[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.377427][ T25] audit: type=1800 audit(1570192092.948:25): pid=7071 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.397072][ T25] audit: type=1800 audit(1570192092.948:26): pid=7071 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.487465][ T25] audit: type=1800 audit(1570192093.058:27): pid=7071 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 '10.128.0.144' (ECDSA) to the list of known hosts. 2019/10/04 12:28:21 fuzzer started 2019/10/04 12:28:22 dialing manager at 10.128.0.105:38119 2019/10/04 12:28:22 syscalls: 2523 2019/10/04 12:28:22 code coverage: enabled 2019/10/04 12:28:22 comparison tracing: enabled 2019/10/04 12:28:22 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:28:22 setuid sandbox: enabled 2019/10/04 12:28:22 namespace sandbox: enabled 2019/10/04 12:28:22 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:28:22 fault injection: enabled 2019/10/04 12:28:22 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:28:22 net packet injection: enabled 2019/10/04 12:28:22 net device setup: enabled 2019/10/04 12:28:22 concurrency sanitizer: enabled syzkaller login: [ 45.011761][ T7236] ================================================================== [ 45.020008][ T7236] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 45.029877][ T7236] [ 45.032201][ T7236] write to 0xffff88812642b32c of 4 bytes by interrupt on cpu 1: [ 45.039827][ T7236] tcp_add_backlog+0x4a0/0xcc0 [ 45.044564][ T7236] tcp_v4_rcv+0x1aba/0x1bf0 [ 45.049172][ T7236] ip_protocol_deliver_rcu+0x51/0x470 [ 45.054516][ T7236] ip_local_deliver_finish+0x110/0x140 [ 45.059948][ T7236] ip_local_deliver+0x133/0x210 [ 45.064769][ T7236] ip_rcv_finish+0x121/0x160 [ 45.069372][ T7236] ip_rcv+0x18f/0x1a0 [ 45.073332][ T7236] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.079026][ T7236] __netif_receive_skb+0x37/0xf0 [ 45.083934][ T7236] netif_receive_skb_internal+0x59/0x190 [ 45.089538][ T7236] napi_gro_receive+0x28f/0x330 [ 45.094397][ T7236] receive_buf+0x284/0x30b0 [ 45.098873][ T7236] virtnet_poll+0x436/0x7d0 [ 45.103383][ T7236] net_rx_action+0x3ae/0xa50 [ 45.107976][ T7236] [ 45.110293][ T7236] read to 0xffff88812642b32c of 4 bytes by task 7236 on cpu 0: [ 45.117822][ T7236] __tcp_select_window+0x6b/0x4d0 [ 45.122824][ T7236] __tcp_transmit_skb+0x679/0x1cd0 [ 45.127909][ T7236] __tcp_send_ack+0x246/0x300 [ 45.132559][ T7236] tcp_send_ack+0x34/0x40 [ 45.136906][ T7236] tcp_cleanup_rbuf+0x130/0x360 [ 45.141728][ T7236] tcp_recvmsg+0x633/0x1a30 [ 45.146227][ T7236] inet_recvmsg+0xbb/0x250 [ 45.150645][ T7236] sock_recvmsg+0x92/0xb0 [ 45.155043][ T7236] sock_read_iter+0x15f/0x1e0 [ 45.159694][ T7236] new_sync_read+0x389/0x4f0 [ 45.164259][ T7236] __vfs_read+0xb1/0xc0 [ 45.168387][ T7236] vfs_read+0x143/0x2c0 [ 45.172516][ T7236] ksys_read+0xd5/0x1b0 [ 45.176638][ T7236] [ 45.178939][ T7236] Reported by Kernel Concurrency Sanitizer on: [ 45.185074][ T7236] CPU: 0 PID: 7236 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 45.192151][ T7236] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.202193][ T7236] ================================================================== [ 45.210224][ T7236] Kernel panic - not syncing: panic_on_warn set ... [ 45.216801][ T7236] CPU: 0 PID: 7236 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 45.223878][ T7236] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.233902][ T7236] Call Trace: [ 45.237169][ T7236] dump_stack+0xf5/0x159 [ 45.241390][ T7236] panic+0x209/0x639 [ 45.245263][ T7236] ? vprintk_func+0x8d/0x140 [ 45.249831][ T7236] kcsan_report.cold+0x57/0xeb [ 45.254572][ T7236] __kcsan_setup_watchpoint+0x342/0x500 [ 45.260103][ T7236] __tsan_read4+0x2c/0x30 [ 45.264408][ T7236] __tcp_select_window+0x6b/0x4d0 [ 45.269409][ T7236] __tcp_transmit_skb+0x679/0x1cd0 [ 45.274501][ T7236] __tcp_send_ack+0x246/0x300 [ 45.279165][ T7236] tcp_send_ack+0x34/0x40 [ 45.283467][ T7236] tcp_cleanup_rbuf+0x130/0x360 [ 45.288295][ T7236] tcp_recvmsg+0x633/0x1a30 [ 45.292781][ T7236] inet_recvmsg+0xbb/0x250 [ 45.297173][ T7236] ? __tsan_read8+0x2c/0x30 [ 45.301653][ T7236] ? inet_sendpage+0x100/0x100 [ 45.306391][ T7236] sock_recvmsg+0x92/0xb0 [ 45.310695][ T7236] sock_read_iter+0x15f/0x1e0 [ 45.315352][ T7236] new_sync_read+0x389/0x4f0 [ 45.319923][ T7236] __vfs_read+0xb1/0xc0 [ 45.324064][ T7236] vfs_read+0x143/0x2c0 [ 45.328195][ T7236] ksys_read+0xd5/0x1b0 [ 45.332327][ T7236] __x64_sys_read+0x4c/0x60 [ 45.336808][ T7236] do_syscall_64+0xcf/0x2f0 [ 45.341290][ T7236] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.347164][ T7236] RIP: 0033:0x47c530 [ 45.351036][ T7236] 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 [ 45.370614][ T7236] RSP: 002b:000000c4204e97d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 45.378997][ T7236] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 45.386940][ T7236] RDX: 0000000000001000 RSI: 000000c420322000 RDI: 0000000000000003 [ 45.394896][ T7236] RBP: 000000c4204e9830 R08: 0000000000000000 R09: 0000000000000000 [ 45.402839][ T7236] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 45.410784][ T7236] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 45.419997][ T7236] Kernel Offset: disabled [ 45.424315][ T7236] Rebooting in 86400 seconds..