[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [ 35.015966][ T25] audit: type=1800 audit(1571789591.861:25): pid=7008 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.054642][ T25] audit: type=1800 audit(1571789591.861:26): pid=7008 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.076413][ T25] audit: type=1800 audit(1571789591.861:27): pid=7008 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[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.15.200' (ECDSA) to the list of known hosts. 2019/10/23 00:13:19 fuzzer started 2019/10/23 00:13:20 dialing manager at 10.128.0.105:33369 2019/10/23 00:13:20 syscalls: 2524 2019/10/23 00:13:20 code coverage: enabled 2019/10/23 00:13:20 comparison tracing: enabled 2019/10/23 00:13:20 extra coverage: extra coverage is not supported by the kernel 2019/10/23 00:13:20 setuid sandbox: enabled 2019/10/23 00:13:20 namespace sandbox: enabled 2019/10/23 00:13:20 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 00:13:20 fault injection: enabled 2019/10/23 00:13:20 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 00:13:20 net packet injection: enabled 2019/10/23 00:13:20 net device setup: enabled 2019/10/23 00:13:20 concurrency sanitizer: enabled syzkaller login: [ 44.252440][ T7158] ================================================================== [ 44.260563][ T7158] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 44.268263][ T7158] [ 44.270612][ T7158] write to 0xffff888123fd932c of 4 bytes by interrupt on cpu 0: [ 44.278229][ T7158] tcp_add_backlog+0x4a0/0xcc0 [ 44.282969][ T7158] tcp_v4_rcv+0x1a60/0x1bb0 [ 44.287450][ T7158] ip_protocol_deliver_rcu+0x4d/0x420 [ 44.292816][ T7158] ip_local_deliver_finish+0x110/0x140 [ 44.298258][ T7158] ip_local_deliver+0x133/0x210 [ 44.303091][ T7158] ip_rcv_finish+0x121/0x160 [ 44.307663][ T7158] ip_rcv+0x18f/0x1a0 [ 44.311634][ T7158] __netif_receive_skb_one_core+0xa7/0xe0 [ 44.317338][ T7158] __netif_receive_skb+0x37/0xf0 [ 44.322264][ T7158] netif_receive_skb_internal+0x59/0x190 [ 44.327970][ T7158] napi_gro_receive+0x28f/0x330 [ 44.332794][ T7158] receive_buf+0x284/0x30b0 [ 44.337270][ T7158] virtnet_poll+0x436/0x7d0 [ 44.341747][ T7158] net_rx_action+0x3ae/0xa90 [ 44.346305][ T7158] [ 44.348611][ T7158] read to 0xffff888123fd932c of 4 bytes by task 7158 on cpu 1: [ 44.356138][ T7158] __tcp_select_window+0x6b/0x4d0 [ 44.361184][ T7158] __tcp_transmit_skb+0x700/0x1d60 [ 44.366311][ T7158] __tcp_send_ack+0x246/0x300 [ 44.370970][ T7158] tcp_send_ack+0x34/0x40 [ 44.375276][ T7158] tcp_cleanup_rbuf+0x130/0x360 [ 44.380101][ T7158] tcp_recvmsg+0x633/0x1a30 [ 44.384752][ T7158] inet_recvmsg+0xbb/0x250 [ 44.389143][ T7158] sock_recvmsg+0x92/0xb0 [ 44.393445][ T7158] sock_read_iter+0x15f/0x1e0 [ 44.398095][ T7158] new_sync_read+0x389/0x4f0 [ 44.402665][ T7158] __vfs_read+0xb1/0xc0 [ 44.406806][ T7158] vfs_read+0x143/0x2c0 [ 44.410946][ T7158] ksys_read+0xd5/0x1b0 [ 44.415072][ T7158] [ 44.417393][ T7158] Reported by Kernel Concurrency Sanitizer on: [ 44.423524][ T7158] CPU: 1 PID: 7158 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.430949][ T7158] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.440977][ T7158] ================================================================== [ 44.449012][ T7158] Kernel panic - not syncing: panic_on_warn set ... [ 44.455680][ T7158] CPU: 1 PID: 7158 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 44.463103][ T7158] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.473141][ T7158] Call Trace: [ 44.476413][ T7158] dump_stack+0xf5/0x159 [ 44.480642][ T7158] panic+0x210/0x640 [ 44.484527][ T7158] ? sock_read_iter+0x15f/0x1e0 [ 44.489364][ T7158] ? vprintk_func+0x8d/0x140 [ 44.493945][ T7158] kcsan_report.cold+0xc/0x10 [ 44.498599][ T7158] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 44.504122][ T7158] __tsan_read4+0x2c/0x30 [ 44.508431][ T7158] __tcp_select_window+0x6b/0x4d0 [ 44.513433][ T7158] __tcp_transmit_skb+0x700/0x1d60 [ 44.518625][ T7158] __tcp_send_ack+0x246/0x300 [ 44.523279][ T7158] tcp_send_ack+0x34/0x40 [ 44.527587][ T7158] tcp_cleanup_rbuf+0x130/0x360 [ 44.532417][ T7158] tcp_recvmsg+0x633/0x1a30 [ 44.536906][ T7158] inet_recvmsg+0xbb/0x250 [ 44.541326][ T7158] ? __tsan_read8+0x2c/0x30 [ 44.545808][ T7158] ? inet_sendpage+0x100/0x100 [ 44.550546][ T7158] sock_recvmsg+0x92/0xb0 [ 44.554853][ T7158] sock_read_iter+0x15f/0x1e0 [ 44.559512][ T7158] new_sync_read+0x389/0x4f0 [ 44.564098][ T7158] __vfs_read+0xb1/0xc0 [ 44.568243][ T7158] vfs_read+0x143/0x2c0 [ 44.572379][ T7158] ksys_read+0xd5/0x1b0 [ 44.576516][ T7158] __x64_sys_read+0x4c/0x60 [ 44.581001][ T7158] do_syscall_64+0xcc/0x370 [ 44.585500][ T7158] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.591366][ T7158] RIP: 0033:0x47c530 [ 44.598205][ T7158] 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 [ 44.617812][ T7158] RSP: 002b:000000c4202d57d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 44.626212][ T7158] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 44.634168][ T7158] RDX: 0000000000001000 RSI: 000000c42036e000 RDI: 0000000000000003 [ 44.642126][ T7158] RBP: 000000c4202d5830 R08: 0000000000000000 R09: 0000000000000000 [ 44.650080][ T7158] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000100 [ 44.658035][ T7158] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 44.667406][ T7158] Kernel Offset: disabled [ 44.671737][ T7158] Rebooting in 86400 seconds..