[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.244' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 485.232868][ T1043] INFO: task syz-executor370:7818 blocked for more than 143 seconds. [ 485.241284][ T1043] Not tainted 5.1.0-rc5+ #70 [ 485.247064][ T1043] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 485.255994][ T1043] syz-executor370 D28120 7818 7794 0x00000004 [ 485.262353][ T1043] Call Trace: [ 485.265883][ T1043] __schedule+0x813/0x1cc0 [ 485.270307][ T1043] ? trace_hardirqs_on+0x67/0x230 [ 485.275468][ T1043] ? kasan_check_read+0x11/0x20 [ 485.280384][ T1043] ? __sched_text_start+0x8/0x8 [ 485.285439][ T1043] ? __lock_acquire+0x548/0x3fb0 [ 485.290385][ T1043] ? finish_task_switch+0x1f0/0x780 [ 485.295697][ T1043] ? __switch_to_asm+0x40/0x70 [ 485.300539][ T1043] schedule+0x92/0x180 [ 485.304709][ T1043] schedule_timeout+0x8ca/0xfd0 [ 485.309562][ T1043] ? wait_for_completion+0x294/0x440 [ 485.315156][ T1043] ? find_held_lock+0x35/0x130 [ 485.319937][ T1043] ? usleep_range+0x170/0x170 [ 485.324815][ T1043] ? mark_held_locks+0xa4/0xf0 [ 485.329707][ T1043] ? _raw_spin_unlock_irq+0x28/0x90 [ 485.335213][ T1043] ? wait_for_completion+0x294/0x440 [ 485.340570][ T1043] ? _raw_spin_unlock_irq+0x28/0x90 [ 485.345885][ T1043] ? lockdep_hardirqs_on+0x418/0x5d0 [ 485.351393][ T1043] ? trace_hardirqs_on+0x67/0x230 [ 485.357367][ T1043] ? kasan_check_read+0x11/0x20 [ 485.362374][ T1043] wait_for_completion+0x29c/0x440 [ 485.367616][ T1043] ? wait_for_completion_interruptible+0x4b0/0x4b0 [ 485.374839][ T1043] ? wake_up_q+0xf0/0xf0 [ 485.379247][ T1043] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 485.385815][ T1043] ? pcrypt_aead_encrypt+0x372/0x470 [ 485.391311][ T1043] aead_recvmsg+0x1492/0x1ab0 [ 485.396131][ T1043] ? aead_release+0x50/0x50 [ 485.400985][ T1043] ? apparmor_socket_recvmsg+0x2a/0x30 [ 485.406594][ T1043] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 485.412913][ T1043] ? security_socket_recvmsg+0x9b/0xd0 [ 485.418482][ T1043] ? aead_release+0x50/0x50 [ 485.423145][ T1043] sock_recvmsg+0xd0/0x110 [ 485.427604][ T1043] sock_read_iter+0x299/0x3b0 [ 485.432365][ T1043] ? sock_recvmsg+0x110/0x110 [ 485.437181][ T1043] ? fsnotify+0xbc0/0xbc0 [ 485.441631][ T1043] do_iter_readv_writev+0x700/0x8e0 [ 485.447054][ T1043] ? vfs_dedupe_file_range+0x780/0x780 [ 485.452666][ T1043] ? rw_verify_area+0x118/0x360 [ 485.457544][ T1043] do_iter_read+0x27c/0x660 [ 485.462143][ T1043] ? dup_iter+0x260/0x260 [ 485.466579][ T1043] ? lock_downgrade+0x880/0x880 [ 485.471454][ T1043] vfs_readv+0xf0/0x160 [ 485.475902][ T1043] ? compat_rw_copy_check_uvector+0x3f0/0x3f0 [ 485.482044][ T1043] ? __sys_sendmmsg+0x3ac/0x4d0 [ 485.487017][ T1043] ? __fd_install+0x200/0x640 [ 485.491867][ T1043] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 485.498279][ T1043] ? __fget_light+0x1a9/0x230 [ 485.503592][ T1043] do_readv+0x15e/0x370 [ 485.508015][ T1043] ? vfs_readv+0x160/0x160 [ 485.512726][ T1043] ? do_syscall_64+0x26/0x610 [ 485.517468][ T1043] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 485.523812][ T1043] ? do_syscall_64+0x26/0x610 [ 485.528513][ T1043] __x64_sys_readv+0x75/0xb0 [ 485.533217][ T1043] do_syscall_64+0x103/0x610 [ 485.537946][ T1043] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 485.543995][ T1043] RIP: 0033:0x441349 [ 485.547924][ T1043] Code: Bad RIP value. [ 485.551987][ T1043] RSP: 002b:00007ffd03d84728 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 [ 485.560621][ T1043] RAX: ffffffffffffffda RBX: 00000000004a23d8 RCX: 0000000000441349 [ 485.569038][ T1043] RDX: 0000000000000001 RSI: 00000000200007c0 RDI: 0000000000000004 [ 485.577312][ T1043] RBP: 0000000000052e64 R08: 00000000004002c8 R09: 00000000004002c8 [ 485.585364][ T1043] R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000402170 [ 485.593443][ T1043] R13: 0000000000402200 R14: 0000000000000000 R15: 0000000000000000 [ 485.601453][ T1043] [ 485.601453][ T1043] Showing all locks held in the system: [ 485.609420][ T1043] 1 lock held by khungtaskd/1043: [ 485.614550][ T1043] #0: 00000000e2e42ae5 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e [ 485.624180][ T1043] 1 lock held by rsyslogd/7678: [ 485.629313][ T1043] #0: 0000000033d8ba67 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 [ 485.639341][ T1043] 2 locks held by getty/7768: [ 485.644397][ T1043] #0: 00000000695c8b33 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 485.653618][ T1043] #1: 00000000b0b463f2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 485.663391][ T1043] 2 locks held by getty/7769: [ 485.668066][ T1043] #0: 000000006818530d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 485.677174][ T1043] #1: 00000000ed610f73 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 485.686958][ T1043] 2 locks held by getty/7770: [ 485.691745][ T1043] #0: 00000000fbcde1ed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 485.700799][ T1043] #1: 00000000817f6048 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 485.710585][ T1043] 2 locks held by getty/7771: [ 485.715765][ T1043] #0: 000000001606e8d4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 485.725090][ T1043] #1: 0000000005557a95 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 485.735676][ T1043] 2 locks held by getty/7772: [ 485.740780][ T1043] #0: 00000000f6ef863e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 485.749877][ T1043] #1: 00000000c55157f8 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 485.759660][ T1043] 2 locks held by getty/7773: [ 485.764913][ T1043] #0: 000000004cd964f4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 485.773999][ T1043] #1: 0000000091a9b2ef (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 485.784096][ T1043] 2 locks held by getty/7774: [ 485.788779][ T1043] #0: 00000000e33d0631 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 [ 485.797946][ T1043] #1: 0000000001081adc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 [ 485.807612][ T1043] 1 lock held by syz-executor370/7818: [ 485.813207][ T1043] #0: 000000009baf1423 (sk_lock-AF_ALG){+.+.}, at: af_alg_wait_for_data+0x215/0x540 [ 485.823393][ T1043] [ 485.825864][ T1043] ============================================= [ 485.825864][ T1043] [ 485.834608][ T1043] NMI backtrace for cpu 0 [ 485.838966][ T1043] CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc5+ #70 [ 485.846554][ T1043] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 485.856616][ T1043] Call Trace: [ 485.859927][ T1043] dump_stack+0x172/0x1f0 [ 485.864288][ T1043] nmi_cpu_backtrace.cold+0x63/0xa4 [ 485.869665][ T1043] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 485.875411][ T1043] nmi_trigger_cpumask_backtrace+0x1be/0x236 [ 485.881430][ T1043] arch_trigger_cpumask_backtrace+0x14/0x20 [ 485.887358][ T1043] watchdog+0x9b7/0xec0 [ 485.891877][ T1043] kthread+0x357/0x430 [ 485.895968][ T1043] ? reset_hung_task_detector+0x30/0x30 [ 485.901748][ T1043] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 485.908105][ T1043] ret_from_fork+0x3a/0x50 [ 485.912768][ T1043] Sending NMI from CPU 0 to CPUs 1: [ 485.918069][ C1] NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x2/0x10 [ 485.919412][ T1043] Kernel panic - not syncing: hung_task: blocked tasks [ 485.933262][ T1043] CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc5+ #70 [ 485.941183][ T1043] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 485.951305][ T1043] Call Trace: [ 485.954767][ T1043] dump_stack+0x172/0x1f0 [ 485.959119][ T1043] panic+0x2cb/0x65c [ 485.963004][ T1043] ? __warn_printk+0xf3/0xf3 [ 485.967590][ T1043] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 485.973216][ T1043] ? ___preempt_schedule+0x16/0x18 [ 485.978336][ T1043] ? nmi_trigger_cpumask_backtrace+0x19e/0x236 [ 485.984580][ T1043] ? nmi_trigger_cpumask_backtrace+0x1fa/0x236 [ 485.991044][ T1043] ? nmi_trigger_cpumask_backtrace+0x204/0x236 [ 485.997207][ T1043] ? nmi_trigger_cpumask_backtrace+0x19e/0x236 [ 486.003408][ T1043] watchdog+0x9c8/0xec0 [ 486.007561][ T1043] kthread+0x357/0x430 [ 486.011735][ T1043] ? reset_hung_task_detector+0x30/0x30 [ 486.017336][ T1043] ? kthread_cancel_delayed_work_sync+0x20/0x20 [ 486.023596][ T1043] ret_from_fork+0x3a/0x50 [ 486.029121][ T1043] Kernel Offset: disabled [ 486.033466][ T1043] Rebooting in 86400 seconds..