[ 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 syzkaller login: [ 27.609600][ T8604] bash (8604) used greatest stack depth: 10408 bytes left Warning: Permanently added '10.128.0.45' (ECDSA) to the list of known hosts. 2020/07/24 05:16:00 fuzzer started 2020/07/24 05:16:01 dialing manager at 10.128.0.105:39647 2020/07/24 05:16:01 syscalls: 3213 2020/07/24 05:16:01 code coverage: enabled 2020/07/24 05:16:01 comparison tracing: enabled 2020/07/24 05:16:01 extra coverage: enabled 2020/07/24 05:16:01 setuid sandbox: enabled 2020/07/24 05:16:01 namespace sandbox: enabled 2020/07/24 05:16:01 Android sandbox: /sys/fs/selinux/policy does not exist 2020/07/24 05:16:01 fault injection: enabled 2020/07/24 05:16:01 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2020/07/24 05:16:01 net packet injection: enabled 2020/07/24 05:16:01 net device setup: enabled 2020/07/24 05:16:01 concurrency sanitizer: enabled 2020/07/24 05:16:01 devlink PCI setup: PCI device 0000:00:10.0 is not available 2020/07/24 05:16:01 USB emulation: enabled 2020/07/24 05:16:04 suppressing KCSAN reports in functions: 'audit_log_start' 'blk_mq_sched_dispatch_requests' 'find_get_pages_range_tag' 'do_sys_poll' 'blk_mq_dispatch_rq_list' 'generic_write_end' 'lookup_fast' '__delayacct_blkio_end' 'ext4_mb_regular_allocator' '__add_to_page_cache_locked' '__xa_set_mark' 'yama_task_free' 'do_epoll_wait' 'ext4_mark_iloc_dirty' '__mod_timer' 'kauditd_thread' 'shmem_add_to_page_cache' 'padata_reorder' 'snd_rawmidi_transmit' '__ext4_update_other_inode_time' 'ext4_free_inode' 'ext4_free_inodes_count' 'step_into' 'xas_clear_mark' '__xa_clear_mark' 'alloc_pid' 'pcpu_alloc' '__delete_from_page_cache' 'io_sq_thread' 'dd_has_work' 'n_tty_receive_buf_common' 'get_signal' '__mark_inode_dirty' '__ext4_new_inode' 'expire_timers' 'kcm_rfree' 'page_counter_charge' 'do_select' 'do_nanosleep' '__process_echoes' 'wg_packet_decrypt_worker' 'blk_mq_rq_ctx_init' 'futex_wait_queue_me' 'snd_rawmidi_poll' 'do_syslog' [ 64.766511][ C0] ================================================================== [ 64.774635][ C0] BUG: KCSAN: data-race in add_timer_on / timer_clear_idle [ 64.782255][ C0] [ 64.784598][ C0] write to 0xffff88812c11cb24 of 1 bytes by task 0 on cpu 1: [ 64.792663][ C0] timer_clear_idle+0x2e/0x40 [ 64.797425][ C0] tick_nohz_idle_retain_tick+0x3e/0x40 [ 64.803412][ C0] do_idle+0x287/0x310 [ 64.808348][ C0] cpu_startup_entry+0x15/0x20 [ 64.813279][ C0] start_secondary+0xe3/0x110 [ 64.818132][ C0] secondary_startup_64+0xa4/0xb0 [ 64.823251][ C0] [ 64.825583][ C0] read to 0xffff88812c11cb24 of 1 bytes by interrupt on cpu 0: [ 64.833404][ C0] add_timer_on+0x218/0x3b0 [ 64.837907][ C0] clocksource_watchdog+0x729/0x760 [ 64.843467][ C0] call_timer_fn+0x30/0x2a0 [ 64.848067][ C0] expire_timers+0x116/0x290 [ 64.852655][ C0] __run_timers+0x443/0x500 [ 64.857242][ C0] run_timer_softirq+0x2e/0x60 [ 64.862202][ C0] __do_softirq+0x198/0x360 [ 64.866790][ C0] run_ksoftirqd+0x2f/0x60 [ 64.871219][ C0] smpboot_thread_fn+0x347/0x530 [ 64.876355][ C0] kthread+0x20d/0x230 [ 64.880620][ C0] ret_from_fork+0x1f/0x30 [ 64.885113][ C0] [ 64.887783][ C0] Reported by Kernel Concurrency Sanitizer on: [ 64.894291][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.8.0-rc6-syzkaller #0 [ 64.902946][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.913003][ C0] ================================================================== [ 64.921134][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 64.928088][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.8.0-rc6-syzkaller #0 [ 64.936265][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 64.946574][ C0] Call Trace: [ 64.949879][ C0] dump_stack+0x10f/0x19d [ 64.954214][ C0] panic+0x207/0x64a [ 64.958108][ C0] ? vprintk_emit+0x44a/0x4f0 [ 64.962776][ C0] kcsan_report+0x684/0x690 [ 64.967278][ C0] ? kcsan_setup_watchpoint+0x453/0x4d0 [ 64.972893][ C0] ? add_timer_on+0x218/0x3b0 [ 64.977556][ C0] ? clocksource_watchdog+0x729/0x760 [ 64.983809][ C0] ? call_timer_fn+0x30/0x2a0 [ 64.988581][ C0] ? expire_timers+0x116/0x290 [ 64.993348][ C0] ? __run_timers+0x443/0x500 [ 64.998468][ C0] ? run_timer_softirq+0x2e/0x60 [ 65.003480][ C0] ? __do_softirq+0x198/0x360 [ 65.008144][ C0] ? run_ksoftirqd+0x2f/0x60 [ 65.012736][ C0] ? smpboot_thread_fn+0x347/0x530 [ 65.017829][ C0] ? kthread+0x20d/0x230 [ 65.022062][ C0] ? ret_from_fork+0x1f/0x30 [ 65.026738][ C0] kcsan_setup_watchpoint+0x453/0x4d0 [ 65.032106][ C0] ? ___cache_free+0x2a/0x510 [ 65.037072][ C0] add_timer_on+0x218/0x3b0 [ 65.041565][ C0] clocksource_watchdog+0x729/0x760 [ 65.046856][ C0] ? __clocksource_select+0x340/0x340 [ 65.052220][ C0] call_timer_fn+0x30/0x2a0 [ 65.056724][ C0] ? __clocksource_select+0x340/0x340 [ 65.062097][ C0] expire_timers+0x116/0x290 [ 65.066669][ C0] __run_timers+0x443/0x500 [ 65.071168][ C0] ? finish_task_switch+0x8b/0x270 [ 65.076262][ C0] ? __x64_sys_wait4+0x9a/0x100 [ 65.081114][ C0] ? sched_clock+0xf/0x20 [ 65.085473][ C0] run_timer_softirq+0x2e/0x60 [ 65.090220][ C0] __do_softirq+0x198/0x360 [ 65.094788][ C0] ? ksoftirqd_should_run+0x20/0x20 [ 65.099978][ C0] run_ksoftirqd+0x2f/0x60 [ 65.104375][ C0] smpboot_thread_fn+0x347/0x530 [ 65.109291][ C0] ? cpu_report_death+0x80/0x80 [ 65.114136][ C0] kthread+0x20d/0x230 [ 65.118215][ C0] ? cpu_report_death+0x80/0x80 [ 65.123044][ C0] ? kthread_blkcg+0x80/0x80 [ 65.127624][ C0] ret_from_fork+0x1f/0x30 [ 66.192426][ C0] Shutting down cpus with NMI [ 66.198305][ C0] Kernel Offset: disabled [ 66.202627][ C0] Rebooting in 86400 seconds..