[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.282903][ T25] audit: type=1800 audit(1570191466.944:25): pid=7068 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 39.303683][ T25] audit: type=1800 audit(1570191466.944:26): pid=7068 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 39.325389][ T25] audit: type=1800 audit(1570191466.944:27): pid=7068 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 '10.128.1.4' (ECDSA) to the list of known hosts. 2019/10/04 12:17:57 fuzzer started 2019/10/04 12:17:59 dialing manager at 10.128.0.105:38119 2019/10/04 12:17:59 syscalls: 2523 2019/10/04 12:17:59 code coverage: enabled 2019/10/04 12:17:59 comparison tracing: enabled 2019/10/04 12:17:59 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:17:59 setuid sandbox: enabled 2019/10/04 12:17:59 namespace sandbox: enabled 2019/10/04 12:17:59 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:17:59 fault injection: enabled 2019/10/04 12:17:59 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:17:59 net packet injection: enabled 2019/10/04 12:17:59 net device setup: enabled 2019/10/04 12:17:59 concurrency sanitizer: enabled syzkaller login: [ 52.842376][ T7229] ================================================================== [ 52.850763][ T7229] BUG: KCSAN: data-race in tcp_add_backlog+0x4a0/0xcc0 and tcp_grow_window.isra.0+0x6b/0x480 [ 52.860881][ T7229] [ 52.863287][ T7229] write to 0xffff8881248a412c of 4 bytes by interrupt on cpu 1: [ 52.871069][ T7229] tcp_add_backlog+0x4a0/0xcc0 [ 52.876435][ T7229] tcp_v4_rcv+0x1aba/0x1bf0 [ 52.880954][ T7229] ip_protocol_deliver_rcu+0x51/0x470 [ 52.886674][ T7229] ip_local_deliver_finish+0x110/0x140 [ 52.892113][ T7229] ip_local_deliver+0x133/0x210 [ 52.897648][ T7229] ip_rcv_finish+0x121/0x160 [ 52.902214][ T7229] ip_rcv+0x18f/0x1a0 [ 52.906193][ T7229] __netif_receive_skb_one_core+0xa7/0xe0 [ 52.912242][ T7229] __netif_receive_skb+0x37/0xf0 [ 52.917186][ T7229] netif_receive_skb_internal+0x59/0x190 [ 52.922897][ T7229] napi_gro_receive+0x28f/0x330 [ 52.928260][ T7229] receive_buf+0x284/0x30b0 [ 52.932918][ T7229] virtnet_poll+0x436/0x7d0 [ 52.937587][ T7229] net_rx_action+0x3ae/0xa50 [ 52.942441][ T7229] [ 52.944905][ T7229] read to 0xffff8881248a412c of 4 bytes by task 7229 on cpu 0: [ 52.952529][ T7229] tcp_grow_window.isra.0+0x6b/0x480 [ 52.958070][ T7229] tcp_event_data_recv+0x68f/0x990 [ 52.963268][ T7229] tcp_rcv_established+0xbfe/0xf50 [ 52.968467][ T7229] tcp_v4_do_rcv+0x381/0x4e0 [ 52.973054][ T7229] __release_sock+0x135/0x1e0 [ 52.977709][ T7229] release_sock+0x61/0x160 [ 52.982114][ T7229] tcp_recvmsg+0x63b/0x1a30 [ 52.986734][ T7229] inet_recvmsg+0xbb/0x250 [ 52.991149][ T7229] sock_recvmsg+0x92/0xb0 [ 52.995556][ T7229] sock_read_iter+0x15f/0x1e0 [ 53.000229][ T7229] new_sync_read+0x389/0x4f0 [ 53.004971][ T7229] __vfs_read+0xb1/0xc0 [ 53.009120][ T7229] vfs_read+0x143/0x2c0 [ 53.013249][ T7229] [ 53.015724][ T7229] Reported by Kernel Concurrency Sanitizer on: [ 53.021892][ T7229] CPU: 0 PID: 7229 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 53.028983][ T7229] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.039015][ T7229] ================================================================== [ 53.047133][ T7229] Kernel panic - not syncing: panic_on_warn set ... [ 53.053695][ T7229] CPU: 0 PID: 7229 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 53.060776][ T7229] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 53.070840][ T7229] Call Trace: [ 53.074121][ T7229] dump_stack+0xf5/0x159 [ 53.078662][ T7229] panic+0x209/0x639 [ 53.082549][ T7229] ? vprintk_func+0x8d/0x140 [ 53.088087][ T7229] kcsan_report.cold+0x57/0xeb [ 53.092857][ T7229] __kcsan_setup_watchpoint+0x342/0x500 [ 53.098447][ T7229] __tsan_read4+0x2c/0x30 [ 53.102770][ T7229] tcp_grow_window.isra.0+0x6b/0x480 [ 53.108048][ T7229] tcp_event_data_recv+0x68f/0x990 [ 53.113338][ T7229] tcp_rcv_established+0xbfe/0xf50 [ 53.118445][ T7229] ? ipv4_dst_check+0xc6/0xf0 [ 53.123111][ T7229] tcp_v4_do_rcv+0x381/0x4e0 [ 53.128815][ T7229] __release_sock+0x135/0x1e0 [ 53.133482][ T7229] release_sock+0x61/0x160 [ 53.138065][ T7229] tcp_recvmsg+0x63b/0x1a30 [ 53.142592][ T7229] inet_recvmsg+0xbb/0x250 [ 53.146987][ T7229] ? __tsan_read8+0x2c/0x30 [ 53.151567][ T7229] ? inet_sendpage+0x100/0x100 [ 53.156308][ T7229] sock_recvmsg+0x92/0xb0 [ 53.160704][ T7229] sock_read_iter+0x15f/0x1e0 [ 53.165378][ T7229] new_sync_read+0x389/0x4f0 [ 53.169952][ T7229] __vfs_read+0xb1/0xc0 [ 53.174097][ T7229] vfs_read+0x143/0x2c0 [ 53.178232][ T7229] ksys_read+0xd5/0x1b0 [ 53.182369][ T7229] __x64_sys_read+0x4c/0x60 [ 53.186851][ T7229] do_syscall_64+0xcf/0x2f0 [ 53.191352][ T7229] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 53.197329][ T7229] RIP: 0033:0x47c530 [ 53.201205][ T7229] 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 [ 53.221132][ T7229] RSP: 002b:000000c4204d5810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 53.229614][ T7229] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 53.237580][ T7229] RDX: 0000000000001000 RSI: 000000c4200a8000 RDI: 0000000000000003 [ 53.245644][ T7229] RBP: 000000c4204d5868 R08: 0000000000000000 R09: 0000000000000000 [ 53.253615][ T7229] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000200 [ 53.261579][ T7229] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 53.271535][ T7229] Kernel Offset: disabled [ 53.275887][ T7229] Rebooting in 86400 seconds..