[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.178859][ T26] audit: type=1800 audit(1571264636.710:25): pid=6999 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.215149][ T26] audit: type=1800 audit(1571264636.710:26): pid=6999 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.242330][ T26] audit: type=1800 audit(1571264636.720:27): pid=6999 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 '10.128.0.216' (ECDSA) to the list of known hosts. 2019/10/16 22:24:03 fuzzer started 2019/10/16 22:24:04 dialing manager at 10.128.0.105:33899 2019/10/16 22:24:04 syscalls: 2524 2019/10/16 22:24:04 code coverage: enabled 2019/10/16 22:24:04 comparison tracing: enabled 2019/10/16 22:24:04 extra coverage: extra coverage is not supported by the kernel 2019/10/16 22:24:04 setuid sandbox: enabled 2019/10/16 22:24:04 namespace sandbox: enabled 2019/10/16 22:24:04 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/16 22:24:04 fault injection: enabled 2019/10/16 22:24:04 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/16 22:24:04 net packet injection: enabled 2019/10/16 22:24:04 net device setup: enabled 2019/10/16 22:24:04 concurrency sanitizer: enabled syzkaller login: [ 42.475794][ C0] ================================================================== [ 42.483932][ C0] BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust [ 42.491709][ C0] [ 42.494024][ C0] write to 0xffff8881231fea4c of 4 bytes by task 7152 on cpu 1: [ 42.501689][ C0] tcp_rcv_space_adjust+0x40f/0x4c0 [ 42.506871][ C0] tcp_recvmsg+0xdaa/0x1a30 [ 42.511353][ C0] inet_recvmsg+0xbb/0x250 [ 42.515753][ C0] sock_recvmsg+0x92/0xb0 [ 42.520066][ C0] sock_read_iter+0x15f/0x1e0 [ 42.524729][ C0] new_sync_read+0x389/0x4f0 [ 42.529299][ C0] __vfs_read+0xb1/0xc0 [ 42.533437][ C0] vfs_read+0x143/0x2c0 [ 42.537574][ C0] ksys_read+0xd5/0x1b0 [ 42.541714][ C0] __x64_sys_read+0x4c/0x60 [ 42.546548][ C0] do_syscall_64+0xcc/0x370 [ 42.551038][ C0] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 42.556916][ C0] [ 42.559258][ C0] read to 0xffff8881231fea4c of 4 bytes by interrupt on cpu 0: [ 42.566816][ C0] tcp_add_backlog+0x43/0xcc0 [ 42.571476][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 42.575960][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 42.581312][ C0] ip_local_deliver_finish+0x110/0x140 [ 42.586754][ C0] ip_local_deliver+0x133/0x210 [ 42.591585][ C0] ip_rcv_finish+0x121/0x160 [ 42.596249][ C0] ip_rcv+0x18f/0x1a0 [ 42.600214][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 42.605914][ C0] __netif_receive_skb+0x37/0xf0 [ 42.610836][ C0] netif_receive_skb_internal+0x59/0x190 [ 42.616468][ C0] napi_gro_receive+0x28f/0x330 [ 42.621312][ C0] receive_buf+0x284/0x30b0 [ 42.625797][ C0] virtnet_poll+0x436/0x7d0 [ 42.630275][ C0] [ 42.632582][ C0] Reported by Kernel Concurrency Sanitizer on: [ 42.638720][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.0-rc3+ #0 [ 42.645980][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.656024][ C0] ================================================================== [ 42.664165][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 42.670737][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.0-rc3+ #0 [ 42.677996][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.688033][ C0] Call Trace: [ 42.691311][ C0] dump_stack+0xf5/0x159 [ 42.695554][ C0] panic+0x210/0x640 [ 42.699438][ C0] ? __netif_receive_skb+0x37/0xf0 [ 42.704543][ C0] ? vprintk_func+0x8d/0x140 [ 42.709120][ C0] kcsan_report.cold+0xc/0x1b [ 42.713787][ C0] __kcsan_setup_watchpoint+0x3ee/0x510 [ 42.719333][ C0] __tsan_read4+0x2c/0x30 [ 42.723648][ C0] tcp_add_backlog+0x43/0xcc0 [ 42.728313][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 42.733944][ C0] ? sk_filter_trim_cap+0x202/0x510 [ 42.739133][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 42.744754][ C0] ? __tsan_write1+0x32/0x40 [ 42.749349][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 42.753844][ C0] ? __tsan_read8+0x2c/0x30 [ 42.758355][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 42.763718][ C0] ip_local_deliver_finish+0x110/0x140 [ 42.769177][ C0] ip_local_deliver+0x133/0x210 [ 42.774017][ C0] ? ip_protocol_deliver_rcu+0x420/0x420 [ 42.779642][ C0] ip_rcv_finish+0x121/0x160 [ 42.784219][ C0] ip_rcv+0x18f/0x1a0 [ 42.788189][ C0] ? ip_sublist_rcv+0x5e0/0x5e0 [ 42.793022][ C0] ? ip_local_deliver+0x210/0x210 [ 42.798817][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 42.804525][ C0] __netif_receive_skb+0x37/0xf0 [ 42.809450][ C0] netif_receive_skb_internal+0x59/0x190 [ 42.815560][ C0] napi_gro_receive+0x28f/0x330 [ 42.820404][ C0] receive_buf+0x284/0x30b0 [ 42.824894][ C0] ? __tsan_write8+0x32/0x40 [ 42.829476][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 42.834920][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 42.840535][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 42.846158][ C0] virtnet_poll+0x436/0x7d0 [ 42.850663][ C0] net_rx_action+0x3ae/0xa90 [ 42.855250][ C0] __do_softirq+0x115/0x33f [ 42.859745][ C0] ? takeover_tasklets+0x250/0x250 [ 42.864866][ C0] run_ksoftirqd+0x46/0x60 [ 42.869281][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 42.874662][ C0] kthread+0x1d4/0x200 [ 42.878737][ C0] ? constant_test_bit.constprop.0+0x30/0x30 [ 42.884728][ C0] ? kthread_stop+0x2d0/0x2d0 [ 42.889409][ C0] ret_from_fork+0x1f/0x30 [ 42.895084][ C0] Kernel Offset: disabled [ 42.899405][ C0] Rebooting in 86400 seconds..