[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.837727][ T26] audit: type=1800 audit(1571739624.772:25): pid=6975 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.872431][ T26] audit: type=1800 audit(1571739624.772:26): pid=6975 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.901383][ T26] audit: type=1800 audit(1571739624.782:27): pid=6975 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 '10.128.0.153' (ECDSA) to the list of known hosts. 2019/10/22 10:20:35 fuzzer started 2019/10/22 10:20:37 dialing manager at 10.128.0.105:37053 2019/10/22 10:20:37 syscalls: 2524 2019/10/22 10:20:37 code coverage: enabled 2019/10/22 10:20:37 comparison tracing: enabled 2019/10/22 10:20:37 extra coverage: extra coverage is not supported by the kernel 2019/10/22 10:20:37 setuid sandbox: enabled 2019/10/22 10:20:37 namespace sandbox: enabled 2019/10/22 10:20:37 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 10:20:37 fault injection: enabled 2019/10/22 10:20:37 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 10:20:37 net packet injection: enabled 2019/10/22 10:20:37 net device setup: enabled 2019/10/22 10:20:37 concurrency sanitizer: enabled syzkaller login: [ 47.829461][ T7130] ================================================================== [ 47.837604][ T7130] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 47.844605][ T7130] [ 47.846917][ T7130] write to 0xffff888126b609f8 of 8 bytes by interrupt on cpu 0: [ 47.854524][ T7130] tcp_add_backlog+0x45a/0xcc0 [ 47.859263][ T7130] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.863737][ T7130] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.869095][ T7130] ip_local_deliver_finish+0x110/0x140 [ 47.874530][ T7130] ip_local_deliver+0x133/0x210 [ 47.879395][ T7130] ip_rcv_finish+0x121/0x160 [ 47.883957][ T7130] ip_rcv+0x18f/0x1a0 [ 47.887914][ T7130] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.893615][ T7130] __netif_receive_skb+0x37/0xf0 [ 47.898527][ T7130] netif_receive_skb_internal+0x59/0x190 [ 47.904134][ T7130] napi_gro_receive+0x28f/0x330 [ 47.908957][ T7130] receive_buf+0x284/0x30b0 [ 47.913433][ T7130] virtnet_poll+0x436/0x7d0 [ 47.917910][ T7130] net_rx_action+0x3ae/0xa90 [ 47.922465][ T7130] [ 47.924771][ T7130] read to 0xffff888126b609f8 of 8 bytes by task 7130 on cpu 1: [ 47.932287][ T7130] tcp_recvmsg+0x470/0x1a30 [ 47.936766][ T7130] inet_recvmsg+0xbb/0x250 [ 47.941155][ T7130] sock_recvmsg+0x92/0xb0 [ 47.945457][ T7130] sock_read_iter+0x15f/0x1e0 [ 47.950106][ T7130] new_sync_read+0x389/0x4f0 [ 47.954669][ T7130] __vfs_read+0xb1/0xc0 [ 47.958797][ T7130] vfs_read+0x143/0x2c0 [ 47.962926][ T7130] ksys_read+0xd5/0x1b0 [ 47.967055][ T7130] __x64_sys_read+0x4c/0x60 [ 47.975017][ T7130] do_syscall_64+0xcc/0x370 [ 47.979496][ T7130] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.985469][ T7130] [ 47.987771][ T7130] Reported by Kernel Concurrency Sanitizer on: [ 47.993900][ T7130] CPU: 1 PID: 7130 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.001324][ T7130] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.011361][ T7130] ================================================================== [ 48.019395][ T7130] Kernel panic - not syncing: panic_on_warn set ... [ 48.025954][ T7130] CPU: 1 PID: 7130 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.033376][ T7130] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.043402][ T7130] Call Trace: [ 48.046670][ T7130] dump_stack+0xf5/0x159 [ 48.050886][ T7130] panic+0x210/0x640 [ 48.054770][ T7130] ? __x64_sys_read+0x4c/0x60 [ 48.059427][ T7130] ? vprintk_func+0x8d/0x140 [ 48.064013][ T7130] kcsan_report.cold+0xc/0x10 [ 48.068668][ T7130] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.074189][ T7130] __tsan_read8+0x2c/0x30 [ 48.078515][ T7130] tcp_recvmsg+0x470/0x1a30 [ 48.083001][ T7130] inet_recvmsg+0xbb/0x250 [ 48.087390][ T7130] ? __tsan_read8+0x2c/0x30 [ 48.091885][ T7130] ? inet_sendpage+0x100/0x100 [ 48.096638][ T7130] sock_recvmsg+0x92/0xb0 [ 48.101043][ T7130] sock_read_iter+0x15f/0x1e0 [ 48.105700][ T7130] new_sync_read+0x389/0x4f0 [ 48.110270][ T7130] __vfs_read+0xb1/0xc0 [ 48.114413][ T7130] vfs_read+0x143/0x2c0 [ 48.118546][ T7130] ksys_read+0xd5/0x1b0 [ 48.122680][ T7130] __x64_sys_read+0x4c/0x60 [ 48.127162][ T7130] do_syscall_64+0xcc/0x370 [ 48.131640][ T7130] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.137596][ T7130] RIP: 0033:0x47c530 [ 48.141467][ T7130] 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 [ 48.161045][ T7130] RSP: 002b:000000c4203117d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.169517][ T7130] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.177492][ T7130] RDX: 0000000000001000 RSI: 000000c420058000 RDI: 0000000000000003 [ 48.185437][ T7130] RBP: 000000c420311830 R08: 0000000000000000 R09: 0000000000000000 [ 48.193386][ T7130] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 48.201342][ T7130] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 48.210716][ T7130] Kernel Offset: disabled [ 48.215044][ T7130] Rebooting in 86400 seconds..