[ 23.736657] audit: type=1800 audit(1542793484.456:21): pid=5771 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="bootlogs" dev="sda1" ino=2419 res=0 [ 23.755543] audit: type=1800 audit(1542793484.456:22): pid=5771 uid=0 auid=4294967295 ses=4294967295 subj=_ op=collect_data cause=failed(directio) comm="startpar" name="motd" dev="sda1" ino=2447 res=0 [....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 25.048588] startpar (5771) used greatest stack depth: 15744 bytes left Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.103' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 100.893936] [ 100.895616] ====================================================== [ 100.901923] WARNING: possible circular locking dependency detected [ 100.908217] 4.20.0-rc3+ #122 Not tainted [ 100.912252] ------------------------------------------------------ [ 100.918552] kworker/0:2/2794 is trying to acquire lock: [ 100.923894] 000000004036ff52 (&sb->s_type->i_mutex_key#9){+.+.}, at: __generic_file_fsync+0xb5/0x200 [ 100.933165] [ 100.933165] but task is already holding lock: [ 100.939112] 000000005a81f984 ((work_completion)(&dio->complete_work)){+.+.}, at: process_one_work+0xb9a/0x1c40 [ 100.949237] [ 100.949237] which lock already depends on the new lock. [ 100.949237] [ 100.957533] [ 100.957533] the existing dependency chain (in reverse order) is: [ 100.965134] [ 100.965134] -> #2 ((work_completion)(&dio->complete_work)){+.+.}: [ 100.972840] process_one_work+0xc0a/0x1c40 [ 100.977569] worker_thread+0x17f/0x1390 [ 100.982056] kthread+0x35a/0x440 [ 100.985935] ret_from_fork+0x3a/0x50 [ 100.990142] [ 100.990142] -> #1 ((wq_completion)"dio/%s"sb->s_id){+.+.}: [ 100.997223] flush_workqueue+0x30a/0x1e10 [ 101.001877] drain_workqueue+0x2a9/0x640 [ 101.006443] destroy_workqueue+0xc6/0x9c0 [ 101.011087] sb_init_dio_done_wq+0x74/0x90 [ 101.015822] do_blockdev_direct_IO+0x1325/0x9db0 [ 101.021073] __blockdev_direct_IO+0x9d/0xc6 [ 101.025895] ext4_direct_IO+0xbe6/0x2230 [ 101.030475] generic_file_direct_write+0x275/0x4b0 [ 101.035910] __generic_file_write_iter+0x2ff/0x630 [ 101.041336] ext4_file_write_iter+0x390/0x1420 [ 101.046415] aio_write+0x3b1/0x610 [ 101.050452] io_submit_one+0xaa1/0xf80 [ 101.054834] __x64_sys_io_submit+0x1b7/0x580 [ 101.059738] do_syscall_64+0x1b9/0x820 [ 101.064132] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 101.069920] [ 101.069920] -> #0 (&sb->s_type->i_mutex_key#9){+.+.}: [ 101.076574] lock_acquire+0x1ed/0x520 [ 101.080875] down_write+0x8a/0x130 [ 101.084993] __generic_file_fsync+0xb5/0x200 [ 101.089906] ext4_sync_file+0xa4f/0x1510 [ 101.094462] vfs_fsync_range+0x140/0x220 [ 101.099018] dio_complete+0x75c/0x9e0 [ 101.103313] dio_aio_complete_work+0x20/0x30 [ 101.108215] process_one_work+0xc90/0x1c40 [ 101.112947] worker_thread+0x17f/0x1390 [ 101.117421] kthread+0x35a/0x440 [ 101.121284] ret_from_fork+0x3a/0x50 [ 101.125489] [ 101.125489] other info that might help us debug this: [ 101.125489] [ 101.133609] Chain exists of: [ 101.133609] &sb->s_type->i_mutex_key#9 --> (wq_completion)"dio/%s"sb->s_id --> (work_completion)(&dio->complete_work) [ 101.133609] [ 101.148876] Possible unsafe locking scenario: [ 101.148876] [ 101.154916] CPU0 CPU1 [ 101.159555] ---- ---- [ 101.164195] lock((work_completion)(&dio->complete_work)); [ 101.169886] lock((wq_completion)"dio/%s"sb->s_id); [ 101.177481] lock((work_completion)(&dio->complete_work)); [ 101.185685] lock(&sb->s_type->i_mutex_key#9); [ 101.190328] [ 101.190328] *** DEADLOCK *** [ 101.190328] [ 101.196381] 2 locks held by kworker/0:2/2794: [ 101.200854] #0: 0000000025665699 ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: process_one_work+0xb43/0x1c40 [ 101.210816] #1: 000000005a81f984 ((work_completion)(&dio->complete_work)){+.+.}, at: process_one_work+0xb9a/0x1c40 [ 101.221374] [ 101.221374] stack backtrace: [ 101.225873] CPU: 0 PID: 2794 Comm: kworker/0:2 Not tainted 4.20.0-rc3+ #122 [ 101.232947] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 101.242404] Workqueue: dio/sda1 dio_aio_complete_work [ 101.247576] Call Trace: [ 101.250155] dump_stack+0x244/0x39d [ 101.253909] ? dump_stack_print_info.cold.1+0x20/0x20 [ 101.259217] ? vprintk_func+0x85/0x181 [ 101.263110] print_circular_bug.isra.35.cold.54+0x1bd/0x27d [ 101.268801] ? save_trace+0xe0/0x290 [ 101.272510] __lock_acquire+0x3399/0x4c20 [ 101.276641] ? mark_held_locks+0x130/0x130 [ 101.280856] ? __read_once_size_nocheck.constprop.8+0x10/0x10 [ 101.286721] ? ret_from_fork+0x3a/0x50 [ 101.290594] ? find_held_lock+0x36/0x1c0 [ 101.294632] ? depot_save_stack+0x292/0x470 [ 101.298934] ? lock_downgrade+0x900/0x900 [ 101.303058] ? zap_class+0x640/0x640 [ 101.306758] ? do_raw_spin_unlock+0xa7/0x330 [ 101.311171] ? trace_hardirqs_on+0x310/0x310 [ 101.315576] ? unwind_next_frame+0x3e/0x50 [ 101.319788] lock_acquire+0x1ed/0x520 [ 101.323568] ? __generic_file_fsync+0xb5/0x200 [ 101.328128] ? lock_release+0xa00/0xa00 [ 101.332086] ? perf_trace_sched_process_exec+0x860/0x860 [ 101.337511] ? __bpf_trace_file_check_and_advance_wb_err+0x30/0x30 [ 101.343818] ? process_one_work+0xc90/0x1c40 [ 101.348199] ? zap_class+0x640/0x640 [ 101.351891] down_write+0x8a/0x130 [ 101.355520] ? __generic_file_fsync+0xb5/0x200 [ 101.360082] ? down_read+0x120/0x120 [ 101.363779] ? file_write_and_wait_range+0x72/0x100 [ 101.368779] __generic_file_fsync+0xb5/0x200 [ 101.373171] ext4_sync_file+0xa4f/0x1510 [ 101.377214] ? ext4_getfsmap+0xd70/0xd70 [ 101.381256] ? ext4_release_io_end+0x1b1/0x250 [ 101.386012] ? rcu_read_lock_sched_held+0x14f/0x180 [ 101.391009] ? kmem_cache_free+0x24f/0x290 [ 101.395218] ? ext4_release_io_end+0x1b1/0x250 [ 101.399779] ? ext4_finish_bio+0xb60/0xb60 [ 101.403995] ? var_wake_function+0x150/0x150 [ 101.408382] ? ext4_getfsmap+0xd70/0xd70 [ 101.412417] vfs_fsync_range+0x140/0x220 [ 101.416486] dio_complete+0x75c/0x9e0 [ 101.420272] dio_aio_complete_work+0x20/0x30 [ 101.424656] process_one_work+0xc90/0x1c40 [ 101.428865] ? mark_held_locks+0x130/0x130 [ 101.433078] ? pwq_dec_nr_in_flight+0x4a0/0x4a0 [ 101.437732] ? __switch_to_asm+0x40/0x70 [ 101.441769] ? __switch_to_asm+0x34/0x70 [ 101.445806] ? __switch_to_asm+0x34/0x70 [ 101.449854] ? __switch_to_asm+0x40/0x70 [ 101.453891] ? __switch_to_asm+0x34/0x70 [ 101.457934] ? __switch_to_asm+0x40/0x70 [ 101.461973] ? __switch_to_asm+0x34/0x70 [ 101.466017] ? __switch_to_asm+0x40/0x70 [ 101.470067] ? __schedule+0x8d7/0x21d0 [ 101.473949] ? lock_downgrade+0x900/0x900 [ 101.478090] ? zap_class+0x640/0x640 [ 101.481889] ? find_held_lock+0x36/0x1c0 [ 101.485931] ? lock_acquire+0x1ed/0x520 [ 101.489886] ? worker_thread+0x3e0/0x1390 [ 101.494015] ? kasan_check_read+0x11/0x20 [ 101.498136] ? do_raw_spin_lock+0x14f/0x350 [ 101.502432] ? kasan_check_read+0x11/0x20 [ 101.506557] ? rwlock_bug.part.2+0x90/0x90 [ 101.510769] ? trace_hardirqs_on+0x310/0x310 [ 101.515167] worker_thread+0x17f/0x1390 [ 101.519120] ? __switch_to_asm+0x34/0x70 [ 101.523165] ? process_one_work+0x1c40/0x1c40 [ 101.527637] ? __sched_text_start+0x8/0x8 [ 101.531766] ? __kthread_parkme+0xce/0x1a0 [ 101.535991] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 101.541082] ? _raw_spin_unlock_irqrestore+0x82/0xd0 [ 101.546158] ? lockdep_hardirqs_on+0x3bb/0x5b0 [ 101.550728] ? trace_hardirqs_on+0xbd/0x310 [ 101.555028] ? kasan_check_read+0x11/0x20 [ 101.559160] ? __kthread_parkme+0xce/0x1a0 [ 101.563377] ? trace_hardirqs_off_caller+0x310/0x310 [ 101.568459] ? _raw_spin_unlock_irqrestore+0x6d/0xd0 [ 101.573551] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 101.579069] ? __kthread_parkme+0xfb/0x1a0 [ 101.583288] ? process_one_work+0x1c40/0x1c40 [ 101.587879] kthread+0x35a/0x440 [ 101.591319] ? kthread_stop+0x900/0x900 [ 101.595272] ret_from_fork+0x3a/0x50 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 101.734226] syz-executor810 (5947) used greatest stack depth: 14752 bytes left 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 [ 101.924567] syz-executor810 (5966) used greatest stack depth: 13976 bytes left 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 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 [ 103.924316] syz-executor810 (6126) used greatest stack depth: 12408 bytes left 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 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 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 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 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