[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.210349][ T25] audit: type=1800 audit(1570191672.337:25): pid=7023 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.237531][ T25] audit: type=1800 audit(1570191672.347:26): pid=7023 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.264401][ T25] audit: type=1800 audit(1570191672.347:27): pid=7023 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 '10.128.0.17' (ECDSA) to the list of known hosts. 2019/10/04 12:21:20 fuzzer started 2019/10/04 12:21:22 dialing manager at 10.128.0.105:38119 2019/10/04 12:21:22 syscalls: 2523 2019/10/04 12:21:22 code coverage: enabled 2019/10/04 12:21:22 comparison tracing: enabled 2019/10/04 12:21:22 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:21:22 setuid sandbox: enabled 2019/10/04 12:21:22 namespace sandbox: enabled 2019/10/04 12:21:22 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:21:22 fault injection: enabled 2019/10/04 12:21:22 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:21:22 net packet injection: enabled 2019/10/04 12:21:22 net device setup: enabled 2019/10/04 12:21:22 concurrency sanitizer: enabled syzkaller login: [ 44.954497][ T7175] ================================================================== [ 44.962750][ T7175] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 44.972646][ T7175] [ 44.974959][ T7175] write to 0xffff8881257fd2ec of 4 bytes by interrupt on cpu 1: [ 44.982579][ T7175] tcp_add_backlog+0x4a0/0xcc0 [ 44.987332][ T7175] tcp_v4_rcv+0x1aba/0x1bf0 [ 44.991811][ T7175] ip_protocol_deliver_rcu+0x51/0x470 [ 44.997173][ T7175] ip_local_deliver_finish+0x110/0x140 [ 45.002782][ T7175] ip_local_deliver+0x133/0x210 [ 45.007606][ T7175] ip_rcv_finish+0x121/0x160 [ 45.012265][ T7175] ip_rcv+0x18f/0x1a0 [ 45.016268][ T7175] __netif_receive_skb_one_core+0xa7/0xe0 [ 45.021969][ T7175] __netif_receive_skb+0x37/0xf0 [ 45.026897][ T7175] netif_receive_skb_internal+0x59/0x190 [ 45.032507][ T7175] napi_gro_receive+0x28f/0x330 [ 45.037368][ T7175] receive_buf+0x284/0x30b0 [ 45.041847][ T7175] virtnet_poll+0x436/0x7d0 [ 45.046323][ T7175] net_rx_action+0x3ae/0xa50 [ 45.050898][ T7175] [ 45.053208][ T7175] read to 0xffff8881257fd2ec of 4 bytes by task 7175 on cpu 0: [ 45.060725][ T7175] __tcp_select_window+0x6b/0x4d0 [ 45.065725][ T7175] __tcp_transmit_skb+0x679/0x1cd0 [ 45.070826][ T7175] __tcp_send_ack+0x246/0x300 [ 45.075515][ T7175] tcp_send_ack+0x34/0x40 [ 45.079830][ T7175] tcp_cleanup_rbuf+0x130/0x360 [ 45.084676][ T7175] tcp_recvmsg+0x633/0x1a30 [ 45.089180][ T7175] inet_recvmsg+0xbb/0x250 [ 45.093576][ T7175] sock_recvmsg+0x92/0xb0 [ 45.097890][ T7175] sock_read_iter+0x15f/0x1e0 [ 45.102544][ T7175] new_sync_read+0x389/0x4f0 [ 45.107108][ T7175] __vfs_read+0xb1/0xc0 [ 45.111239][ T7175] vfs_read+0x143/0x2c0 [ 45.115383][ T7175] ksys_read+0xd5/0x1b0 [ 45.119523][ T7175] [ 45.121825][ T7175] Reported by Kernel Concurrency Sanitizer on: [ 45.127971][ T7175] CPU: 0 PID: 7175 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 45.135053][ T7175] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.145084][ T7175] ================================================================== [ 45.153119][ T7175] Kernel panic - not syncing: panic_on_warn set ... [ 45.159681][ T7175] CPU: 0 PID: 7175 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 45.166771][ T7175] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.176831][ T7175] Call Trace: [ 45.180101][ T7175] dump_stack+0xf5/0x159 [ 45.184343][ T7175] panic+0x209/0x639 [ 45.188222][ T7175] ? vprintk_func+0x8d/0x140 [ 45.192791][ T7175] kcsan_report.cold+0x57/0xeb [ 45.197533][ T7175] __kcsan_setup_watchpoint+0x342/0x500 [ 45.203055][ T7175] __tsan_read4+0x2c/0x30 [ 45.207368][ T7175] __tcp_select_window+0x6b/0x4d0 [ 45.212374][ T7175] __tcp_transmit_skb+0x679/0x1cd0 [ 45.217568][ T7175] __tcp_send_ack+0x246/0x300 [ 45.222222][ T7175] tcp_send_ack+0x34/0x40 [ 45.226614][ T7175] tcp_cleanup_rbuf+0x130/0x360 [ 45.231455][ T7175] tcp_recvmsg+0x633/0x1a30 [ 45.235945][ T7175] inet_recvmsg+0xbb/0x250 [ 45.240343][ T7175] ? __tsan_read8+0x2c/0x30 [ 45.244860][ T7175] ? inet_sendpage+0x100/0x100 [ 45.249616][ T7175] sock_recvmsg+0x92/0xb0 [ 45.253931][ T7175] sock_read_iter+0x15f/0x1e0 [ 45.258592][ T7175] new_sync_read+0x389/0x4f0 [ 45.263175][ T7175] __vfs_read+0xb1/0xc0 [ 45.267314][ T7175] vfs_read+0x143/0x2c0 [ 45.271453][ T7175] ksys_read+0xd5/0x1b0 [ 45.275590][ T7175] __x64_sys_read+0x4c/0x60 [ 45.280086][ T7175] do_syscall_64+0xcf/0x2f0 [ 45.284585][ T7175] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 45.290453][ T7175] RIP: 0033:0x47c530 [ 45.294326][ T7175] 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 [ 45.313910][ T7175] RSP: 002b:000000c4203577d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 45.322295][ T7175] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 45.330252][ T7175] RDX: 0000000000001000 RSI: 000000c42018c000 RDI: 0000000000000003 [ 45.338210][ T7175] RBP: 000000c420357830 R08: 0000000000000000 R09: 0000000000000000 [ 45.346159][ T7175] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 45.354139][ T7175] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 45.363352][ T7175] Kernel Offset: disabled [ 45.367684][ T7175] Rebooting in 86400 seconds..