[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.954343][ T25] audit: type=1800 audit(1570192692.602:25): pid=7132 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.975103][ T25] audit: type=1800 audit(1570192692.602:26): pid=7132 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.995151][ T25] audit: type=1800 audit(1570192692.612:27): pid=7132 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 '10.128.15.213' (ECDSA) to the list of known hosts. 2019/10/04 12:38:23 fuzzer started 2019/10/04 12:38:24 dialing manager at 10.128.0.105:38119 2019/10/04 12:38:24 syscalls: 2523 2019/10/04 12:38:24 code coverage: enabled 2019/10/04 12:38:24 comparison tracing: enabled 2019/10/04 12:38:24 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:38:24 setuid sandbox: enabled 2019/10/04 12:38:24 namespace sandbox: enabled 2019/10/04 12:38:24 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:38:24 fault injection: enabled 2019/10/04 12:38:24 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:38:24 net packet injection: enabled 2019/10/04 12:38:24 net device setup: enabled 2019/10/04 12:38:24 concurrency sanitizer: enabled syzkaller login: [ 49.136989][ T7286] ================================================================== [ 49.145284][ T7286] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 49.155294][ T7286] [ 49.157609][ T7286] write to 0xffff8881255eb2ec of 4 bytes by interrupt on cpu 0: [ 49.165222][ T7286] tcp_add_backlog+0x4a0/0xcc0 [ 49.169969][ T7286] tcp_v4_rcv+0x1aba/0x1bf0 [ 49.174467][ T7286] ip_protocol_deliver_rcu+0x51/0x470 [ 49.179823][ T7286] ip_local_deliver_finish+0x110/0x140 [ 49.185266][ T7286] ip_local_deliver+0x133/0x210 [ 49.190097][ T7286] ip_rcv_finish+0x121/0x160 [ 49.194682][ T7286] ip_rcv+0x18f/0x1a0 [ 49.198673][ T7286] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.204392][ T7286] __netif_receive_skb+0x37/0xf0 [ 49.209315][ T7286] netif_receive_skb_internal+0x59/0x190 [ 49.214944][ T7286] napi_gro_receive+0x28f/0x330 [ 49.219802][ T7286] receive_buf+0x284/0x30b0 [ 49.224281][ T7286] virtnet_poll+0x436/0x7d0 [ 49.228935][ T7286] net_rx_action+0x3ae/0xa50 [ 49.233501][ T7286] [ 49.235812][ T7286] read to 0xffff8881255eb2ec of 4 bytes by task 7286 on cpu 1: [ 49.243601][ T7286] __tcp_select_window+0x6b/0x4d0 [ 49.248612][ T7286] __tcp_transmit_skb+0x679/0x1cd0 [ 49.253719][ T7286] __tcp_send_ack+0x246/0x300 [ 49.258378][ T7286] tcp_send_ack+0x34/0x40 [ 49.262693][ T7286] tcp_cleanup_rbuf+0x130/0x360 [ 49.267663][ T7286] tcp_recvmsg+0x633/0x1a30 [ 49.272281][ T7286] inet_recvmsg+0xbb/0x250 [ 49.276704][ T7286] sock_recvmsg+0x92/0xb0 [ 49.281044][ T7286] sock_read_iter+0x15f/0x1e0 [ 49.285714][ T7286] new_sync_read+0x389/0x4f0 [ 49.290397][ T7286] __vfs_read+0xb1/0xc0 [ 49.294705][ T7286] vfs_read+0x143/0x2c0 [ 49.298841][ T7286] ksys_read+0xd5/0x1b0 [ 49.302978][ T7286] [ 49.305308][ T7286] Reported by Kernel Concurrency Sanitizer on: [ 49.311470][ T7286] CPU: 1 PID: 7286 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 49.318655][ T7286] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.328702][ T7286] ================================================================== [ 49.336756][ T7286] Kernel panic - not syncing: panic_on_warn set ... [ 49.343344][ T7286] CPU: 1 PID: 7286 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 49.350538][ T7286] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.361017][ T7286] Call Trace: [ 49.364292][ T7286] dump_stack+0xf5/0x159 [ 49.368786][ T7286] panic+0x209/0x639 [ 49.372682][ T7286] ? vprintk_func+0x8d/0x140 [ 49.377269][ T7286] kcsan_report.cold+0x57/0xeb [ 49.382026][ T7286] __kcsan_setup_watchpoint+0x342/0x500 [ 49.387557][ T7286] __tsan_read4+0x2c/0x30 [ 49.391871][ T7286] __tcp_select_window+0x6b/0x4d0 [ 49.396889][ T7286] __tcp_transmit_skb+0x679/0x1cd0 [ 49.402010][ T7286] __tcp_send_ack+0x246/0x300 [ 49.406669][ T7286] tcp_send_ack+0x34/0x40 [ 49.410979][ T7286] tcp_cleanup_rbuf+0x130/0x360 [ 49.415815][ T7286] tcp_recvmsg+0x633/0x1a30 [ 49.420317][ T7286] inet_recvmsg+0xbb/0x250 [ 49.424715][ T7286] ? __tsan_read8+0x2c/0x30 [ 49.429202][ T7286] ? inet_sendpage+0x100/0x100 [ 49.433954][ T7286] sock_recvmsg+0x92/0xb0 [ 49.438310][ T7286] sock_read_iter+0x15f/0x1e0 [ 49.442977][ T7286] new_sync_read+0x389/0x4f0 [ 49.447563][ T7286] __vfs_read+0xb1/0xc0 [ 49.451709][ T7286] vfs_read+0x143/0x2c0 [ 49.455880][ T7286] ksys_read+0xd5/0x1b0 [ 49.460048][ T7286] __x64_sys_read+0x4c/0x60 [ 49.464553][ T7286] do_syscall_64+0xcf/0x2f0 [ 49.469325][ T7286] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.475193][ T7286] RIP: 0033:0x47c530 [ 49.479072][ T7286] 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 [ 49.498655][ T7286] RSP: 002b:000000c4203c97d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 49.507064][ T7286] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 49.515031][ T7286] RDX: 0000000000001000 RSI: 000000c42031e000 RDI: 0000000000000003 [ 49.522990][ T7286] RBP: 000000c4203c9830 R08: 0000000000000000 R09: 0000000000000000 [ 49.530942][ T7286] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 49.538896][ T7286] R13: ffffffffffffffff R14: 0000000000000020 R15: ffffffffffffffff [ 49.548303][ T7286] Kernel Offset: disabled [ 49.552629][ T7286] Rebooting in 86400 seconds..