[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.755234][ T26] audit: type=1800 audit(1570191710.260:25): pid=7065 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.774992][ T26] audit: type=1800 audit(1570191710.260:26): pid=7065 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.801762][ T26] audit: type=1800 audit(1570191710.260:27): pid=7065 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 '10.128.1.26' (ECDSA) to the list of known hosts. 2019/10/04 12:22:00 fuzzer started 2019/10/04 12:22:01 dialing manager at 10.128.0.105:38119 2019/10/04 12:22:01 syscalls: 2523 2019/10/04 12:22:01 code coverage: enabled 2019/10/04 12:22:01 comparison tracing: enabled 2019/10/04 12:22:01 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:22:01 setuid sandbox: enabled 2019/10/04 12:22:01 namespace sandbox: enabled 2019/10/04 12:22:01 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:22:01 fault injection: enabled 2019/10/04 12:22:01 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:22:01 net packet injection: enabled 2019/10/04 12:22:01 net device setup: enabled 2019/10/04 12:22:01 concurrency sanitizer: enabled syzkaller login: [ 47.098602][ T7234] ================================================================== [ 47.106863][ T7234] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 47.116515][ T7234] [ 47.118875][ T7234] write to 0xffff8881236009f8 of 8 bytes by interrupt on cpu 0: [ 47.126934][ T7234] tcp_add_backlog+0x45a/0xcc0 [ 47.131672][ T7234] tcp_v4_rcv+0x1aba/0x1bf0 [ 47.136241][ T7234] ip_protocol_deliver_rcu+0x51/0x470 [ 47.141589][ T7234] ip_local_deliver_finish+0x110/0x140 [ 47.147024][ T7234] ip_local_deliver+0x133/0x210 [ 47.151865][ T7234] ip_rcv_finish+0x121/0x160 [ 47.156566][ T7234] ip_rcv+0x18f/0x1a0 [ 47.160534][ T7234] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.166232][ T7234] __netif_receive_skb+0x37/0xf0 [ 47.171150][ T7234] netif_receive_skb_internal+0x59/0x190 [ 47.176759][ T7234] napi_gro_receive+0x28f/0x330 [ 47.181604][ T7234] receive_buf+0x284/0x30b0 [ 47.186100][ T7234] virtnet_poll+0x436/0x7d0 [ 47.190583][ T7234] net_rx_action+0x3ae/0xa50 [ 47.195152][ T7234] [ 47.197506][ T7234] read to 0xffff8881236009f8 of 8 bytes by task 7234 on cpu 1: [ 47.205090][ T7234] tcp_recvmsg+0x470/0x1a30 [ 47.209911][ T7234] inet_recvmsg+0xbb/0x250 [ 47.214310][ T7234] sock_recvmsg+0x92/0xb0 [ 47.218631][ T7234] sock_read_iter+0x15f/0x1e0 [ 47.223296][ T7234] new_sync_read+0x389/0x4f0 [ 47.227870][ T7234] __vfs_read+0xb1/0xc0 [ 47.232005][ T7234] vfs_read+0x143/0x2c0 [ 47.236149][ T7234] ksys_read+0xd5/0x1b0 [ 47.240280][ T7234] __x64_sys_read+0x4c/0x60 [ 47.244760][ T7234] do_syscall_64+0xcf/0x2f0 [ 47.249243][ T7234] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.255111][ T7234] [ 47.257411][ T7234] Reported by Kernel Concurrency Sanitizer on: [ 47.263540][ T7234] CPU: 1 PID: 7234 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.270625][ T7234] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.280668][ T7234] ================================================================== [ 47.288713][ T7234] Kernel panic - not syncing: panic_on_warn set ... [ 47.295283][ T7234] CPU: 1 PID: 7234 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.302377][ T7234] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.313376][ T7234] Call Trace: [ 47.316656][ T7234] dump_stack+0xf5/0x159 [ 47.320894][ T7234] panic+0x209/0x639 [ 47.324770][ T7234] ? vprintk_func+0x8d/0x140 [ 47.329350][ T7234] kcsan_report.cold+0x57/0xeb [ 47.334121][ T7234] __kcsan_setup_watchpoint+0x342/0x500 [ 47.339691][ T7234] __tsan_read8+0x2c/0x30 [ 47.344561][ T7234] tcp_recvmsg+0x470/0x1a30 [ 47.349080][ T7234] inet_recvmsg+0xbb/0x250 [ 47.353522][ T7234] ? __tsan_read8+0x2c/0x30 [ 47.359238][ T7234] ? inet_sendpage+0x100/0x100 [ 47.363996][ T7234] sock_recvmsg+0x92/0xb0 [ 47.368407][ T7234] sock_read_iter+0x15f/0x1e0 [ 47.373081][ T7234] new_sync_read+0x389/0x4f0 [ 47.377658][ T7234] __vfs_read+0xb1/0xc0 [ 47.381807][ T7234] vfs_read+0x143/0x2c0 [ 47.385945][ T7234] ksys_read+0xd5/0x1b0 [ 47.390094][ T7234] __x64_sys_read+0x4c/0x60 [ 47.394902][ T7234] do_syscall_64+0xcf/0x2f0 [ 47.399399][ T7234] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.405298][ T7234] RIP: 0033:0x47c530 [ 47.409471][ T7234] 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 [ 47.429437][ T7234] RSP: 002b:000000c4204d37d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.437836][ T7234] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.445794][ T7234] RDX: 0000000000001000 RSI: 000000c4202b0000 RDI: 0000000000000003 [ 47.453933][ T7234] RBP: 000000c4204d3830 R08: 0000000000000000 R09: 0000000000000000 [ 47.462066][ T7234] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 47.470121][ T7234] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 47.479197][ T7234] Kernel Offset: disabled [ 47.483752][ T7234] Rebooting in 86400 seconds..