[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 45.523522][ T26] audit: type=1800 audit(1570192864.278:25): pid=7136 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 45.573574][ T26] audit: type=1800 audit(1570192864.278:26): pid=7136 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 45.596978][ T26] audit: type=1800 audit(1570192864.278:27): pid=7136 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 '10.128.10.47' (ECDSA) to the list of known hosts. 2019/10/04 12:41:14 fuzzer started 2019/10/04 12:41:15 dialing manager at 10.128.0.105:38119 2019/10/04 12:41:15 syscalls: 2523 2019/10/04 12:41:15 code coverage: enabled 2019/10/04 12:41:15 comparison tracing: enabled 2019/10/04 12:41:15 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:41:15 setuid sandbox: enabled 2019/10/04 12:41:15 namespace sandbox: enabled 2019/10/04 12:41:15 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:41:15 fault injection: enabled 2019/10/04 12:41:15 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:41:15 net packet injection: enabled 2019/10/04 12:41:15 net device setup: enabled 2019/10/04 12:41:15 concurrency sanitizer: enabled syzkaller login: [ 57.685173][ T7299] ================================================================== [ 57.693596][ T7299] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 57.702957][ T7299] [ 57.705297][ T7299] write to 0xffff88812a4a12f8 of 8 bytes by interrupt on cpu 1: [ 57.713013][ T7299] tcp_add_backlog+0x45a/0xcc0 [ 57.717775][ T7299] tcp_v4_rcv+0x1aba/0x1bf0 [ 57.722459][ T7299] ip_protocol_deliver_rcu+0x51/0x470 [ 57.727985][ T7299] ip_local_deliver_finish+0x110/0x140 [ 57.733432][ T7299] ip_local_deliver+0x133/0x210 [ 57.738267][ T7299] ip_rcv_finish+0x121/0x160 [ 57.742871][ T7299] ip_rcv+0x18f/0x1a0 [ 57.746854][ T7299] __netif_receive_skb_one_core+0xa7/0xe0 [ 57.753402][ T7299] __netif_receive_skb+0x37/0xf0 [ 57.758431][ T7299] netif_receive_skb_internal+0x59/0x190 [ 57.764044][ T7299] napi_gro_receive+0x28f/0x330 [ 57.768877][ T7299] receive_buf+0x284/0x30b0 [ 57.773371][ T7299] virtnet_poll+0x436/0x7d0 [ 57.777867][ T7299] net_rx_action+0x3ae/0xa50 [ 57.782935][ T7299] [ 57.785364][ T7299] read to 0xffff88812a4a12f8 of 8 bytes by task 7299 on cpu 0: [ 57.792912][ T7299] tcp_recvmsg+0x470/0x1a30 [ 57.797487][ T7299] inet_recvmsg+0xbb/0x250 [ 57.801893][ T7299] sock_recvmsg+0x92/0xb0 [ 57.806201][ T7299] sock_read_iter+0x15f/0x1e0 [ 57.810871][ T7299] new_sync_read+0x389/0x4f0 [ 57.815457][ T7299] __vfs_read+0xb1/0xc0 [ 57.819686][ T7299] vfs_read+0x143/0x2c0 [ 57.823816][ T7299] ksys_read+0xd5/0x1b0 [ 57.827951][ T7299] __x64_sys_read+0x4c/0x60 [ 57.832438][ T7299] do_syscall_64+0xcf/0x2f0 [ 57.836933][ T7299] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 57.843000][ T7299] [ 57.845417][ T7299] Reported by Kernel Concurrency Sanitizer on: [ 57.851583][ T7299] CPU: 0 PID: 7299 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 57.858683][ T7299] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.868724][ T7299] ================================================================== [ 57.876874][ T7299] Kernel panic - not syncing: panic_on_warn set ... [ 57.883525][ T7299] CPU: 0 PID: 7299 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 57.890629][ T7299] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.901022][ T7299] Call Trace: [ 57.904313][ T7299] dump_stack+0xf5/0x159 [ 57.908544][ T7299] panic+0x209/0x639 [ 57.912429][ T7299] ? vprintk_func+0x8d/0x140 [ 57.917004][ T7299] kcsan_report.cold+0x57/0xeb [ 57.921750][ T7299] __kcsan_setup_watchpoint+0x342/0x500 [ 57.927308][ T7299] __tsan_read8+0x2c/0x30 [ 57.931884][ T7299] tcp_recvmsg+0x470/0x1a30 [ 57.936411][ T7299] ? __tsan_read8+0x2c/0x30 [ 57.940930][ T7299] inet_recvmsg+0xbb/0x250 [ 57.945444][ T7299] ? __tsan_read8+0x2c/0x30 [ 57.950078][ T7299] ? inet_sendpage+0x100/0x100 [ 57.954980][ T7299] sock_recvmsg+0x92/0xb0 [ 57.959304][ T7299] sock_read_iter+0x15f/0x1e0 [ 57.963982][ T7299] new_sync_read+0x389/0x4f0 [ 57.968563][ T7299] __vfs_read+0xb1/0xc0 [ 57.972723][ T7299] vfs_read+0x143/0x2c0 [ 57.976860][ T7299] ksys_read+0xd5/0x1b0 [ 57.980997][ T7299] __x64_sys_read+0x4c/0x60 [ 57.985503][ T7299] do_syscall_64+0xcf/0x2f0 [ 57.990005][ T7299] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 57.995982][ T7299] RIP: 0033:0x47c530 [ 57.999863][ T7299] 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 [ 58.019534][ T7299] RSP: 002b:000000c42038f7d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 58.027926][ T7299] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 58.035881][ T7299] RDX: 0000000000001000 RSI: 000000c420370000 RDI: 0000000000000003 [ 58.044173][ T7299] RBP: 000000c42038f828 R08: 0000000000000000 R09: 0000000000000000 [ 58.052130][ T7299] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 58.060086][ T7299] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 58.069812][ T7299] Kernel Offset: disabled [ 58.074189][ T7299] Rebooting in 86400 seconds..