[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.832810][ T26] audit: type=1800 audit(1570192856.170:25): pid=7081 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.859863][ T26] audit: type=1800 audit(1570192856.170:26): pid=7081 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.879896][ T26] audit: type=1800 audit(1570192856.170:27): pid=7081 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 '10.128.0.158' (ECDSA) to the list of known hosts. 2019/10/04 12:41:05 fuzzer started 2019/10/04 12:41:06 dialing manager at 10.128.0.105:38119 2019/10/04 12:41:06 syscalls: 2523 2019/10/04 12:41:06 code coverage: enabled 2019/10/04 12:41:06 comparison tracing: enabled 2019/10/04 12:41:06 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:41:06 setuid sandbox: enabled 2019/10/04 12:41:06 namespace sandbox: enabled 2019/10/04 12:41:06 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:41:06 fault injection: enabled 2019/10/04 12:41:06 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:41:06 net packet injection: enabled 2019/10/04 12:41:06 net device setup: enabled 2019/10/04 12:41:06 concurrency sanitizer: enabled syzkaller login: [ 44.799230][ C1] ================================================================== [ 44.807464][ C1] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0xb8f/0xcc0 [ 44.817323][ C1] [ 44.819639][ C1] read to 0xffff88812458132c of 4 bytes by task 7239 on cpu 0: [ 44.827163][ C1] __tcp_select_window+0x6b/0x4d0 [ 44.832169][ C1] __tcp_transmit_skb+0x679/0x1cd0 [ 44.837260][ C1] __tcp_send_ack+0x246/0x300 [ 44.841916][ C1] tcp_send_ack+0x34/0x40 [ 44.846226][ C1] tcp_cleanup_rbuf+0x130/0x360 [ 44.851059][ C1] tcp_recvmsg+0x633/0x1a30 [ 44.855544][ C1] inet_recvmsg+0xbb/0x250 [ 44.859942][ C1] sock_recvmsg+0x92/0xb0 [ 44.864249][ C1] sock_read_iter+0x15f/0x1e0 [ 44.868909][ C1] new_sync_read+0x389/0x4f0 [ 44.873480][ C1] __vfs_read+0xb1/0xc0 [ 44.877627][ C1] vfs_read+0x143/0x2c0 [ 44.881763][ C1] ksys_read+0xd5/0x1b0 [ 44.885902][ C1] __x64_sys_read+0x4c/0x60 [ 44.890379][ C1] [ 44.892766][ C1] write to 0xffff88812458132c of 4 bytes by interrupt on cpu 1: [ 44.900412][ C1] tcp_add_backlog+0xb8f/0xcc0 [ 44.905159][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 44.909666][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 44.915019][ C1] ip_local_deliver_finish+0x110/0x140 [ 44.920475][ C1] ip_local_deliver+0x133/0x210 [ 44.925344][ C1] ip_rcv_finish+0x121/0x160 [ 44.929923][ C1] ip_rcv+0x18f/0x1a0 [ 44.933899][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 44.939610][ C1] __netif_receive_skb+0x37/0xf0 [ 44.944535][ C1] netif_receive_skb_internal+0x59/0x190 [ 44.950151][ C1] napi_gro_receive+0x28f/0x330 [ 44.954985][ C1] receive_buf+0x284/0x30b0 [ 44.959471][ C1] virtnet_poll+0x436/0x7d0 [ 44.963946][ C1] [ 44.966273][ C1] Reported by Kernel Concurrency Sanitizer on: [ 44.972409][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 44.979407][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.989448][ C1] ================================================================== [ 44.997499][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 45.004077][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 45.011077][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.021126][ C1] Call Trace: [ 45.024403][ C1] dump_stack+0xf5/0x159 [ 45.028633][ C1] panic+0x209/0x639 [ 45.032514][ C1] ? vprintk_func+0x8d/0x140 [ 45.037090][ C1] kcsan_report.cold+0x57/0xeb [ 45.041840][ C1] __kcsan_setup_watchpoint+0x342/0x500 [ 45.047367][ C1] __tsan_write4+0x32/0x40 [ 45.051767][ C1] tcp_add_backlog+0xb8f/0xcc0 [ 45.056798][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 45.061297][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 45.066671][ C1] ip_local_deliver_finish+0x110/0x140 [ 45.072122][ C1] ip_local_deliver+0x133/0x210 [ 45.076967][ C1] ? ip_protocol_deliver_rcu+0x470/0x470 [ 45.082589][ C1] ip_rcv_finish+0x121/0x160 [ 45.087190][ C1] ip_rcv+0x18f/0x1a0 [ 45.091184][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 45.096110][ C1] ? ip_local_deliver+0x210/0x210 [ 45.101129][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.106841][ C1] __netif_receive_skb+0x37/0xf0 [ 45.111774][ C1] netif_receive_skb_internal+0x59/0x190 [ 45.117401][ C1] napi_gro_receive+0x28f/0x330 [ 45.122242][ C1] receive_buf+0x284/0x30b0 [ 45.126728][ C1] ? __tsan_write8+0x32/0x40 [ 45.131311][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 45.136769][ C1] virtnet_poll+0x436/0x7d0 [ 45.141264][ C1] net_rx_action+0x3ae/0xa50 [ 45.145877][ C1] __do_softirq+0x115/0x33f [ 45.150367][ C1] ? takeover_tasklets+0x250/0x250 [ 45.155926][ C1] run_ksoftirqd+0x46/0x60 [ 45.160333][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 45.165260][ C1] kthread+0x1d4/0x200 [ 45.169316][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 45.175278][ C1] ? kthread_bind+0x50/0x50 [ 45.179768][ C1] ret_from_fork+0x1f/0x30 [ 45.185608][ C1] Kernel Offset: disabled [ 45.189953][ C1] Rebooting in 86400 seconds..