[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.332832][ T26] audit: type=1800 audit(1570191090.350:25): pid=7084 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.385016][ T26] audit: type=1800 audit(1570191090.350:26): pid=7084 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.407066][ T26] audit: type=1800 audit(1570191090.360:27): pid=7084 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 '10.128.0.5' (ECDSA) to the list of known hosts. 2019/10/04 12:11:38 fuzzer started 2019/10/04 12:11:39 dialing manager at 10.128.0.105:38119 2019/10/04 12:11:39 syscalls: 2523 2019/10/04 12:11:39 code coverage: enabled 2019/10/04 12:11:39 comparison tracing: enabled 2019/10/04 12:11:39 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:11:39 setuid sandbox: enabled 2019/10/04 12:11:39 namespace sandbox: enabled 2019/10/04 12:11:39 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:11:39 fault injection: enabled 2019/10/04 12:11:39 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:11:39 net packet injection: enabled 2019/10/04 12:11:39 net device setup: enabled 2019/10/04 12:11:39 concurrency sanitizer: enabled syzkaller login: [ 43.965584][ T7232] ================================================================== [ 43.973830][ T7232] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 43.983702][ T7232] [ 43.986008][ T7232] write to 0xffff888126b569ec of 4 bytes by interrupt on cpu 0: [ 43.993617][ T7232] tcp_add_backlog+0x4a0/0xcc0 [ 43.998360][ T7232] tcp_v4_rcv+0x1aba/0x1bf0 [ 44.002870][ T7232] ip_protocol_deliver_rcu+0x51/0x470 [ 44.008846][ T7232] ip_local_deliver_finish+0x110/0x140 [ 44.014288][ T7232] ip_local_deliver+0x133/0x210 [ 44.019813][ T7232] ip_rcv_finish+0x121/0x160 [ 44.024380][ T7232] ip_rcv+0x18f/0x1a0 [ 44.028353][ T7232] __netif_receive_skb_one_core+0xa7/0xe0 [ 44.034047][ T7232] __netif_receive_skb+0x37/0xf0 [ 44.038990][ T7232] netif_receive_skb_internal+0x59/0x190 [ 44.044604][ T7232] napi_gro_receive+0x28f/0x330 [ 44.049477][ T7232] receive_buf+0x284/0x30b0 [ 44.053972][ T7232] virtnet_poll+0x436/0x7d0 [ 44.058642][ T7232] net_rx_action+0x3ae/0xa50 [ 44.063205][ T7232] [ 44.065515][ T7232] read to 0xffff888126b569ec of 4 bytes by task 7232 on cpu 1: [ 44.073048][ T7232] __tcp_select_window+0x6b/0x4d0 [ 44.078062][ T7232] __tcp_transmit_skb+0x679/0x1cd0 [ 44.083157][ T7232] __tcp_send_ack+0x246/0x300 [ 44.087813][ T7232] tcp_send_ack+0x34/0x40 [ 44.092129][ T7232] tcp_cleanup_rbuf+0x130/0x360 [ 44.096955][ T7232] tcp_recvmsg+0x633/0x1a30 [ 44.101459][ T7232] inet_recvmsg+0xbb/0x250 [ 44.105857][ T7232] sock_recvmsg+0x92/0xb0 [ 44.110163][ T7232] sock_read_iter+0x15f/0x1e0 [ 44.115038][ T7232] new_sync_read+0x389/0x4f0 [ 44.119606][ T7232] __vfs_read+0xb1/0xc0 [ 44.123739][ T7232] vfs_read+0x143/0x2c0 [ 44.127877][ T7232] ksys_read+0xd5/0x1b0 [ 44.132024][ T7232] [ 44.134324][ T7232] Reported by Kernel Concurrency Sanitizer on: [ 44.140474][ T7232] CPU: 1 PID: 7232 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 44.147666][ T7232] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.157701][ T7232] ================================================================== [ 44.165743][ T7232] Kernel panic - not syncing: panic_on_warn set ... [ 44.172316][ T7232] CPU: 1 PID: 7232 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 44.179404][ T7232] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 44.189452][ T7232] Call Trace: [ 44.192745][ T7232] dump_stack+0xf5/0x159 [ 44.196973][ T7232] panic+0x209/0x639 [ 44.200847][ T7232] ? vprintk_func+0x8d/0x140 [ 44.205418][ T7232] kcsan_report.cold+0x57/0xeb [ 44.210163][ T7232] __kcsan_setup_watchpoint+0x342/0x500 [ 44.215713][ T7232] __tsan_read4+0x2c/0x30 [ 44.220038][ T7232] __tcp_select_window+0x6b/0x4d0 [ 44.225066][ T7232] __tcp_transmit_skb+0x679/0x1cd0 [ 44.230178][ T7232] __tcp_send_ack+0x246/0x300 [ 44.234845][ T7232] tcp_send_ack+0x34/0x40 [ 44.239171][ T7232] tcp_cleanup_rbuf+0x130/0x360 [ 44.244002][ T7232] tcp_recvmsg+0x633/0x1a30 [ 44.248492][ T7232] inet_recvmsg+0xbb/0x250 [ 44.252886][ T7232] ? __tsan_read8+0x2c/0x30 [ 44.257381][ T7232] ? inet_sendpage+0x100/0x100 [ 44.262124][ T7232] sock_recvmsg+0x92/0xb0 [ 44.266452][ T7232] sock_read_iter+0x15f/0x1e0 [ 44.271135][ T7232] new_sync_read+0x389/0x4f0 [ 44.275718][ T7232] __vfs_read+0xb1/0xc0 [ 44.279858][ T7232] vfs_read+0x143/0x2c0 [ 44.283994][ T7232] ksys_read+0xd5/0x1b0 [ 44.288155][ T7232] __x64_sys_read+0x4c/0x60 [ 44.292651][ T7232] do_syscall_64+0xcf/0x2f0 [ 44.297137][ T7232] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 44.303017][ T7232] RIP: 0033:0x47c530 [ 44.306903][ T7232] 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 [ 44.326570][ T7232] RSP: 002b:000000c4204e97d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 44.334973][ T7232] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 44.342932][ T7232] RDX: 0000000000001000 RSI: 000000c420322000 RDI: 0000000000000003 [ 44.350912][ T7232] RBP: 000000c4204e9830 R08: 0000000000000000 R09: 0000000000000000 [ 44.358872][ T7232] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 44.366846][ T7232] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 44.376392][ T7232] Kernel Offset: disabled [ 44.380817][ T7232] Rebooting in 86400 seconds..