[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
[ 33.594888][ T26] audit: type=1800 audit(1572773173.579:25): pid=7052 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0
[ 33.614577][ T26] audit: type=1800 audit(1572773173.579:26): pid=7052 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0
[ 33.636412][ T26] audit: type=1800 audit(1572773173.579:27): pid=7052 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[1G[[32m ok [39;49m8[?25h[?0c.
[....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c.
Debian GNU/Linux 7 syzkaller ttyS0
Warning: Permanently added '10.128.0.109' (ECDSA) to the list of known hosts.
2019/11/03 09:26:24 fuzzer started
2019/11/03 09:26:25 dialing manager at 10.128.0.105:43165
2019/11/03 09:26:25 syscalls: 2554
2019/11/03 09:26:25 code coverage: enabled
2019/11/03 09:26:25 comparison tracing: enabled
2019/11/03 09:26:25 extra coverage: extra coverage is not supported by the kernel
2019/11/03 09:26:25 setuid sandbox: enabled
2019/11/03 09:26:25 namespace sandbox: enabled
2019/11/03 09:26:25 Android sandbox: /sys/fs/selinux/policy does not exist
2019/11/03 09:26:25 fault injection: enabled
2019/11/03 09:26:25 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled
2019/11/03 09:26:25 net packet injection: enabled
2019/11/03 09:26:25 net device setup: enabled
2019/11/03 09:26:25 concurrency sanitizer: enabled
2019/11/03 09:26:26 adding functions to KCSAN blacklist: '__hrtimer_run_queues' 'task_dump_owner' 'tick_sched_do_timer'
syzkaller login: [ 46.471871][ C1] ==================================================================
[ 46.479978][ C1] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog
[ 46.487676][ C1]
[ 46.490003][ C1] read to 0xffff888122eb016c of 4 bytes by task 7202 on cpu 0:
[ 46.497536][ C1] __tcp_select_window+0x6b/0x4d0
[ 46.502539][ C1] __tcp_transmit_skb+0x700/0x1d60
[ 46.507630][ C1] __tcp_send_ack+0x246/0x300
[ 46.512286][ C1] tcp_send_ack+0x34/0x40
[ 46.516596][ C1] tcp_cleanup_rbuf+0x130/0x360
[ 46.521427][ C1] tcp_recvmsg+0x633/0x1a30
[ 46.525918][ C1] inet_recvmsg+0xbb/0x250
[ 46.530333][ C1] sock_recvmsg+0x92/0xb0
[ 46.534645][ C1] sock_read_iter+0x15f/0x1e0
[ 46.539306][ C1] new_sync_read+0x389/0x4f0
[ 46.543877][ C1] __vfs_read+0xb1/0xc0
[ 46.548019][ C1] vfs_read+0x143/0x2c0
[ 46.552155][ C1] ksys_read+0xd5/0x1b0
[ 46.556292][ C1] __x64_sys_read+0x4c/0x60
[ 46.560767][ C1]
[ 46.563083][ C1] write to 0xffff888122eb016c of 4 bytes by interrupt on cpu 1:
[ 46.570694][ C1] tcp_add_backlog+0x4a0/0xcc0
[ 46.575440][ C1] tcp_v4_rcv+0x1a60/0x1bb0
[ 46.579926][ C1] ip_protocol_deliver_rcu+0x4d/0x420
[ 46.585280][ C1] ip_local_deliver_finish+0x110/0x140
[ 46.590728][ C1] ip_local_deliver+0x133/0x210
[ 46.595578][ C1] ip_rcv_finish+0x121/0x160
[ 46.600147][ C1] ip_rcv+0x18f/0x1a0
[ 46.604127][ C1] __netif_receive_skb_one_core+0xa7/0xe0
[ 46.609831][ C1] __netif_receive_skb+0x37/0xf0
[ 46.614752][ C1] netif_receive_skb_internal+0x59/0x190
[ 46.620366][ C1] napi_gro_receive+0x28f/0x330
[ 46.625197][ C1] receive_buf+0x284/0x30b0
[ 46.629682][ C1] virtnet_poll+0x436/0x7d0
[ 46.634160][ C1]
[ 46.636466][ C1] Reported by Kernel Concurrency Sanitizer on:
[ 46.642601][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.4.0-rc3+ #0
[ 46.649686][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 46.659740][ C1] ==================================================================
[ 46.667782][ C1] Kernel panic - not syncing: panic_on_warn set ...
[ 46.674351][ C1] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.4.0-rc3+ #0
[ 46.681441][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 46.691491][ C1] Call Trace:
[ 46.694754][ C1]
[ 46.697595][ C1] dump_stack+0xf5/0x159
[ 46.701833][ C1] panic+0x210/0x640
[ 46.705714][ C1] ? __netif_receive_skb+0x37/0xf0
[ 46.710810][ C1] ? vprintk_func+0x8d/0x140
[ 46.715389][ C1] kcsan_report.cold+0xc/0x10
[ 46.720052][ C1] __kcsan_setup_watchpoint+0x32e/0x4a0
[ 46.725587][ C1] __tsan_write4+0x32/0x40
[ 46.730000][ C1] tcp_add_backlog+0x4a0/0xcc0
[ 46.734758][ C1] tcp_v4_rcv+0x1a60/0x1bb0
[ 46.739253][ C1] ? __tsan_read8+0x2c/0x30
[ 46.743748][ C1] ip_protocol_deliver_rcu+0x4d/0x420
[ 46.749104][ C1] ip_local_deliver_finish+0x110/0x140
[ 46.754558][ C1] ip_local_deliver+0x133/0x210
[ 46.759392][ C1] ? ip_protocol_deliver_rcu+0x420/0x420
[ 46.765019][ C1] ip_rcv_finish+0x121/0x160
[ 46.769595][ C1] ip_rcv+0x18f/0x1a0
[ 46.773560][ C1] ? ip_sublist_rcv+0x5e0/0x5e0
[ 46.778393][ C1] ? ip_local_deliver+0x210/0x210
[ 46.783399][ C1] __netif_receive_skb_one_core+0xa7/0xe0
[ 46.789101][ C1] __netif_receive_skb+0x37/0xf0
[ 46.794111][ C1] netif_receive_skb_internal+0x59/0x190
[ 46.799728][ C1] napi_gro_receive+0x28f/0x330
[ 46.804564][ C1] receive_buf+0x284/0x30b0
[ 46.809050][ C1] ? __tsan_write8+0x32/0x40
[ 46.813630][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0
[ 46.819080][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0
[ 46.824702][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0
[ 46.830319][ C1] virtnet_poll+0x436/0x7d0
[ 46.834820][ C1] net_rx_action+0x3ae/0xa90
[ 46.839416][ C1] __do_softirq+0x115/0x33f
[ 46.843908][ C1] irq_exit+0xbb/0xe0
[ 46.847871][ C1] do_IRQ+0xa6/0x180
[ 46.851747][ C1] common_interrupt+0xf/0xf
[ 46.856238][ C1]
[ 46.859163][ C1] RIP: 0010:native_safe_halt+0xe/0x10
[ 46.864521][ C1] Code: 90 90 90 90 90 90 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d fc b2 4b 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d ec b2 4b 00 fb f4 90 55 48 89 e5 41 55 41 54 53 e8 72 12 a4 fc e8 6d 8e b8 fd 0f
[ 46.884105][ C1] RSP: 0018:ffffc90000cd3e48 EFLAGS: 00000282 ORIG_RAX: ffffffffffffffde
[ 46.892507][ C1] RAX: d916872b020cc5e5 RBX: ffff88812b3850c0 RCX: 00000000000006a5
[ 46.900462][ C1] RDX: 00000000006bc1f0 RSI: 020c49ba5e353f7d RDI: ffffffff85a563b8
[ 46.908415][ C1] RBP: ffffc90000cd3e80 R08: 0000000000000000 R09: 0000ffff85a563bf
[ 46.916381][ C1] R10: 00000000aaaaaaab R11: ffffffff86045cc8 R12: 0000000000000001
[ 46.924334][ C1] R13: ffff88812b3850c0 R14: 0000000000000000 R15: 0000000000000000
[ 46.932304][ C1] ? default_idle+0x50/0x230
[ 46.936883][ C1] arch_cpu_idle+0x1f/0x30
[ 46.941284][ C1] default_idle_call+0x1e/0x40
[ 46.946031][ C1] do_idle+0x1af/0x280
[ 46.950081][ C1] ? complete+0x44/0x50
[ 46.954225][ C1] cpu_startup_entry+0x1b/0x20
[ 46.958984][ C1] start_secondary+0x208/0x260
[ 46.963734][ C1] secondary_startup_64+0xa4/0xb0
[ 46.969849][ C1] Kernel Offset: disabled
[ 46.974166][ C1] Rebooting in 86400 seconds..