[ OK ] Started OpenBSD Secure Shell server. [ OK ] Reached target Multi-User System. [ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.219' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 309.280467] MINIX-fs: mounting unchecked file system, running fsck is recommended [ 309.285744] MINIX-fs: mounting unchecked file system, running fsck is recommended [ 309.296901] MINIX-fs: mounting unchecked file system, running fsck is recommended [ 309.305198] MINIX-fs: mounting unchecked file system, running fsck is recommended [ 309.317101] MINIX-fs: mounting unchecked file system, running fsck is recommended [ 309.330508] hrtimer: interrupt took 25716 ns [ 414.344024] INFO: rcu_preempt detected stalls on CPUs/tasks: [ 414.349974] (detected by 0, t=10502 jiffies, g=985, c=984, q=145) [ 414.356291] All QSes seen, last rcu_preempt kthread activity 10503 (4294978738-4294968235), jiffies_till_next_fqs=1, root ->qsmask 0x0 [ 414.368496] syz-executor136 R running task 25736 7994 7987 0x80000000 [ 414.375721] Call Trace: [ 414.378323] [ 414.381200] sched_show_task.cold+0x333/0x39a [ 414.385735] rcu_check_callbacks.cold+0xd29/0xd99 [ 414.390591] ? __raise_softirq_irqoff+0x14e/0x1d0 [ 414.395457] update_process_times+0x28/0xa0 [ 414.399796] tick_sched_handle+0x7d/0x150 [ 414.403931] tick_sched_timer+0x92/0x200 [ 414.407982] __hrtimer_run_queues+0x30b/0xc80 [ 414.412559] ? tick_do_update_jiffies64.part.0+0x270/0x270 [ 414.418173] ? retrigger_next_event+0x310/0x310 [ 414.422830] ? ktime_get_update_offsets_now+0x272/0x3f0 [ 414.428184] hrtimer_interrupt+0x1e6/0x5e0 [ 414.432487] smp_apic_timer_interrupt+0x117/0x5e0 [ 414.437321] apic_timer_interrupt+0x93/0xa0 [ 414.441627] [ 414.443852] RIP: 0010:_raw_spin_unlock_irq+0x50/0x80 [ 414.448939] RSP: 0018:ffff88809d6b71e8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 [ 414.456636] RAX: 1ffffffff11e1233 RBX: ffff88808e3252e8 RCX: 1ffff110169b616d [ 414.463892] RDX: dffffc0000000000 RSI: ffff8880b4db0b48 RDI: ffff8880b4db0b44 [ 414.471188] RBP: ffff88808e3252e8 R08: 0000000000000000 R09: 0000000000000000 [ 414.478449] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 414.485709] R13: 1ffff11013ad6e43 R14: 0000000000000000 R15: ffff88808e3252d0 [ 414.492988] ? _raw_spin_unlock_irq+0x24/0x80 [ 414.497517] __add_to_page_cache_locked+0x499/0x840 [ 414.502523] ? page_cache_tree_insert+0x2a0/0x2a0 [ 414.507389] ? __lru_cache_add+0x178/0x250 [ 414.511615] add_to_page_cache_lru+0xcf/0x2b0 [ 414.516099] ? add_to_page_cache_locked+0x40/0x40 [ 414.520956] __do_page_cache_readahead+0x659/0x940 [ 414.525880] ? read_cache_pages+0x6a0/0x6a0 [ 414.530188] ? find_get_entry+0x312/0x630 [ 414.534381] ? inode_congested+0x31f/0x5d0 [ 414.538626] ? lock_acquire+0x170/0x3f0 [ 414.542589] ? lock_downgrade+0x740/0x740 [ 414.546727] ondemand_readahead.isra.0+0x514/0xb60 [ 414.551996] page_cache_async_readahead+0x16e/0x1d0 [ 414.557003] generic_file_read_iter+0xea3/0x21c0 [ 414.561818] ? iov_iter_init+0xa6/0x1c0 [ 414.565830] __vfs_read+0x449/0x620 [ 414.569448] ? vfs_copy_file_range+0x9b0/0x9b0 [ 414.574038] ? kernel_fpu_end+0xf4/0x140 [ 414.578093] ? kernel_fpu_enable+0x30/0x30 [ 414.582447] integrity_kernel_read+0x11b/0x1b0 [ 414.587017] ? integrity_inode_free+0x300/0x300 [ 414.591678] ima_calc_file_hash+0x430/0x830 [ 414.595992] ? ima_alloc_tfm+0x9a/0xc0 [ 414.599869] ? ima_calc_file_hash+0x148/0x830 [ 414.604358] ima_collect_measurement+0x39d/0x430 [ 414.609104] ? ima_get_action+0x70/0x70 [ 414.613068] ? vfs_getxattr_alloc+0xc8/0x2d0 [ 414.617468] ? ima_get_cache_status+0x170/0x170 [ 414.622129] process_measurement+0x78b/0xb20 [ 414.626529] ? ima_rdwr_violation_check+0x3a0/0x3a0 [ 414.631576] ? apparmor_file_open+0x4ed/0x910 [ 414.636063] ? retint_kernel+0x2d/0x2d [ 414.639939] ? apparmor_file_alloc_security+0x800/0x800 [ 414.645354] ? security_file_open+0x82/0x190 [ 414.649748] ? file_ra_state_init+0xc4/0x1e0 [ 414.654145] ? do_dentry_open+0x698/0xec0 [ 414.658300] ? __inode_permission+0xcd/0x2f0 [ 414.662700] ? vfs_open+0x10d/0x220 [ 414.666320] path_openat+0x10ad/0x2970 [ 414.670204] ? path_lookupat+0x780/0x780 [ 414.674253] ? trace_hardirqs_on+0x10/0x10 [ 414.678502] ? retint_kernel+0x2d/0x2d [ 414.682382] do_filp_open+0x179/0x3c0 [ 414.686194] ? may_open_dev+0xe0/0xe0 [ 414.689992] ? lock_downgrade+0x740/0x740 [ 414.694176] ? do_raw_spin_unlock+0x164/0x220 [ 414.698661] ? _raw_spin_unlock+0x29/0x40 [ 414.702794] ? __alloc_fd+0x1be/0x490 [ 414.706591] do_sys_open+0x296/0x410 [ 414.710293] ? filp_open+0x60/0x60 [ 414.713837] ? do_syscall_64+0x4c/0x640 [ 414.717883] ? do_sys_open+0x410/0x410 [ 414.721759] do_syscall_64+0x1d5/0x640 [ 414.725641] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 414.730903] RIP: 0033:0x4456e9 [ 414.734080] RSP: 002b:00007ffd6e6eaaa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 [ 414.741776] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004456e9 [ 414.749038] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200000c0 [ 414.756293] RBP: 00000000006d0018 R08: 0000000000000001 R09: 0000000000000001 [ 414.763550] R10: 0000000000000001 R11: 0000000000000246 R12: 00000000004027a0 [ 414.770805] R13: 0000000000402830 R14: 0000000000000000 R15: 0000000000000000 [ 414.778077] rcu_preempt kthread starved for 10545 jiffies! g985 c984 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0 [ 414.788389] rcu_preempt R running task 30008 8 2 0x80000000 [ 414.795581] Call Trace: [ 414.798161] __schedule+0x88b/0x1de0 [ 414.801894] ? schedule_timeout+0x4a5/0xe90 [ 414.806208] ? io_schedule_timeout+0x140/0x140 [ 414.810780] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 414.815874] schedule+0x8d/0x1b0 [ 414.819229] schedule_timeout+0x4af/0xe90 [ 414.823364] ? _raw_spin_unlock_irqrestore+0x79/0xe0 [ 414.828473] ? usleep_range+0x130/0x130 [ 414.832436] ? _raw_spin_unlock_irqrestore+0x66/0xe0 [ 414.837526] ? prepare_to_swait+0x115/0x2a0 [ 414.841836] ? run_timer_softirq+0x5a0/0x5a0 [ 414.846242] rcu_gp_kthread+0xc0a/0x1e60 [ 414.850302] ? force_qs_rnp+0x4f0/0x4f0 [ 414.854265] ? force_qs_rnp+0x4f0/0x4f0 [ 414.858282] kthread+0x30d/0x420 [ 414.861638] ? kthread_create_on_node+0xd0/0xd0 [ 414.866299] ret_from_fork+0x24/0x30