[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [ 36.509079][ T25] audit: type=1800 audit(1572816472.878:25): pid=7068 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.532519][ T25] audit: type=1800 audit(1572816472.878:26): pid=7068 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.556250][ T25] audit: type=1800 audit(1572816472.878:27): pid=7068 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[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.1.31' (ECDSA) to the list of known hosts. 2019/11/03 21:28:04 fuzzer started 2019/11/03 21:28:06 dialing manager at 10.128.0.105:42255 2019/11/03 21:28:06 syscalls: 2553 2019/11/03 21:28:06 code coverage: enabled 2019/11/03 21:28:06 comparison tracing: enabled 2019/11/03 21:28:06 extra coverage: extra coverage is not supported by the kernel 2019/11/03 21:28:06 setuid sandbox: enabled 2019/11/03 21:28:06 namespace sandbox: enabled 2019/11/03 21:28:06 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/03 21:28:06 fault injection: enabled 2019/11/03 21:28:06 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/03 21:28:06 net packet injection: enabled 2019/11/03 21:28:06 net device setup: enabled 2019/11/03 21:28:06 concurrency sanitizer: enabled 2019/11/03 21:28:06 devlink PCI setup: PCI device 0000:00:10.0 is not available 2019/11/03 21:28:06 adding functions to KCSAN blacklist: 'get_wchan' 'pid_update_inode' 'generic_permission' 'ktime_get_real_seconds' '__hrtimer_run_queues' syzkaller login: [ 50.852335][ C0] ================================================================== [ 50.860565][ C0] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 50.868269][ C0] [ 50.870673][ C0] read to 0xffff8881268ef2ec of 4 bytes by task 7233 on cpu 1: [ 50.878202][ C0] __tcp_select_window+0x6b/0x4d0 [ 50.883225][ C0] __tcp_transmit_skb+0x700/0x1d60 [ 50.888422][ C0] __tcp_send_ack+0x246/0x300 [ 50.893085][ C0] tcp_send_ack+0x34/0x40 [ 50.897403][ C0] tcp_cleanup_rbuf+0x130/0x360 [ 50.902238][ C0] tcp_recvmsg+0x633/0x1a30 [ 50.906730][ C0] inet_recvmsg+0xbb/0x250 [ 50.911144][ C0] sock_recvmsg+0x92/0xb0 [ 50.915551][ C0] sock_read_iter+0x15f/0x1e0 [ 50.920312][ C0] new_sync_read+0x389/0x4f0 [ 50.924887][ C0] __vfs_read+0xb1/0xc0 [ 50.929213][ C0] vfs_read+0x143/0x2c0 [ 50.933800][ C0] ksys_read+0xd5/0x1b0 [ 50.937960][ C0] __x64_sys_read+0x4c/0x60 [ 50.942439][ C0] [ 50.944753][ C0] write to 0xffff8881268ef2ec of 4 bytes by interrupt on cpu 0: [ 50.952464][ C0] tcp_add_backlog+0x4a0/0xcc0 [ 50.957229][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 50.961719][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.967096][ C0] ip_local_deliver_finish+0x110/0x140 [ 50.972711][ C0] ip_local_deliver+0x133/0x210 [ 50.977546][ C0] ip_rcv_finish+0x121/0x160 [ 50.982118][ C0] ip_rcv+0x18f/0x1a0 [ 50.986119][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.991822][ C0] __netif_receive_skb+0x37/0xf0 [ 50.996744][ C0] netif_receive_skb_internal+0x59/0x190 [ 51.003547][ C0] napi_gro_receive+0x28f/0x330 [ 51.008388][ C0] receive_buf+0x284/0x30b0 [ 51.012880][ C0] virtnet_poll+0x436/0x7d0 [ 51.017362][ C0] [ 51.019673][ C0] Reported by Kernel Concurrency Sanitizer on: [ 51.025812][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3+ #0 [ 51.032897][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.043033][ C0] ================================================================== [ 51.051083][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 51.058264][ C0] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3+ #0 [ 51.065365][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.075750][ C0] Call Trace: [ 51.079020][ C0] <IRQ> [ 51.081887][ C0] dump_stack+0xf5/0x159 [ 51.086133][ C0] panic+0x210/0x640 [ 51.090030][ C0] ? __netif_receive_skb+0x37/0xf0 [ 51.095131][ C0] ? vprintk_func+0x8d/0x140 [ 51.099816][ C0] kcsan_report.cold+0xc/0x10 [ 51.104482][ C0] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.110027][ C0] __tsan_write4+0x32/0x40 [ 51.114436][ C0] tcp_add_backlog+0x4a0/0xcc0 [ 51.119233][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 51.123734][ C0] ? __tsan_read8+0x2c/0x30 [ 51.128239][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 51.133610][ C0] ip_local_deliver_finish+0x110/0x140 [ 51.139059][ C0] ip_local_deliver+0x133/0x210 [ 51.143899][ C0] ? ip_protocol_deliver_rcu+0x420/0x420 [ 51.149521][ C0] ip_rcv_finish+0x121/0x160 [ 51.154106][ C0] ip_rcv+0x18f/0x1a0 [ 51.158097][ C0] ? ip_sublist_rcv+0x5e0/0x5e0 [ 51.162953][ C0] ? ip_local_deliver+0x210/0x210 [ 51.167967][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 51.173677][ C0] __netif_receive_skb+0x37/0xf0 [ 51.178608][ C0] netif_receive_skb_internal+0x59/0x190 [ 51.184229][ C0] napi_gro_receive+0x28f/0x330 [ 51.189069][ C0] receive_buf+0x284/0x30b0 [ 51.193560][ C0] ? __tsan_write8+0x32/0x40 [ 51.198151][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 51.203596][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 51.209750][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 51.215376][ C0] virtnet_poll+0x436/0x7d0 [ 51.219877][ C0] net_rx_action+0x3ae/0xa90 [ 51.224568][ C0] __do_softirq+0x115/0x33f [ 51.229068][ C0] irq_exit+0xbb/0xe0 [ 51.233138][ C0] do_IRQ+0xa6/0x180 [ 51.237128][ C0] common_interrupt+0xf/0xf [ 51.241751][ C0] </IRQ> [ 51.244698][ C0] RIP: 0010:native_safe_halt+0xe/0x10 [ 51.250149][ C0] Code: 90 90 90 90 90 90 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d fc b2 4b 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d ec b2 4b 00 fb f4 <c3> 90 55 48 89 e5 41 55 41 54 53 e8 72 12 a4 fc e8 6d 8e b8 fd 0f [ 51.272370][ C0] RSP: 0018:ffffffff85a03de0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffda [ 51.280773][ C0] RAX: 26e978d4fdf3dace RBX: ffffffff85a2b780 RCX: 000000000000013e [ 51.288733][ C0] RDX: 00000000001fb530 RSI: 020c49ba5e353f7d RDI: ffffffff85a563b8 [ 51.296703][ C0] RBP: ffffffff85a03e18 R08: 0000000000000000 R09: 0000ffff85a563bf [ 51.304749][ C0] R10: 00000000aaaaaaab R11: ffffffff86045cc8 R12: 0000000000000000 [ 51.312722][ C0] R13: ffffffff85a2b780 R14: 0000000000000000 R15: 0000000000000000 [ 51.320717][ C0] ? default_idle+0x50/0x230 [ 51.325299][ C0] arch_cpu_idle+0x1f/0x30 [ 51.329716][ C0] default_idle_call+0x1e/0x40 [ 51.334653][ C0] do_idle+0x1af/0x280 [ 51.338734][ C0] cpu_startup_entry+0x1b/0x20 [ 51.343503][ C0] rest_init+0xec/0xf6 [ 51.347573][ C0] ? trace_event_define_fields_vector_free_moved+0xce/0xce [ 51.354761][ C0] arch_call_rest_init+0x17/0x37 [ 51.359695][ C0] start_kernel+0x838/0x85e [ 51.364191][ C0] x86_64_start_reservations+0x29/0x2b [ 51.369638][ C0] x86_64_start_kernel+0x72/0x76 [ 51.374564][ C0] secondary_startup_64+0xa4/0xb0 [ 51.380804][ C0] Kernel Offset: disabled [ 51.385230][ C0] Rebooting in 86400 seconds..