[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.1.75' (ECDSA) to the list of known hosts. executing program executing program executing program syzkaller login: [ 1158.653355] hrtimer: interrupt took 69591 ns [ 1263.658638] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: [ 1263.664976] rcu: (detected by 0, t=10502 jiffies, g=4633, q=28) [ 1263.671131] rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295063364-4295052862), jiffies_till_next_fqs=1, root ->qsmask 0x0 [ 1263.683777] syz-executor765 R running task 27216 8117 8113 0x00000000 [ 1263.690969] Call Trace: [ 1263.693542] [ 1263.695698] sched_show_task.cold+0x332/0x396 [ 1263.700194] ? __se_sys_sched_getattr+0x480/0x480 [ 1263.705037] rcu_check_callbacks.cold+0xb37/0xe19 [ 1263.709894] update_process_times+0x2a/0x70 [ 1263.714214] tick_sched_handle+0x9b/0x180 [ 1263.718362] tick_sched_timer+0xfc/0x290 [ 1263.722432] __hrtimer_run_queues+0x3f6/0xe60 [ 1263.726928] ? tick_nohz_restart_sched_tick+0x310/0x310 [ 1263.732294] ? hrtimer_fixup_free+0xa0/0xa0 [ 1263.736610] ? kvm_clock_get_cycles+0x14/0x30 [ 1263.741101] ? ktime_get_update_offsets_now+0x2ec/0x460 [ 1263.746467] hrtimer_interrupt+0x326/0x9e0 [ 1263.750713] smp_apic_timer_interrupt+0x10c/0x550 [ 1263.755557] apic_timer_interrupt+0xf/0x20 [ 1263.759781] [ 1263.762037] RIP: 0010:__sanitizer_cov_trace_pc+0x22/0x50 [ 1263.767545] Code: 90 90 90 90 90 90 90 90 48 8b 34 24 65 48 8b 04 25 c0 df 01 00 65 8b 15 cc 59 9f 7e 81 e2 00 01 1f 00 75 2b 8b 90 60 13 00 00 <83> fa 02 75 20 48 8b 88 68 13 00 00 8b 80 64 13 00 00 48 8b 11 48 [ 1263.786441] RSP: 0018:ffff8880b02a7200 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 [ 1263.794147] RAX: ffff8880afa421c0 RBX: ffffea00021af840 RCX: ffffffff87eef3cc [ 1263.801416] RDX: 0000000000000000 RSI: ffffffff87eef3e3 RDI: 0000000000000007 [ 1263.808682] RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000001 [ 1263.815943] R10: 0000000000000007 R11: 0000000000000000 R12: ffffea00021af840 [ 1263.823206] R13: ffff8880b1a27740 R14: dffffc0000000000 R15: 0000000000000000 [ 1263.830485] ? __radix_tree_lookup+0x18c/0x370 [ 1263.835064] ? __radix_tree_lookup+0x1a3/0x370 [ 1263.839648] __radix_tree_lookup+0x1a3/0x370 [ 1263.844063] radix_tree_lookup_slot+0x70/0xc0 [ 1263.848552] ? __radix_tree_lookup+0x370/0x370 [ 1263.853131] ? check_preemption_disabled+0x41/0x280 [ 1263.858148] find_get_entry+0x109/0x8a0 [ 1263.862122] ? ext4_expand_extra_isize+0x500/0x500 [ 1263.867048] ? find_get_pages_range_tag+0xc50/0xc50 [ 1263.872072] pagecache_get_page+0x56/0xd50 [ 1263.876313] grab_cache_page_write_begin+0x6a/0xa0 [ 1263.881275] ext4_da_write_begin+0x2ba/0x10e0 [ 1263.885857] ? mark_held_locks+0xa6/0xf0 [ 1263.889918] ? ext4_write_begin+0x1610/0x1610 [ 1263.894412] ? iov_iter_init+0x1d0/0x1d0 [ 1263.898475] generic_perform_write+0x1f8/0x4d0 [ 1263.903079] ? filemap_page_mkwrite+0x2f0/0x2f0 [ 1263.907745] ? current_time+0x1c0/0x1c0 [ 1263.911718] ? lock_acquire+0x170/0x3c0 [ 1263.915691] __generic_file_write_iter+0x24b/0x610 [ 1263.920618] ext4_file_write_iter+0x2fe/0xf20 [ 1263.925109] ? kasan_kmalloc+0x139/0x160 [ 1263.929165] ? ext4_file_open+0x600/0x600 [ 1263.933306] ? iter_file_splice_write+0x168/0xbb0 [ 1263.938145] ? direct_splice_actor+0x115/0x160 [ 1263.942721] ? splice_direct_to_actor+0x33f/0x8d0 [ 1263.947557] ? do_sendfile+0x550/0xc30 [ 1263.951437] ? __se_sys_sendfile64+0xc4/0x160 [ 1263.955926] ? do_syscall_64+0xf9/0x620 [ 1263.959896] ? entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1263.965257] ? common_file_perm+0x4e5/0x850 [ 1263.969580] do_iter_readv_writev+0x668/0x790 [ 1263.974071] ? clone_verify_area+0x240/0x240 [ 1263.978476] ? mark_held_locks+0xa6/0xf0 [ 1263.982539] ? security_file_permission+0x1c0/0x220 [ 1263.987558] do_iter_write+0x182/0x5d0 [ 1263.991446] vfs_iter_write+0x70/0xa0 [ 1263.995246] iter_file_splice_write+0x60d/0xbb0 [ 1263.999918] ? splice_from_pipe_next.part.0+0x360/0x360 [ 1264.005299] ? security_file_permission+0x1c0/0x220 [ 1264.010322] ? splice_from_pipe_next.part.0+0x360/0x360 [ 1264.015692] direct_splice_actor+0x115/0x160 [ 1264.020106] splice_direct_to_actor+0x33f/0x8d0 [ 1264.024783] ? generic_pipe_buf_nosteal+0x10/0x10 [ 1264.029630] ? do_splice_to+0x160/0x160 [ 1264.033609] do_splice_direct+0x1a7/0x270 [ 1264.037756] ? splice_direct_to_actor+0x8d0/0x8d0 [ 1264.042600] ? rcu_read_lock_sched_held+0x16c/0x1d0 [ 1264.047616] do_sendfile+0x550/0xc30 [ 1264.051335] ? do_compat_pwritev64+0x1b0/0x1b0 [ 1264.055916] ? __might_fault+0x192/0x1d0 [ 1264.059987] __se_sys_sendfile64+0xc4/0x160 [ 1264.064321] ? __se_sys_sendfile+0x180/0x180 [ 1264.068749] ? trace_hardirqs_off_caller+0x6e/0x210 [ 1264.073768] ? do_syscall_64+0x21/0x620 [ 1264.077755] do_syscall_64+0xf9/0x620 [ 1264.081560] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 1264.086746] RIP: 0033:0x7f6d8dd06c59 [ 1264.090458] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 [ 1264.109353] RSP: 002b:00007fff7bee0d38 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 [ 1264.117057] RAX: ffffffffffffffda RBX: 00007fff7bee0f18 RCX: 00007f6d8dd06c59 [ 1264.124319] RDX: 00000000200001c0 RSI: 0000000000000003 RDI: 0000000000000003 [ 1264.131679] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 [ 1264.138940] R10: 000000000200a198 R11: 0000000000000246 R12: 00007fff7bee0d6c [ 1264.146209] R13: 0000000000000000 R14: 00007fff7bee0d80 R15: 0000000000000000 [ 1264.153491] rcu: rcu_preempt kthread starved for 10502 jiffies! g4633 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 [ 1264.163876] rcu: RCU grace-period kthread stack dump: [ 1264.169052] rcu_preempt R running task 29208 10 2 0x80000000 [ 1264.176239] Call Trace: [ 1264.178824] __schedule+0x887/0x2040 [ 1264.182537] ? io_schedule_timeout+0x140/0x140 [ 1264.187123] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 1264.192220] schedule+0x8d/0x1b0 [ 1264.195581] schedule_timeout+0x4cf/0xfe0 [ 1264.199723] ? prepare_to_swait_event+0x5b/0x540 [ 1264.204472] ? usleep_range+0x170/0x170 [ 1264.208437] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 1264.213535] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 1264.218116] ? collect_expired_timers+0x2a0/0x2a0 [ 1264.222954] ? swake_up_all+0x340/0x340 [ 1264.226930] rcu_gp_kthread+0xdad/0x21c0 [ 1264.230996] ? lock_acquire+0x170/0x3c0 [ 1264.234968] ? __rcu_read_unlock+0x160/0x160 [ 1264.239374] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 1264.244471] ? lockdep_hardirqs_on+0x3a8/0x5c0 [ 1264.249060] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 1264.254156] ? __kthread_parkme+0x133/0x1e0 [ 1264.258476] ? __rcu_read_unlock+0x160/0x160 [ 1264.262878] kthread+0x33f/0x460 [ 1264.266237] ? kthread_park+0x180/0x180 [ 1264.270207] ret_from_fork+0x24/0x30