[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.506355][ T26] audit: type=1800 audit(1571795839.393:25): pid=7176 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.526140][ T26] audit: type=1800 audit(1571795839.393:26): pid=7176 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.547982][ T26] audit: type=1800 audit(1571795839.393:27): pid=7176 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 '10.128.1.21' (ECDSA) to the list of known hosts. 2019/10/23 01:57:30 fuzzer started 2019/10/23 01:57:31 dialing manager at 10.128.0.105:33369 2019/10/23 01:57:31 syscalls: 2524 2019/10/23 01:57:31 code coverage: enabled 2019/10/23 01:57:31 comparison tracing: enabled 2019/10/23 01:57:31 extra coverage: extra coverage is not supported by the kernel 2019/10/23 01:57:31 setuid sandbox: enabled 2019/10/23 01:57:31 namespace sandbox: enabled 2019/10/23 01:57:31 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 01:57:31 fault injection: enabled 2019/10/23 01:57:31 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 01:57:31 net packet injection: enabled 2019/10/23 01:57:31 net device setup: enabled 2019/10/23 01:57:31 concurrency sanitizer: enabled syzkaller login: [ 47.153127][ C0] ================================================================== [ 47.161263][ C0] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 47.168955][ C0] [ 47.171274][ C0] read to 0xffff8881233e812c of 4 bytes by task 7346 on cpu 1: [ 47.178801][ C0] __tcp_select_window+0x6b/0x4d0 [ 47.183808][ C0] __tcp_transmit_skb+0x700/0x1d60 [ 47.188911][ C0] __tcp_send_ack+0x246/0x300 [ 47.193569][ C0] tcp_send_ack+0x34/0x40 [ 47.197880][ C0] tcp_cleanup_rbuf+0x130/0x360 [ 47.202715][ C0] tcp_recvmsg+0x633/0x1a30 [ 47.207202][ C0] inet_recvmsg+0xbb/0x250 [ 47.211601][ C0] sock_recvmsg+0x92/0xb0 [ 47.215927][ C0] sock_read_iter+0x15f/0x1e0 [ 47.220589][ C0] new_sync_read+0x389/0x4f0 [ 47.225168][ C0] __vfs_read+0xb1/0xc0 [ 47.229304][ C0] vfs_read+0x143/0x2c0 [ 47.233439][ C0] ksys_read+0xd5/0x1b0 [ 47.237586][ C0] __x64_sys_read+0x4c/0x60 [ 47.242063][ C0] [ 47.244377][ C0] write to 0xffff8881233e812c of 4 bytes by interrupt on cpu 0: [ 47.251992][ C0] tcp_add_backlog+0x4a0/0xcc0 [ 47.256748][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.261247][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.266602][ C0] ip_local_deliver_finish+0x110/0x140 [ 47.272042][ C0] ip_local_deliver+0x133/0x210 [ 47.276872][ C0] ip_rcv_finish+0x121/0x160 [ 47.281439][ C0] ip_rcv+0x18f/0x1a0 [ 47.285491][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.291193][ C0] __netif_receive_skb+0x37/0xf0 [ 47.296124][ C0] netif_receive_skb_internal+0x59/0x190 [ 47.301737][ C0] napi_gro_receive+0x28f/0x330 [ 47.306570][ C0] receive_buf+0x284/0x30b0 [ 47.311068][ C0] virtnet_poll+0x436/0x7d0 [ 47.315547][ C0] [ 47.317852][ C0] Reported by Kernel Concurrency Sanitizer on: [ 47.324032][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.0-rc3+ #0 [ 47.331291][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.341337][ C0] ================================================================== [ 47.349386][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 47.355953][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.0-rc3+ #0 [ 47.363296][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.373342][ C0] Call Trace: [ 47.376622][ C0] dump_stack+0xf5/0x159 [ 47.380851][ C0] panic+0x210/0x640 [ 47.384746][ C0] ? __netif_receive_skb+0x37/0xf0 [ 47.389841][ C0] ? vprintk_func+0x8d/0x140 [ 47.394415][ C0] kcsan_report.cold+0xc/0x10 [ 47.399081][ C0] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.404630][ C0] __tsan_write4+0x32/0x40 [ 47.409050][ C0] tcp_add_backlog+0x4a0/0xcc0 [ 47.413828][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.418333][ C0] ? __tsan_read8+0x2c/0x30 [ 47.422847][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.428220][ C0] ip_local_deliver_finish+0x110/0x140 [ 47.433664][ C0] ip_local_deliver+0x133/0x210 [ 47.438501][ C0] ? ip_protocol_deliver_rcu+0x420/0x420 [ 47.444133][ C0] ip_rcv_finish+0x121/0x160 [ 47.448708][ C0] ip_rcv+0x18f/0x1a0 [ 47.452675][ C0] ? ip_sublist_rcv+0x5e0/0x5e0 [ 47.457507][ C0] ? ip_local_deliver+0x210/0x210 [ 47.462519][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.468225][ C0] __netif_receive_skb+0x37/0xf0 [ 47.473150][ C0] netif_receive_skb_internal+0x59/0x190 [ 47.478769][ C0] napi_gro_receive+0x28f/0x330 [ 47.483604][ C0] receive_buf+0x284/0x30b0 [ 47.488112][ C0] ? __tsan_write8+0x32/0x40 [ 47.492707][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 47.498156][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.503794][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.509418][ C0] virtnet_poll+0x436/0x7d0 [ 47.513915][ C0] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 47.520151][ C0] net_rx_action+0x3ae/0xa90 [ 47.524735][ C0] __do_softirq+0x115/0x33f [ 47.529228][ C0] ? takeover_tasklets+0x250/0x250 [ 47.534323][ C0] run_ksoftirqd+0x46/0x60 [ 47.538724][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 47.543646][ C0] kthread+0x1d4/0x200 [ 47.547697][ C0] ? constant_test_bit.constprop.0+0x30/0x30 [ 47.553661][ C0] ? kthread_stop+0x2d0/0x2d0 [ 47.558322][ C0] ret_from_fork+0x1f/0x30 [ 47.564026][ C0] Kernel Offset: disabled [ 47.568347][ C0] Rebooting in 86400 seconds..