[ 57.557888][ T25] audit: type=1800 audit(1573231865.637:25): pid=7833 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 57.580392][ T25] audit: type=1800 audit(1573231865.637:26): pid=7833 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 57.629015][ T25] audit: type=1800 audit(1573231865.647:27): pid=7833 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0 [ 57.649391][ T25] audit: type=1800 audit(1573231865.647:28): pid=7833 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2450 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 '10.128.10.1' (ECDSA) to the list of known hosts. 2019/11/08 16:51:15 fuzzer started 2019/11/08 16:51:17 dialing manager at 10.128.0.105:41185 2019/11/08 16:51:18 syscalls: 2553 2019/11/08 16:51:18 code coverage: enabled 2019/11/08 16:51:18 comparison tracing: enabled 2019/11/08 16:51:18 extra coverage: extra coverage is not supported by the kernel 2019/11/08 16:51:18 setuid sandbox: enabled 2019/11/08 16:51:18 namespace sandbox: enabled 2019/11/08 16:51:18 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/08 16:51:18 fault injection: enabled 2019/11/08 16:51:18 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/08 16:51:18 net packet injection: enabled 2019/11/08 16:51:18 net device setup: enabled 2019/11/08 16:51:18 concurrency sanitizer: enabled 2019/11/08 16:51:18 devlink PCI setup: PCI device 0000:00:10.0 is not available syzkaller login: [ 71.740198][ T8004] KCSAN: could not find function: 'poll_schedule_timeout' [ 81.613392][ T8004] KCSAN: could not find function: 'may_open' 2019/11/08 16:51:33 adding functions to KCSAN blacklist: 'task_dump_owner' 'do_exit' '__dev_queue_xmit' '__ext4_new_inode' 'ktime_get_seconds' 'p9_poll_workfn' 'poll_schedule_timeout' 'mem_cgroup_select_victim_node' 'timer_clear_idle' 'ext4_da_write_end' 'snd_seq_check_queue' 'do_dentry_open' 'blk_mq_dispatch_rq_list' 'ext4_nonda_switch' 'xas_clear_mark' 'ext4_has_free_clusters' 'audit_log_start' 'kauditd_thread' 'd_lru_del' 'run_timer_softirq' 'find_get_pages_range_tag' 'enqueue_timer' 'pid_update_inode' 'n_tty_receive_buf_common' 'blk_mq_get_request' 'inactive_list_is_low' 'ext4_free_inodes_count' '__hrtimer_run_queues' 'common_perm_cond' 'wbc_attach_and_unlock_inode' '__perf_event_overflow' 'inet_putpeer' 'add_timer' 'tick_nohz_idle_stop_tick' 'find_next_bit' 'pipe_poll' 'tcp_add_backlog' 'ep_poll' 'pcpu_alloc' 'copy_process' 'fanout_demux_rollover' '__alloc_file' 'generic_permission' 'tomoyo_supervisor' 'shmem_file_read_iter' 'vm_area_dup' 'rcu_gp_fqs_loop' 'xas_find_marked' '__snd_rawmidi_transmit_ack' 'futex_wait_queue_me' 'add_timer_on' 'snd_seq_prioq_cell_out' 'list_lru_count_one' 'mod_timer' '__tcp_transmit_skb' '__ext4_abort' 'exit_signals' 'shrink_node' 'virtqueue_disable_cb' 'ext4_free_inode' '__inode_add_bytes' 'writeback_sb_inodes' 'inode_sync_complete' 'ktime_get_real_seconds' 'generic_write_end' 'blk_mq_sched_dispatch_requests' 'queue_access_lock' 'wbc_detach_inode' 'fsnotify' 'hrtimer_wakeup' 'may_open' 'taskstats_exit' 'blk_mq_run_hw_queue' 'generic_fillattr' '__ip6_datagram_connect' '__remove_hrtimer' 'snapshot_refaults' 'evict' 'tick_sched_do_timer' 'pipe_wait' 'lruvec_lru_size' 'sit_tunnel_xmit' 'atime_needs_update' 'page_counter_try_charge' 'do_syslog' 'do_nanosleep' 'process_srcu' 'echo_char' 'mm_update_next_owner' 'rcu_gp_fqs_check_wake' 'padata_find_next' 'wbt_done' 'kcm_rfree' 'kvm_arch_vcpu_load' 'tick_do_update_jiffies64' 'ima_file_free' 'dd_has_work' '__d_lookup_done' [ 92.393991][ T2637] ================================================================== [ 92.402308][ T2637] BUG: KCSAN: data-race in calc_wb_limits.part.0 / wbt_wait [ 92.409729][ T2637] [ 92.412084][ T2637] write to 0xffff888128c69d04 of 4 bytes by interrupt on cpu 0: [ 92.419883][ T2637] calc_wb_limits.part.0+0x7b/0xb0 [ 92.425026][ T2637] scale_up+0x7f/0x250 [ 92.429358][ T2637] wb_timer_fn+0x2cd/0xad0 [ 92.434337][ T2637] blk_stat_timer_fn+0x3b0/0x3d0 [ 92.439304][ T2637] call_timer_fn+0x5f/0x2f0 [ 92.443846][ T2637] run_timer_softirq+0xc0c/0xcd0 [ 92.448809][ T2637] __do_softirq+0x115/0x33f [ 92.453350][ T2637] run_ksoftirqd+0x46/0x60 [ 92.457799][ T2637] smpboot_thread_fn+0x37d/0x4a0 [ 92.462765][ T2637] kthread+0x1d4/0x200 [ 92.466853][ T2637] ret_from_fork+0x1f/0x30 [ 92.471267][ T2637] [ 92.473622][ T2637] read to 0xffff888128c69d04 of 4 bytes by task 2637 on cpu 1: [ 92.481189][ T2637] wbt_wait+0x52/0x250 [ 92.485287][ T2637] __rq_qos_throttle+0x47/0x70 [ 92.490068][ T2637] blk_mq_make_request+0x29c/0xf60 [ 92.495200][ T2637] generic_make_request+0x196/0x740 [ 92.500407][ T2637] submit_bio+0x96/0x3c0 [ 92.504671][ T2637] ext4_io_submit+0xdf/0x110 [ 92.509283][ T2637] ext4_writepages+0xea9/0x2300 [ 92.514160][ T2637] do_writepages+0x6b/0x170 [ 92.518706][ T2637] __writeback_single_inode+0xaf/0x8e0 [ 92.524186][ T2637] writeback_sb_inodes+0x4ba/0xa50 [ 92.529319][ T2637] __writeback_inodes_wb+0xe8/0x1b0 [ 92.534543][ T2637] wb_writeback+0x557/0x6a0 [ 92.539073][ T2637] wb_workfn+0x7bb/0x970 [ 92.543349][ T2637] process_one_work+0x3d4/0x890 [ 92.548223][ T2637] worker_thread+0xa0/0x800 [ 92.552738][ T2637] kthread+0x1d4/0x200 [ 92.556811][ T2637] ret_from_fork+0x1f/0x30 [ 92.561220][ T2637] [ 92.563553][ T2637] Reported by Kernel Concurrency Sanitizer on: [ 92.569724][ T2637] CPU: 1 PID: 2637 Comm: kworker/u4:4 Not tainted 5.4.0-rc6+ #0 [ 92.577365][ T2637] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 92.587445][ T2637] Workqueue: writeback wb_workfn (flush-8:0) [ 92.593432][ T2637] ================================================================== [ 92.601502][ T2637] Kernel panic - not syncing: panic_on_warn set ... [ 92.608109][ T2637] CPU: 1 PID: 2637 Comm: kworker/u4:4 Not tainted 5.4.0-rc6+ #0 [ 92.615748][ T2637] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 92.625828][ T2637] Workqueue: writeback wb_workfn (flush-8:0) [ 92.631825][ T2637] Call Trace: [ 92.635154][ T2637] dump_stack+0xf5/0x159 [ 92.639413][ T2637] panic+0x210/0x640 [ 92.644555][ T2637] ? vprintk_func+0x8d/0x140 [ 92.649170][ T2637] kcsan_report.cold+0xc/0xe [ 92.653794][ T2637] kcsan_setup_watchpoint+0x3fe/0x410 [ 92.659197][ T2637] __tsan_read4+0x145/0x1f0 [ 92.663718][ T2637] ? wbt_cleanup+0x80/0x80 [ 92.668151][ T2637] wbt_wait+0x52/0x250 [ 92.672252][ T2637] ? bio_integrity_prep+0x111/0x560 [ 92.677483][ T2637] ? wbt_cleanup+0x80/0x80 [ 92.681932][ T2637] __rq_qos_throttle+0x47/0x70 [ 92.686720][ T2637] blk_mq_make_request+0x29c/0xf60 [ 92.691865][ T2637] generic_make_request+0x196/0x740 [ 92.697102][ T2637] ? mpage_release_unused_pages+0x438/0x4f0 [ 92.703012][ T2637] submit_bio+0x96/0x3c0 [ 92.707283][ T2637] ext4_io_submit+0xdf/0x110 [ 92.711894][ T2637] ext4_writepages+0xea9/0x2300 [ 92.716785][ T2637] ? __ext4_get_inode_loc+0x272/0x960 [ 92.722190][ T2637] ? ext4_mark_inode_dirty+0x420/0x420 [ 92.727672][ T2637] do_writepages+0x6b/0x170 [ 92.732197][ T2637] ? do_writepages+0x6b/0x170 [ 92.736895][ T2637] ? ext4_write_inode+0xa9/0x330 [ 92.741863][ T2637] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 92.747785][ T2637] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 92.753707][ T2637] __writeback_single_inode+0xaf/0x8e0 [ 92.759218][ T2637] ? __sanitizer_cov_trace_const_cmp8+0x18/0x20 [ 92.765487][ T2637] ? __sanitizer_cov_trace_switch+0x49/0x80 [ 92.771412][ T2637] writeback_sb_inodes+0x4ba/0xa50 [ 92.776575][ T2637] __writeback_inodes_wb+0xe8/0x1b0 [ 92.781814][ T2637] wb_writeback+0x557/0x6a0 [ 92.786354][ T2637] ? cpumask_next+0x35/0x40 [ 92.790891][ T2637] wb_workfn+0x7bb/0x970 [ 92.795157][ T2637] process_one_work+0x3d4/0x890 [ 92.800039][ T2637] worker_thread+0xa0/0x800 [ 92.804577][ T2637] kthread+0x1d4/0x200 [ 92.808686][ T2637] ? rescuer_thread+0x6a0/0x6a0 [ 92.813548][ T2637] ? kthread_stop+0x2d0/0x2d0 [ 92.818250][ T2637] ret_from_fork+0x1f/0x30 [ 92.824080][ T2637] Kernel Offset: disabled [ 92.828441][ T2637] Rebooting in 86400 seconds..