[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.907530][ T26] audit: type=1800 audit(1571334181.377:25): pid=7017 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.959180][ T26] audit: type=1800 audit(1571334181.387:26): pid=7017 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.998987][ T26] audit: type=1800 audit(1571334181.387:27): pid=7017 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 '10.128.0.217' (ECDSA) to the list of known hosts. 2019/10/17 17:43:12 fuzzer started 2019/10/17 17:43:13 dialing manager at 10.128.0.105:43535 2019/10/17 17:43:13 syscalls: 2524 2019/10/17 17:43:13 code coverage: enabled 2019/10/17 17:43:13 comparison tracing: enabled 2019/10/17 17:43:13 extra coverage: extra coverage is not supported by the kernel 2019/10/17 17:43:13 setuid sandbox: enabled 2019/10/17 17:43:13 namespace sandbox: enabled 2019/10/17 17:43:13 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/17 17:43:13 fault injection: enabled 2019/10/17 17:43:13 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/17 17:43:13 net packet injection: enabled 2019/10/17 17:43:13 net device setup: enabled 2019/10/17 17:43:13 concurrency sanitizer: enabled syzkaller login: [ 48.120238][ C1] ================================================================== [ 48.128362][ C1] BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust [ 48.136142][ C1] [ 48.138459][ C1] write to 0xffff888123af614c of 4 bytes by task 7169 on cpu 0: [ 48.146074][ C1] tcp_rcv_space_adjust+0x40f/0x4c0 [ 48.151258][ C1] tcp_recvmsg+0xdaa/0x1a30 [ 48.155763][ C1] inet_recvmsg+0xbb/0x250 [ 48.160163][ C1] sock_recvmsg+0x92/0xb0 [ 48.164496][ C1] sock_read_iter+0x15f/0x1e0 [ 48.169154][ C1] new_sync_read+0x389/0x4f0 [ 48.173726][ C1] __vfs_read+0xb1/0xc0 [ 48.177864][ C1] vfs_read+0x143/0x2c0 [ 48.182017][ C1] ksys_read+0xd5/0x1b0 [ 48.186166][ C1] __x64_sys_read+0x4c/0x60 [ 48.190656][ C1] do_syscall_64+0xcc/0x370 [ 48.195144][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.201009][ C1] [ 48.203322][ C1] read to 0xffff888123af614c of 4 bytes by interrupt on cpu 1: [ 48.210846][ C1] tcp_add_backlog+0x43/0xcc0 [ 48.215506][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.219994][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.225346][ C1] ip_local_deliver_finish+0x110/0x140 [ 48.230786][ C1] ip_local_deliver+0x133/0x210 [ 48.235632][ C1] ip_rcv_finish+0x121/0x160 [ 48.240204][ C1] ip_rcv+0x18f/0x1a0 [ 48.244169][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.249883][ C1] __netif_receive_skb+0x37/0xf0 [ 48.254816][ C1] netif_receive_skb_internal+0x59/0x190 [ 48.260435][ C1] napi_gro_receive+0x28f/0x330 [ 48.265270][ C1] receive_buf+0x284/0x30b0 [ 48.269759][ C1] virtnet_poll+0x436/0x7d0 [ 48.274325][ C1] [ 48.276741][ C1] Reported by Kernel Concurrency Sanitizer on: [ 48.282900][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 48.290251][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.300288][ C1] ================================================================== [ 48.308604][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 48.315180][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 48.322524][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.332560][ C1] Call Trace: [ 48.335858][ C1] dump_stack+0xf5/0x159 [ 48.340096][ C1] panic+0x210/0x640 [ 48.343980][ C1] ? __netif_receive_skb+0x37/0xf0 [ 48.349079][ C1] ? vprintk_func+0x8d/0x140 [ 48.353665][ C1] kcsan_report.cold+0xc/0x10 [ 48.358329][ C1] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.363868][ C1] __tsan_read4+0x2c/0x30 [ 48.368186][ C1] tcp_add_backlog+0x43/0xcc0 [ 48.372858][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.378475][ C1] ? sk_filter_trim_cap+0x202/0x510 [ 48.383667][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.389284][ C1] ? __tsan_write1+0x32/0x40 [ 48.393861][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.398346][ C1] ? __tsan_read8+0x2c/0x30 [ 48.402841][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.408199][ C1] ip_local_deliver_finish+0x110/0x140 [ 48.413641][ C1] ip_local_deliver+0x133/0x210 [ 48.418476][ C1] ? ip_protocol_deliver_rcu+0x420/0x420 [ 48.424095][ C1] ip_rcv_finish+0x121/0x160 [ 48.428670][ C1] ip_rcv+0x18f/0x1a0 [ 48.432649][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 48.437483][ C1] ? ip_local_deliver+0x210/0x210 [ 48.442489][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.448201][ C1] __netif_receive_skb+0x37/0xf0 [ 48.453282][ C1] netif_receive_skb_internal+0x59/0x190 [ 48.458900][ C1] napi_gro_receive+0x28f/0x330 [ 48.463736][ C1] receive_buf+0x284/0x30b0 [ 48.468223][ C1] ? __tsan_write8+0x32/0x40 [ 48.472803][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 48.478427][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.484041][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.489670][ C1] virtnet_poll+0x436/0x7d0 [ 48.494469][ C1] ? __sanitizer_cov_trace_cmp2+0x18/0x20 [ 48.500371][ C1] net_rx_action+0x3ae/0xa90 [ 48.505045][ C1] __do_softirq+0x115/0x33f [ 48.509562][ C1] ? takeover_tasklets+0x250/0x250 [ 48.514678][ C1] run_ksoftirqd+0x46/0x60 [ 48.519086][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 48.524749][ C1] kthread+0x1d4/0x200 [ 48.528924][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 48.534902][ C1] ? kthread_stop+0x2d0/0x2d0 [ 48.539913][ C1] ret_from_fork+0x1f/0x30 [ 48.545638][ C1] Kernel Offset: disabled [ 48.549971][ C1] Rebooting in 86400 seconds..