[ 39.487474] audit: type=1800 audit(1562046465.883:29): pid=7566 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 39.508470] audit: type=1800 audit(1562046465.893:30): pid=7566 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 Starting mcstransd: [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?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 '10.128.0.80' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 765.113816] kauditd_printk_skb: 5 callbacks suppressed [ 765.113834] audit: type=1400 audit(1562047191.513:36): avc: denied { map } for pid=7755 comm="syz-executor084" path="/root/syz-executor084409957" dev="sda1" ino=1426 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 [ 765.271359] block nbd0: shutting down sockets [ 916.337998] INFO: task syz-executor084:7757 blocked for more than 140 seconds. [ 916.345773] Not tainted 4.19.56 #28 [ 916.350014] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 916.358267] syz-executor084 D28928 7757 7753 0x00000004 [ 916.364035] Call Trace: [ 916.366737] __schedule+0x80d/0x1c70 [ 916.370726] ? blk_insert_flush+0x519/0x980 [ 916.375196] ? pci_mmcfg_check_reserved+0x170/0x170 [ 916.380500] schedule+0x92/0x1c0 [ 916.383905] schedule_timeout+0x8c8/0xfc0 [ 916.390193] ? usleep_range+0x170/0x170 [ 916.394266] ? find_held_lock+0x35/0x130 [ 916.398444] ? wait_for_completion_io+0x294/0x440 [ 916.403441] ? _raw_spin_unlock_irq+0x28/0x90 [ 916.408050] ? wait_for_completion_io+0x294/0x440 [ 916.412932] ? _raw_spin_unlock_irq+0x28/0x90 [ 916.417445] ? lockdep_hardirqs_on+0x415/0x5d0 [ 916.422967] io_schedule_timeout+0x26/0x80 [ 916.427229] wait_for_completion_io+0x29c/0x440 [ 916.432034] ? bit_wait_io_timeout+0x140/0x140 [ 916.436755] ? wake_up_q+0x100/0x100 [ 916.440582] ? __lockdep_init_map+0x10c/0x5b0 [ 916.445411] submit_bio_wait+0x11d/0x1c0 [ 916.449592] ? submit_bio_wait_endio+0x40/0x40 [ 916.454277] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 916.460004] ? file_check_and_advance_wb_err+0x9e/0x3a0 [ 916.465562] blkdev_issue_flush+0x20b/0x300 [ 916.470210] blkdev_fsync+0x95/0xd0 [ 916.473881] ? thaw_bdev+0x1a0/0x1a0 [ 916.477679] vfs_fsync_range+0x141/0x230 [ 916.482172] ? __fget_light+0x1a9/0x230 [ 916.486183] do_fsync+0x54/0xa0 [ 916.489768] __x64_sys_fdatasync+0x36/0x50 [ 916.494176] do_syscall_64+0xfd/0x620 [ 916.498594] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 916.504282] RIP: 0033:0x449789 [ 916.507597] Code: Bad RIP value. [ 916.511213] RSP: 002b:00007fba8e1fcce8 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 916.519010] RAX: ffffffffffffffda RBX: 00000000006dac58 RCX: 0000000000449789 [ 916.526504] RDX: 0000000000449789 RSI: 0000000000000000 RDI: 0000000000000009 [ 916.534049] RBP: 00000000006dac50 R08: 0000000000000000 R09: 0000000000000000 [ 916.541881] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac5c [ 916.550118] R13: 00007ffc01d74a5f R14: 00007fba8e1fd9c0 R15: 20c49ba5e353f7cf [ 916.557666] [ 916.557666] Showing all locks held in the system: [ 916.564114] 1 lock held by khungtaskd/1029: [ 916.568650] #0: 00000000eca0e8c4 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e [ 916.577397] 1 lock held by rsyslogd/7604: [ 916.581707] 2 locks held by getty/7727: [ 916.585759] #0: 00000000f0204946 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 916.594232] #1: 0000000015efb458 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 [ 916.603300] 2 locks held by getty/7728: [ 916.607377] #0: 00000000cb5b1147 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 916.615974] #1: 00000000560cdf4e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 [ 916.625422] 2 locks held by getty/7729: [ 916.629465] #0: 000000007bddcd1c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 916.637843] #1: 000000001997f524 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 [ 916.646851] 2 locks held by getty/7730: [ 916.651029] #0: 0000000030ce0a67 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 916.659450] #1: 00000000cf60cb1e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 [ 916.668400] 2 locks held by getty/7731: [ 916.672474] #0: 000000007a208e32 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 916.681459] #1: 0000000016a3b44d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 [ 916.690610] 2 locks held by getty/7732: [ 916.694734] #0: 00000000540a4f7b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 916.703125] #1: 000000009493c284 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 [ 916.712292] 2 locks held by getty/7733: [ 916.716365] #0: 0000000098989f02 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 916.724989] #1: 00000000a7619b96 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 [ 916.734293] [ 916.735928] ============================================= [ 916.735928] [ 916.743119] NMI backtrace for cpu 0 [ 916.746774] CPU: 0 PID: 1029 Comm: khungtaskd Not tainted 4.19.56 #28 [ 916.753648] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 916.763189] Call Trace: [ 916.765883] dump_stack+0x172/0x1f0 [ 916.769533] nmi_cpu_backtrace.cold+0x63/0xa4 [ 916.774162] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 916.779453] nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 [ 916.784816] arch_trigger_cpumask_backtrace+0x14/0x20 [ 916.790035] watchdog+0x9df/0xee0 [ 916.793572] kthread+0x354/0x420 [ 916.796955] ? reset_hung_task_detector+0x30/0x30 [ 916.801961] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 916.807513] ret_from_fork+0x24/0x30 [ 916.811372] Sending NMI from CPU 0 to CPUs 1: [ 916.816169] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 [ 916.817994] Kernel panic - not syncing: hung_task: blocked tasks [ 916.829905] CPU: 0 PID: 1029 Comm: khungtaskd Not tainted 4.19.56 #28 [ 916.836522] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 916.846502] Call Trace: [ 916.849149] dump_stack+0x172/0x1f0 [ 916.852894] panic+0x263/0x507 [ 916.856925] ? __warn_printk+0xf3/0xf3 [ 916.860827] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 916.865961] ? ___preempt_schedule+0x16/0x18 [ 916.870887] ? nmi_trigger_cpumask_backtrace+0x165/0x1f8 [ 916.876410] ? nmi_trigger_cpumask_backtrace+0x1c1/0x1f8 [ 916.881953] ? nmi_trigger_cpumask_backtrace+0x1cb/0x1f8 [ 916.887429] ? nmi_trigger_cpumask_backtrace+0x165/0x1f8 [ 916.893009] watchdog+0x9f0/0xee0 [ 916.896481] kthread+0x354/0x420 [ 916.899926] ? reset_hung_task_detector+0x30/0x30 [ 916.905024] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 916.910583] ret_from_fork+0x24/0x30 [ 916.915707] Kernel Offset: disabled [ 916.919397] Rebooting in 86400 seconds..