[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.189211][ T26] audit: type=1800 audit(1571785662.372:25): pid=7126 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.216282][ T26] audit: type=1800 audit(1571785662.372:26): pid=7126 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.243245][ T26] audit: type=1800 audit(1571785662.372:27): pid=7126 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 '10.128.10.58' (ECDSA) to the list of known hosts. 2019/10/22 23:07:53 fuzzer started 2019/10/22 23:07:54 dialing manager at 10.128.0.105:33369 2019/10/22 23:07:54 syscalls: 2524 2019/10/22 23:07:54 code coverage: enabled 2019/10/22 23:07:54 comparison tracing: enabled 2019/10/22 23:07:54 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:07:54 setuid sandbox: enabled 2019/10/22 23:07:54 namespace sandbox: enabled 2019/10/22 23:07:54 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:07:54 fault injection: enabled 2019/10/22 23:07:54 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:07:54 net packet injection: enabled 2019/10/22 23:07:54 net device setup: enabled 2019/10/22 23:07:54 concurrency sanitizer: enabled syzkaller login: [ 46.872960][ C0] ================================================================== [ 46.881086][ C0] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 46.888776][ C0] [ 46.891100][ C0] read to 0xffff8881261612ec of 4 bytes by task 7293 on cpu 1: [ 46.898628][ C0] __tcp_select_window+0x6b/0x4d0 [ 46.903632][ C0] __tcp_transmit_skb+0x700/0x1d60 [ 46.908726][ C0] __tcp_send_ack+0x246/0x300 [ 46.913384][ C0] tcp_send_ack+0x34/0x40 [ 46.917695][ C0] tcp_cleanup_rbuf+0x130/0x360 [ 46.922528][ C0] tcp_recvmsg+0x633/0x1a30 [ 46.927013][ C0] inet_recvmsg+0xbb/0x250 [ 46.931424][ C0] sock_recvmsg+0x92/0xb0 [ 46.935738][ C0] sock_read_iter+0x15f/0x1e0 [ 46.940400][ C0] new_sync_read+0x389/0x4f0 [ 46.944974][ C0] __vfs_read+0xb1/0xc0 [ 46.949111][ C0] vfs_read+0x143/0x2c0 [ 46.953254][ C0] ksys_read+0xd5/0x1b0 [ 46.957391][ C0] __x64_sys_read+0x4c/0x60 [ 46.961866][ C0] [ 46.964178][ C0] write to 0xffff8881261612ec of 4 bytes by interrupt on cpu 0: [ 46.971942][ C0] tcp_add_backlog+0x4a0/0xcc0 [ 46.976699][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 46.981191][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 46.986549][ C0] ip_local_deliver_finish+0x110/0x140 [ 46.991990][ C0] ip_local_deliver+0x133/0x210 [ 46.996823][ C0] ip_rcv_finish+0x121/0x160 [ 47.001396][ C0] ip_rcv+0x18f/0x1a0 [ 47.005378][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.011079][ C0] __netif_receive_skb+0x37/0xf0 [ 47.016000][ C0] netif_receive_skb_internal+0x59/0x190 [ 47.021647][ C0] napi_gro_receive+0x28f/0x330 [ 47.026489][ C0] receive_buf+0x284/0x30b0 [ 47.030976][ C0] virtnet_poll+0x436/0x7d0 [ 47.035456][ C0] [ 47.037766][ C0] Reported by Kernel Concurrency Sanitizer on: [ 47.043903][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.0-rc3+ #0 [ 47.051176][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.061211][ C0] ================================================================== [ 47.069251][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 47.075821][ C0] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.4.0-rc3+ #0 [ 47.083088][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.094081][ C0] Call Trace: [ 47.097454][ C0] dump_stack+0xf5/0x159 [ 47.101684][ C0] panic+0x210/0x640 [ 47.105566][ C0] ? __netif_receive_skb+0x37/0xf0 [ 47.110663][ C0] ? vprintk_func+0x8d/0x140 [ 47.115415][ C0] kcsan_report.cold+0xc/0x10 [ 47.120082][ C0] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.125613][ C0] __tsan_write4+0x32/0x40 [ 47.130025][ C0] tcp_add_backlog+0x4a0/0xcc0 [ 47.134790][ C0] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.139279][ C0] ? __tsan_read8+0x2c/0x30 [ 47.143772][ C0] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.149140][ C0] ip_local_deliver_finish+0x110/0x140 [ 47.155125][ C0] ip_local_deliver+0x133/0x210 [ 47.159969][ C0] ? ip_protocol_deliver_rcu+0x420/0x420 [ 47.165676][ C0] ip_rcv_finish+0x121/0x160 [ 47.170265][ C0] ip_rcv+0x18f/0x1a0 [ 47.174236][ C0] ? ip_sublist_rcv+0x5e0/0x5e0 [ 47.179082][ C0] ? ip_local_deliver+0x210/0x210 [ 47.184093][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.189801][ C0] __netif_receive_skb+0x37/0xf0 [ 47.194731][ C0] netif_receive_skb_internal+0x59/0x190 [ 47.200354][ C0] napi_gro_receive+0x28f/0x330 [ 47.205189][ C0] receive_buf+0x284/0x30b0 [ 47.209679][ C0] ? __tsan_write8+0x32/0x40 [ 47.214260][ C0] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 47.219700][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.225317][ C0] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.230937][ C0] virtnet_poll+0x436/0x7d0 [ 47.235432][ C0] net_rx_action+0x3ae/0xa90 [ 47.240014][ C0] __do_softirq+0x115/0x33f [ 47.244503][ C0] ? takeover_tasklets+0x250/0x250 [ 47.249599][ C0] run_ksoftirqd+0x46/0x60 [ 47.253998][ C0] smpboot_thread_fn+0x37d/0x4a0 [ 47.258919][ C0] kthread+0x1d4/0x200 [ 47.262982][ C0] ? constant_test_bit.constprop.0+0x30/0x30 [ 47.268943][ C0] ? kthread_stop+0x2d0/0x2d0 [ 47.273605][ C0] ret_from_fork+0x1f/0x30 [ 47.279392][ C0] Kernel Offset: disabled [ 47.283717][ C0] Rebooting in 86400 seconds..