[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.095243][ T25] audit: type=1800 audit(1570191534.309:25): pid=7074 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.132639][ T25] audit: type=1800 audit(1570191534.309:26): pid=7074 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.152852][ T25] audit: type=1800 audit(1570191534.309:27): pid=7074 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 '10.128.10.34' (ECDSA) to the list of known hosts. 2019/10/04 12:19:04 fuzzer started 2019/10/04 12:19:05 dialing manager at 10.128.0.105:38119 2019/10/04 12:19:05 syscalls: 2523 2019/10/04 12:19:05 code coverage: enabled 2019/10/04 12:19:05 comparison tracing: enabled 2019/10/04 12:19:05 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:19:05 setuid sandbox: enabled 2019/10/04 12:19:05 namespace sandbox: enabled 2019/10/04 12:19:05 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:19:05 fault injection: enabled 2019/10/04 12:19:05 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:19:05 net packet injection: enabled 2019/10/04 12:19:05 net device setup: enabled 2019/10/04 12:19:05 concurrency sanitizer: enabled syzkaller login: [ 49.997030][ T7237] ================================================================== [ 50.005253][ T7237] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 50.014602][ T7237] [ 50.016907][ T7237] write to 0xffff88811f8b09f8 of 8 bytes by interrupt on cpu 1: [ 50.024507][ T7237] tcp_add_backlog+0x45a/0xcc0 [ 50.029251][ T7237] tcp_v4_rcv+0x1aba/0x1bf0 [ 50.033729][ T7237] ip_protocol_deliver_rcu+0x51/0x470 [ 50.039072][ T7237] ip_local_deliver_finish+0x110/0x140 [ 50.044502][ T7237] ip_local_deliver+0x133/0x210 [ 50.049329][ T7237] ip_rcv_finish+0x121/0x160 [ 50.053922][ T7237] ip_rcv+0x18f/0x1a0 [ 50.057898][ T7237] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.063592][ T7237] __netif_receive_skb+0x37/0xf0 [ 50.068513][ T7237] netif_receive_skb_internal+0x59/0x190 [ 50.074116][ T7237] napi_gro_receive+0x28f/0x330 [ 50.078942][ T7237] receive_buf+0x284/0x30b0 [ 50.083417][ T7237] virtnet_poll+0x436/0x7d0 [ 50.087989][ T7237] net_rx_action+0x3ae/0xa50 [ 50.092545][ T7237] [ 50.094850][ T7237] read to 0xffff88811f8b09f8 of 8 bytes by task 7237 on cpu 0: [ 50.102372][ T7237] tcp_recvmsg+0x470/0x1a30 [ 50.106847][ T7237] inet_recvmsg+0xbb/0x250 [ 50.111241][ T7237] sock_recvmsg+0x92/0xb0 [ 50.115540][ T7237] sock_read_iter+0x15f/0x1e0 [ 50.120193][ T7237] new_sync_read+0x389/0x4f0 [ 50.124753][ T7237] __vfs_read+0xb1/0xc0 [ 50.128883][ T7237] vfs_read+0x143/0x2c0 [ 50.133012][ T7237] ksys_read+0xd5/0x1b0 [ 50.137140][ T7237] __x64_sys_read+0x4c/0x60 [ 50.141617][ T7237] do_syscall_64+0xcf/0x2f0 [ 50.146107][ T7237] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.151966][ T7237] [ 50.154286][ T7237] Reported by Kernel Concurrency Sanitizer on: [ 50.160414][ T7237] CPU: 0 PID: 7237 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 50.167490][ T7237] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.177516][ T7237] ================================================================== [ 50.185550][ T7237] Kernel panic - not syncing: panic_on_warn set ... [ 50.192110][ T7237] CPU: 0 PID: 7237 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 50.199185][ T7237] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.209220][ T7237] Call Trace: [ 50.212501][ T7237] dump_stack+0xf5/0x159 [ 50.216722][ T7237] panic+0x209/0x639 [ 50.220596][ T7237] ? vprintk_func+0x8d/0x140 [ 50.225163][ T7237] kcsan_report.cold+0x57/0xeb [ 50.229904][ T7237] __kcsan_setup_watchpoint+0x342/0x500 [ 50.235422][ T7237] __tsan_read8+0x2c/0x30 [ 50.239724][ T7237] tcp_recvmsg+0x470/0x1a30 [ 50.244219][ T7237] inet_recvmsg+0xbb/0x250 [ 50.248611][ T7237] ? __tsan_read8+0x2c/0x30 [ 50.253088][ T7237] ? inet_sendpage+0x100/0x100 [ 50.257829][ T7237] sock_recvmsg+0x92/0xb0 [ 50.262133][ T7237] sock_read_iter+0x15f/0x1e0 [ 50.266790][ T7237] new_sync_read+0x389/0x4f0 [ 50.271364][ T7237] __vfs_read+0xb1/0xc0 [ 50.275525][ T7237] vfs_read+0x143/0x2c0 [ 50.279656][ T7237] ksys_read+0xd5/0x1b0 [ 50.283787][ T7237] __x64_sys_read+0x4c/0x60 [ 50.288396][ T7237] do_syscall_64+0xcf/0x2f0 [ 50.292883][ T7237] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.298751][ T7237] RIP: 0033:0x47c530 [ 50.302652][ T7237] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 50.322229][ T7237] RSP: 002b:000000c4202c57d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 50.330614][ T7237] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 50.338558][ T7237] RDX: 0000000000001000 RSI: 000000c4202e2000 RDI: 0000000000000003 [ 50.346502][ T7237] RBP: 000000c4202c5830 R08: 0000000000000000 R09: 0000000000000000 [ 50.354445][ T7237] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 50.362387][ T7237] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 50.371518][ T7237] Kernel Offset: disabled [ 50.375833][ T7237] Rebooting in 86400 seconds..