[....] 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. [ 56.749315][ T27] kauditd_printk_skb: 8 callbacks suppressed [ 56.749332][ T27] audit: type=1800 audit(1586693346.190:29): pid=7605 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2465 res=0 [ 56.775404][ T27] audit: type=1800 audit(1586693346.190:30): pid=7605 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2456 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.160' (ECDSA) to the list of known hosts. 2020/04/12 12:09:16 fuzzer started 2020/04/12 12:09:17 dialing manager at 10.128.0.105:34613 2020/04/12 12:09:19 syscalls: 2955 2020/04/12 12:09:19 code coverage: enabled 2020/04/12 12:09:19 comparison tracing: enabled 2020/04/12 12:09:19 extra coverage: enabled 2020/04/12 12:09:19 setuid sandbox: enabled 2020/04/12 12:09:19 namespace sandbox: enabled 2020/04/12 12:09:19 Android sandbox: /sys/fs/selinux/policy does not exist 2020/04/12 12:09:19 fault injection: enabled 2020/04/12 12:09:19 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2020/04/12 12:09:19 net packet injection: enabled 2020/04/12 12:09:19 net device setup: enabled 2020/04/12 12:09:19 concurrency sanitizer: enabled 2020/04/12 12:09:19 devlink PCI setup: PCI device 0000:00:10.0 is not available 2020/04/12 12:09:19 USB emulation: /dev/raw-gadget does not exist 2020/04/12 12:09:20 adding functions to KCSAN blacklist: 'xas_clear_mark' 'ep_poll' 'blk_mq_get_request' 'generic_fillattr' 'find_get_pages_range_tag' 'lruvec_lru_size' 'blk_mq_sched_dispatch_requests' 'generic_write_end' 'mod_timer' '__ext4_new_inode' 'ext4_has_free_clusters' 'do_syslog' syzkaller login: [ 83.233147][ T0] ================================================================== [ 83.241304][ T0] BUG: KCSAN: data-race in tick_nohz_next_event / tick_sched_do_timer [ 83.249444][ T0] [ 83.251778][ T0] write to 0xffffffff85d056d0 of 4 bytes by interrupt on cpu 0: [ 83.259679][ T0] tick_sched_do_timer+0xb4/0xd0 [ 83.264644][ T0] tick_sched_timer+0x3f/0xd0 [ 83.269323][ T0] __hrtimer_run_queues+0x271/0x600 [ 83.274527][ T0] hrtimer_interrupt+0x226/0x490 [ 83.279490][ T0] smp_apic_timer_interrupt+0xd8/0x270 [ 83.284954][ T0] apic_timer_interrupt+0xf/0x20 [ 83.289895][ T0] __tsan_read2+0x8a/0x100 [ 83.294308][ T0] ip_rcv_core.isra.0+0x319/0x660 [ 83.299313][ T0] ip_list_rcv+0x260/0x321 [ 83.303716][ T0] __netif_receive_skb_list_core+0x368/0x5c0 [ 83.309676][ T0] netif_receive_skb_list_internal+0x5c7/0x810 [ 83.315810][ T0] gro_normal_list.part.0+0x37/0xa0 [ 83.320991][ T0] gro_normal_one+0x14c/0x160 [ 83.325648][ T0] napi_gro_receive+0x27d/0x2f0 [ 83.330477][ T0] receive_buf+0x24e/0x2e20 [ 83.334957][ T0] virtnet_poll+0x343/0x790 [ 83.339440][ T0] net_rx_action+0x3ad/0xac0 [ 83.344013][ T0] __do_softirq+0x118/0x34a [ 83.348497][ T0] run_ksoftirqd+0x41/0x60 [ 83.352893][ T0] smpboot_thread_fn+0x374/0x4a0 [ 83.357814][ T0] kthread+0x1cb/0x1f0 [ 83.361868][ T0] ret_from_fork+0x1f/0x30 [ 83.366257][ T0] [ 83.368572][ T0] read to 0xffffffff85d056d0 of 4 bytes by task 0 on cpu 1: [ 83.375885][ T0] tick_nohz_next_event+0x192/0x350 [ 83.381085][ T0] tick_nohz_idle_stop_tick+0x3b9/0x680 [ 83.386608][ T0] do_idle+0x1ad/0x290 [ 83.390655][ T0] cpu_startup_entry+0x14/0x20 [ 83.395434][ T0] start_secondary+0x164/0x1b0 [ 83.400180][ T0] secondary_startup_64+0xa4/0xb0 [ 83.405182][ T0] [ 83.407486][ T0] Reported by Kernel Concurrency Sanitizer on: [ 83.413642][ T0] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc1-syzkaller #0 [ 83.421529][ T0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 83.431560][ T0] ================================================================== [ 83.439602][ T0] Kernel panic - not syncing: panic_on_warn set ... [ 83.446182][ T0] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.6.0-rc1-syzkaller #0 [ 83.454049][ T0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 83.464080][ T0] Call Trace: [ 83.467355][ T0] dump_stack+0x11d/0x187 [ 83.471668][ T0] panic+0x210/0x640 [ 83.475546][ T0] ? vprintk_func+0x89/0x13a [ 83.480138][ T0] kcsan_report.cold+0xc/0xf [ 83.484712][ T0] kcsan_setup_watchpoint+0x3fb/0x440 [ 83.490066][ T0] tick_nohz_next_event+0x192/0x350 [ 83.495260][ T0] tick_nohz_idle_stop_tick+0x3b9/0x680 [ 83.500785][ T0] ? ktime_get+0x1c9/0x210 [ 83.505182][ T0] ? debug_smp_processor_id+0x3f/0x129 [ 83.510622][ T0] do_idle+0x1ad/0x290 [ 83.514675][ T0] cpu_startup_entry+0x14/0x20 [ 83.519418][ T0] start_secondary+0x164/0x1b0 [ 83.524270][ T0] secondary_startup_64+0xa4/0xb0 [ 83.530534][ T0] Kernel Offset: disabled [ 83.534857][ T0] Rebooting in 86400 seconds..