ T1043] ? wait_for_completion_io+0x294/0x440 [ 872.277650][ T1043] ? kasan_check_write+0x14/0x20 [ 872.282599][ T1043] ? _raw_spin_unlock_irq+0x28/0x90 [ 872.287899][ T1043] ? wait_for_completion_io+0x294/0x440 [ 872.293445][ T1043] ? _raw_spin_unlock_irq+0x28/0x90 [ 872.298675][ T1043] ? lockdep_hardirqs_on+0x418/0x5d0 [ 872.303959][ T1043] io_schedule_timeout+0x26/0x80 [ 872.308937][ T1043] wait_for_completion_io+0x29c/0x440 [ 872.314316][ T1043] ? bit_wait_io_timeout+0x140/0x140 [ 872.319650][ T1043] ? wake_up_q+0xf0/0xf0 [ 872.323905][ T1043] ? lockdep_init_map+0x1be/0x6d0 [ 872.329060][ T1043] submit_bio_wait+0x11d/0x1c0 [ 872.333832][ T1043] ? submit_bio_wait_endio+0x40/0x40 [ 872.339186][ T1043] ? bio_associate_blkg+0x143/0x390 [ 872.344392][ T1043] blkdev_issue_flush+0x20d/0x300 [ 872.349461][ T1043] blkdev_fsync+0x95/0xd0 [ 872.353789][ T1043] ? thaw_bdev+0x1a0/0x1a0 [ 872.358266][ T1043] vfs_fsync_range+0x141/0x230 [ 872.363088][ T1043] ? __fget_light+0x1a9/0x230 [ 872.367888][ T1043] do_fsync+0x54/0xa0 [ 872.371882][ T1043] __x64_sys_fdatasync+0x36/0x50 [ 872.376875][ T1043] do_syscall_64+0xfd/0x680 [ 872.381393][ T1043] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 872.387364][ T1043] RIP: 0033:0x449749 [ 872.391265][ T1043] Code: Bad RIP value. [ 872.395348][ T1043] RSP: 002b:00007fa817de2ce8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 872.403802][ T1043] RAX: ffffffffffffffda RBX: 00000000006dac58 RCX: 0000000000449749 [ 872.411838][ T1043] RDX: 0000000000449749 RSI: 0000000000000000 RDI: 0000000000000009 [ 872.419833][ T1043] RBP: 00000000006dac50 R08: 0000000000000000 R09: 0000000000000000 [ 872.427840][ T1043] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac5c [ 872.435818][ T1043] R13: 00007fff567b6b5f R14: 00007fa817de39c0 R15: 20c49ba5e353f7cf [ 872.443850][ T1043] [ 872.443850][ T1043] Showing all locks held in the system: [ 872.451605][ T1043] 1 lock held by khungtaskd/1043: [ 872.456606][ T1043] #0: 00000000f7c610b3 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e [ 872.465970][ T1043] 2 locks held by rsyslogd/8451: [ 872.470950][ T1043] #0: 00000000dfc1566f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 872.479591][ T1043] #1: 0000000054220207 (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1560 [ 872.487889][ T1043] 2 locks held by getty/8541: [ 872.492545][ T1043] #0: 000000004ff543bd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 872.501535][ T1043] #1: 000000002a3905f3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 872.511137][ T1043] 2 locks held by getty/8542: [ 872.515788][ T1043] #0: 000000006e67fcec (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 872.524757][ T1043] #1: 00000000ee71e4f3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 872.534356][ T1043] 2 locks held by getty/8543: [ 872.539070][ T1043] #0: 00000000bd0907a0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 872.548064][ T1043] #1: 000000000876abce (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 872.557650][ T1043] 2 locks held by getty/8544: [ 872.562318][ T1043] #0: 00000000710d6f7d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 872.571291][ T1043] #1: 00000000af289586 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 872.580874][ T1043] 2 locks held by getty/8545: [ 872.585522][ T1043] #0: 000000003399e62d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 872.594487][ T1043] #1: 00000000ee97f91a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 872.604265][ T1043] 2 locks held by getty/8546: [ 872.608970][ T1043] #0: 00000000ff2274c6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 872.617951][ T1043] #1: 00000000b96c5a9f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 872.627545][ T1043] 2 locks held by getty/8547: [ 872.632261][ T1043] #0: 000000005165f028 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 872.641241][ T1043] #1: 00000000e89d5b4a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 872.650879][ T1043] [ 872.653215][ T1043] ============================================= [ 872.653215][ T1043] [ 872.661648][ T1043] NMI backtrace for cpu 1 [ 872.666015][ T1043] CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.2.0-rc7 #46 [ 872.673496][ T1043] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 872.683533][ T1043] Call Trace: [ 872.686809][ T1043] dump_stack+0x172/0x1f0 [ 872.691133][ T1043] nmi_cpu_backtrace.cold+0x63/0xa4 [ 872.696529][ T1043] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 872.702189][ T1043] nmi_trigger_cpumask_backtrace+0x1be/0x236 [ 872.708164][ T1043] arch_trigger_cpumask_backtrace+0x14/0x20 [ 872.714047][ T1043] watchdog+0x9b7/0xec0 [ 872.718193][ T1043] kthread+0x354/0x420 [ 872.722280][ T1043] ? reset_hung_task_detector+0x30/0x30 [ 872.727813][ T1043] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 872.734137][ T1043] ret_from_fork+0x24/0x30 [ 872.738632][ T1043] Sending NMI from CPU 1 to CPUs 0: [ 872.743932][ C0] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 [ 872.744840][ T1043] Kernel panic - not syncing: hung_task: blocked tasks [ 872.759020][ T1043] CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.2.0-rc7 #46 [ 872.766518][ T1043] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 872.776707][ T1043] Call Trace: [ 872.779997][ T1043] dump_stack+0x172/0x1f0 [ 872.784382][ T1043] panic+0x2cb/0x744 [ 872.788268][ T1043] ? __warn_printk+0xf3/0xf3 [ 872.792950][ T1043] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 872.798651][ T1043] ? printk_safe_flush+0xf2/0x140 [ 872.803764][ T1043] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 872.809989][ T1043] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 872.815598][ T1043] ? nmi_trigger_cpumask_backtrace+0x1a7/0x236 [ 872.821729][ T1043] ? nmi_trigger_cpumask_backtrace+0x19e/0x236 [ 872.827862][ T1043] watchdog+0x9c8/0xec0 [ 872.831998][ T1043] kthread+0x354/0x420 [ 872.836053][ T1043] ? reset_hung_task_detector+0x30/0x30 [ 872.841584][ T1043] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 872.847813][ T1043] ret_from_fork+0x24/0x30 [ 872.853382][ T1043] Kernel Offset: disabled [ 872.857711][ T1043] Rebooting in 86400 seconds..