[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.832133][ T25] audit: type=1800 audit(1570192458.539:25): pid=7039 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.870330][ T25] audit: type=1800 audit(1570192458.539:26): pid=7039 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.898842][ T25] audit: type=1800 audit(1570192458.539:27): pid=7039 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 12:34:28 fuzzer started 2019/10/04 12:34:29 dialing manager at 10.128.0.105:38119 2019/10/04 12:34:29 syscalls: 2523 2019/10/04 12:34:29 code coverage: enabled 2019/10/04 12:34:29 comparison tracing: enabled 2019/10/04 12:34:29 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:34:29 setuid sandbox: enabled 2019/10/04 12:34:29 namespace sandbox: enabled 2019/10/04 12:34:29 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:34:29 fault injection: enabled 2019/10/04 12:34:29 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:34:29 net packet injection: enabled 2019/10/04 12:34:29 net device setup: enabled 2019/10/04 12:34:29 concurrency sanitizer: enabled syzkaller login: [ 46.425749][ C1] ================================================================== [ 46.434106][ C1] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0xb8f/0xcc0 [ 46.443979][ C1] [ 46.446364][ C1] read to 0xffff888122c312ec of 4 bytes by task 7192 on cpu 0: [ 46.453986][ C1] __tcp_select_window+0x6b/0x4d0 [ 46.459004][ C1] __tcp_transmit_skb+0x679/0x1cd0 [ 46.464455][ C1] __tcp_send_ack+0x246/0x300 [ 46.469129][ C1] tcp_send_ack+0x34/0x40 [ 46.473463][ C1] tcp_cleanup_rbuf+0x130/0x360 [ 46.478348][ C1] tcp_recvmsg+0x633/0x1a30 [ 46.482851][ C1] inet_recvmsg+0xbb/0x250 [ 46.487260][ C1] sock_recvmsg+0x92/0xb0 [ 46.491584][ C1] sock_read_iter+0x15f/0x1e0 [ 46.496340][ C1] new_sync_read+0x389/0x4f0 [ 46.500972][ C1] __vfs_read+0xb1/0xc0 [ 46.505399][ C1] vfs_read+0x143/0x2c0 [ 46.509630][ C1] ksys_read+0xd5/0x1b0 [ 46.513777][ C1] __x64_sys_read+0x4c/0x60 [ 46.518346][ C1] [ 46.520791][ C1] write to 0xffff888122c312ec of 4 bytes by interrupt on cpu 1: [ 46.528413][ C1] tcp_add_backlog+0xb8f/0xcc0 [ 46.533263][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 46.537759][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 46.543118][ C1] ip_local_deliver_finish+0x110/0x140 [ 46.548626][ C1] ip_local_deliver+0x133/0x210 [ 46.553514][ C1] ip_rcv_finish+0x121/0x160 [ 46.558092][ C1] ip_rcv+0x18f/0x1a0 [ 46.562067][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 46.567779][ C1] __netif_receive_skb+0x37/0xf0 [ 46.572707][ C1] netif_receive_skb_internal+0x59/0x190 [ 46.578585][ C1] napi_gro_receive+0x28f/0x330 [ 46.583431][ C1] receive_buf+0x284/0x30b0 [ 46.587935][ C1] virtnet_poll+0x436/0x7d0 [ 46.592419][ C1] [ 46.594821][ C1] Reported by Kernel Concurrency Sanitizer on: [ 46.601005][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 46.608011][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.618065][ C1] ================================================================== [ 46.626122][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 46.633052][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 46.640069][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.650553][ C1] Call Trace: [ 46.653846][ C1] dump_stack+0xf5/0x159 [ 46.658086][ C1] panic+0x209/0x639 [ 46.661979][ C1] ? vprintk_func+0x8d/0x140 [ 46.666567][ C1] kcsan_report.cold+0x57/0xeb [ 46.671514][ C1] __kcsan_setup_watchpoint+0x342/0x500 [ 46.677183][ C1] __tsan_write4+0x32/0x40 [ 46.681595][ C1] tcp_add_backlog+0xb8f/0xcc0 [ 46.686359][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 46.691058][ C1] ? __tsan_read8+0x2c/0x30 [ 46.695637][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 46.701053][ C1] ip_local_deliver_finish+0x110/0x140 [ 46.706510][ C1] ip_local_deliver+0x133/0x210 [ 46.711358][ C1] ? ip_protocol_deliver_rcu+0x470/0x470 [ 46.717021][ C1] ip_rcv_finish+0x121/0x160 [ 46.721609][ C1] ip_rcv+0x18f/0x1a0 [ 46.725716][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 46.730687][ C1] ? ip_local_deliver+0x210/0x210 [ 46.735829][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 46.741723][ C1] __netif_receive_skb+0x37/0xf0 [ 46.746651][ C1] netif_receive_skb_internal+0x59/0x190 [ 46.752429][ C1] napi_gro_receive+0x28f/0x330 [ 46.757285][ C1] receive_buf+0x284/0x30b0 [ 46.761780][ C1] ? __tsan_write8+0x32/0x40 [ 46.766429][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 46.771986][ C1] ? virtqueue_get_buf+0x31/0x40 [ 46.776923][ C1] virtnet_poll+0x436/0x7d0 [ 46.781513][ C1] ? __sanitizer_cov_trace_cmp2+0x18/0x20 [ 46.787229][ C1] net_rx_action+0x3ae/0xa50 [ 46.791914][ C1] __do_softirq+0x115/0x33f [ 46.796526][ C1] ? takeover_tasklets+0x250/0x250 [ 46.801687][ C1] run_ksoftirqd+0x46/0x60 [ 46.806193][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 46.811214][ C1] kthread+0x1d4/0x200 [ 46.815274][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 46.821249][ C1] ? kthread_bind+0x50/0x50 [ 46.825751][ C1] ret_from_fork+0x1f/0x30 [ 46.831813][ C1] Kernel Offset: disabled [ 46.836229][ C1] Rebooting in 86400 seconds..