[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 56.042163][ T26] audit: type=1800 audit(1573548923.208:25): pid=7445 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 56.082476][ T26] audit: type=1800 audit(1573548923.208:26): pid=7445 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 56.112618][ T26] audit: type=1800 audit(1573548923.208:27): pid=7445 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 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 '10.128.0.29' (ECDSA) to the list of known hosts. 2019/11/12 08:55:34 fuzzer started 2019/11/12 08:55:36 dialing manager at 10.128.0.105:45453 2019/11/12 08:55:37 syscalls: 2566 2019/11/12 08:55:37 code coverage: enabled 2019/11/12 08:55:37 comparison tracing: enabled 2019/11/12 08:55:37 extra coverage: extra coverage is not supported by the kernel 2019/11/12 08:55:37 setuid sandbox: enabled 2019/11/12 08:55:37 namespace sandbox: enabled 2019/11/12 08:55:37 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/12 08:55:37 fault injection: enabled 2019/11/12 08:55:37 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/12 08:55:37 net packet injection: enabled 2019/11/12 08:55:37 net device setup: enabled 2019/11/12 08:55:37 concurrency sanitizer: enabled 2019/11/12 08:55:37 devlink PCI setup: PCI device 0000:00:10.0 is not available 2019/11/12 08:55:40 adding functions to KCSAN blacklist: 'tick_sched_do_timer' 'vfs_fsync_range' 'find_get_pages_range_tag' 'kauditd_thread' 'generic_write_end' 'pid_update_inode' 'tick_do_update_jiffies64' 'generic_file_read_iter' 'ep_poll' 'vm_area_dup' 'blk_mq_free_request' 'mod_timer' 'add_timer' 'find_next_bit' 'tcp_add_backlog' 'taskstats_exit' 'xas_clear_mark' 'blk_mq_sched_dispatch_requests' 'run_timer_softirq' 'do_nanosleep' '__hrtimer_run_queues' 'blk_mq_dispatch_rq_list' 'tomoyo_supervisor' 'pipe_poll' '__ext4_new_inode' syzkaller login: [ 88.937313][ T0] ================================================================== [ 88.945449][ T0] BUG: KCSAN: data-race in tick_nohz_idle_stop_tick / tick_nohz_idle_stop_tick [ 88.954395][ T0] [ 88.956714][ T0] write to 0xffffffff85cb3c90 of 4 bytes by task 0 on cpu 1: [ 88.964070][ T0] tick_nohz_idle_stop_tick+0x525/0x670 [ 88.969594][ T0] do_idle+0x1a5/0x280 [ 88.973759][ T0] cpu_startup_entry+0x1b/0x20 [ 88.978543][ T0] start_secondary+0x208/0x260 [ 88.983328][ T0] secondary_startup_64+0xa4/0xb0 [ 88.989678][ T0] [ 88.992033][ T0] read to 0xffffffff85cb3c90 of 4 bytes by task 0 on cpu 0: [ 88.999299][ T0] tick_nohz_idle_stop_tick+0x193/0x670 [ 89.004824][ T0] do_idle+0x1a5/0x280 [ 89.008993][ T0] cpu_startup_entry+0x1b/0x20 [ 89.013835][ T0] rest_init+0xec/0xf6 [ 89.017888][ T0] arch_call_rest_init+0x17/0x37 [ 89.022809][ T0] start_kernel+0x838/0x85e [ 89.027295][ T0] x86_64_start_reservations+0x29/0x2b [ 89.032733][ T0] x86_64_start_kernel+0x72/0x76 [ 89.037809][ T0] secondary_startup_64+0xa4/0xb0 [ 89.042810][ T0] [ 89.045115][ T0] Reported by Kernel Concurrency Sanitizer on: [ 89.051244][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc7+ #0 [ 89.058350][ T0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 89.068386][ T0] ================================================================== [ 89.076730][ T0] Kernel panic - not syncing: panic_on_warn set ... [ 89.083305][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc7+ #0 [ 89.090479][ T0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 89.100508][ T0] Call Trace: [ 89.103785][ T0] dump_stack+0x11d/0x181 [ 89.108103][ T0] panic+0x210/0x640 [ 89.111979][ T0] ? vprintk_func+0x8d/0x140 [ 89.116553][ T0] kcsan_report.cold+0xc/0x1a [ 89.121225][ T0] kcsan_setup_watchpoint+0x3fe/0x460 [ 89.126585][ T0] __tsan_read4+0xc6/0x100 [ 89.130993][ T0] tick_nohz_idle_stop_tick+0x193/0x670 [ 89.136516][ T0] ? check_tsc_unstable+0x27/0x30 [ 89.141526][ T0] ? debug_smp_processor_id+0x4c/0x172 [ 89.146976][ T0] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 89.153197][ T0] do_idle+0x1a5/0x280 [ 89.157252][ T0] cpu_startup_entry+0x1b/0x20 [ 89.161998][ T0] rest_init+0xec/0xf6 [ 89.166069][ T0] ? trace_event_define_fields_vector_free_moved+0xce/0xce [ 89.173248][ T0] arch_call_rest_init+0x17/0x37 [ 89.178169][ T0] start_kernel+0x838/0x85e [ 89.182672][ T0] x86_64_start_reservations+0x29/0x2b [ 89.188114][ T0] x86_64_start_kernel+0x72/0x76 [ 89.193043][ T0] secondary_startup_64+0xa4/0xb0 [ 89.199484][ T0] Kernel Offset: disabled [ 89.203815][ T0] Rebooting in 86400 seconds..