[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.948710][ T25] audit: type=1800 audit(1570191721.381:25): pid=7084 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.999939][ T25] audit: type=1800 audit(1570191721.391:26): pid=7084 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.031385][ T25] audit: type=1800 audit(1570191721.391:27): pid=7084 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 '10.128.15.209' (ECDSA) to the list of known hosts. 2019/10/04 12:22:09 fuzzer started 2019/10/04 12:22:10 dialing manager at 10.128.0.105:38119 2019/10/04 12:22:10 syscalls: 2523 2019/10/04 12:22:10 code coverage: enabled 2019/10/04 12:22:10 comparison tracing: enabled 2019/10/04 12:22:10 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:22:10 setuid sandbox: enabled 2019/10/04 12:22:10 namespace sandbox: enabled 2019/10/04 12:22:10 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:22:10 fault injection: enabled 2019/10/04 12:22:10 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:22:10 net packet injection: enabled 2019/10/04 12:22:10 net device setup: enabled 2019/10/04 12:22:10 concurrency sanitizer: enabled syzkaller login: [ 45.885209][ T7250] ================================================================== [ 45.893468][ T7250] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 45.903359][ T7250] [ 45.905668][ T7250] write to 0xffff88812647c12c of 4 bytes by interrupt on cpu 1: [ 45.913277][ T7250] tcp_add_backlog+0x4a0/0xcc0 [ 45.918033][ T7250] tcp_v4_rcv+0x1aba/0x1bf0 [ 45.922513][ T7250] ip_protocol_deliver_rcu+0x51/0x470 [ 45.927860][ T7250] ip_local_deliver_finish+0x110/0x140 [ 45.933308][ T7250] ip_local_deliver+0x133/0x210 [ 45.938144][ T7250] ip_rcv_finish+0x121/0x160 [ 45.942710][ T7250] ip_rcv+0x18f/0x1a0 [ 45.947235][ T7250] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.952953][ T7250] __netif_receive_skb+0x37/0xf0 [ 45.957871][ T7250] netif_receive_skb_internal+0x59/0x190 [ 45.963497][ T7250] napi_gro_receive+0x28f/0x330 [ 45.968336][ T7250] receive_buf+0x284/0x30b0 [ 45.972820][ T7250] virtnet_poll+0x436/0x7d0 [ 45.977301][ T7250] net_rx_action+0x3ae/0xa50 [ 45.981891][ T7250] [ 45.984223][ T7250] read to 0xffff88812647c12c of 4 bytes by task 7250 on cpu 0: [ 45.991746][ T7250] __tcp_select_window+0x6b/0x4d0 [ 45.996757][ T7250] __tcp_transmit_skb+0x679/0x1cd0 [ 46.001845][ T7250] __tcp_send_ack+0x246/0x300 [ 46.006498][ T7250] tcp_send_ack+0x34/0x40 [ 46.010829][ T7250] tcp_cleanup_rbuf+0x130/0x360 [ 46.015670][ T7250] tcp_recvmsg+0x633/0x1a30 [ 46.020199][ T7250] inet_recvmsg+0xbb/0x250 [ 46.024627][ T7250] sock_recvmsg+0x92/0xb0 [ 46.028947][ T7250] sock_read_iter+0x15f/0x1e0 [ 46.033638][ T7250] new_sync_read+0x389/0x4f0 [ 46.038204][ T7250] __vfs_read+0xb1/0xc0 [ 46.042336][ T7250] vfs_read+0x143/0x2c0 [ 46.046468][ T7250] ksys_read+0xd5/0x1b0 [ 46.050605][ T7250] [ 46.052937][ T7250] Reported by Kernel Concurrency Sanitizer on: [ 46.059078][ T7250] CPU: 0 PID: 7250 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 46.066158][ T7250] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.076199][ T7250] ================================================================== [ 46.084235][ T7250] Kernel panic - not syncing: panic_on_warn set ... [ 46.090805][ T7250] CPU: 0 PID: 7250 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 46.097896][ T7250] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.107980][ T7250] Call Trace: [ 46.111275][ T7250] dump_stack+0xf5/0x159 [ 46.115577][ T7250] panic+0x209/0x639 [ 46.119460][ T7250] ? vprintk_func+0x8d/0x140 [ 46.124052][ T7250] kcsan_report.cold+0x57/0xeb [ 46.128803][ T7250] __kcsan_setup_watchpoint+0x342/0x500 [ 46.134347][ T7250] __tsan_read4+0x2c/0x30 [ 46.138662][ T7250] __tcp_select_window+0x6b/0x4d0 [ 46.143678][ T7250] __tcp_transmit_skb+0x679/0x1cd0 [ 46.148779][ T7250] __tcp_send_ack+0x246/0x300 [ 46.153449][ T7250] tcp_send_ack+0x34/0x40 [ 46.157761][ T7250] tcp_cleanup_rbuf+0x130/0x360 [ 46.162593][ T7250] tcp_recvmsg+0x633/0x1a30 [ 46.167086][ T7250] inet_recvmsg+0xbb/0x250 [ 46.171497][ T7250] ? __tsan_read8+0x2c/0x30 [ 46.175988][ T7250] ? inet_sendpage+0x100/0x100 [ 46.180922][ T7250] sock_recvmsg+0x92/0xb0 [ 46.185351][ T7250] sock_read_iter+0x15f/0x1e0 [ 46.190023][ T7250] new_sync_read+0x389/0x4f0 [ 46.194607][ T7250] __vfs_read+0xb1/0xc0 [ 46.198766][ T7250] vfs_read+0x143/0x2c0 [ 46.202928][ T7250] ksys_read+0xd5/0x1b0 [ 46.207084][ T7250] __x64_sys_read+0x4c/0x60 [ 46.211571][ T7250] do_syscall_64+0xcf/0x2f0 [ 46.216068][ T7250] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 46.221967][ T7250] RIP: 0033:0x47c530 [ 46.225853][ T7250] 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 [ 46.245452][ T7250] RSP: 002b:000000c4200517d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 46.253845][ T7250] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 46.261807][ T7250] RDX: 0000000000001000 RSI: 000000c42031e000 RDI: 0000000000000003 [ 46.269768][ T7250] RBP: 000000c420051830 R08: 0000000000000000 R09: 0000000000000000 [ 46.277724][ T7250] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000100 [ 46.285684][ T7250] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 46.295099][ T7250] Kernel Offset: disabled [ 46.299428][ T7250] Rebooting in 86400 seconds..