[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.999473][ T25] audit: type=1800 audit(1570201790.284:25): pid=7110 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.019975][ T25] audit: type=1800 audit(1570201790.284:26): pid=7110 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.041797][ T25] audit: type=1800 audit(1570201790.284:27): pid=7110 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 '10.128.0.91' (ECDSA) to the list of known hosts. 2019/10/04 15:10:00 fuzzer started 2019/10/04 15:10:02 dialing manager at 10.128.0.105:44881 2019/10/04 15:10:02 syscalls: 2523 2019/10/04 15:10:02 code coverage: enabled 2019/10/04 15:10:02 comparison tracing: enabled 2019/10/04 15:10:02 extra coverage: extra coverage is not supported by the kernel 2019/10/04 15:10:02 setuid sandbox: enabled 2019/10/04 15:10:02 namespace sandbox: enabled 2019/10/04 15:10:02 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 15:10:02 fault injection: enabled 2019/10/04 15:10:02 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 15:10:02 net packet injection: enabled 2019/10/04 15:10:02 net device setup: enabled 2019/10/04 15:10:02 concurrency sanitizer: enabled syzkaller login: [ 48.136219][ T7271] ================================================================== [ 48.144637][ T7271] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 48.151815][ T7271] [ 48.154145][ T7271] write to 0xffff88812ab369f8 of 8 bytes by interrupt on cpu 1: [ 48.161870][ T7271] tcp_add_backlog+0x45a/0xcc0 [ 48.166623][ T7271] tcp_v4_rcv+0x1aba/0x1bf0 [ 48.171117][ T7271] ip_protocol_deliver_rcu+0x51/0x470 [ 48.176488][ T7271] ip_local_deliver_finish+0x110/0x140 [ 48.181924][ T7271] ip_local_deliver+0x133/0x210 [ 48.186792][ T7271] ip_rcv_finish+0x121/0x160 [ 48.191379][ T7271] ip_rcv+0x18f/0x1a0 [ 48.195347][ T7271] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.201056][ T7271] __netif_receive_skb+0x37/0xf0 [ 48.205971][ T7271] netif_receive_skb_internal+0x59/0x190 [ 48.211667][ T7271] napi_gro_receive+0x28f/0x330 [ 48.216500][ T7271] receive_buf+0x284/0x30b0 [ 48.220987][ T7271] virtnet_poll+0x436/0x7d0 [ 48.225491][ T7271] net_rx_action+0x3ae/0xa50 [ 48.230054][ T7271] [ 48.232374][ T7271] read to 0xffff88812ab369f8 of 8 bytes by task 7271 on cpu 0: [ 48.239894][ T7271] tcp_recvmsg+0x470/0x1a30 [ 48.244378][ T7271] inet_recvmsg+0xbb/0x250 [ 48.249486][ T7271] sock_recvmsg+0x92/0xb0 [ 48.253793][ T7271] sock_read_iter+0x15f/0x1e0 [ 48.258458][ T7271] new_sync_read+0x389/0x4f0 [ 48.263025][ T7271] __vfs_read+0xb1/0xc0 [ 48.267317][ T7271] vfs_read+0x143/0x2c0 [ 48.271508][ T7271] ksys_read+0xd5/0x1b0 [ 48.275657][ T7271] __x64_sys_read+0x4c/0x60 [ 48.280143][ T7271] do_syscall_64+0xcf/0x2f0 [ 48.284638][ T7271] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.290601][ T7271] [ 48.292990][ T7271] Reported by Kernel Concurrency Sanitizer on: [ 48.299123][ T7271] CPU: 0 PID: 7271 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.306202][ T7271] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.316252][ T7271] ================================================================== [ 48.324377][ T7271] Kernel panic - not syncing: panic_on_warn set ... [ 48.330939][ T7271] CPU: 0 PID: 7271 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.338026][ T7271] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.348063][ T7271] Call Trace: [ 48.351334][ T7271] dump_stack+0xf5/0x159 [ 48.355558][ T7271] panic+0x209/0x639 [ 48.359442][ T7271] ? vprintk_func+0x8d/0x140 [ 48.364019][ T7271] kcsan_report.cold+0x57/0xeb [ 48.368763][ T7271] __kcsan_setup_watchpoint+0x342/0x500 [ 48.374287][ T7271] __tsan_read8+0x2c/0x30 [ 48.378595][ T7271] tcp_recvmsg+0x470/0x1a30 [ 48.383083][ T7271] inet_recvmsg+0xbb/0x250 [ 48.387834][ T7271] ? __tsan_read8+0x2c/0x30 [ 48.392334][ T7271] ? inet_sendpage+0x100/0x100 [ 48.397084][ T7271] sock_recvmsg+0x92/0xb0 [ 48.401389][ T7271] sock_read_iter+0x15f/0x1e0 [ 48.406050][ T7271] new_sync_read+0x389/0x4f0 [ 48.410621][ T7271] __vfs_read+0xb1/0xc0 [ 48.414755][ T7271] vfs_read+0x143/0x2c0 [ 48.418898][ T7271] ksys_read+0xd5/0x1b0 [ 48.423130][ T7271] __x64_sys_read+0x4c/0x60 [ 48.427611][ T7271] do_syscall_64+0xcf/0x2f0 [ 48.432116][ T7271] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.437985][ T7271] RIP: 0033:0x47c530 [ 48.441861][ T7271] 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 [ 48.461447][ T7271] RSP: 002b:000000c4203a7810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 48.469834][ T7271] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.477874][ T7271] RDX: 0000000000001000 RSI: 000000c420052000 RDI: 0000000000000003 [ 48.485837][ T7271] RBP: 000000c4203a7868 R08: 0000000000000000 R09: 0000000000000000 [ 48.493786][ T7271] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000020 [ 48.501744][ T7271] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 48.511194][ T7271] Kernel Offset: disabled [ 48.515516][ T7271] Rebooting in 86400 seconds..