[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.243705][ T26] audit: type=1800 audit(1570192405.246:25): pid=7115 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 39.281151][ T26] audit: type=1800 audit(1570192405.246:26): pid=7115 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 39.308456][ T26] audit: type=1800 audit(1570192405.256:27): pid=7115 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 '10.128.10.58' (ECDSA) to the list of known hosts. 2019/10/04 12:33:36 fuzzer started 2019/10/04 12:33:38 dialing manager at 10.128.0.105:38119 2019/10/04 12:33:38 syscalls: 2523 2019/10/04 12:33:38 code coverage: enabled 2019/10/04 12:33:38 comparison tracing: enabled 2019/10/04 12:33:38 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:33:38 setuid sandbox: enabled 2019/10/04 12:33:38 namespace sandbox: enabled 2019/10/04 12:33:38 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:33:38 fault injection: enabled 2019/10/04 12:33:38 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:33:38 net packet injection: enabled 2019/10/04 12:33:38 net device setup: enabled 2019/10/04 12:33:38 concurrency sanitizer: enabled syzkaller login: [ 53.098579][ T7279] ================================================================== [ 53.107164][ T7279] BUG: KCSAN: data-race in tcp_add_backlog+0x4a0/0xcc0 and tcp_grow_window.isra.0+0x6b/0x480 [ 53.117949][ T7279] [ 53.120311][ T7279] write to 0xffff8881257869ec of 4 bytes by interrupt on cpu 1: [ 53.127973][ T7279] tcp_add_backlog+0x4a0/0xcc0 [ 53.132815][ T7279] tcp_v4_rcv+0x1aba/0x1bf0 [ 53.137393][ T7279] ip_protocol_deliver_rcu+0x51/0x470 [ 53.142963][ T7279] ip_local_deliver_finish+0x110/0x140 [ 53.149860][ T7279] ip_local_deliver+0x133/0x210 [ 53.155481][ T7279] ip_rcv_finish+0x121/0x160 [ 53.160065][ T7279] ip_rcv+0x18f/0x1a0 [ 53.164409][ T7279] __netif_receive_skb_one_core+0xa7/0xe0 [ 53.170691][ T7279] __netif_receive_skb+0x37/0xf0 [ 53.175797][ T7279] netif_receive_skb_internal+0x59/0x190 [ 53.181519][ T7279] napi_gro_receive+0x28f/0x330 [ 53.186546][ T7279] receive_buf+0x284/0x30b0 [ 53.191463][ T7279] virtnet_poll+0x436/0x7d0 [ 53.196033][ T7279] net_rx_action+0x3ae/0xa50 [ 53.200836][ T7279] [ 53.203409][ T7279] read to 0xffff8881257869ec of 4 bytes by task 7279 on cpu 0: [ 53.211469][ T7279] tcp_grow_window.isra.0+0x6b/0x480 [ 53.217093][ T7279] tcp_event_data_recv+0x68f/0x990 [ 53.222181][ T7279] tcp_rcv_established+0xbfe/0xf50 [ 53.227269][ T7279] tcp_v4_do_rcv+0x381/0x4e0 [ 53.232568][ T7279] __release_sock+0x135/0x1e0 [ 53.237240][ T7279] release_sock+0x61/0x160 [ 53.241838][ T7279] tcp_recvmsg+0x63b/0x1a30 [ 53.246528][ T7279] inet_recvmsg+0xbb/0x250 [ 53.250994][ T7279] sock_recvmsg+0x92/0xb0 [ 53.255472][ T7279] sock_read_iter+0x15f/0x1e0 [ 53.260130][ T7279] new_sync_read+0x389/0x4f0 [ 53.264711][ T7279] __vfs_read+0xb1/0xc0 [ 53.268847][ T7279] vfs_read+0x143/0x2c0 [ 53.273609][ T7279] [ 53.275911][ T7279] Reported by Kernel Concurrency Sanitizer on: [ 53.282049][ T7279] CPU: 0 PID: 7279 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 53.289142][ T7279] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.299296][ T7279] ================================================================== [ 53.307366][ T7279] Kernel panic - not syncing: panic_on_warn set ... [ 53.314025][ T7279] CPU: 0 PID: 7279 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 53.321565][ T7279] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.332091][ T7279] Call Trace: [ 53.335661][ T7279] dump_stack+0xf5/0x159 [ 53.340093][ T7279] panic+0x209/0x639 [ 53.343976][ T7279] ? vprintk_func+0x8d/0x140 [ 53.349198][ T7279] kcsan_report.cold+0x57/0xeb [ 53.354048][ T7279] __kcsan_setup_watchpoint+0x342/0x500 [ 53.360006][ T7279] __tsan_read4+0x2c/0x30 [ 53.364403][ T7279] tcp_grow_window.isra.0+0x6b/0x480 [ 53.369841][ T7279] tcp_event_data_recv+0x68f/0x990 [ 53.375087][ T7279] tcp_rcv_established+0xbfe/0xf50 [ 53.380206][ T7279] ? ipv4_dst_check+0xc6/0xf0 [ 53.384890][ T7279] tcp_v4_do_rcv+0x381/0x4e0 [ 53.390888][ T7279] __release_sock+0x135/0x1e0 [ 53.395550][ T7279] release_sock+0x61/0x160 [ 53.400031][ T7279] tcp_recvmsg+0x63b/0x1a30 [ 53.405130][ T7279] inet_recvmsg+0xbb/0x250 [ 53.409725][ T7279] ? __tsan_read8+0x2c/0x30 [ 53.414301][ T7279] ? inet_sendpage+0x100/0x100 [ 53.419217][ T7279] sock_recvmsg+0x92/0xb0 [ 53.423648][ T7279] sock_read_iter+0x15f/0x1e0 [ 53.428333][ T7279] new_sync_read+0x389/0x4f0 [ 53.433098][ T7279] __vfs_read+0xb1/0xc0 [ 53.437255][ T7279] vfs_read+0x143/0x2c0 [ 53.441607][ T7279] ksys_read+0xd5/0x1b0 [ 53.445859][ T7279] __x64_sys_read+0x4c/0x60 [ 53.450367][ T7279] do_syscall_64+0xcf/0x2f0 [ 53.454966][ T7279] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 53.460929][ T7279] RIP: 0033:0x47c530 [ 53.464827][ T7279] 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 [ 53.485309][ T7279] RSP: 002b:000000c4204f0808 EFLAGS: 00000216 ORIG_RAX: 0000000000000000 [ 53.493869][ T7279] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 53.502042][ T7279] RDX: 0000000000001000 RSI: 000000c42019c000 RDI: 0000000000000003 [ 53.509990][ T7279] RBP: 000000c4204f0860 R08: 0000000000000000 R09: 0000000000000000 [ 53.518039][ T7279] R10: 0000000000000000 R11: 0000000000000216 R12: 0000000000000007 [ 53.526682][ T7279] R13: 000000c4200214f0 R14: 0000000000000004 R15: ffffffffffffffff [ 53.536953][ T7279] Kernel Offset: disabled [ 53.542588][ T7279] Rebooting in 86400 seconds..