[info] Using makefile-style concurrent boot in runlevel 2.
[   44.393181][   T25] audit: type=1800 audit(1571795885.772:21): pid=7186 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="bootlogs" dev="sda1" ino=2452 res=0
[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c.
[....] 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 '10.128.0.139' (ECDSA) to the list of known hosts.
2019/10/23 01:58:17 fuzzer started
2019/10/23 01:58:19 dialing manager at 10.128.0.105:33369
2019/10/23 01:58:19 syscalls: 2524
2019/10/23 01:58:19 code coverage: enabled
2019/10/23 01:58:19 comparison tracing: enabled
2019/10/23 01:58:19 extra coverage: extra coverage is not supported by the kernel
2019/10/23 01:58:19 setuid sandbox: enabled
2019/10/23 01:58:19 namespace sandbox: enabled
2019/10/23 01:58:19 Android sandbox: /sys/fs/selinux/policy does not exist
2019/10/23 01:58:19 fault injection: enabled
2019/10/23 01:58:19 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled
2019/10/23 01:58:19 net packet injection: enabled
2019/10/23 01:58:19 net device setup: enabled
2019/10/23 01:58:19 concurrency sanitizer: enabled
syzkaller login: [   58.955425][ T7351] ==================================================================
[   58.963555][ T7351] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg
[   58.971083][ T7351] 
[   58.973406][ T7351] write to 0xffff88811df9a138 of 8 bytes by interrupt on cpu 1:
[   58.981023][ T7351]  tcp_add_backlog+0x45a/0xcc0
[   58.985763][ T7351]  tcp_v4_rcv+0x1a60/0x1bb0
[   58.990253][ T7351]  ip_protocol_deliver_rcu+0x4d/0x420
[   58.995612][ T7351]  ip_local_deliver_finish+0x110/0x140
[   59.001139][ T7351]  ip_local_deliver+0x133/0x210
[   59.005966][ T7351]  ip_rcv_finish+0x121/0x160
[   59.010531][ T7351]  ip_rcv+0x18f/0x1a0
[   59.014495][ T7351]  __netif_receive_skb_one_core+0xa7/0xe0
[   59.020192][ T7351]  __netif_receive_skb+0x37/0xf0
[   59.025114][ T7351]  netif_receive_skb_internal+0x59/0x190
[   59.030726][ T7351]  napi_gro_receive+0x28f/0x330
[   59.035963][ T7351]  receive_buf+0x284/0x30b0
[   59.040464][ T7351]  virtnet_poll+0x436/0x7d0
[   59.045209][ T7351]  net_rx_action+0x3ae/0xa90
[   59.049769][ T7351] 
[   59.052087][ T7351] read to 0xffff88811df9a138 of 8 bytes by task 7351 on cpu 0:
[   59.059611][ T7351]  tcp_recvmsg+0x470/0x1a30
[   59.064098][ T7351]  inet_recvmsg+0xbb/0x250
[   59.068489][ T7351]  sock_recvmsg+0x92/0xb0
[   59.072791][ T7351]  sock_read_iter+0x15f/0x1e0
[   59.077444][ T7351]  new_sync_read+0x389/0x4f0
[   59.082007][ T7351]  __vfs_read+0xb1/0xc0
[   59.086144][ T7351]  vfs_read+0x143/0x2c0
[   59.090272][ T7351]  ksys_read+0xd5/0x1b0
[   59.094403][ T7351]  __x64_sys_read+0x4c/0x60
[   59.098886][ T7351]  do_syscall_64+0xcc/0x370
[   59.103377][ T7351]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   59.109239][ T7351] 
[   59.111538][ T7351] Reported by Kernel Concurrency Sanitizer on:
[   59.117677][ T7351] CPU: 0 PID: 7351 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0
[   59.125108][ T7351] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   59.135163][ T7351] ==================================================================
[   59.143200][ T7351] Kernel panic - not syncing: panic_on_warn set ...
[   59.149763][ T7351] CPU: 0 PID: 7351 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0
[   59.157186][ T7351] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[   59.167212][ T7351] Call Trace:
[   59.170484][ T7351]  dump_stack+0xf5/0x159
[   59.174702][ T7351]  panic+0x210/0x640
[   59.178588][ T7351]  ? __x64_sys_read+0x4c/0x60
[   59.183242][ T7351]  ? vprintk_func+0x8d/0x140
[   59.187812][ T7351]  kcsan_report.cold+0xc/0x10
[   59.192465][ T7351]  __kcsan_setup_watchpoint+0x32e/0x4a0
[   59.198005][ T7351]  __tsan_read8+0x2c/0x30
[   59.202315][ T7351]  tcp_recvmsg+0x470/0x1a30
[   59.206800][ T7351]  inet_recvmsg+0xbb/0x250
[   59.211189][ T7351]  ? __tsan_read8+0x2c/0x30
[   59.215669][ T7351]  ? inet_sendpage+0x100/0x100
[   59.220410][ T7351]  sock_recvmsg+0x92/0xb0
[   59.224753][ T7351]  sock_read_iter+0x15f/0x1e0
[   59.229410][ T7351]  new_sync_read+0x389/0x4f0
[   59.233989][ T7351]  __vfs_read+0xb1/0xc0
[   59.238132][ T7351]  vfs_read+0x143/0x2c0
[   59.242268][ T7351]  ksys_read+0xd5/0x1b0
[   59.246403][ T7351]  __x64_sys_read+0x4c/0x60
[   59.250898][ T7351]  do_syscall_64+0xcc/0x370
[   59.255389][ T7351]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   59.261252][ T7351] RIP: 0033:0x47c530
[   59.265140][ T7351] 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
[   59.284726][ T7351] RSP: 002b:000000c42033b7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000
[   59.293110][ T7351] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530
[   59.301056][ T7351] RDX: 0000000000001000 RSI: 000000c42031a000 RDI: 0000000000000003
[   59.309013][ T7351] RBP: 000000c42033b830 R08: 0000000000000000 R09: 0000000000000000
[   59.316966][ T7351] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000003
[   59.324920][ T7351] R13: 000000c420020b78 R14: 0000000000000002 R15: ffffffffffffffff
[   59.334254][ T7351] Kernel Offset: disabled
[   59.338602][ T7351] Rebooting in 86400 seconds..