[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 41.746338][ T25] audit: type=1800 audit(1570192844.905:25): pid=7058 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 41.773754][ T25] audit: type=1800 audit(1570192844.905:26): pid=7058 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 41.813636][ T25] audit: type=1800 audit(1570192844.905:27): pid=7058 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 '10.128.10.39' (ECDSA) to the list of known hosts. 2019/10/04 12:40:52 fuzzer started 2019/10/04 12:40:54 dialing manager at 10.128.0.105:38119 2019/10/04 12:40:54 syscalls: 2523 2019/10/04 12:40:54 code coverage: enabled 2019/10/04 12:40:54 comparison tracing: enabled 2019/10/04 12:40:54 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:40:54 setuid sandbox: enabled 2019/10/04 12:40:54 namespace sandbox: enabled 2019/10/04 12:40:54 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:40:54 fault injection: enabled 2019/10/04 12:40:54 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:40:54 net packet injection: enabled 2019/10/04 12:40:54 net device setup: enabled 2019/10/04 12:40:54 concurrency sanitizer: enabled syzkaller login: [ 51.902350][ C0] ================================================================== [ 51.910654][ C0] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 51.920003][ C0] [ 51.922316][ C0] read to 0xffff88811ee809f8 of 8 bytes by task 7210 on cpu 1: [ 51.929844][ C0] tcp_recvmsg+0x470/0x1a30 [ 51.934329][ C0] inet_recvmsg+0xbb/0x250 [ 51.938730][ C0] sock_recvmsg+0x92/0xb0 [ 51.943053][ C0] sock_read_iter+0x15f/0x1e0 [ 51.947720][ C0] new_sync_read+0x389/0x4f0 [ 51.952288][ C0] __vfs_read+0xb1/0xc0 [ 51.956428][ C0] vfs_read+0x143/0x2c0 [ 51.960563][ C0] ksys_read+0xd5/0x1b0 [ 51.964701][ C0] __x64_sys_read+0x4c/0x60 [ 51.969186][ C0] do_syscall_64+0xcf/0x2f0 [ 51.973671][ C0] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.979532][ C0] [ 51.981845][ C0] write to 0xffff88811ee809f8 of 8 bytes by interrupt on cpu 0: [ 51.989452][ C0] tcp_add_backlog+0x45a/0xcc0 [ 51.994206][ C0] tcp_v4_rcv+0x1aba/0x1bf0 [ 51.998692][ C0] ip_protocol_deliver_rcu+0x51/0x470 [ 52.004046][ C0] ip_local_deliver_finish+0x110/0x140 [ 52.009495][ C0] ip_local_deliver+0x133/0x210 [ 52.014327][ C0] ip_rcv_finish+0x121/0x160 [ 52.018905][ C0] ip_rcv+0x18f/0x1a0 [ 52.022883][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 52.028583][ C0] __netif_receive_skb+0x37/0xf0 [ 52.033499][ C0] netif_receive_skb_internal+0x59/0x190 [ 52.039115][ C0] napi_gro_receive+0x28f/0x330 [ 52.043959][ C0] receive_buf+0x284/0x30b0 [ 52.048444][ C0] virtnet_poll+0x436/0x7d0 [ 52.052921][ C0] [ 52.055227][ C0] Reported by Kernel Concurrency Sanitizer on: [ 52.061370][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 52.068296][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.078334][ C0] ================================================================== [ 52.086379][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 52.092968][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0+ #0 [ 52.100042][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.110080][ C0] Call Trace: [ 52.113361][ C0] dump_stack+0xf5/0x159 [ 52.117592][ C0] panic+0x209/0x639 [ 52.121497][ C0] ? vprintk_func+0x8d/0x140 [ 52.126103][ C0] kcsan_report.cold+0x57/0xeb [ 52.130866][ C0] __kcsan_setup_watchpoint+0x342/0x500 [ 52.136402][ C0] __tsan_write8+0x32/0x40 [ 52.140818][ C0] tcp_add_backlog+0x45a/0xcc0 [ 52.145565][ C0] ? __rcu_read_unlock+0x62/0xe0 [ 52.150493][ C0] tcp_v4_rcv+0x1aba/0x1bf0 [ 52.154986][ C0] ? __tsan_read8+0x2c/0x30 [ 52.159481][ C0] ip_protocol_deliver_rcu+0x51/0x470 [ 52.164839][ C0] ip_local_deliver_finish+0x110/0x140 [ 52.170283][ C0] ip_local_deliver+0x133/0x210 [ 52.175116][ C0] ? ip_protocol_deliver_rcu+0x470/0x470 [ 52.180733][ C0] ip_rcv_finish+0x121/0x160 [ 52.185417][ C0] ip_rcv+0x18f/0x1a0 [ 52.189389][ C0] ? ip_sublist_rcv+0x5e0/0x5e0 [ 52.194238][ C0] ? ip_local_deliver+0x210/0x210 [ 52.199247][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 52.204983][ C0] __netif_receive_skb+0x37/0xf0 [ 52.209906][ C0] netif_receive_skb_internal+0x59/0x190 [ 52.215526][ C0] napi_gro_receive+0x28f/0x330 [ 52.220463][ C0] receive_buf+0x284/0x30b0 [ 52.224954][ C0] ? __tsan_write8+0x32/0x40 [ 52.229537][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 52.234979][ C0] ? virtqueue_get_buf+0x31/0x40 [ 52.239906][ C0] virtnet_poll+0x436/0x7d0 [ 52.244398][ C0] net_rx_action+0x3ae/0xa50 [ 52.248989][ C0] __do_softirq+0x115/0x33f [ 52.253479][ C0] ? takeover_tasklets+0x250/0x250 [ 52.258579][ C0] run_ksoftirqd+0x46/0x60 [ 52.262978][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 52.267904][ C0] kthread+0x1d4/0x200 [ 52.271957][ C0] ? constant_test_bit.constprop.0+0x30/0x30 [ 52.277929][ C0] ? kthread_bind+0x50/0x50 [ 52.282424][ C0] ret_from_fork+0x1f/0x30 [ 52.288294][ C0] Kernel Offset: disabled [ 52.292656][ C0] Rebooting in 86400 seconds..