[ OK ] Reached target Login Prompts. [ 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 Warning: Permanently added '10.128.0.47' (ECDSA) to the list of known hosts. 2020/07/02 00:00:55 fuzzer started 2020/07/02 00:00:55 dialing manager at 10.128.0.105:39949 2020/07/02 00:01:00 syscalls: 3106 2020/07/02 00:01:00 code coverage: enabled 2020/07/02 00:01:00 comparison tracing: enabled 2020/07/02 00:01:00 extra coverage: enabled 2020/07/02 00:01:00 setuid sandbox: enabled 2020/07/02 00:01:00 namespace sandbox: enabled 2020/07/02 00:01:00 Android sandbox: /sys/fs/selinux/policy does not exist 2020/07/02 00:01:00 fault injection: enabled 2020/07/02 00:01:00 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2020/07/02 00:01:00 net packet injection: enabled 2020/07/02 00:01:00 net device setup: enabled 2020/07/02 00:01:00 concurrency sanitizer: enabled 2020/07/02 00:01:00 devlink PCI setup: PCI device 0000:00:10.0 is not available 2020/07/02 00:01:00 USB emulation: enabled 2020/07/02 00:01:02 suppressing KCSAN reports in functions: 'find_get_pages_range_tag' '__ext4_update_other_inode_time' 'wbt_issue' 'do_epoll_wait' '__delayacct_blkio_end' 'ext4_free_inode' 'ext4_writepages' 'copy_process' 'do_nanosleep' 'page_counter_charge' 'expire_timers' 'alloc_pid' 'futex_wait_queue_me' '__delete_from_page_cache' '__mod_timer' 'do_select' '__xa_clear_mark' 'blk_mq_dispatch_rq_list' 'blk_mq_sched_dispatch_requests' 'dd_has_work' '__ext4_new_inode' 'blk_mq_rq_ctx_init' 'exit_mm' 'generic_write_end' 'io_sq_thread' 'ext4_mb_good_group' 'ext4_free_inodes_count' 'af_alg_sendpage' 'generic_file_buffered_read' syzkaller login: [ 64.869333][ T0] ================================================================== [ 64.877442][ T0] BUG: KCSAN: data-race in tick_nohz_next_event / tick_sched_timer [ 64.886087][ T0] [ 64.888399][ T0] write to 0xffffffff87f50c10 of 4 bytes by interrupt on cpu 1: [ 64.896164][ T0] tick_sched_timer+0x205/0x220 [ 64.901524][ T0] __run_hrtimer+0x154/0x4b0 [ 64.906442][ T0] hrtimer_interrupt+0x37c/0xa40 [ 64.912961][ T0] __sysvec_apic_timer_interrupt+0xa3/0x280 [ 64.919226][ T0] asm_call_on_stack+0xf/0x20 [ 64.924208][ T0] sysvec_apic_timer_interrupt+0x80/0xd0 [ 64.930035][ T0] asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 64.936045][ T0] __tsan_read8+0xf0/0x180 [ 64.940571][ T0] ip_local_deliver+0x17d/0x2a0 [ 64.945670][ T0] ip_sublist_rcv+0x4d4/0x5a0 [ 64.950509][ T0] ip_list_rcv+0x262/0x290 [ 64.955062][ T0] __netif_receive_skb_list_core+0x34b/0x450 [ 64.961181][ T0] __netif_receive_skb_list+0x298/0x310 [ 64.966976][ T0] netif_receive_skb_list_internal+0xda/0x330 [ 64.982585][ T0] napi_gro_receive+0x329/0x5a0 [ 64.987416][ T0] receive_buf+0x7a4/0xcf0 [ 64.991811][ T0] virtnet_poll+0x2fa/0x780 [ 64.996514][ T0] napi_poll+0x178/0x4a0 [ 65.000734][ T0] net_rx_action+0x1ba/0x530 [ 65.005348][ T0] __do_softirq+0x198/0x360 [ 65.009917][ T0] run_ksoftirqd+0x2f/0x60 [ 65.014316][ T0] smpboot_thread_fn+0x347/0x530 [ 65.019500][ T0] kthread+0x20d/0x230 [ 65.023891][ T0] ret_from_fork+0x1f/0x30 [ 65.028436][ T0] [ 65.030769][ T0] read to 0xffffffff87f50c10 of 4 bytes by task 0 on cpu 0: [ 65.038060][ T0] tick_nohz_next_event+0x21d/0x310 [ 65.043531][ T0] tick_nohz_get_sleep_length+0xca/0x140 [ 65.049299][ T0] menu_select+0x328/0x1030 [ 65.054863][ T0] cpuidle_select+0x3d/0x50 [ 65.059377][ T0] do_idle+0x1eb/0x310 [ 65.063815][ T0] cpu_startup_entry+0x15/0x20 [ 65.068617][ T0] rest_init+0xd8/0xe0 [ 65.072670][ T0] arch_call_rest_init+0xa/0xb [ 65.077414][ T0] start_kernel+0x608/0x6d0 [ 65.081898][ T0] secondary_startup_64+0xa4/0xb0 [ 65.086895][ T0] [ 65.089369][ T0] Reported by Kernel Concurrency Sanitizer on: [ 65.095534][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.8.0-rc3-syzkaller #0 [ 65.103571][ T0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.113915][ T0] ================================================================== [ 65.121957][ T0] Kernel panic - not syncing: panic_on_warn set ... [ 65.128572][ T0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.8.0-rc3-syzkaller #0 [ 65.136437][ T0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 65.146731][ T0] Call Trace: [ 65.150102][ T0] dump_stack+0x10f/0x19d [ 65.154587][ T0] panic+0x207/0x64a [ 65.158641][ T0] ? vprintk_emit+0x44a/0x4f0 [ 65.163497][ T0] kcsan_report+0x684/0x690 [ 65.168132][ T0] ? kcsan_setup_watchpoint+0x453/0x4d0 [ 65.173976][ T0] ? tick_nohz_next_event+0x21d/0x310 [ 65.179508][ T0] ? tick_nohz_get_sleep_length+0xca/0x140 [ 65.185533][ T0] ? menu_select+0x328/0x1030 [ 65.190305][ T0] ? cpuidle_select+0x3d/0x50 [ 65.195259][ T0] ? do_idle+0x1eb/0x310 [ 65.199489][ T0] ? cpu_startup_entry+0x15/0x20 [ 65.204749][ T0] ? rest_init+0xd8/0xe0 [ 65.209063][ T0] ? arch_call_rest_init+0xa/0xb [ 65.214562][ T0] ? start_kernel+0x608/0x6d0 [ 65.219442][ T0] ? secondary_startup_64+0xa4/0xb0 [ 65.224752][ T0] kcsan_setup_watchpoint+0x453/0x4d0 [ 65.230738][ T0] tick_nohz_next_event+0x21d/0x310 [ 65.237285][ T0] tick_nohz_get_sleep_length+0xca/0x140 [ 65.243015][ T0] menu_select+0x328/0x1030 [ 65.247541][ T0] ? _raw_spin_unlock_irq+0x4b/0x70 [ 65.252998][ T0] cpuidle_select+0x3d/0x50 [ 65.257583][ T0] do_idle+0x1eb/0x310 [ 65.261872][ T0] cpu_startup_entry+0x15/0x20 [ 65.267499][ T0] rest_init+0xd8/0xe0 [ 65.271810][ T0] ? time_init+0xc/0xc [ 65.275981][ T0] arch_call_rest_init+0xa/0xb [ 65.280815][ T0] start_kernel+0x608/0x6d0 [ 65.285461][ T0] secondary_startup_64+0xa4/0xb0 [ 65.292455][ T0] Kernel Offset: disabled [ 65.296954][ T0] Rebooting in 86400 seconds..