[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.072643][ T23] audit: type=1800 audit(1570191062.351:25): pid=7046 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.123203][ T23] audit: type=1800 audit(1570191062.351:26): pid=7046 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.146327][ T23] audit: type=1800 audit(1570191062.351:27): pid=7046 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 '10.128.0.7' (ECDSA) to the list of known hosts. 2019/10/04 12:11:09 fuzzer started 2019/10/04 12:11:11 dialing manager at 10.128.0.105:38119 2019/10/04 12:11:11 syscalls: 2523 2019/10/04 12:11:11 code coverage: enabled 2019/10/04 12:11:11 comparison tracing: enabled 2019/10/04 12:11:11 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:11:11 setuid sandbox: enabled 2019/10/04 12:11:11 namespace sandbox: enabled 2019/10/04 12:11:11 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:11:11 fault injection: enabled 2019/10/04 12:11:11 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:11:11 net packet injection: enabled 2019/10/04 12:11:11 net device setup: enabled 2019/10/04 12:11:11 concurrency sanitizer: enabled syzkaller login: [ 47.240228][ T7195] ================================================================== [ 47.248456][ T7195] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 47.257806][ T7195] [ 47.260116][ T7195] write to 0xffff888122568138 of 8 bytes by interrupt on cpu 0: [ 47.267726][ T7195] tcp_add_backlog+0x45a/0xcc0 [ 47.272463][ T7195] tcp_v4_rcv+0x1aba/0x1bf0 [ 47.276945][ T7195] ip_protocol_deliver_rcu+0x51/0x470 [ 47.282292][ T7195] ip_local_deliver_finish+0x110/0x140 [ 47.287775][ T7195] ip_local_deliver+0x133/0x210 [ 47.292600][ T7195] ip_rcv_finish+0x121/0x160 [ 47.297162][ T7195] ip_rcv+0x18f/0x1a0 [ 47.301170][ T7195] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.306908][ T7195] __netif_receive_skb+0x37/0xf0 [ 47.311824][ T7195] netif_receive_skb_internal+0x59/0x190 [ 47.317434][ T7195] napi_gro_receive+0x28f/0x330 [ 47.322262][ T7195] receive_buf+0x284/0x30b0 [ 47.326741][ T7195] virtnet_poll+0x436/0x7d0 [ 47.331217][ T7195] net_rx_action+0x3ae/0xa50 [ 47.335774][ T7195] [ 47.338092][ T7195] read to 0xffff888122568138 of 8 bytes by task 7195 on cpu 1: [ 47.345610][ T7195] tcp_recvmsg+0x470/0x1a30 [ 47.350092][ T7195] inet_recvmsg+0xbb/0x250 [ 47.354484][ T7195] sock_recvmsg+0x92/0xb0 [ 47.358791][ T7195] sock_read_iter+0x15f/0x1e0 [ 47.363452][ T7195] new_sync_read+0x389/0x4f0 [ 47.368031][ T7195] __vfs_read+0xb1/0xc0 [ 47.372166][ T7195] vfs_read+0x143/0x2c0 [ 47.376312][ T7195] ksys_read+0xd5/0x1b0 [ 47.380443][ T7195] __x64_sys_read+0x4c/0x60 [ 47.384922][ T7195] do_syscall_64+0xcf/0x2f0 [ 47.389427][ T7195] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.395290][ T7195] [ 47.397594][ T7195] Reported by Kernel Concurrency Sanitizer on: [ 47.403722][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.410803][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.420832][ T7195] ================================================================== [ 47.428880][ T7195] Kernel panic - not syncing: panic_on_warn set ... [ 47.435441][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.442525][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.452554][ T7195] Call Trace: [ 47.455866][ T7195] dump_stack+0xf5/0x159 [ 47.460263][ T7195] panic+0x209/0x639 [ 47.464140][ T7195] ? vprintk_func+0x8d/0x140 [ 47.468756][ T7195] kcsan_report.cold+0x57/0xeb [ 47.473515][ T7195] __kcsan_setup_watchpoint+0x342/0x500 [ 47.479055][ T7195] __tsan_read8+0x2c/0x30 [ 47.483364][ T7195] tcp_recvmsg+0x470/0x1a30 [ 47.487856][ T7195] inet_recvmsg+0xbb/0x250 [ 47.492247][ T7195] ? __tsan_read8+0x2c/0x30 [ 47.496741][ T7195] ? inet_sendpage+0x100/0x100 [ 47.501482][ T7195] sock_recvmsg+0x92/0xb0 [ 47.505790][ T7195] sock_read_iter+0x15f/0x1e0 [ 47.510456][ T7195] new_sync_read+0x389/0x4f0 [ 47.515029][ T7195] __vfs_read+0xb1/0xc0 [ 47.519179][ T7195] vfs_read+0x143/0x2c0 [ 47.523313][ T7195] ksys_read+0xd5/0x1b0 [ 47.527449][ T7195] __x64_sys_read+0x4c/0x60 [ 47.531940][ T7195] do_syscall_64+0xcf/0x2f0 [ 47.536423][ T7195] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.542288][ T7195] RIP: 0033:0x47c530 [ 47.546163][ T7195] 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 [ 47.565754][ T7195] RSP: 002b:000000c4201417d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.574138][ T7195] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.582084][ T7195] RDX: 0000000000001000 RSI: 000000c420312000 RDI: 0000000000000003 [ 47.590044][ T7195] RBP: 000000c420141830 R08: 0000000000000000 R09: 0000000000000000 [ 47.597990][ T7195] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 47.605937][ T7195] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 47.615244][ T7195] Kernel Offset: disabled [ 47.621471][ T7195] Rebooting in 86400 seconds..