[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 32.615603][ T26] audit: type=1800 audit(1570191865.599:25): pid=7011 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 32.658225][ T26] audit: type=1800 audit(1570191865.599:26): pid=7011 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 32.679710][ T26] audit: type=1800 audit(1570191865.599:27): pid=7011 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 '10.128.1.58' (ECDSA) to the list of known hosts. 2019/10/04 12:24:43 fuzzer started 2019/10/04 12:24:44 dialing manager at 10.128.0.105:38119 2019/10/04 12:24:45 syscalls: 2523 2019/10/04 12:24:45 code coverage: enabled 2019/10/04 12:24:45 comparison tracing: enabled 2019/10/04 12:24:45 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:24:45 setuid sandbox: enabled 2019/10/04 12:24:45 namespace sandbox: enabled 2019/10/04 12:24:45 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:24:45 fault injection: enabled 2019/10/04 12:24:45 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:24:45 net packet injection: enabled 2019/10/04 12:24:45 net device setup: enabled 2019/10/04 12:24:45 concurrency sanitizer: enabled syzkaller login: [ 52.919585][ C1] ================================================================== [ 52.927761][ C1] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 52.937097][ C1] [ 52.939407][ C1] read to 0xffff88812256c138 of 8 bytes by task 7168 on cpu 0: [ 52.946925][ C1] tcp_recvmsg+0x470/0x1a30 [ 52.951406][ C1] inet_recvmsg+0xbb/0x250 [ 52.955812][ C1] sock_recvmsg+0x92/0xb0 [ 52.960117][ C1] sock_read_iter+0x15f/0x1e0 [ 52.964773][ C1] new_sync_read+0x389/0x4f0 [ 52.969376][ C1] __vfs_read+0xb1/0xc0 [ 52.973515][ C1] vfs_read+0x143/0x2c0 [ 52.977644][ C1] ksys_read+0xd5/0x1b0 [ 52.981774][ C1] __x64_sys_read+0x4c/0x60 [ 52.986263][ C1] do_syscall_64+0xcf/0x2f0 [ 52.990748][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.996611][ C1] [ 52.998918][ C1] write to 0xffff88812256c138 of 8 bytes by interrupt on cpu 1: [ 53.006531][ C1] tcp_add_backlog+0x45a/0xcc0 [ 53.011268][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 53.015752][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 53.021102][ C1] ip_local_deliver_finish+0x110/0x140 [ 53.026539][ C1] ip_local_deliver+0x133/0x210 [ 53.031362][ C1] ip_rcv_finish+0x121/0x160 [ 53.035929][ C1] ip_rcv+0x18f/0x1a0 [ 53.039894][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 53.045587][ C1] __netif_receive_skb+0x37/0xf0 [ 53.050499][ C1] netif_receive_skb_internal+0x59/0x190 [ 53.056106][ C1] napi_gro_receive+0x28f/0x330 [ 53.060938][ C1] receive_buf+0x284/0x30b0 [ 53.065418][ C1] virtnet_poll+0x436/0x7d0 [ 53.069890][ C1] [ 53.072192][ C1] Reported by Kernel Concurrency Sanitizer on: [ 53.078323][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 53.085316][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.095348][ C1] ================================================================== [ 53.103382][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 53.109965][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0+ #0 [ 53.116958][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.126986][ C1] Call Trace: [ 53.130257][ C1] dump_stack+0xf5/0x159 [ 53.134488][ C1] panic+0x209/0x639 [ 53.138365][ C1] ? vprintk_func+0x8d/0x140 [ 53.142961][ C1] kcsan_report.cold+0x57/0xeb [ 53.147706][ C1] __kcsan_setup_watchpoint+0x342/0x500 [ 53.153230][ C1] __tsan_write8+0x32/0x40 [ 53.157641][ C1] tcp_add_backlog+0x45a/0xcc0 [ 53.162391][ C1] tcp_v4_rcv+0x1aba/0x1bf0 [ 53.166872][ C1] ? __tsan_read8+0x2c/0x30 [ 53.171359][ C1] ip_protocol_deliver_rcu+0x51/0x470 [ 53.176719][ C1] ip_local_deliver_finish+0x110/0x140 [ 53.182153][ C1] ip_local_deliver+0x133/0x210 [ 53.187008][ C1] ? ip_protocol_deliver_rcu+0x470/0x470 [ 53.192622][ C1] ip_rcv_finish+0x121/0x160 [ 53.197193][ C1] ip_rcv+0x18f/0x1a0 [ 53.201155][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 53.205988][ C1] ? ip_local_deliver+0x210/0x210 [ 53.210998][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 53.216703][ C1] __netif_receive_skb+0x37/0xf0 [ 53.221618][ C1] netif_receive_skb_internal+0x59/0x190 [ 53.227231][ C1] napi_gro_receive+0x28f/0x330 [ 53.232073][ C1] receive_buf+0x284/0x30b0 [ 53.236568][ C1] ? __tsan_write8+0x32/0x40 [ 53.241145][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 53.246585][ C1] ? virtqueue_get_buf+0x31/0x40 [ 53.251508][ C1] virtnet_poll+0x436/0x7d0 [ 53.256003][ C1] net_rx_action+0x3ae/0xa50 [ 53.260581][ C1] __do_softirq+0x115/0x33f [ 53.265075][ C1] ? takeover_tasklets+0x250/0x250 [ 53.270165][ C1] run_ksoftirqd+0x46/0x60 [ 53.274559][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 53.279475][ C1] kthread+0x1d4/0x200 [ 53.283521][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 53.289480][ C1] ? kthread_bind+0x50/0x50 [ 53.293977][ C1] ret_from_fork+0x1f/0x30 [ 53.299611][ C1] Kernel Offset: disabled [ 53.303924][ C1] Rebooting in 86400 seconds..