[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.196404][ T26] audit: type=1800 audit(1571793540.615:25): pid=7028 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.223505][ T26] audit: type=1800 audit(1571793540.625:26): pid=7028 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.254101][ T26] audit: type=1800 audit(1571793540.625:27): pid=7028 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 '10.128.1.38' (ECDSA) to the list of known hosts. 2019/10/23 01:19:10 fuzzer started 2019/10/23 01:19:11 dialing manager at 10.128.0.105:33369 2019/10/23 01:19:12 syscalls: 2524 2019/10/23 01:19:12 code coverage: enabled 2019/10/23 01:19:12 comparison tracing: enabled 2019/10/23 01:19:12 extra coverage: extra coverage is not supported by the kernel 2019/10/23 01:19:12 setuid sandbox: enabled 2019/10/23 01:19:12 namespace sandbox: enabled 2019/10/23 01:19:12 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 01:19:12 fault injection: enabled 2019/10/23 01:19:12 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 01:19:12 net packet injection: enabled 2019/10/23 01:19:12 net device setup: enabled 2019/10/23 01:19:12 concurrency sanitizer: enabled syzkaller login: [ 47.261306][ C1] ================================================================== [ 47.269525][ C1] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 47.276529][ C1] [ 47.278858][ C1] read to 0xffff888129c28a38 of 8 bytes by task 7184 on cpu 0: [ 47.286393][ C1] tcp_recvmsg+0x470/0x1a30 [ 47.290884][ C1] inet_recvmsg+0xbb/0x250 [ 47.295285][ C1] sock_recvmsg+0x92/0xb0 [ 47.299599][ C1] sock_read_iter+0x15f/0x1e0 [ 47.304258][ C1] new_sync_read+0x389/0x4f0 [ 47.308829][ C1] __vfs_read+0xb1/0xc0 [ 47.312966][ C1] vfs_read+0x143/0x2c0 [ 47.317104][ C1] ksys_read+0xd5/0x1b0 [ 47.321241][ C1] __x64_sys_read+0x4c/0x60 [ 47.325729][ C1] do_syscall_64+0xcc/0x370 [ 47.330225][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.336091][ C1] [ 47.338406][ C1] write to 0xffff888129c28a38 of 8 bytes by interrupt on cpu 1: [ 47.346017][ C1] tcp_add_backlog+0x45a/0xcc0 [ 47.350763][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.355248][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.360599][ C1] ip_local_deliver_finish+0x110/0x140 [ 47.366038][ C1] ip_local_deliver+0x133/0x210 [ 47.370868][ C1] ip_rcv_finish+0x121/0x160 [ 47.375435][ C1] ip_rcv+0x18f/0x1a0 [ 47.379400][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.385184][ C1] __netif_receive_skb+0x37/0xf0 [ 47.390103][ C1] netif_receive_skb_internal+0x59/0x190 [ 47.395715][ C1] napi_gro_receive+0x28f/0x330 [ 47.400549][ C1] receive_buf+0x284/0x30b0 [ 47.405032][ C1] virtnet_poll+0x436/0x7d0 [ 47.409512][ C1] [ 47.411819][ C1] Reported by Kernel Concurrency Sanitizer on: [ 47.417954][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 47.425307][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.435340][ C1] ================================================================== [ 47.443380][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 47.449957][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 47.457303][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.467333][ C1] Call Trace: [ 47.470612][ C1] dump_stack+0xf5/0x159 [ 47.474851][ C1] panic+0x210/0x640 [ 47.478730][ C1] ? __netif_receive_skb+0x37/0xf0 [ 47.483833][ C1] ? vprintk_func+0x8d/0x140 [ 47.488419][ C1] kcsan_report.cold+0xc/0x10 [ 47.493081][ C1] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.498610][ C1] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 47.504311][ C1] __tsan_write8+0x32/0x40 [ 47.508715][ C1] tcp_add_backlog+0x45a/0xcc0 [ 47.513472][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.517959][ C1] ? __tsan_read8+0x2c/0x30 [ 47.522448][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.527805][ C1] ip_local_deliver_finish+0x110/0x140 [ 47.533247][ C1] ip_local_deliver+0x133/0x210 [ 47.538092][ C1] ? ip_protocol_deliver_rcu+0x420/0x420 [ 47.543728][ C1] ip_rcv_finish+0x121/0x160 [ 47.548312][ C1] ip_rcv+0x18f/0x1a0 [ 47.552277][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 47.557121][ C1] ? ip_local_deliver+0x210/0x210 [ 47.562132][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.567839][ C1] __netif_receive_skb+0x37/0xf0 [ 47.572772][ C1] netif_receive_skb_internal+0x59/0x190 [ 47.578392][ C1] napi_gro_receive+0x28f/0x330 [ 47.583229][ C1] receive_buf+0x284/0x30b0 [ 47.587730][ C1] ? __tsan_write8+0x32/0x40 [ 47.592310][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 47.597749][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.603372][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.608991][ C1] virtnet_poll+0x436/0x7d0 [ 47.613483][ C1] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 47.619724][ C1] net_rx_action+0x3ae/0xa90 [ 47.624304][ C1] __do_softirq+0x115/0x33f [ 47.628795][ C1] ? takeover_tasklets+0x250/0x250 [ 47.633888][ C1] run_ksoftirqd+0x46/0x60 [ 47.638303][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 47.643245][ C1] kthread+0x1d4/0x200 [ 47.647303][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 47.653266][ C1] ? kthread_stop+0x2d0/0x2d0 [ 47.657925][ C1] ret_from_fork+0x1f/0x30 [ 47.663605][ C1] Kernel Offset: disabled [ 47.667924][ C1] Rebooting in 86400 seconds..