[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.246518][ T25] audit: type=1800 audit(1570191071.254:25): pid=7088 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.266549][ T25] audit: type=1800 audit(1570191071.254:26): pid=7088 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.296633][ T25] audit: type=1800 audit(1570191071.254:27): pid=7088 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 '10.128.0.110' (ECDSA) to the list of known hosts. 2019/10/04 12:11:27 fuzzer started 2019/10/04 12:11:28 dialing manager at 10.128.0.105:38119 2019/10/04 12:11:28 syscalls: 2523 2019/10/04 12:11:28 code coverage: enabled 2019/10/04 12:11:28 comparison tracing: enabled 2019/10/04 12:11:28 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:11:28 setuid sandbox: enabled 2019/10/04 12:11:28 namespace sandbox: enabled 2019/10/04 12:11:28 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:11:28 fault injection: enabled 2019/10/04 12:11:28 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:11:28 net packet injection: enabled 2019/10/04 12:11:28 net device setup: enabled 2019/10/04 12:11:28 concurrency sanitizer: enabled syzkaller login: [ 53.392775][ T7259] ================================================================== [ 53.400955][ T7259] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 53.410963][ T7259] [ 53.413371][ T7259] write to 0xffff888123c1b2ec of 4 bytes by interrupt on cpu 1: [ 53.420991][ T7259] tcp_add_backlog+0x4a0/0xcc0 [ 53.425749][ T7259] tcp_v4_rcv+0x1aba/0x1bf0 [ 53.430229][ T7259] ip_protocol_deliver_rcu+0x51/0x470 [ 53.435575][ T7259] ip_local_deliver_finish+0x110/0x140 [ 53.441009][ T7259] ip_local_deliver+0x133/0x210 [ 53.445841][ T7259] ip_rcv_finish+0x121/0x160 [ 53.450407][ T7259] ip_rcv+0x18f/0x1a0 [ 53.454372][ T7259] __netif_receive_skb_one_core+0xa7/0xe0 [ 53.460068][ T7259] __netif_receive_skb+0x37/0xf0 [ 53.464981][ T7259] netif_receive_skb_internal+0x59/0x190 [ 53.470588][ T7259] napi_gro_receive+0x28f/0x330 [ 53.475416][ T7259] receive_buf+0x284/0x30b0 [ 53.479898][ T7259] virtnet_poll+0x436/0x7d0 [ 53.484376][ T7259] net_rx_action+0x3ae/0xa50 [ 53.488936][ T7259] [ 53.491254][ T7259] read to 0xffff888123c1b2ec of 4 bytes by task 7259 on cpu 0: [ 53.498786][ T7259] __tcp_select_window+0x6b/0x4d0 [ 53.503786][ T7259] __tcp_transmit_skb+0x679/0x1cd0 [ 53.508886][ T7259] __tcp_send_ack+0x246/0x300 [ 53.513559][ T7259] tcp_send_ack+0x34/0x40 [ 53.517862][ T7259] tcp_cleanup_rbuf+0x130/0x360 [ 53.522698][ T7259] tcp_recvmsg+0x633/0x1a30 [ 53.527177][ T7259] inet_recvmsg+0xbb/0x250 [ 53.531567][ T7259] sock_recvmsg+0x92/0xb0 [ 53.535885][ T7259] sock_read_iter+0x15f/0x1e0 [ 53.540549][ T7259] new_sync_read+0x389/0x4f0 [ 53.545172][ T7259] __vfs_read+0xb1/0xc0 [ 53.549312][ T7259] vfs_read+0x143/0x2c0 [ 53.553469][ T7259] ksys_read+0xd5/0x1b0 [ 53.557701][ T7259] [ 53.560021][ T7259] Reported by Kernel Concurrency Sanitizer on: [ 53.566169][ T7259] CPU: 0 PID: 7259 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 53.573250][ T7259] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.583283][ T7259] ================================================================== [ 53.591323][ T7259] Kernel panic - not syncing: panic_on_warn set ... [ 53.597888][ T7259] CPU: 0 PID: 7259 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 53.604977][ T7259] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.615015][ T7259] Call Trace: [ 53.618292][ T7259] dump_stack+0xf5/0x159 [ 53.622516][ T7259] panic+0x209/0x639 [ 53.626391][ T7259] ? vprintk_func+0x8d/0x140 [ 53.630961][ T7259] kcsan_report.cold+0x57/0xeb [ 53.635712][ T7259] __kcsan_setup_watchpoint+0x342/0x500 [ 53.641236][ T7259] __tsan_read4+0x2c/0x30 [ 53.645547][ T7259] __tcp_select_window+0x6b/0x4d0 [ 53.650563][ T7259] __tcp_transmit_skb+0x679/0x1cd0 [ 53.655663][ T7259] __tcp_send_ack+0x246/0x300 [ 53.660321][ T7259] tcp_send_ack+0x34/0x40 [ 53.665689][ T7259] tcp_cleanup_rbuf+0x130/0x360 [ 53.670530][ T7259] tcp_recvmsg+0x633/0x1a30 [ 53.675020][ T7259] inet_recvmsg+0xbb/0x250 [ 53.679433][ T7259] ? __tsan_read8+0x2c/0x30 [ 53.683928][ T7259] ? inet_sendpage+0x100/0x100 [ 53.688667][ T7259] sock_recvmsg+0x92/0xb0 [ 53.692974][ T7259] sock_read_iter+0x15f/0x1e0 [ 53.697632][ T7259] new_sync_read+0x389/0x4f0 [ 53.702205][ T7259] __vfs_read+0xb1/0xc0 [ 53.706364][ T7259] vfs_read+0x143/0x2c0 [ 53.710498][ T7259] ksys_read+0xd5/0x1b0 [ 53.714646][ T7259] __x64_sys_read+0x4c/0x60 [ 53.719131][ T7259] do_syscall_64+0xcf/0x2f0 [ 53.723640][ T7259] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 53.729508][ T7259] RIP: 0033:0x47c530 [ 53.733398][ T7259] 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 [ 53.752988][ T7259] RSP: 002b:000000c4202cd7d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 53.761375][ T7259] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 53.769338][ T7259] RDX: 0000000000001000 RSI: 000000c420052000 RDI: 0000000000000003 [ 53.777294][ T7259] RBP: 000000c4202cd828 R08: 0000000000000000 R09: 0000000000000000 [ 53.785244][ T7259] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000010 [ 53.793209][ T7259] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 53.802523][ T7259] Kernel Offset: disabled [ 53.806841][ T7259] Rebooting in 86400 seconds..