[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.823003][ T25] audit: type=1800 audit(1571788615.674:25): pid=7022 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.859974][ T25] audit: type=1800 audit(1571788615.674:26): pid=7022 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.892627][ T25] audit: type=1800 audit(1571788615.674:27): pid=7022 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 '10.128.0.220' (ECDSA) to the list of known hosts. 2019/10/22 23:57:06 fuzzer started 2019/10/22 23:57:08 dialing manager at 10.128.0.105:33369 2019/10/22 23:57:08 syscalls: 2524 2019/10/22 23:57:08 code coverage: enabled 2019/10/22 23:57:08 comparison tracing: enabled 2019/10/22 23:57:08 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:57:08 setuid sandbox: enabled 2019/10/22 23:57:08 namespace sandbox: enabled 2019/10/22 23:57:08 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:57:08 fault injection: enabled 2019/10/22 23:57:08 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:57:08 net packet injection: enabled 2019/10/22 23:57:08 net device setup: enabled 2019/10/22 23:57:08 concurrency sanitizer: enabled syzkaller login: [ 51.855082][ C1] ================================================================== [ 51.863207][ C1] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 51.871177][ C1] [ 51.873494][ C1] read to 0xffff88812223c12c of 4 bytes by task 7180 on cpu 0: [ 51.881020][ C1] tcp_grow_window.isra.0+0x6b/0x480 [ 51.886290][ C1] tcp_event_data_recv+0x68f/0x990 [ 51.891387][ C1] tcp_rcv_established+0xbfe/0xf50 [ 51.896480][ C1] tcp_v4_do_rcv+0x381/0x4e0 [ 51.901053][ C1] __release_sock+0x135/0x1e0 [ 51.905712][ C1] release_sock+0x61/0x160 [ 51.910114][ C1] tcp_recvmsg+0x63b/0x1a30 [ 51.914599][ C1] inet_recvmsg+0xbb/0x250 [ 51.918998][ C1] sock_recvmsg+0x92/0xb0 [ 51.923312][ C1] sock_read_iter+0x15f/0x1e0 [ 51.927974][ C1] new_sync_read+0x389/0x4f0 [ 51.932557][ C1] __vfs_read+0xb1/0xc0 [ 51.936696][ C1] vfs_read+0x143/0x2c0 [ 51.940832][ C1] ksys_read+0xd5/0x1b0 [ 51.944963][ C1] [ 51.947281][ C1] write to 0xffff88812223c12c of 4 bytes by interrupt on cpu 1: [ 51.955155][ C1] tcp_add_backlog+0x4a0/0xcc0 [ 51.960085][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 51.964584][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 51.970114][ C1] ip_local_deliver_finish+0x110/0x140 [ 51.975570][ C1] ip_local_deliver+0x133/0x210 [ 51.980405][ C1] ip_rcv_finish+0x121/0x160 [ 51.984980][ C1] ip_rcv+0x18f/0x1a0 [ 51.988948][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 51.995345][ C1] __netif_receive_skb+0x37/0xf0 [ 52.000965][ C1] netif_receive_skb_internal+0x59/0x190 [ 52.007362][ C1] napi_gro_receive+0x28f/0x330 [ 52.012198][ C1] receive_buf+0x284/0x30b0 [ 52.016683][ C1] virtnet_poll+0x436/0x7d0 [ 52.021333][ C1] [ 52.024002][ C1] Reported by Kernel Concurrency Sanitizer on: [ 52.030138][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 52.037501][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.047537][ C1] ================================================================== [ 52.055587][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 52.062159][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 52.069506][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.079560][ C1] Call Trace: [ 52.082839][ C1] dump_stack+0xf5/0x159 [ 52.087082][ C1] panic+0x210/0x640 [ 52.090961][ C1] ? __netif_receive_skb+0x37/0xf0 [ 52.096054][ C1] ? vprintk_func+0x8d/0x140 [ 52.100638][ C1] kcsan_report.cold+0xc/0x10 [ 52.105301][ C1] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 52.110836][ C1] __tsan_write4+0x32/0x40 [ 52.115241][ C1] tcp_add_backlog+0x4a0/0xcc0 [ 52.119998][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 52.124485][ C1] ? __tsan_read8+0x2c/0x30 [ 52.128982][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 52.134343][ C1] ip_local_deliver_finish+0x110/0x140 [ 52.140137][ C1] ip_local_deliver+0x133/0x210 [ 52.144974][ C1] ? ip_protocol_deliver_rcu+0x420/0x420 [ 52.150594][ C1] ip_rcv_finish+0x121/0x160 [ 52.155167][ C1] ip_rcv+0x18f/0x1a0 [ 52.159134][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 52.163967][ C1] ? ip_local_deliver+0x210/0x210 [ 52.169063][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 52.174767][ C1] __netif_receive_skb+0x37/0xf0 [ 52.179691][ C1] netif_receive_skb_internal+0x59/0x190 [ 52.185308][ C1] napi_gro_receive+0x28f/0x330 [ 52.190145][ C1] receive_buf+0x284/0x30b0 [ 52.194632][ C1] ? __tsan_write8+0x32/0x40 [ 52.199227][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 52.204667][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.210291][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.215909][ C1] virtnet_poll+0x436/0x7d0 [ 52.220941][ C1] net_rx_action+0x3ae/0xa90 [ 52.225536][ C1] __do_softirq+0x115/0x33f [ 52.230030][ C1] ? takeover_tasklets+0x250/0x250 [ 52.235125][ C1] run_ksoftirqd+0x46/0x60 [ 52.239526][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 52.244451][ C1] kthread+0x1d4/0x200 [ 52.248503][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 52.254465][ C1] ? kthread_stop+0x2d0/0x2d0 [ 52.259127][ C1] ret_from_fork+0x1f/0x30 [ 52.264784][ C1] Kernel Offset: disabled [ 52.269143][ C1] Rebooting in 86400 seconds..