[ 38.225821] audit: type=1800 audit(1550582312.021:26): pid=7726 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 38.262526] audit: type=1800 audit(1550582312.031:27): pid=7726 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [ 38.295564] audit: type=1800 audit(1550582312.031:28): pid=7726 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2417 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. [....] startpar: service(s) returned failure: ssh ...[?25l[?1c7[FAIL8[?25h[?0c failed! Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.71' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 718.592451] hrtimer: interrupt took 47971 ns [ 963.862409] rcu: INFO: rcu_preempt self-detected stall on CPU [ 963.868469] rcu: 1-....: (1 GPs behind) idle=546/1/0x4000000000000002 softirq=14137/14138 fqs=5244 [ 963.877842] rcu: (t=10500 jiffies g=5469 q=1) [ 963.882655] NMI backtrace for cpu 1 [ 963.886280] CPU: 1 PID: 7902 Comm: syz-executor623 Not tainted 5.0.0-rc7+ #79 [ 963.893530] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 963.902976] Call Trace: [ 963.905537] [ 963.907675] dump_stack+0x172/0x1f0 [ 963.911287] nmi_cpu_backtrace.cold+0x63/0xa4 [ 963.915767] ? lapic_can_unplug_cpu.cold+0x38/0x38 [ 963.920681] nmi_trigger_cpumask_backtrace+0x1be/0x236 [ 963.925941] arch_trigger_cpumask_backtrace+0x14/0x20 [ 963.931112] rcu_dump_cpu_stacks+0x183/0x1cf [ 963.935502] ? find_next_bit+0x107/0x130 [ 963.939550] rcu_check_callbacks.cold+0x500/0xa4a [ 963.944382] ? raise_softirq+0x11f/0x310 [ 963.948432] update_process_times+0x32/0x80 [ 963.952742] tick_sched_handle+0xa2/0x190 [ 963.956875] tick_sched_timer+0x47/0x130 [ 963.960921] __hrtimer_run_queues+0x33e/0xde0 [ 963.965402] ? tick_sched_do_timer+0x1b0/0x1b0 [ 963.969969] ? hrtimer_start_range_ns+0xc80/0xc80 [ 963.974794] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 963.979794] ? ktime_get_update_offsets_now+0x2d9/0x440 [ 963.985148] hrtimer_interrupt+0x314/0x770 [ 963.989430] smp_apic_timer_interrupt+0x120/0x570 [ 963.994268] apic_timer_interrupt+0xf/0x20 [ 963.998481] [ 964.000710] RIP: 0010:preempt_count_sub+0x7/0x160 [ 964.005541] Code: d2 fb ff ff 89 4d d0 e8 37 2e 59 00 8b 4d d0 e9 65 fe ff ff 0f 1f 44 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 c7 c0 a0 6a 55 8a <55> 48 ba 00 00 00 00 00 fc ff df 48 89 c1 48 89 e5 53 83 e0 07 48 [ 964.024531] RSP: 0018:ffff888090f875e8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 [ 964.032222] RAX: ffffffff8a556aa0 RBX: 0000000000000002 RCX: 1ffffffff10dcc0d [ 964.039474] RDX: 1ffffffff1134d2d RSI: ffffffff832b0978 RDI: 0000000000000001 [ 964.046728] RBP: ffff888090f87608 R08: ffff88809058a240 R09: ffffed1015d25bd0 [ 964.053986] R10: ffffed1015d25bcf R11: ffff8880ae92de7b R12: ffffffff889a6900 [ 964.061239] R13: ffff888090f876f8 R14: ffffea0002114800 R15: ffff888096c89ab8 [ 964.068508] ? check_preemption_disabled+0x48/0x290 [ 964.073532] ? rcu_lockdep_current_cpu_online+0xe3/0x130 [ 964.078965] rcu_read_lock_held+0x8a/0xd0 [ 964.083105] find_get_entry+0x71d/0x8d0 [ 964.087110] ? find_get_pages_range_tag+0xd90/0xd90 [ 964.092182] ? __lock_is_held+0xb6/0x140 [ 964.096235] pagecache_get_page+0x4a/0x740 [ 964.100461] generic_file_read_iter+0x716/0x2870 [ 964.105266] ? lock_downgrade+0x810/0x810 [ 964.109408] ? filemap_write_and_wait_range+0xd0/0xd0 [ 964.114588] ? aa_file_perm+0x3f6/0xdc0 [ 964.118609] ? aa_path_link+0x460/0x460 [ 964.122577] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 964.128098] ? pipe_unlock+0x57/0x80 [ 964.131792] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 964.137312] ? iter_file_splice_write+0x5a3/0xbe0 [ 964.142144] ? atime_needs_update+0x5f0/0x5f0 [ 964.146628] ext4_file_read_iter+0x180/0x3c0 [ 964.151028] generic_file_splice_read+0x4b2/0x800 [ 964.155870] ? add_to_pipe+0x350/0x350 [ 964.159749] ? rw_verify_area+0x118/0x360 [ 964.163957] ? add_to_pipe+0x350/0x350 [ 964.167844] do_splice_to+0x12a/0x190 [ 964.171646] splice_direct_to_actor+0x2d2/0x970 [ 964.176299] ? generic_pipe_buf_nosteal+0x10/0x10 [ 964.181129] ? do_splice_to+0x190/0x190 [ 964.185087] ? do_splice_direct+0x1b9/0x2a0 [ 964.189394] ? generic_pipe_buf_nosteal+0x10/0x10 [ 964.194219] ? splice_direct_to_actor+0x6/0x970 [ 964.198896] do_splice_direct+0x1da/0x2a0 [ 964.203043] ? splice_direct_to_actor+0x970/0x970 [ 964.208072] ? rcu_read_lock_sched_held+0x110/0x130 [ 964.213077] ? rcu_sync_lockdep_assert+0x73/0xb0 [ 964.217823] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 964.223401] ? __sb_start_write+0x1ac/0x360 [ 964.227721] do_sendfile+0x597/0xd00 [ 964.231430] ? do_compat_pwritev64+0x1c0/0x1c0 [ 964.236005] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 964.241646] ? _copy_from_user+0xdd/0x150 [ 964.245896] __x64_sys_sendfile64+0x15a/0x220 [ 964.250390] ? __ia32_sys_sendfile+0x230/0x230 [ 964.254973] ? do_syscall_64+0x26/0x610 [ 964.258947] ? lockdep_hardirqs_on+0x415/0x5d0 [ 964.263625] ? trace_hardirqs_on+0x67/0x230 [ 964.268429] do_syscall_64+0x103/0x610 [ 964.272312] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 964.277690] RIP: 0033:0x4401c9 [ 964.280884] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 964.299888] RSP: 002b:00007ffe8c94ecc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 [ 964.307589] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401c9 [ 964.314852] RDX: 0000000020000000 RSI: 0000000000000003 RDI: 0000000000000003 [ 964.322478] RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8 [ 964.329894] R10: 00008080fffffffe R11: 0000000000000246 R12: 0000000000401a50 [ 964.337158] R13: 0000000000401ae0 R14: 0000000000000000 R15: 0000000000000000