[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[ 34.999556][ T25] audit: type=1800 audit(1570902172.330:25): pid=7111 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0
[ 35.041104][ T25] audit: type=1800 audit(1570902172.330:26): pid=7111 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0
[ 35.066899][ T25] audit: type=1800 audit(1570902172.330:27): pid=7111 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[1G[[32m ok [39;49m8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
Debian GNU/Linux 7 syzkaller ttyS0
Warning: Permanently added '10.128.0.6' (ECDSA) to the list of known hosts.
2019/10/12 17:43:00 fuzzer started
2019/10/12 17:43:02 dialing manager at 10.128.0.105:43913
2019/10/12 17:43:02 syscalls: 2523
2019/10/12 17:43:02 code coverage: enabled
2019/10/12 17:43:02 comparison tracing: enabled
2019/10/12 17:43:02 extra coverage: extra coverage is not supported by the kernel
2019/10/12 17:43:02 setuid sandbox: enabled
2019/10/12 17:43:02 namespace sandbox: enabled
2019/10/12 17:43:02 Android sandbox: /sys/fs/selinux/policy does not exist
2019/10/12 17:43:02 fault injection: enabled
2019/10/12 17:43:02 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled
2019/10/12 17:43:02 net packet injection: enabled
2019/10/12 17:43:02 net device setup: enabled
2019/10/12 17:43:02 concurrency sanitizer: enabled
syzkaller login: [ 44.966919][ C0] ==================================================================
[ 44.975233][ C0] BUG: KCSAN: data-race in tick_sched_do_timer / tick_sched_do_timer
[ 44.983285][ C0]
[ 44.985600][ C0] write to 0xffffffff85caf310 of 4 bytes by interrupt on cpu 1:
[ 44.993360][ C0] tick_sched_do_timer+0xc0/0xe0
[ 44.998341][ C0] tick_sched_timer+0x43/0xe0
[ 45.003004][ C0] __hrtimer_run_queues+0x288/0x600
[ 45.008446][ C0] hrtimer_interrupt+0x22a/0x480
[ 45.013480][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 45.018923][ C0] apic_timer_interrupt+0xf/0x20
[ 45.023853][ C0] __sanitizer_cov_trace_pc+0x1a/0x50
[ 45.029447][ C0] nf_conntrack_tcp_packet+0x1697/0x3390
[ 45.035062][ C0] nf_conntrack_in+0x410/0xaa0
[ 45.040066][ C0] ipv4_conntrack_local+0xbe/0x130
[ 45.045165][ C0] nf_hook_slow+0x83/0x160
[ 45.049559][ C0] __ip_local_out+0x1f7/0x2b0
[ 45.054228][ C0] ip_local_out+0x31/0x90
[ 45.058557][ C0] __ip_queue_xmit+0x3a8/0xa40
[ 45.063291][ C0]
[ 45.065602][ C0] read to 0xffffffff85caf310 of 4 bytes by interrupt on cpu 0:
[ 45.073131][ C0] tick_sched_do_timer+0x33/0xe0
[ 45.078113][ C0] tick_sched_timer+0x43/0xe0
[ 45.082772][ C0] __hrtimer_run_queues+0x288/0x600
[ 45.088094][ C0] hrtimer_interrupt+0x22a/0x480
[ 45.093137][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 45.098696][ C0] apic_timer_interrupt+0xf/0x20
[ 45.103623][ C0] __kcsan_check_watchpoint+0x101/0x180
[ 45.109148][ C0] refcount_inc_not_zero_checked+0x44/0x150
[ 45.115029][ C0] refcount_inc_checked+0x20/0x90
[ 45.120036][ C0] __netif_receive_skb_core+0xde6/0x1a90
[ 45.125659][ C0] __netif_receive_skb_one_core+0x67/0xe0
[ 45.131356][ C0] __netif_receive_skb+0x37/0xf0
[ 45.136271][ C0] netif_receive_skb_internal+0x59/0x190
[ 45.141905][ C0]
[ 45.144219][ C0] Reported by Kernel Concurrency Sanitizer on:
[ 45.150358][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0
[ 45.157268][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 45.167392][ C0] ==================================================================
[ 45.175447][ C0] Kernel panic - not syncing: panic_on_warn set ...
[ 45.182017][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0
[ 45.188925][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 45.198958][ C0] Call Trace:
[ 45.202223][ C0]
[ 45.205064][ C0] dump_stack+0xf5/0x159
[ 45.209320][ C0] panic+0x209/0x639
[ 45.213203][ C0] ? refcount_inc_checked+0x20/0x90
[ 45.218380][ C0] ? vprintk_func+0x8d/0x140
[ 45.222955][ C0] kcsan_report.cold+0xc/0x1b
[ 45.227632][ C0] __kcsan_setup_watchpoint+0x3ee/0x510
[ 45.233160][ C0] __tsan_read4+0x2c/0x30
[ 45.237475][ C0] tick_sched_do_timer+0x33/0xe0
[ 45.242392][ C0] tick_sched_timer+0x43/0xe0
[ 45.247055][ C0] __hrtimer_run_queues+0x288/0x600
[ 45.252258][ C0] ? tick_sched_do_timer+0xe0/0xe0
[ 45.257357][ C0] hrtimer_interrupt+0x22a/0x480
[ 45.262299][ C0] smp_apic_timer_interrupt+0xdc/0x280
[ 45.267745][ C0] apic_timer_interrupt+0xf/0x20
[ 45.272677][ C0]
[ 45.275612][ C0] RIP: 0010:__kcsan_check_watchpoint+0x101/0x180
[ 45.281938][ C0] Code: 78 05 45 84 c0 74 0f 4d 39 cf 77 0a 49 8d 5c 1f ff 48 39 df 76 2f 83 fa 03 75 8a b8 01 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d 65 8b 0d 47 96 af 7e 85 c9 0f 84 40 ff ff ff 5b 41 5c 41 5d 41
[ 45.301525][ C0] RSP: 0018:ffffc90000cb3960 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
[ 45.310006][ C0] RAX: 0000000000000001 RBX: ffffffff85cc8340 RCX: 0000ffffffffffff
[ 45.317963][ C0] RDX: 0000000000000003 RSI: 0000000000000033 RDI: 0000c90000cb3984
[ 45.326093][ C0] RBP: ffffc90000cb3970 R08: 0000000000000000 R09: 0000c90000cb3987
[ 45.334057][ C0] R10: 00000000aaaaaaab R11: ffffffff86042db0 R12: ffffc90000cb3984
[ 45.342010][ C0] R13: ffff88812331bd40 R14: ffffffff85cc8370 R15: ffff8881229d42c0
[ 45.349994][ C0] ? __tsan_read4+0x15/0x30
[ 45.354501][ C0] refcount_inc_not_zero_checked+0x44/0x150
[ 45.360390][ C0] refcount_inc_checked+0x20/0x90
[ 45.365407][ C0] __netif_receive_skb_core+0xde6/0x1a90
[ 45.371035][ C0] ? __tsan_write2+0x32/0x40
[ 45.375612][ C0] ? __kcsan_setup_watchpoint+0x96/0x510
[ 45.381244][ C0] __netif_receive_skb_one_core+0x67/0xe0
[ 45.387008][ C0] __netif_receive_skb+0x37/0xf0
[ 45.391932][ C0] netif_receive_skb_internal+0x59/0x190
[ 45.397547][ C0] napi_gro_receive+0x28f/0x330
[ 45.402383][ C0] receive_buf+0x284/0x30b0
[ 45.406893][ C0] ? __tsan_write8+0x32/0x40
[ 45.411469][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0
[ 45.416910][ C0] ? __kcsan_setup_watchpoint+0x96/0x510
[ 45.422537][ C0] ? __kcsan_setup_watchpoint+0x96/0x510
[ 45.428155][ C0] virtnet_poll+0x436/0x7d0
[ 45.432635][ C0] ? __udelay+0x10/0x20
[ 45.436775][ C0] net_rx_action+0x3ae/0xa50
[ 45.441548][ C0] __do_softirq+0x115/0x33f
[ 45.446034][ C0] ? takeover_tasklets+0x250/0x250
[ 45.451127][ C0] run_ksoftirqd+0x46/0x60
[ 45.455520][ C0] smpboot_thread_fn+0x37d/0x4a0
[ 45.460441][ C0] kthread+0x1d4/0x200
[ 45.464495][ C0] ? constant_test_bit.constprop.0+0x30/0x30
[ 45.470460][ C0] ? kthread_bind+0x50/0x50
[ 45.474944][ C0] ret_from_fork+0x1f/0x30
[ 45.480748][ C0] Kernel Offset: disabled
[ 45.485103][ C0] Rebooting in 86400 seconds..