Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.192' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 545.958188][ T1041] INFO: task syz-executor048:7798 blocked for more than 143 seconds. [ 545.966524][ T1041] Not tainted 5.1.0-rc1+ #35 [ 545.971790][ T1041] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 545.980797][ T1041] syz-executor048 D28216 7798 7796 0xa0020000 [ 545.987199][ T1041] Call Trace: [ 545.990732][ T1041] __schedule+0x817/0x1cc0 [ 545.995367][ T1041] ? __sched_text_start+0x8/0x8 [ 546.000322][ T1041] ? __lock_acquire+0x242a/0x3fb0 [ 546.005355][ T1041] schedule+0x92/0x180 [ 546.010270][ T1041] schedule_timeout+0x8ca/0xfd0 [ 546.015107][ T1041] ? wait_for_completion+0x294/0x440 [ 546.020447][ T1041] ? find_held_lock+0x35/0x130 [ 546.025558][ T1041] ? usleep_range+0x170/0x170 [ 546.030350][ T1041] ? kasan_check_write+0x14/0x20 [ 546.035333][ T1041] ? _raw_spin_unlock_irq+0x28/0x90 [ 546.040725][ T1041] ? wait_for_completion+0x294/0x440 [ 546.046187][ T1041] ? _raw_spin_unlock_irq+0x28/0x90 [ 546.051618][ T1041] ? lockdep_hardirqs_on+0x418/0x5d0 [ 546.056961][ T1041] ? trace_hardirqs_on+0x67/0x230 [ 546.062131][ T1041] ? kasan_check_read+0x11/0x20 [ 546.066980][ T1041] wait_for_completion+0x29c/0x440 [ 546.072143][ T1041] ? lockdep_hardirqs_on+0x418/0x5d0 [ 546.077463][ T1041] ? wait_for_completion_interruptible+0x4b0/0x4b0 [ 546.084229][ T1041] ? wake_up_q+0xf0/0xf0 [ 546.088630][ T1041] ? percpu_ref_kill_and_confirm+0x1b7/0x3b0 [ 546.094770][ T1041] exit_aio+0x321/0x3a0 [ 546.099067][ T1041] ? io_submit_one+0x1cf0/0x1cf0 [ 546.104004][ T1041] ? mutex_unlock+0xd/0x10 [ 546.108556][ T1041] mmput+0xcf/0x4c0 [ 546.112396][ T1041] do_exit+0x816/0x2fa0 [ 546.116586][ T1041] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 546.122927][ T1041] ? cache_grow_begin.cold+0x1e/0x31 [ 546.128244][ T1041] ? mm_update_next_owner+0x640/0x640 [ 546.133675][ T1041] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 546.139985][ T1041] ? __ia32_compat_sys_io_submit+0x356/0x570 [ 546.146047][ T1041] ? __ia32_sys_io_submit+0x560/0x560 [ 546.151546][ T1041] ? kasan_check_write+0x14/0x20 [ 546.156561][ T1041] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 546.162087][ T1041] do_group_exit+0x135/0x370 [ 546.166668][ T1041] __ia32_sys_exit_group+0x44/0x50 [ 546.172125][ T1041] do_fast_syscall_32+0x281/0xc98 [ 546.177270][ T1041] entry_SYSENTER_compat+0x70/0x7f [ 546.182438][ T1041] RIP: 0023:0xf7f75869 [ 546.186490][ T1041] Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 [ 546.206301][ T1041] RSP: 002b:00000000ffd3671c EFLAGS: 00000292 ORIG_RAX: 00000000000000fc [ 546.214821][ T1041] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000080eb2b8 [ 546.223033][ T1041] RDX: 0000000000000000 RSI: 00000000080d5e78 RDI: 00000000080eb2c0 [ 546.231058][ T1041] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 [ 546.239254][ T1041] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 546.247381][ T1041] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 546.255547][ T1041] [ 546.255547][ T1041] Showing all locks held in the system: [ 546.263307][ T1041] 1 lock held by khungtaskd/1041: [ 546.268375][ T1041] #0: 000000008a64e07e (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e [ 546.277750][ T1041] 1 lock held by rsyslogd/7663: [ 546.282669][ T1041] 2 locks held by getty/7775: [ 546.287328][ T1041] #0: 00000000659f7839 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.296335][ T1041] #1: 00000000907437d9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.306123][ T1041] 2 locks held by getty/7776: [ 546.310848][ T1041] #0: 00000000c47af5ff (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.319972][ T1041] #1: 000000003bf64669 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.329821][ T1041] 2 locks held by getty/7777: [ 546.334490][ T1041] #0: 000000005fbb1038 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.343728][ T1041] #1: 0000000045afb3be (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.353559][ T1041] 2 locks held by getty/7778: [ 546.358326][ T1041] #0: 00000000de7961da (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.367439][ T1041] #1: 00000000882288f4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.377609][ T1041] 2 locks held by getty/7779: [ 546.382298][ T1041] #0: 00000000ddfc5ec4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.391387][ T1041] #1: 0000000002961abd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.400973][ T1041] 2 locks held by getty/7780: [ 546.405630][ T1041] #0: 0000000070f72c9a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.414905][ T1041] #1: 00000000c18064d9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.424513][ T1041] 2 locks held by getty/7781: [ 546.429219][ T1041] #0: 0000000021adbd7b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 546.438519][ T1041] #1: 00000000971d569f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 546.448328][ T1041] [ 546.450651][ T1041] ============================================= [ 546.450651][ T1041] [ 546.459203][ T1041] NMI backtrace for cpu 0 [ 546.463964][ T1041] CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.1.0-rc1+ #35 [ 546.471492][ T1041] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 546.481532][ T1041] Call Trace: [ 546.484868][ T1041] dump_stack+0x172/0x1f0 [ 546.489198][ T1041] nmi_cpu_backtrace.cold+0x63/0xa4 [ 546.494531][ T1041] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 546.500156][ T1041] nmi_trigger_cpumask_backtrace+0x1be/0x236 [ 546.506598][ T1041] arch_trigger_cpumask_backtrace+0x14/0x20 [ 546.512493][ T1041] watchdog+0x9b7/0xec0 [ 546.516706][ T1041] kthread+0x357/0x430 [ 546.520804][ T1041] ? reset_hung_task_detector+0x30/0x30 [ 546.526426][ T1041] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 546.533012][ T1041] ret_from_fork+0x3a/0x50 [ 546.537678][ T1041] Sending NMI from CPU 0 to CPUs 1: [ 546.542987][ C1] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x2/0x10 [ 546.543926][ T1041] Kernel panic - not syncing: hung_task: blocked tasks [ 546.558691][ T1041] CPU: 0 PID: 1041 Comm: khungtaskd Not tainted 5.1.0-rc1+ #35 [ 546.566253][ T1041] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 546.576755][ T1041] Call Trace: [ 546.580060][ T1041] dump_stack+0x172/0x1f0 [ 546.584391][ T1041] panic+0x2cb/0x65c [ 546.588274][ T1041] ? __warn_printk+0xf3/0xf3 [ 546.592853][ T1041] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 546.598601][ T1041] ? printk_safe_flush+0xf2/0x140 [ 546.603782][ T1041] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 546.610013][ T1041] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 546.615668][ T1041] ? nmi_trigger_cpumask_backtrace+0x1a7/0x236 [ 546.621814][ T1041] ? nmi_trigger_cpumask_backtrace+0x19e/0x236 [ 546.627963][ T1041] watchdog+0x9c8/0xec0 [ 546.632117][ T1041] kthread+0x357/0x430 [ 546.636280][ T1041] ? reset_hung_task_detector+0x30/0x30 [ 546.641822][ T1041] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 546.648059][ T1041] ret_from_fork+0x3a/0x50 [ 546.653538][ T1041] Kernel Offset: disabled [ 546.657926][ T1041] Rebooting in 86400 seconds..