[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.744822][ T26] audit: type=1800 audit(1570191469.300:25): pid=7030 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.789776][ T26] audit: type=1800 audit(1570191469.300:26): pid=7030 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.810844][ T26] audit: type=1800 audit(1570191469.300:27): pid=7030 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[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.174' (ECDSA) to the list of known hosts. 2019/10/04 12:17:59 fuzzer started 2019/10/04 12:18:00 dialing manager at 10.128.0.105:38119 2019/10/04 12:18:00 syscalls: 2523 2019/10/04 12:18:00 code coverage: enabled 2019/10/04 12:18:00 comparison tracing: enabled 2019/10/04 12:18:00 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:18:00 setuid sandbox: enabled 2019/10/04 12:18:00 namespace sandbox: enabled 2019/10/04 12:18:00 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:18:00 fault injection: enabled 2019/10/04 12:18:00 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:18:00 net packet injection: enabled 2019/10/04 12:18:00 net device setup: enabled 2019/10/04 12:18:00 concurrency sanitizer: enabled syzkaller login: [ 46.935091][ T7180] ================================================================== [ 46.943313][ T7180] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 46.952781][ T7180] [ 46.955090][ T7180] write to 0xffff888129c0e138 of 8 bytes by interrupt on cpu 1: [ 46.962703][ T7180] tcp_add_backlog+0x45a/0xcc0 [ 46.967533][ T7180] tcp_v4_rcv+0x1aba/0x1bf0 [ 46.972015][ T7180] ip_protocol_deliver_rcu+0x51/0x470 [ 46.977362][ T7180] ip_local_deliver_finish+0x110/0x140 [ 46.982795][ T7180] ip_local_deliver+0x133/0x210 [ 46.987619][ T7180] ip_rcv_finish+0x121/0x160 [ 46.992184][ T7180] ip_rcv+0x18f/0x1a0 [ 46.996145][ T7180] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.001842][ T7180] __netif_receive_skb+0x37/0xf0 [ 47.006757][ T7180] netif_receive_skb_internal+0x59/0x190 [ 47.012410][ T7180] napi_gro_receive+0x28f/0x330 [ 47.017239][ T7180] receive_buf+0x284/0x30b0 [ 47.021716][ T7180] virtnet_poll+0x436/0x7d0 [ 47.026195][ T7180] net_rx_action+0x3ae/0xa50 [ 47.030756][ T7180] [ 47.033063][ T7180] read to 0xffff888129c0e138 of 8 bytes by task 7180 on cpu 0: [ 47.040584][ T7180] tcp_recvmsg+0x470/0x1a30 [ 47.045075][ T7180] inet_recvmsg+0xbb/0x250 [ 47.049466][ T7180] sock_recvmsg+0x92/0xb0 [ 47.053782][ T7180] sock_read_iter+0x15f/0x1e0 [ 47.058433][ T7180] new_sync_read+0x389/0x4f0 [ 47.062997][ T7180] __vfs_read+0xb1/0xc0 [ 47.067126][ T7180] vfs_read+0x143/0x2c0 [ 47.071255][ T7180] ksys_read+0xd5/0x1b0 [ 47.075404][ T7180] __x64_sys_read+0x4c/0x60 [ 47.079902][ T7180] do_syscall_64+0xcf/0x2f0 [ 47.084383][ T7180] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.090245][ T7180] [ 47.092544][ T7180] Reported by Kernel Concurrency Sanitizer on: [ 47.098672][ T7180] CPU: 0 PID: 7180 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.105751][ T7180] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.115782][ T7180] ================================================================== [ 47.123817][ T7180] Kernel panic - not syncing: panic_on_warn set ... [ 47.130388][ T7180] CPU: 0 PID: 7180 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.137478][ T7180] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.147504][ T7180] Call Trace: [ 47.150775][ T7180] dump_stack+0xf5/0x159 [ 47.155000][ T7180] panic+0x209/0x639 [ 47.158886][ T7180] ? vprintk_func+0x8d/0x140 [ 47.163455][ T7180] kcsan_report.cold+0x57/0xeb [ 47.168201][ T7180] __kcsan_setup_watchpoint+0x342/0x500 [ 47.173732][ T7180] __tsan_read8+0x2c/0x30 [ 47.178036][ T7180] tcp_recvmsg+0x470/0x1a30 [ 47.182522][ T7180] ? preempt_schedule_common+0x37/0x90 [ 47.187983][ T7180] inet_recvmsg+0xbb/0x250 [ 47.192375][ T7180] ? __tsan_read8+0x2c/0x30 [ 47.196857][ T7180] ? inet_sendpage+0x100/0x100 [ 47.201594][ T7180] sock_recvmsg+0x92/0xb0 [ 47.205900][ T7180] sock_read_iter+0x15f/0x1e0 [ 47.210577][ T7180] new_sync_read+0x389/0x4f0 [ 47.215150][ T7180] __vfs_read+0xb1/0xc0 [ 47.219372][ T7180] vfs_read+0x143/0x2c0 [ 47.223522][ T7180] ksys_read+0xd5/0x1b0 [ 47.227669][ T7180] __x64_sys_read+0x4c/0x60 [ 47.232152][ T7180] do_syscall_64+0xcf/0x2f0 [ 47.236640][ T7180] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.242519][ T7180] RIP: 0033:0x47c530 [ 47.246395][ T7180] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 47.265988][ T7180] RSP: 002b:000000c4204ff810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 47.274375][ T7180] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.282320][ T7180] RDX: 0000000000001000 RSI: 000000c4203d2000 RDI: 0000000000000003 [ 47.290266][ T7180] RBP: 000000c4204ff868 R08: 0000000000000000 R09: 0000000000000000 [ 47.298215][ T7180] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000020 [ 47.306164][ T7180] R13: ffffffffffffffff R14: 0000000000000020 R15: ffffffffffffffff [ 47.315565][ T7180] Kernel Offset: disabled [ 47.319885][ T7180] Rebooting in 86400 seconds..