[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 70.603029][ T27] audit: type=1800 audit(1576164883.165:25): pid=8889 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 70.638217][ T27] audit: type=1800 audit(1576164883.165:26): pid=8889 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 70.664984][ T27] audit: type=1800 audit(1576164883.165:27): pid=8889 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 '10.128.0.150' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program executing program executing program executing program syzkaller login: [ 919.770269][ C0] hrtimer: interrupt took 27202 ns executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 1025.698220][ C0] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: [ 1025.705265][ C0] (detected by 0, t=10502 jiffies, g=8389, q=39) [ 1025.711684][ C0] rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295039703-4295029200), jiffies_till_next_fqs=1, root ->qsmask 0x0 [ 1025.725123][ C0] syz-executor062 R running task 26152 9337 9045 0x00004000 [ 1025.733025][ C0] Call Trace: [ 1025.736305][ C0] [ 1025.739272][ C0] sched_show_task.cold+0x2ee/0x35d [ 1025.744474][ C0] ? can_nice.part.0+0x20/0x20 [ 1025.749277][ C0] ? __sanitizer_cov_trace_cmp8+0x18/0x20 [ 1025.755054][ C0] rcu_sched_clock_irq.cold+0xaf4/0xc02 [ 1025.760652][ C0] update_process_times+0x2d/0x70 [ 1025.765780][ C0] tick_sched_handle+0xa2/0x190 [ 1025.770642][ C0] tick_sched_timer+0x53/0x140 [ 1025.775410][ C0] __hrtimer_run_queues+0x364/0xe40 [ 1025.780615][ C0] ? tick_sched_do_timer+0x1b0/0x1b0 [ 1025.785901][ C0] ? hrtimer_init+0x330/0x330 [ 1025.790575][ C0] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 1025.796286][ C0] ? ktime_get_update_offsets_now+0x2ce/0x430 [ 1025.802354][ C0] hrtimer_interrupt+0x314/0x770 [ 1025.807362][ C0] smp_apic_timer_interrupt+0x160/0x610 [ 1025.812909][ C0] apic_timer_interrupt+0xf/0x20 [ 1025.817835][ C0] [ 1025.820817][ C0] RIP: 0010:kfree+0x239/0x2c0 [ 1025.825494][ C0] Code: 4f 7e 0f 85 20 fe ff ff e8 45 ee 4d ff e9 16 fe ff ff e8 8a 46 c8 ff 48 83 3d fa bb e0 07 00 0f 84 85 00 00 00 48 89 df 57 9d <0f> 1f 44 00 00 5b 41 5c 41 5d 41 5e 5d c3 e8 64 46 c8 ff 48 83 3d [ 1025.845094][ C0] RSP: 0018:ffffc900023e77f8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 [ 1025.854080][ C0] RAX: 0000000000000007 RBX: 0000000000000286 RCX: 0000000000000000 [ 1025.862046][ C0] RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000286 [ 1025.870012][ C0] RBP: ffffc900023e7818 R08: ffff88809eebc300 R09: 0000000000000000 [ 1025.877992][ C0] R10: 0000000000000000 R11: 0000000000000000 R12: ffff888095f8ebc0 [ 1025.885969][ C0] R13: ffff8880aa4001c0 R14: ffffffff83daaa1a R15: dffffc0000000000 [ 1025.894019][ C0] ? tty_open+0x59a/0xbb0 [ 1025.898366][ C0] tty_open+0x59a/0xbb0 [ 1025.902525][ C0] ? tty_init_dev+0x470/0x470 [ 1025.907269][ C0] ? do_raw_spin_unlock+0x178/0x270 [ 1025.912556][ C0] ? tty_init_dev+0x470/0x470 [ 1025.917366][ C0] chrdev_open+0x245/0x6b0 [ 1025.921787][ C0] ? cdev_put.part.0+0x50/0x50 [ 1025.926588][ C0] ? security_file_open+0x87/0x300 [ 1025.931765][ C0] do_dentry_open+0x4e6/0x1380 [ 1025.936532][ C0] ? __kasan_check_read+0x11/0x20 [ 1025.941557][ C0] ? cdev_put.part.0+0x50/0x50 [ 1025.946326][ C0] ? chown_common+0x5c0/0x5c0 [ 1025.953003][ C0] ? inode_permission+0xb4/0x520 [ 1025.957940][ C0] vfs_open+0xa0/0xd0 [ 1025.961971][ C0] path_openat+0x10df/0x4500 [ 1025.966665][ C0] ? save_stack+0x23/0x90 [ 1025.971006][ C0] ? __kasan_kmalloc.constprop.0+0xcf/0xe0 [ 1025.976814][ C0] ? kasan_slab_alloc+0xf/0x20 [ 1025.981573][ C0] ? kmem_cache_alloc+0x121/0x710 [ 1025.986600][ C0] ? getname_flags+0xd6/0x5b0 [ 1025.991299][ C0] ? path_lookupat.isra.0+0x8d0/0x8d0 [ 1025.996747][ C0] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 1026.002260][ C0] ? __alloc_fd+0x487/0x620 [ 1026.006792][ C0] do_filp_open+0x1a1/0x280 [ 1026.011293][ C0] ? may_open_dev+0x100/0x100 [ 1026.015984][ C0] ? do_raw_spin_unlock+0x178/0x270 [ 1026.021195][ C0] do_sys_open+0x3fe/0x5d0 [ 1026.025608][ C0] ? filp_open+0x80/0x80 [ 1026.029857][ C0] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 1026.035312][ C0] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 1026.040769][ C0] ? do_syscall_64+0x26/0x790 [ 1026.045445][ C0] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1026.051509][ C0] ? do_syscall_64+0x26/0x790 [ 1026.056206][ C0] __x64_sys_openat+0x9d/0x100 [ 1026.060968][ C0] do_syscall_64+0xfa/0x790 [ 1026.065473][ C0] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1026.071359][ C0] RIP: 0033:0x4468f9 [ 1026.075256][ C0] Code: e8 0c e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 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 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 1026.094856][ C0] RSP: 002b:00007f505dd44db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 [ 1026.103262][ C0] RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 00000000004468f9 [ 1026.111233][ C0] RDX: 0000000000000000 RSI: 0000000020000380 RDI: ffffffffffffff9c [ 1026.119197][ C0] RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000 [ 1026.127160][ C0] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c [ 1026.135132][ C0] R13: 00007ffe574a581f R14: 00007f505dd459c0 R15: 000000000000002d [ 1026.143124][ C0] rcu: rcu_preempt kthread starved for 10546 jiffies! g8389 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 [ 1026.154212][ C0] rcu: RCU grace-period kthread stack dump: [ 1026.160095][ C0] rcu_preempt R running task 29272 10 2 0x80004000 [ 1026.167990][ C0] Call Trace: [ 1026.171281][ C0] __schedule+0x934/0x1f90 [ 1026.175698][ C0] ? __sched_text_start+0x8/0x8 [ 1026.180556][ C0] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 1026.186353][ C0] ? schedule_timeout+0x47c/0xc50 [ 1026.191472][ C0] ? lockdep_hardirqs_on+0x421/0x5e0 [ 1026.196756][ C0] schedule+0xdc/0x2b0 [ 1026.200822][ C0] schedule_timeout+0x486/0xc50 [ 1026.205758][ C0] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 1026.211824][ C0] ? usleep_range+0x170/0x170 [ 1026.216608][ C0] ? trace_hardirqs_on+0x67/0x240 [ 1026.221641][ C0] ? __next_timer_interrupt+0x1a0/0x1a0 [ 1026.227189][ C0] ? swake_up_one+0x60/0x60 [ 1026.231702][ C0] rcu_gp_kthread+0x9b2/0x18d0 [ 1026.236488][ C0] ? rcu_barrier+0x350/0x350 [ 1026.241077][ C0] ? trace_hardirqs_on+0x67/0x240 [ 1026.246101][ C0] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 1026.252420][ C0] ? __kthread_parkme+0x108/0x1c0 [ 1026.257440][ C0] ? __kasan_check_read+0x11/0x20 [ 1026.262467][ C0] kthread+0x361/0x430 [ 1026.266530][ C0] ? rcu_barrier+0x350/0x350 [ 1026.271115][ C0] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 1026.276839][ C0] ret_from_fork+0x24/0x30