[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[ 35.518375][ T26] audit: type=1800 audit(1572278851.667:25): pid=7071 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0
[ 35.569152][ T26] audit: type=1800 audit(1572278851.677:26): pid=7071 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0
[ 35.603152][ T26] audit: type=1800 audit(1572278851.677:27): pid=7071 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 '10.128.0.127' (ECDSA) to the list of known hosts.
2019/10/28 16:07:40 fuzzer started
2019/10/28 16:07:42 dialing manager at 10.128.0.105:45117
2019/10/28 16:07:42 syscalls: 2540
2019/10/28 16:07:42 code coverage: enabled
2019/10/28 16:07:42 comparison tracing: enabled
2019/10/28 16:07:42 extra coverage: extra coverage is not supported by the kernel
2019/10/28 16:07:42 setuid sandbox: enabled
2019/10/28 16:07:42 namespace sandbox: enabled
2019/10/28 16:07:42 Android sandbox: /sys/fs/selinux/policy does not exist
2019/10/28 16:07:42 fault injection: enabled
2019/10/28 16:07:42 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled
2019/10/28 16:07:42 net packet injection: enabled
2019/10/28 16:07:42 net device setup: enabled
2019/10/28 16:07:42 concurrency sanitizer: enabled
2019/10/28 16:07:42 adding functions to KCSAN blacklist: '__hrtimer_run_queues' 'pid_update_inode' 'tick_sched_do_timer' 'rcu_gp_fqs_loop'
syzkaller login: [ 46.787865][ C0] ==================================================================
[ 46.796201][ C0] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog
[ 46.803909][ C0]
[ 46.806342][ C0] read to 0xffff8881255a612c of 4 bytes by task 7235 on cpu 1:
[ 46.814418][ C0] __tcp_select_window+0x6b/0x4d0
[ 46.819434][ C0] __tcp_transmit_skb+0x700/0x1d60
[ 46.824538][ C0] __tcp_send_ack+0x246/0x300
[ 46.830239][ C0] tcp_send_ack+0x34/0x40
[ 46.834745][ C0] tcp_cleanup_rbuf+0x130/0x360
[ 46.839675][ C0] tcp_recvmsg+0x633/0x1a30
[ 46.844166][ C0] inet_recvmsg+0xbb/0x250
[ 46.848571][ C0] sock_recvmsg+0x92/0xb0
[ 46.852886][ C0] sock_read_iter+0x15f/0x1e0
[ 46.857636][ C0] new_sync_read+0x389/0x4f0
[ 46.862210][ C0] __vfs_read+0xb1/0xc0
[ 46.866855][ C0] vfs_read+0x143/0x2c0
[ 46.871000][ C0] ksys_read+0xd5/0x1b0
[ 46.875154][ C0] __x64_sys_read+0x4c/0x60
[ 46.879639][ C0]
[ 46.882317][ C0] write to 0xffff8881255a612c of 4 bytes by interrupt on cpu 0:
[ 46.890032][ C0] tcp_add_backlog+0x4a0/0xcc0
[ 46.894880][ C0] tcp_v4_rcv+0x1a60/0x1bb0
[ 46.900428][ C0] ip_protocol_deliver_rcu+0x4d/0x420
[ 46.905787][ C0] ip_local_deliver_finish+0x110/0x140
[ 46.911237][ C0] ip_local_deliver+0x133/0x210
[ 46.916159][ C0] ip_rcv_finish+0x121/0x160
[ 46.920745][ C0] ip_rcv+0x18f/0x1a0
[ 46.924809][ C0] __netif_receive_skb_one_core+0xa7/0xe0
[ 46.930513][ C0] __netif_receive_skb+0x37/0xf0
[ 46.935444][ C0] netif_receive_skb_internal+0x59/0x190
[ 46.941065][ C0] napi_gro_receive+0x28f/0x330
[ 46.945903][ C0] receive_buf+0x284/0x30b0
[ 46.951781][ C0] virtnet_poll+0x436/0x7d0
[ 46.956354][ C0]
[ 46.958669][ C0] Reported by Kernel Concurrency Sanitizer on:
[ 46.965015][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3+ #0
[ 46.972197][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 46.982418][ C0] ==================================================================
[ 46.990473][ C0] Kernel panic - not syncing: panic_on_warn set ...
[ 46.997060][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3+ #0
[ 47.004153][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 47.014189][ C0] Call Trace:
[ 47.017538][ C0]
[ 47.020382][ C0] dump_stack+0xf5/0x159
[ 47.024610][ C0] panic+0x210/0x640
[ 47.028493][ C0] ? __netif_receive_skb+0x37/0xf0
[ 47.033884][ C0] ? vprintk_func+0x8d/0x140
[ 47.038463][ C0] kcsan_report.cold+0xc/0x10
[ 47.043300][ C0] __kcsan_setup_watchpoint+0x32e/0x4a0
[ 47.048870][ C0] __tsan_write4+0x32/0x40
[ 47.053319][ C0] tcp_add_backlog+0x4a0/0xcc0
[ 47.058385][ C0] tcp_v4_rcv+0x1a60/0x1bb0
[ 47.063338][ C0] ? __tsan_read8+0x2c/0x30
[ 47.068330][ C0] ip_protocol_deliver_rcu+0x4d/0x420
[ 47.073741][ C0] ip_local_deliver_finish+0x110/0x140
[ 47.079311][ C0] ip_local_deliver+0x133/0x210
[ 47.085221][ C0] ? ip_protocol_deliver_rcu+0x420/0x420
[ 47.090852][ C0] ip_rcv_finish+0x121/0x160
[ 47.096317][ C0] ip_rcv+0x18f/0x1a0
[ 47.100290][ C0] ? ip_sublist_rcv+0x5e0/0x5e0
[ 47.105215][ C0] ? ip_local_deliver+0x210/0x210
[ 47.110225][ C0] __netif_receive_skb_one_core+0xa7/0xe0
[ 47.116162][ C0] __netif_receive_skb+0x37/0xf0
[ 47.121271][ C0] netif_receive_skb_internal+0x59/0x190
[ 47.127074][ C0] napi_gro_receive+0x28f/0x330
[ 47.132008][ C0] receive_buf+0x284/0x30b0
[ 47.136503][ C0] ? __tsan_write8+0x32/0x40
[ 47.141356][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0
[ 47.146886][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0
[ 47.152590][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0
[ 47.158210][ C0] virtnet_poll+0x436/0x7d0
[ 47.162718][ C0] net_rx_action+0x3ae/0xa90
[ 47.167304][ C0] __do_softirq+0x115/0x33f
[ 47.171803][ C0] irq_exit+0xbb/0xe0
[ 47.175775][ C0] do_IRQ+0xa6/0x180
[ 47.179655][ C0] common_interrupt+0xf/0xf
[ 47.184315][ C0]
[ 47.187252][ C0] RIP: 0010:native_safe_halt+0xe/0x10
[ 47.192612][ C0] Code: 90 90 90 90 90 90 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d fc b2 4b 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d ec b2 4b 00 fb f4 90 55 48 89 e5 41 55 41 54 53 e8 72 12 a4 fc e8 6d 8e b8 fd 0f
[ 47.212370][ C0] RSP: 0018:ffffffff85a03de0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffda
[ 47.220777][ C0] RAX: ae147ae147ae6164 RBX: ffffffff85a2b780 RCX: 0000000000000558
[ 47.228743][ C0] RDX: 000000000042bdf0 RSI: 020c49ba5e353f7d RDI: ffffffff85a563b8
[ 47.236710][ C0] RBP: ffffffff85a03e18 R08: 0000000000000000 R09: 0000ffff85a563bf
[ 47.244763][ C0] R10: 00000000aaaaaaab R11: ffffffff86045cc8 R12: 0000000000000000
[ 47.252725][ C0] R13: ffffffff85a2b780 R14: 0000000000000000 R15: 0000000000000000
[ 47.260726][ C0] ? default_idle+0x50/0x230
[ 47.265544][ C0] arch_cpu_idle+0x1f/0x30
[ 47.269972][ C0] default_idle_call+0x1e/0x40
[ 47.274918][ C0] do_idle+0x1af/0x280
[ 47.279155][ C0] cpu_startup_entry+0x1b/0x20
[ 47.284251][ C0] rest_init+0xec/0xf6
[ 47.288318][ C0] ? trace_event_define_fields_vector_free_moved+0xce/0xce
[ 47.295531][ C0] arch_call_rest_init+0x17/0x37
[ 47.300479][ C0] start_kernel+0x838/0x85e
[ 47.305210][ C0] x86_64_start_reservations+0x29/0x2b
[ 47.311281][ C0] x86_64_start_kernel+0x72/0x76
[ 47.316613][ C0] secondary_startup_64+0xa4/0xb0
[ 47.322409][ C0] Kernel Offset: disabled
[ 47.326890][ C0] Rebooting in 86400 seconds..