[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.025111][ T25] audit: type=1800 audit(1570192660.684:25): pid=7007 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.044680][ T25] audit: type=1800 audit(1570192660.684:26): pid=7007 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.044693][ T25] audit: type=1800 audit(1570192660.684:27): pid=7007 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 '10.128.0.249' (ECDSA) to the list of known hosts. 2019/10/04 12:37:51 fuzzer started 2019/10/04 12:37:52 dialing manager at 10.128.0.105:38119 2019/10/04 12:37:53 syscalls: 2523 2019/10/04 12:37:53 code coverage: enabled 2019/10/04 12:37:53 comparison tracing: enabled 2019/10/04 12:37:53 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:37:53 setuid sandbox: enabled 2019/10/04 12:37:53 namespace sandbox: enabled 2019/10/04 12:37:53 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:37:53 fault injection: enabled 2019/10/04 12:37:53 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:37:53 net packet injection: enabled 2019/10/04 12:37:53 net device setup: enabled 2019/10/04 12:37:53 concurrency sanitizer: enabled syzkaller login: [ 47.738382][ C1] ================================================================== [ 47.746818][ C1] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 47.756949][ C1] [ 47.759278][ C1] read to 0xffff8881237672ec of 4 bytes by task 7155 on cpu 0: [ 47.766884][ C1] __tcp_select_window+0x6b/0x4d0 [ 47.771994][ C1] __tcp_transmit_skb+0x679/0x1cd0 [ 47.777102][ C1] __tcp_send_ack+0x246/0x300 [ 47.781777][ C1] tcp_send_ack+0x34/0x40 [ 47.786155][ C1] tcp_cleanup_rbuf+0x130/0x360 [ 47.790995][ C1] tcp_recvmsg+0x633/0x1a30 [ 47.795657][ C1] inet_recvmsg+0xbb/0x250 [ 47.800073][ C1] sock_recvmsg+0x92/0xb0 [ 47.804392][ C1] sock_read_iter+0x15f/0x1e0 [ 47.809192][ C1] new_sync_read+0x389/0x4f0 [ 47.813774][ C1] __vfs_read+0xb1/0xc0 [ 47.817918][ C1] vfs_read+0x143/0x2c0 [ 47.822189][ C1] ksys_read+0xd5/0x1b0 [ 47.826335][ C1] __x64_sys_read+0x4c/0x60 [ 47.830881][ C1] [ 47.833202][ C1] write to 0xffff8881237672ec of 4 bytes by interrupt on cpu 1: [ 47.840994][ C1] tcp_add_backlog+0x4a0/0xcc0 [ 47.845751][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 47.850279][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 47.855638][ C1] ip_local_deliver_finish+0x110/0x140 [ 47.861086][ C1] ip_local_deliver+0x133/0x210 [ 47.865934][ C1] ip_rcv_finish+0x121/0x160 [ 47.872100][ C1] ip_rcv+0x18f/0x1a0 [ 47.876280][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.881989][ C1] __netif_receive_skb+0x37/0xf0 [ 47.887003][ C1] netif_receive_skb_internal+0x59/0x190 [ 47.892626][ C1] napi_gro_receive+0x28f/0x330 [ 47.897553][ C1] receive_buf+0x284/0x30b0 [ 47.902044][ C1] virtnet_poll+0x436/0x7d0 [ 47.906528][ C1] [ 47.908851][ C1] Reported by Kernel Concurrency Sanitizer on: [ 47.915866][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 47.922870][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.932909][ C1] ================================================================== [ 47.940960][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 47.947652][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 47.954783][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.964906][ C1] Call Trace: [ 47.968211][ C1] dump_stack+0xf5/0x159 [ 47.972923][ C1] panic+0x209/0x639 [ 47.976829][ C1] ? vprintk_func+0x8d/0x140 [ 47.982546][ C1] kcsan_report.cold+0x57/0xeb [ 47.987306][ C1] __kcsan_setup_watchpoint+0x342/0x500 [ 47.992841][ C1] __tsan_write4+0x32/0x40 [ 47.997255][ C1] tcp_add_backlog+0x4a0/0xcc0 [ 48.002014][ C1] ? __rcu_read_unlock+0x62/0xe0 [ 48.006942][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 48.012732][ C1] ? __tsan_read8+0x2c/0x30 [ 48.017858][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 48.023216][ C1] ip_local_deliver_finish+0x110/0x140 [ 48.028656][ C1] ip_local_deliver+0x133/0x210 [ 48.034879][ C1] ? ip_protocol_deliver_rcu+0x470/0x470 [ 48.040496][ C1] ip_rcv_finish+0x121/0x160 [ 48.045083][ C1] ip_rcv+0x18f/0x1a0 [ 48.049050][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 48.053899][ C1] ? ip_local_deliver+0x210/0x210 [ 48.058913][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.064619][ C1] __netif_receive_skb+0x37/0xf0 [ 48.069741][ C1] netif_receive_skb_internal+0x59/0x190 [ 48.075361][ C1] napi_gro_receive+0x28f/0x330 [ 48.080202][ C1] receive_buf+0x284/0x30b0 [ 48.084704][ C1] ? __tsan_write8+0x32/0x40 [ 48.089285][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 48.094748][ C1] ? virtqueue_get_buf+0x31/0x40 [ 48.099671][ C1] virtnet_poll+0x436/0x7d0 [ 48.104165][ C1] net_rx_action+0x3ae/0xa50 [ 48.108745][ C1] __do_softirq+0x115/0x33f [ 48.113344][ C1] ? takeover_tasklets+0x250/0x250 [ 48.118456][ C1] run_ksoftirqd+0x46/0x60 [ 48.122857][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 48.128412][ C1] kthread+0x1d4/0x200 [ 48.132480][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 48.138442][ C1] ? kthread_bind+0x50/0x50 [ 48.142935][ C1] ret_from_fork+0x1f/0x30 [ 48.148794][ C1] Kernel Offset: disabled [ 48.153158][ C1] Rebooting in 86400 seconds..