[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 38.262160][ T26] audit: type=1800 audit(1571782603.880:25): pid=7135 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 38.307767][ T26] audit: type=1800 audit(1571782603.880:26): pid=7135 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 38.329153][ T26] audit: type=1800 audit(1571782603.880:27): pid=7135 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 '10.128.0.141' (ECDSA) to the list of known hosts. 2019/10/22 22:16:53 fuzzer started 2019/10/22 22:16:55 dialing manager at 10.128.0.105:33369 2019/10/22 22:16:55 syscalls: 2524 2019/10/22 22:16:55 code coverage: enabled 2019/10/22 22:16:55 comparison tracing: enabled 2019/10/22 22:16:55 extra coverage: extra coverage is not supported by the kernel 2019/10/22 22:16:55 setuid sandbox: enabled 2019/10/22 22:16:55 namespace sandbox: enabled 2019/10/22 22:16:55 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 22:16:55 fault injection: enabled 2019/10/22 22:16:55 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 22:16:55 net packet injection: enabled 2019/10/22 22:16:55 net device setup: enabled 2019/10/22 22:16:55 concurrency sanitizer: enabled syzkaller login: [ 50.743077][ T7289] ================================================================== [ 50.751258][ T7289] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 50.759312][ T7289] [ 50.761669][ T7289] write to 0xffff888122f852ec of 4 bytes by interrupt on cpu 0: [ 50.769416][ T7289] tcp_add_backlog+0x4a0/0xcc0 [ 50.774166][ T7289] tcp_v4_rcv+0x1a60/0x1bb0 [ 50.778649][ T7289] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.784148][ T7289] ip_local_deliver_finish+0x110/0x140 [ 50.789591][ T7289] ip_local_deliver+0x133/0x210 [ 50.794421][ T7289] ip_rcv_finish+0x121/0x160 [ 50.798993][ T7289] ip_rcv+0x18f/0x1a0 [ 50.802980][ T7289] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.808727][ T7289] __netif_receive_skb+0x37/0xf0 [ 50.813683][ T7289] netif_receive_skb_internal+0x59/0x190 [ 50.819421][ T7289] napi_gro_receive+0x28f/0x330 [ 50.824365][ T7289] receive_buf+0x284/0x30b0 [ 50.828875][ T7289] virtnet_poll+0x436/0x7d0 [ 50.833358][ T7289] net_rx_action+0x3ae/0xa90 [ 50.838004][ T7289] [ 50.840317][ T7289] read to 0xffff888122f852ec of 4 bytes by task 7289 on cpu 1: [ 50.847839][ T7289] tcp_grow_window.isra.0+0x6b/0x480 [ 50.853116][ T7289] tcp_event_data_recv+0x68f/0x990 [ 50.858222][ T7289] tcp_rcv_established+0xbfe/0xf50 [ 50.864492][ T7289] tcp_v4_do_rcv+0x381/0x4e0 [ 50.869078][ T7289] __release_sock+0x135/0x1e0 [ 50.873736][ T7289] release_sock+0x61/0x160 [ 50.878136][ T7289] tcp_recvmsg+0x63b/0x1a30 [ 50.882622][ T7289] inet_recvmsg+0xbb/0x250 [ 50.887019][ T7289] sock_recvmsg+0x92/0xb0 [ 50.891328][ T7289] sock_read_iter+0x15f/0x1e0 [ 50.895983][ T7289] new_sync_read+0x389/0x4f0 [ 50.900567][ T7289] __vfs_read+0xb1/0xc0 [ 50.904731][ T7289] vfs_read+0x143/0x2c0 [ 50.908861][ T7289] [ 50.911180][ T7289] Reported by Kernel Concurrency Sanitizer on: [ 50.917316][ T7289] CPU: 1 PID: 7289 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.924762][ T7289] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.934924][ T7289] ================================================================== [ 50.946822][ T7289] Kernel panic - not syncing: panic_on_warn set ... [ 50.954172][ T7289] CPU: 1 PID: 7289 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.961603][ T7289] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.971639][ T7289] Call Trace: [ 50.974931][ T7289] dump_stack+0xf5/0x159 [ 50.979163][ T7289] panic+0x210/0x640 [ 50.983062][ T7289] ? sock_recvmsg+0x92/0xb0 [ 50.987548][ T7289] ? vprintk_func+0x8d/0x140 [ 50.992296][ T7289] kcsan_report.cold+0xc/0x10 [ 50.996958][ T7289] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 51.002501][ T7289] __tsan_read4+0x2c/0x30 [ 51.006830][ T7289] tcp_grow_window.isra.0+0x6b/0x480 [ 51.012095][ T7289] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 51.017711][ T7289] tcp_event_data_recv+0x68f/0x990 [ 51.022822][ T7289] tcp_rcv_established+0xbfe/0xf50 [ 51.027920][ T7289] ? ipv4_dst_check+0xc6/0xf0 [ 51.032609][ T7289] tcp_v4_do_rcv+0x381/0x4e0 [ 51.037180][ T7289] __release_sock+0x135/0x1e0 [ 51.041982][ T7289] release_sock+0x61/0x160 [ 51.046405][ T7289] tcp_recvmsg+0x63b/0x1a30 [ 51.050911][ T7289] inet_recvmsg+0xbb/0x250 [ 51.055311][ T7289] ? __tsan_read8+0x2c/0x30 [ 51.059813][ T7289] ? inet_sendpage+0x100/0x100 [ 51.064562][ T7289] sock_recvmsg+0x92/0xb0 [ 51.068875][ T7289] sock_read_iter+0x15f/0x1e0 [ 51.073555][ T7289] new_sync_read+0x389/0x4f0 [ 51.078130][ T7289] __vfs_read+0xb1/0xc0 [ 51.082284][ T7289] vfs_read+0x143/0x2c0 [ 51.086467][ T7289] ksys_read+0xd5/0x1b0 [ 51.090608][ T7289] __x64_sys_read+0x4c/0x60 [ 51.095121][ T7289] do_syscall_64+0xcc/0x370 [ 51.099625][ T7289] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 51.105496][ T7289] RIP: 0033:0x47c530 [ 51.109381][ T7289] 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 [ 51.129073][ T7289] RSP: 002b:000000c42048f7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 51.137482][ T7289] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 51.145473][ T7289] RDX: 0000000000001000 RSI: 000000c420312000 RDI: 0000000000000003 [ 51.153613][ T7289] RBP: 000000c42048f830 R08: 0000000000000000 R09: 0000000000000000 [ 51.161585][ T7289] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000002 [ 51.170408][ T7289] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 51.180146][ T7289] Kernel Offset: disabled [ 51.184480][ T7289] Rebooting in 86400 seconds..