[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.374902][ T26] audit: type=1800 audit(1571766301.541:25): pid=7087 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.394765][ T26] audit: type=1800 audit(1571766301.541:26): pid=7087 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.415065][ T26] audit: type=1800 audit(1571766301.541:27): pid=7087 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 '10.128.0.180' (ECDSA) to the list of known hosts. 2019/10/22 17:45:09 fuzzer started 2019/10/22 17:45:10 dialing manager at 10.128.0.105:33369 2019/10/22 17:45:10 syscalls: 2524 2019/10/22 17:45:10 code coverage: enabled 2019/10/22 17:45:10 comparison tracing: enabled 2019/10/22 17:45:10 extra coverage: extra coverage is not supported by the kernel 2019/10/22 17:45:10 setuid sandbox: enabled 2019/10/22 17:45:10 namespace sandbox: enabled 2019/10/22 17:45:10 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 17:45:10 fault injection: enabled 2019/10/22 17:45:10 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 17:45:10 net packet injection: enabled 2019/10/22 17:45:10 net device setup: enabled 2019/10/22 17:45:10 concurrency sanitizer: enabled syzkaller login: [ 45.632941][ C1] ================================================================== [ 45.641080][ C1] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 45.648080][ C1] [ 45.650396][ C1] read to 0xffff888123611338 of 8 bytes by task 7242 on cpu 0: [ 45.657923][ C1] tcp_recvmsg+0x470/0x1a30 [ 45.662409][ C1] inet_recvmsg+0xbb/0x250 [ 45.667075][ C1] sock_recvmsg+0x92/0xb0 [ 45.671390][ C1] sock_read_iter+0x15f/0x1e0 [ 45.677703][ C1] new_sync_read+0x389/0x4f0 [ 45.682288][ C1] __vfs_read+0xb1/0xc0 [ 45.686428][ C1] vfs_read+0x143/0x2c0 [ 45.713139][ C1] ksys_read+0xd5/0x1b0 [ 45.717280][ C1] __x64_sys_read+0x4c/0x60 [ 45.721770][ C1] do_syscall_64+0xcc/0x370 [ 45.726259][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.732126][ C1] [ 45.734443][ C1] write to 0xffff888123611338 of 8 bytes by interrupt on cpu 1: [ 45.742058][ C1] tcp_add_backlog+0x45a/0xcc0 [ 45.746808][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 45.751294][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 45.756734][ C1] ip_local_deliver_finish+0x110/0x140 [ 45.762176][ C1] ip_local_deliver+0x133/0x210 [ 45.767021][ C1] ip_rcv_finish+0x121/0x160 [ 45.771592][ C1] ip_rcv+0x18f/0x1a0 [ 45.775561][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.781279][ C1] __netif_receive_skb+0x37/0xf0 [ 45.786201][ C1] netif_receive_skb_internal+0x59/0x190 [ 45.791818][ C1] napi_gro_receive+0x28f/0x330 [ 45.796655][ C1] receive_buf+0x284/0x30b0 [ 45.801142][ C1] virtnet_poll+0x436/0x7d0 [ 45.805622][ C1] [ 45.807932][ C1] Reported by Kernel Concurrency Sanitizer on: [ 45.814068][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 45.821415][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.831452][ C1] ================================================================== [ 45.839496][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 45.846069][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 45.853441][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.863483][ C1] Call Trace: [ 45.866763][ C1] dump_stack+0xf5/0x159 [ 45.870994][ C1] panic+0x210/0x640 [ 45.874877][ C1] ? __netif_receive_skb+0x37/0xf0 [ 45.879975][ C1] ? vprintk_func+0x8d/0x140 [ 45.884571][ C1] kcsan_report.cold+0xc/0x10 [ 45.889236][ C1] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 45.894771][ C1] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 45.900478][ C1] __tsan_write8+0x32/0x40 [ 45.904884][ C1] tcp_add_backlog+0x45a/0xcc0 [ 45.909642][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 45.914132][ C1] ? __tsan_read8+0x2c/0x30 [ 45.918625][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 45.923993][ C1] ip_local_deliver_finish+0x110/0x140 [ 45.929439][ C1] ip_local_deliver+0x133/0x210 [ 45.934278][ C1] ? ip_protocol_deliver_rcu+0x420/0x420 [ 45.939896][ C1] ip_rcv_finish+0x121/0x160 [ 45.944472][ C1] ip_rcv+0x18f/0x1a0 [ 45.948457][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 45.953308][ C1] ? ip_local_deliver+0x210/0x210 [ 45.958316][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.964023][ C1] __netif_receive_skb+0x37/0xf0 [ 45.968950][ C1] netif_receive_skb_internal+0x59/0x190 [ 45.974573][ C1] napi_gro_receive+0x28f/0x330 [ 45.979410][ C1] receive_buf+0x284/0x30b0 [ 45.983992][ C1] ? __tsan_write8+0x32/0x40 [ 45.988576][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 45.994020][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 45.999655][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 46.005297][ C1] virtnet_poll+0x436/0x7d0 [ 46.009839][ C1] net_rx_action+0x3ae/0xa90 [ 46.014428][ C1] __do_softirq+0x115/0x33f [ 46.018925][ C1] ? takeover_tasklets+0x250/0x250 [ 46.024022][ C1] run_ksoftirqd+0x46/0x60 [ 46.028426][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 46.033350][ C1] kthread+0x1d4/0x200 [ 46.037406][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 46.043370][ C1] ? kthread_stop+0x2d0/0x2d0 [ 46.048048][ C1] ret_from_fork+0x1f/0x30 [ 46.053813][ C1] Kernel Offset: disabled [ 46.058177][ C1] Rebooting in 86400 seconds..