[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 40.647221][ T23] audit: type=1800 audit(1570192226.886:25): pid=7139 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 40.666978][ T23] audit: type=1800 audit(1570192226.896:26): pid=7139 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 40.710628][ T23] audit: type=1800 audit(1570192226.896:27): pid=7139 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 '10.128.0.98' (ECDSA) to the list of known hosts. 2019/10/04 12:30:37 fuzzer started 2019/10/04 12:30:39 dialing manager at 10.128.0.105:38119 2019/10/04 12:30:39 syscalls: 2523 2019/10/04 12:30:39 code coverage: enabled 2019/10/04 12:30:39 comparison tracing: enabled 2019/10/04 12:30:39 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:30:39 setuid sandbox: enabled 2019/10/04 12:30:39 namespace sandbox: enabled 2019/10/04 12:30:39 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:30:39 fault injection: enabled 2019/10/04 12:30:39 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:30:39 net packet injection: enabled 2019/10/04 12:30:39 net device setup: enabled 2019/10/04 12:30:39 concurrency sanitizer: enabled syzkaller login: [ 53.992584][ T7306] ================================================================== [ 54.001520][ T7306] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 54.010885][ T7306] [ 54.013226][ T7306] write to 0xffff888125c229f8 of 8 bytes by interrupt on cpu 0: [ 54.020938][ T7306] tcp_add_backlog+0x45a/0xcc0 [ 54.025676][ T7306] tcp_v4_rcv+0x1aba/0x1bf0 [ 54.030262][ T7306] ip_protocol_deliver_rcu+0x51/0x470 [ 54.035617][ T7306] ip_local_deliver_finish+0x110/0x140 [ 54.041059][ T7306] ip_local_deliver+0x133/0x210 [ 54.045896][ T7306] ip_rcv_finish+0x121/0x160 [ 54.050482][ T7306] ip_rcv+0x18f/0x1a0 [ 54.054449][ T7306] __netif_receive_skb_one_core+0xa7/0xe0 [ 54.060275][ T7306] __netif_receive_skb+0x37/0xf0 [ 54.065299][ T7306] netif_receive_skb_internal+0x59/0x190 [ 54.070993][ T7306] napi_gro_receive+0x28f/0x330 [ 54.075830][ T7306] receive_buf+0x284/0x30b0 [ 54.080319][ T7306] virtnet_poll+0x436/0x7d0 [ 54.084803][ T7306] net_rx_action+0x3ae/0xa50 [ 54.089372][ T7306] [ 54.091690][ T7306] read to 0xffff888125c229f8 of 8 bytes by task 7306 on cpu 1: [ 54.099222][ T7306] tcp_recvmsg+0x470/0x1a30 [ 54.103712][ T7306] inet_recvmsg+0xbb/0x250 [ 54.108101][ T7306] sock_recvmsg+0x92/0xb0 [ 54.112405][ T7306] sock_read_iter+0x15f/0x1e0 [ 54.117098][ T7306] new_sync_read+0x389/0x4f0 [ 54.121673][ T7306] __vfs_read+0xb1/0xc0 [ 54.125897][ T7306] vfs_read+0x143/0x2c0 [ 54.130140][ T7306] ksys_read+0xd5/0x1b0 [ 54.134295][ T7306] __x64_sys_read+0x4c/0x60 [ 54.138781][ T7306] do_syscall_64+0xcf/0x2f0 [ 54.143272][ T7306] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 54.149351][ T7306] [ 54.151667][ T7306] Reported by Kernel Concurrency Sanitizer on: [ 54.157988][ T7306] CPU: 1 PID: 7306 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 54.165073][ T7306] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.175123][ T7306] ================================================================== [ 54.183160][ T7306] Kernel panic - not syncing: panic_on_warn set ... [ 54.189731][ T7306] CPU: 1 PID: 7306 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 54.196818][ T7306] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.206864][ T7306] Call Trace: [ 54.210234][ T7306] dump_stack+0xf5/0x159 [ 54.214468][ T7306] panic+0x209/0x639 [ 54.218351][ T7306] ? vprintk_func+0x8d/0x140 [ 54.222927][ T7306] kcsan_report.cold+0x57/0xeb [ 54.227670][ T7306] __kcsan_setup_watchpoint+0x342/0x500 [ 54.233199][ T7306] __tsan_read8+0x2c/0x30 [ 54.237504][ T7306] tcp_recvmsg+0x470/0x1a30 [ 54.241997][ T7306] inet_recvmsg+0xbb/0x250 [ 54.246411][ T7306] ? __tsan_read8+0x2c/0x30 [ 54.250889][ T7306] ? inet_sendpage+0x100/0x100 [ 54.255633][ T7306] sock_recvmsg+0x92/0xb0 [ 54.259951][ T7306] sock_read_iter+0x15f/0x1e0 [ 54.265315][ T7306] new_sync_read+0x389/0x4f0 [ 54.269904][ T7306] __vfs_read+0xb1/0xc0 [ 54.274052][ T7306] vfs_read+0x143/0x2c0 [ 54.278283][ T7306] ksys_read+0xd5/0x1b0 [ 54.282418][ T7306] __x64_sys_read+0x4c/0x60 [ 54.286905][ T7306] do_syscall_64+0xcf/0x2f0 [ 54.291391][ T7306] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 54.297267][ T7306] RIP: 0033:0x47c530 [ 54.301147][ T7306] 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 [ 54.320723][ T7306] RSP: 002b:000000c4201c0810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 54.329110][ T7306] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 54.337056][ T7306] RDX: 0000000000001000 RSI: 000000c4202aa000 RDI: 0000000000000003 [ 54.345004][ T7306] RBP: 000000c4201c0868 R08: 0000000000000000 R09: 0000000000000000 [ 54.352948][ T7306] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 [ 54.360956][ T7306] R13: 000000c420083db0 R14: 0000000000000002 R15: ffffffffffffffff [ 54.374105][ T7306] Kernel Offset: disabled [ 54.378434][ T7306] Rebooting in 86400 seconds..