[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.781803][ T25] audit: type=1800 audit(1571773250.252:25): pid=7063 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.834239][ T25] audit: type=1800 audit(1571773250.252:26): pid=7063 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.862013][ T25] audit: type=1800 audit(1571773250.252:27): pid=7063 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 '10.128.0.193' (ECDSA) to the list of known hosts. 2019/10/22 19:41:01 fuzzer started 2019/10/22 19:41:02 dialing manager at 10.128.0.105:33369 2019/10/22 19:41:02 syscalls: 2524 2019/10/22 19:41:02 code coverage: enabled 2019/10/22 19:41:02 comparison tracing: enabled 2019/10/22 19:41:02 extra coverage: extra coverage is not supported by the kernel 2019/10/22 19:41:02 setuid sandbox: enabled 2019/10/22 19:41:02 namespace sandbox: enabled 2019/10/22 19:41:02 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 19:41:02 fault injection: enabled 2019/10/22 19:41:02 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 19:41:02 net packet injection: enabled 2019/10/22 19:41:02 net device setup: enabled 2019/10/22 19:41:02 concurrency sanitizer: enabled syzkaller login: [ 47.925134][ T7218] ================================================================== [ 47.933281][ T7218] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 47.943486][ T7218] [ 47.945803][ T7218] write to 0xffff88812262012c of 4 bytes by interrupt on cpu 1: [ 47.953520][ T7218] tcp_add_backlog+0x4a0/0xcc0 [ 47.958278][ T7218] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.962769][ T7218] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.968125][ T7218] ip_local_deliver_finish+0x110/0x140 [ 47.974021][ T7218] ip_local_deliver+0x133/0x210 [ 47.978855][ T7218] ip_rcv_finish+0x121/0x160 [ 47.984050][ T7218] ip_rcv+0x18f/0x1a0 [ 47.988033][ T7218] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.993736][ T7218] __netif_receive_skb+0x37/0xf0 [ 47.998685][ T7218] netif_receive_skb_internal+0x59/0x190 [ 48.004373][ T7218] napi_gro_receive+0x28f/0x330 [ 48.009215][ T7218] receive_buf+0x284/0x30b0 [ 48.013698][ T7218] virtnet_poll+0x436/0x7d0 [ 48.018340][ T7218] net_rx_action+0x3ae/0xa90 [ 48.022930][ T7218] [ 48.025243][ T7218] read to 0xffff88812262012c of 4 bytes by task 7218 on cpu 0: [ 48.032786][ T7218] __tcp_select_window+0x6b/0x4d0 [ 48.037801][ T7218] __tcp_transmit_skb+0x700/0x1d60 [ 48.042944][ T7218] __tcp_send_ack+0x246/0x300 [ 48.047605][ T7218] tcp_send_ack+0x34/0x40 [ 48.051930][ T7218] tcp_cleanup_rbuf+0x130/0x360 [ 48.056761][ T7218] tcp_recvmsg+0x633/0x1a30 [ 48.061247][ T7218] inet_recvmsg+0xbb/0x250 [ 48.065655][ T7218] sock_recvmsg+0x92/0xb0 [ 48.069965][ T7218] sock_read_iter+0x15f/0x1e0 [ 48.074636][ T7218] new_sync_read+0x389/0x4f0 [ 48.079202][ T7218] __vfs_read+0xb1/0xc0 [ 48.083876][ T7218] vfs_read+0x143/0x2c0 [ 48.088012][ T7218] ksys_read+0xd5/0x1b0 [ 48.092146][ T7218] [ 48.094499][ T7218] Reported by Kernel Concurrency Sanitizer on: [ 48.100733][ T7218] CPU: 0 PID: 7218 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.108255][ T7218] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.118285][ T7218] ================================================================== [ 48.126328][ T7218] Kernel panic - not syncing: panic_on_warn set ... [ 48.132901][ T7218] CPU: 0 PID: 7218 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.140348][ T7218] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.150395][ T7218] Call Trace: [ 48.153685][ T7218] dump_stack+0xf5/0x159 [ 48.157919][ T7218] panic+0x210/0x640 [ 48.163197][ T7218] ? sock_read_iter+0x15f/0x1e0 [ 48.168027][ T7218] ? vprintk_func+0x8d/0x140 [ 48.172598][ T7218] kcsan_report.cold+0xc/0x10 [ 48.177263][ T7218] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.182809][ T7218] __tsan_read4+0x2c/0x30 [ 48.187135][ T7218] __tcp_select_window+0x6b/0x4d0 [ 48.192155][ T7218] __tcp_transmit_skb+0x700/0x1d60 [ 48.197250][ T7218] __tcp_send_ack+0x246/0x300 [ 48.201920][ T7218] tcp_send_ack+0x34/0x40 [ 48.206244][ T7218] tcp_cleanup_rbuf+0x130/0x360 [ 48.211087][ T7218] tcp_recvmsg+0x633/0x1a30 [ 48.215576][ T7218] ? finish_task_switch+0x7b/0x260 [ 48.220690][ T7218] inet_recvmsg+0xbb/0x250 [ 48.225096][ T7218] ? __tsan_read8+0x2c/0x30 [ 48.229579][ T7218] ? inet_sendpage+0x100/0x100 [ 48.234334][ T7218] sock_recvmsg+0x92/0xb0 [ 48.238665][ T7218] sock_read_iter+0x15f/0x1e0 [ 48.243343][ T7218] new_sync_read+0x389/0x4f0 [ 48.247915][ T7218] __vfs_read+0xb1/0xc0 [ 48.252049][ T7218] vfs_read+0x143/0x2c0 [ 48.256184][ T7218] ksys_read+0xd5/0x1b0 [ 48.260326][ T7218] __x64_sys_read+0x4c/0x60 [ 48.264810][ T7218] do_syscall_64+0xcc/0x370 [ 48.269316][ T7218] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.275197][ T7218] RIP: 0033:0x47c530 [ 48.279077][ T7218] 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 [ 48.298671][ T7218] RSP: 002b:000000c4204fb7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.307082][ T7218] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.315234][ T7218] RDX: 0000000000001000 RSI: 000000c4201ae000 RDI: 0000000000000003 [ 48.323202][ T7218] RBP: 000000c4204fb830 R08: 0000000000000000 R09: 0000000000000000 [ 48.331164][ T7218] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000100 [ 48.339118][ T7218] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 48.348518][ T7218] Kernel Offset: disabled [ 48.352893][ T7218] Rebooting in 86400 seconds..