[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 37.098555][ T25] audit: type=1800 audit(1570191272.071:25): pid=7133 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 37.118510][ T25] audit: type=1800 audit(1570191272.071:26): pid=7133 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 37.140351][ T25] audit: type=1800 audit(1570191272.071:27): pid=7133 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 '10.128.0.9' (ECDSA) to the list of known hosts. 2019/10/04 12:14:43 fuzzer started 2019/10/04 12:14:45 dialing manager at 10.128.0.105:38119 2019/10/04 12:14:45 syscalls: 2523 2019/10/04 12:14:45 code coverage: enabled 2019/10/04 12:14:45 comparison tracing: enabled 2019/10/04 12:14:45 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:14:45 setuid sandbox: enabled 2019/10/04 12:14:45 namespace sandbox: enabled 2019/10/04 12:14:45 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:14:45 fault injection: enabled 2019/10/04 12:14:45 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:14:45 net packet injection: enabled 2019/10/04 12:14:45 net device setup: enabled 2019/10/04 12:14:45 concurrency sanitizer: enabled syzkaller login: [ 50.932415][ T7305] ================================================================== [ 50.940605][ T7305] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 50.950579][ T7305] [ 50.952891][ T7305] write to 0xffff888128c029ec of 4 bytes by interrupt on cpu 1: [ 50.960498][ T7305] tcp_add_backlog+0x4a0/0xcc0 [ 50.965234][ T7305] tcp_v4_rcv+0x1aba/0x1bf0 [ 50.969736][ T7305] ip_protocol_deliver_rcu+0x51/0x470 [ 50.975090][ T7305] ip_local_deliver_finish+0x110/0x140 [ 50.980542][ T7305] ip_local_deliver+0x133/0x210 [ 50.985371][ T7305] ip_rcv_finish+0x121/0x160 [ 50.990034][ T7305] ip_rcv+0x18f/0x1a0 [ 50.994023][ T7305] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.999730][ T7305] __netif_receive_skb+0x37/0xf0 [ 51.004642][ T7305] netif_receive_skb_internal+0x59/0x190 [ 51.010249][ T7305] napi_gro_receive+0x28f/0x330 [ 51.015081][ T7305] receive_buf+0x284/0x30b0 [ 51.019571][ T7305] virtnet_poll+0x436/0x7d0 [ 51.024049][ T7305] net_rx_action+0x3ae/0xa50 [ 51.028632][ T7305] [ 51.030948][ T7305] read to 0xffff888128c029ec of 4 bytes by task 7305 on cpu 0: [ 51.038480][ T7305] __tcp_select_window+0x6b/0x4d0 [ 51.043571][ T7305] __tcp_transmit_skb+0x679/0x1cd0 [ 51.048667][ T7305] __tcp_send_ack+0x246/0x300 [ 51.053329][ T7305] tcp_send_ack+0x34/0x40 [ 51.057637][ T7305] tcp_cleanup_rbuf+0x130/0x360 [ 51.062473][ T7305] tcp_recvmsg+0x633/0x1a30 [ 51.066958][ T7305] inet_recvmsg+0xbb/0x250 [ 51.071361][ T7305] sock_recvmsg+0x92/0xb0 [ 51.075682][ T7305] sock_read_iter+0x15f/0x1e0 [ 51.080346][ T7305] new_sync_read+0x389/0x4f0 [ 51.084920][ T7305] __vfs_read+0xb1/0xc0 [ 51.089062][ T7305] vfs_read+0x143/0x2c0 [ 51.093201][ T7305] ksys_read+0xd5/0x1b0 [ 51.097332][ T7305] [ 51.099643][ T7305] Reported by Kernel Concurrency Sanitizer on: [ 51.105771][ T7305] CPU: 0 PID: 7305 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 51.112847][ T7305] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.122879][ T7305] ================================================================== [ 51.130914][ T7305] Kernel panic - not syncing: panic_on_warn set ... [ 51.137478][ T7305] CPU: 0 PID: 7305 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 51.144585][ T7305] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 51.154613][ T7305] Call Trace: [ 51.158501][ T7305] dump_stack+0xf5/0x159 [ 51.162749][ T7305] panic+0x209/0x639 [ 51.166645][ T7305] ? vprintk_func+0x8d/0x140 [ 51.171229][ T7305] kcsan_report.cold+0x57/0xeb [ 51.176141][ T7305] __kcsan_setup_watchpoint+0x342/0x500 [ 51.181686][ T7305] __tsan_read4+0x2c/0x30 [ 51.186010][ T7305] __tcp_select_window+0x6b/0x4d0 [ 51.191044][ T7305] __tcp_transmit_skb+0x679/0x1cd0 [ 51.196152][ T7305] __tcp_send_ack+0x246/0x300 [ 51.200912][ T7305] tcp_send_ack+0x34/0x40 [ 51.205224][ T7305] tcp_cleanup_rbuf+0x130/0x360 [ 51.210071][ T7305] tcp_recvmsg+0x633/0x1a30 [ 51.214579][ T7305] inet_recvmsg+0xbb/0x250 [ 51.218991][ T7305] ? __tsan_read8+0x2c/0x30 [ 51.223488][ T7305] ? inet_sendpage+0x100/0x100 [ 51.228243][ T7305] sock_recvmsg+0x92/0xb0 [ 51.232562][ T7305] sock_read_iter+0x15f/0x1e0 [ 51.237232][ T7305] new_sync_read+0x389/0x4f0 [ 51.241821][ T7305] __vfs_read+0xb1/0xc0 [ 51.245954][ T7305] vfs_read+0x143/0x2c0 [ 51.250087][ T7305] ksys_read+0xd5/0x1b0 [ 51.254223][ T7305] __x64_sys_read+0x4c/0x60 [ 51.258707][ T7305] do_syscall_64+0xcf/0x2f0 [ 51.263192][ T7305] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.269060][ T7305] RIP: 0033:0x47c530 [ 51.272935][ T7305] 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 [ 51.292529][ T7305] RSP: 002b:000000c420399810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 51.300943][ T7305] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 51.308910][ T7305] RDX: 0000000000001000 RSI: 000000c420162000 RDI: 0000000000000003 [ 51.316872][ T7305] RBP: 000000c420399868 R08: 0000000000000000 R09: 0000000000000000 [ 51.324824][ T7305] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000040 [ 51.332774][ T7305] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 51.342292][ T7305] Kernel Offset: disabled [ 51.346629][ T7305] Rebooting in 86400 seconds..