[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 83.683523][ T27] kauditd_printk_skb: 4 callbacks suppressed [ 83.683534][ T27] audit: type=1800 audit(1584706421.058:29): pid=9722 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 83.711404][ T27] audit: type=1800 audit(1584706421.068:30): pid=9722 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.0' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 404.338200][ T9880] FAULT_INJECTION: forcing a failure. [ 404.338200][ T9880] name failslab, interval 1, probability 0, space 0, times 1 [ 404.351033][ T9880] CPU: 0 PID: 9880 Comm: syz-executor975 Not tainted 5.6.0-rc6-syzkaller #0 [ 404.359717][ T9880] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 404.369762][ T9880] Call Trace: [ 404.373154][ T9880] dump_stack+0x188/0x20d [ 404.377524][ T9880] should_fail.cold+0x5/0xa [ 404.382025][ T9880] ? fault_create_debugfs_attr+0x140/0x140 [ 404.387854][ T9880] should_failslab+0x5/0xf [ 404.392262][ T9880] kmem_cache_alloc_trace+0x2d0/0x7d0 [ 404.397630][ T9880] ? lockdep_init_map+0x1b0/0x6c0 [ 404.402754][ T9880] ? lockdep_init_map+0x1b0/0x6c0 [ 404.407783][ T9880] io_queue_file_removal+0xd0/0x1e0 [ 404.412973][ T9880] ? trace_event_raw_event_io_uring_submit_sqe+0x2f0/0x2f0 [ 404.420152][ T9880] ? lock_downgrade+0x7f0/0x7f0 [ 404.425019][ T9880] ? lock_acquire+0x197/0x420 [ 404.429678][ T9880] ? __might_fault+0xef/0x1d0 [ 404.434351][ T9880] ? __might_fault+0x190/0x1d0 [ 404.439113][ T9880] ? _copy_from_user+0x123/0x190 [ 404.444041][ T9880] __io_sqe_files_update.isra.0+0x3a1/0xb00 [ 404.449919][ T9880] ? lock_downgrade+0x7f0/0x7f0 [ 404.454794][ T9880] ? __io_sqe_files_scm+0x7d0/0x7d0 [ 404.459986][ T9880] ? __might_fault+0x190/0x1d0 [ 404.464735][ T9880] __io_uring_register+0x377/0x2c00 [ 404.469940][ T9880] ? vfs_write+0x342/0x5c0 [ 404.474350][ T9880] ? __x64_sys_io_uring_register+0x181/0x560 [ 404.480381][ T9880] ? mutex_trylock+0x2c0/0x2c0 [ 404.485142][ T9880] ? rcu_read_lock_any_held+0xcd/0xf0 [ 404.490509][ T9880] ? __io_sqe_files_update.isra.0+0xb00/0xb00 [ 404.496561][ T9880] ? vfs_write+0x15b/0x5c0 [ 404.500964][ T9880] __x64_sys_io_uring_register+0x192/0x560 [ 404.506763][ T9880] ? do_syscall_64+0x21/0x7d0 [ 404.511422][ T9880] do_syscall_64+0xf6/0x7d0 [ 404.515915][ T9880] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 404.521833][ T9880] RIP: 0033:0x440659 [ 404.525742][ T9880] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 5b 14 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 404.545333][ T9880] RSP: 002b:00007ffc4689a358 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab [ 404.556473][ T9880] RAX: ffffffffffffffda RBX: 00007ffc4689a360 RCX: 0000000000440659 [ 404.564426][ T9880] RDX: 0000000020000300 RSI: 0000000000000006 RDI: 0000000000000003 [ 404.572382][ T9880] RBP: 0000000000000005 R08: 0000000000000001 R09: 00007ffc46890031 [ 404.580430][ T9880] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000401f40 [ 404.588385][ T9880] R13: 0000000000401fd0 R14: 0000000000000000 R15: 0000000000000000 [ 548.676334][ T1137] INFO: task syz-executor975:9880 blocked for more than 143 seconds. [ 548.684706][ T1137] Not tainted 5.6.0-rc6-syzkaller #0 [ 548.690670][ T1137] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 548.699407][ T1137] syz-executor975 D27576 9880 9878 0x80004000 [ 548.705740][ T1137] Call Trace: [ 548.709159][ T1137] ? __schedule+0x934/0x1f90 [ 548.713782][ T1137] ? __sched_text_start+0x8/0x8 [ 548.718747][ T1137] ? __lock_acquire+0x2413/0x3ca0 [ 548.723791][ T1137] schedule+0xd0/0x2a0 [ 548.727924][ T1137] schedule_timeout+0x6db/0xba0 [ 548.732786][ T1137] ? find_held_lock+0x2d/0x110 [ 548.737635][ T1137] ? usleep_range+0x160/0x160 [ 548.742326][ T1137] ? wait_for_completion+0x262/0x3c0 [ 548.747691][ T1137] ? mark_lock+0xbc/0x1220 [ 548.752116][ T1137] ? do_raw_spin_lock+0x129/0x2e0 [ 548.757255][ T1137] ? mark_held_locks+0x9f/0xe0 [ 548.762038][ T1137] ? _raw_spin_unlock_irq+0x1f/0x80 [ 548.767301][ T1137] wait_for_completion+0x26a/0x3c0 [ 548.772425][ T1137] ? wait_for_completion_interruptible+0x420/0x420 [ 548.779019][ T1137] ? lock_acquire+0x197/0x420 [ 548.783723][ T1137] ? wake_up_q+0x140/0x140 [ 548.788196][ T1137] ? mark_held_locks+0x9f/0xe0 [ 548.792963][ T1137] ? _raw_spin_unlock_irqrestore+0x62/0xe0 [ 548.798846][ T1137] io_queue_file_removal+0x1af/0x1e0 [ 548.804147][ T1137] ? trace_event_raw_event_io_uring_submit_sqe+0x2f0/0x2f0 [ 548.811431][ T1137] ? lock_acquire+0x197/0x420 [ 548.816205][ T1137] ? __might_fault+0xef/0x1d0 [ 548.820881][ T1137] ? __might_fault+0x190/0x1d0 [ 548.825630][ T1137] ? _copy_from_user+0x123/0x190 [ 548.830650][ T1137] __io_sqe_files_update.isra.0+0x3a1/0xb00 [ 548.836590][ T1137] ? lock_downgrade+0x7f0/0x7f0 [ 548.841449][ T1137] ? __io_sqe_files_scm+0x7d0/0x7d0 [ 548.846723][ T1137] ? __might_fault+0x190/0x1d0 [ 548.851506][ T1137] __io_uring_register+0x377/0x2c00 [ 548.856792][ T1137] ? vfs_write+0x342/0x5c0 [ 548.861262][ T1137] ? __x64_sys_io_uring_register+0x181/0x560 [ 548.867319][ T1137] ? mutex_trylock+0x2c0/0x2c0 [ 548.872087][ T1137] ? rcu_read_lock_any_held+0xcd/0xf0 [ 548.877645][ T1137] ? __io_sqe_files_update.isra.0+0xb00/0xb00 [ 548.884689][ T1137] ? vfs_write+0x15b/0x5c0 [ 548.889179][ T1137] __x64_sys_io_uring_register+0x192/0x560 [ 548.894992][ T1137] ? do_syscall_64+0x21/0x7d0 [ 548.899770][ T1137] do_syscall_64+0xf6/0x7d0 [ 548.904312][ T1137] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 548.910254][ T1137] RIP: 0033:0x440659 [ 548.914158][ T1137] Code: Bad RIP value. [ 548.918275][ T1137] RSP: 002b:00007ffc4689a358 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab [ 548.926738][ T1137] RAX: ffffffffffffffda RBX: 00007ffc4689a360 RCX: 0000000000440659 [ 548.934702][ T1137] RDX: 0000000020000300 RSI: 0000000000000006 RDI: 0000000000000003 [ 548.942754][ T1137] RBP: 0000000000000005 R08: 0000000000000001 R09: 00007ffc46890031 [ 548.952606][ T1137] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000401f40 [ 548.960636][ T1137] R13: 0000000000401fd0 R14: 0000000000000000 R15: 0000000000000000 [ 548.968736][ T1137] [ 548.968736][ T1137] Showing all locks held in the system: [ 548.976545][ T1137] 1 lock held by khungtaskd/1137: [ 548.981578][ T1137] #0: ffffffff897accc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x260 [ 548.991023][ T1137] 1 lock held by rsyslogd/9761: [ 548.995889][ T1137] #0: ffff8880a8f3ada0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 [ 549.004603][ T1137] 2 locks held by getty/9850: [ 549.009330][ T1137] #0: ffff88809fad3090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 549.018634][ T1137] #1: ffffc900017bb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 [ 549.028261][ T1137] 2 locks held by getty/9851: [ 549.032928][ T1137] #0: ffff8880a7b96090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 549.042201][ T1137] #1: ffffc900017cb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 [ 549.051870][ T1137] 2 locks held by getty/9852: [ 549.056606][ T1137] #0: ffff88809e41c090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 549.065877][ T1137] #1: ffffc900017eb2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 [ 549.075545][ T1137] 2 locks held by getty/9853: [ 549.080276][ T1137] #0: ffff888090392090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 549.089548][ T1137] #1: ffffc900017ab2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 [ 549.099181][ T1137] 2 locks held by getty/9854: [ 549.103839][ T1137] #0: ffff88809fb1b090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 549.113109][ T1137] #1: ffffc900017db2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 [ 549.122747][ T1137] 2 locks held by getty/9855: [ 549.127482][ T1137] #0: ffff88809a302090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 549.136741][ T1137] #1: ffffc9000178b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 [ 549.146380][ T1137] 2 locks held by getty/9856: [ 549.151050][ T1137] #0: ffff88809d9dc090 (&tty->ldisc_sem){++++}, at: tty_ldisc_ref_wait+0x22/0x80 [ 549.160318][ T1137] #1: ffffc9000172b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x21d/0x1b30 [ 549.169937][ T1137] 1 lock held by syz-executor975/9880: [ 549.175421][ T1137] #0: ffff88808f392320 (&ctx->uring_lock){+.+.}, at: __x64_sys_io_uring_register+0x181/0x560 [ 549.185747][ T1137] [ 549.188111][ T1137] ============================================= [ 549.188111][ T1137] [ 549.196563][ T1137] NMI backtrace for cpu 1 [ 549.200927][ T1137] CPU: 1 PID: 1137 Comm: khungtaskd Not tainted 5.6.0-rc6-syzkaller #0 [ 549.209142][ T1137] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 549.219182][ T1137] Call Trace: [ 549.222467][ T1137] dump_stack+0x188/0x20d [ 549.226782][ T1137] nmi_cpu_backtrace.cold+0x70/0xb1 [ 549.231996][ T1137] ? lapic_can_unplug_cpu.cold+0x3b/0x3b [ 549.237663][ T1137] nmi_trigger_cpumask_backtrace+0x231/0x27e [ 549.243644][ T1137] watchdog+0xa8c/0x1010 [ 549.247888][ T1137] ? reset_hung_task_detector+0x30/0x30 [ 549.253415][ T1137] kthread+0x357/0x430 [ 549.257466][ T1137] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 549.263183][ T1137] ret_from_fork+0x24/0x30 [ 549.267691][ T1137] Sending NMI from CPU 1 to CPUs 0: [ 549.273118][ C0] NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 [ 549.273919][ T1137] Kernel panic - not syncing: hung_task: blocked tasks [ 549.288219][ T1137] CPU: 1 PID: 1137 Comm: khungtaskd Not tainted 5.6.0-rc6-syzkaller #0 [ 549.296448][ T1137] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 549.306526][ T1137] Call Trace: [ 549.309808][ T1137] dump_stack+0x188/0x20d [ 549.314159][ T1137] panic+0x2e3/0x75c [ 549.318035][ T1137] ? add_taint.cold+0x16/0x16 [ 549.322694][ T1137] ? cpumask_next+0x3c/0x40 [ 549.327194][ T1137] ? printk_safe_flush+0xd9/0x120 [ 549.332295][ T1137] ? watchdog+0xa8c/0x1010 [ 549.336693][ T1137] ? nmi_trigger_cpumask_backtrace+0x214/0x27e [ 549.342844][ T1137] watchdog+0xa9d/0x1010 [ 549.347081][ T1137] ? reset_hung_task_detector+0x30/0x30 [ 549.352609][ T1137] kthread+0x357/0x430 [ 549.356658][ T1137] ? kthread_mod_delayed_work+0x1a0/0x1a0 [ 549.362359][ T1137] ret_from_fork+0x24/0x30 [ 549.368414][ T1137] Kernel Offset: disabled [ 549.372754][ T1137] Rebooting in 86400 seconds..