[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.052638][ T26] audit: type=1800 audit(1571762366.038:25): pid=7029 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.092659][ T26] audit: type=1800 audit(1571762366.048:26): pid=7029 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.127940][ T26] audit: type=1800 audit(1571762366.048:27): pid=7029 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 '10.128.10.30' (ECDSA) to the list of known hosts. 2019/10/22 16:39:37 fuzzer started 2019/10/22 16:39:37 dialing manager at 10.128.0.105:33369 2019/10/22 16:39:37 syscalls: 2524 2019/10/22 16:39:37 code coverage: enabled 2019/10/22 16:39:37 comparison tracing: enabled 2019/10/22 16:39:37 extra coverage: extra coverage is not supported by the kernel 2019/10/22 16:39:37 setuid sandbox: enabled 2019/10/22 16:39:37 namespace sandbox: enabled 2019/10/22 16:39:37 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 16:39:37 fault injection: enabled 2019/10/22 16:39:37 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 16:39:37 net packet injection: enabled 2019/10/22 16:39:37 net device setup: enabled 2019/10/22 16:39:37 concurrency sanitizer: enabled syzkaller login: [ 47.133420][ T7180] ================================================================== [ 47.141660][ T7180] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 47.149754][ T7180] [ 47.152080][ T7180] write to 0xffff888126a6612c of 4 bytes by interrupt on cpu 0: [ 47.159706][ T7180] tcp_add_backlog+0x4a0/0xcc0 [ 47.164451][ T7180] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.168932][ T7180] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.174279][ T7180] ip_local_deliver_finish+0x110/0x140 [ 47.179709][ T7180] ip_local_deliver+0x133/0x210 [ 47.185676][ T7180] ip_rcv_finish+0x121/0x160 [ 47.190242][ T7180] ip_rcv+0x18f/0x1a0 [ 47.194210][ T7180] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.199913][ T7180] __netif_receive_skb+0x37/0xf0 [ 47.204824][ T7180] netif_receive_skb_internal+0x59/0x190 [ 47.210440][ T7180] napi_gro_receive+0x28f/0x330 [ 47.215280][ T7180] receive_buf+0x284/0x30b0 [ 47.219759][ T7180] virtnet_poll+0x436/0x7d0 [ 47.224242][ T7180] net_rx_action+0x3ae/0xa90 [ 47.228927][ T7180] [ 47.231780][ T7180] read to 0xffff888126a6612c of 4 bytes by task 7180 on cpu 1: [ 47.239307][ T7180] tcp_grow_window.isra.0+0x6b/0x480 [ 47.244590][ T7180] tcp_event_data_recv+0x68f/0x990 [ 47.249700][ T7180] tcp_rcv_established+0xbfe/0xf50 [ 47.254792][ T7180] tcp_v4_do_rcv+0x381/0x4e0 [ 47.259360][ T7180] __release_sock+0x135/0x1e0 [ 47.264013][ T7180] release_sock+0x61/0x160 [ 47.268416][ T7180] tcp_recvmsg+0x63b/0x1a30 [ 47.272902][ T7180] inet_recvmsg+0xbb/0x250 [ 47.277316][ T7180] sock_recvmsg+0x92/0xb0 [ 47.281652][ T7180] sock_read_iter+0x15f/0x1e0 [ 47.286319][ T7180] new_sync_read+0x389/0x4f0 [ 47.290884][ T7180] __vfs_read+0xb1/0xc0 [ 47.295018][ T7180] vfs_read+0x143/0x2c0 [ 47.299151][ T7180] [ 47.301452][ T7180] Reported by Kernel Concurrency Sanitizer on: [ 47.307668][ T7180] CPU: 1 PID: 7180 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.315104][ T7180] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.325138][ T7180] ================================================================== [ 47.333473][ T7180] Kernel panic - not syncing: panic_on_warn set ... [ 47.340050][ T7180] CPU: 1 PID: 7180 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.347484][ T7180] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.357607][ T7180] Call Trace: [ 47.360882][ T7180] dump_stack+0xf5/0x159 [ 47.365108][ T7180] panic+0x210/0x640 [ 47.368984][ T7180] ? sock_recvmsg+0x92/0xb0 [ 47.374855][ T7180] ? vprintk_func+0x8d/0x140 [ 47.379436][ T7180] kcsan_report.cold+0xc/0x10 [ 47.384102][ T7180] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.389665][ T7180] __tsan_read4+0x2c/0x30 [ 47.393997][ T7180] tcp_grow_window.isra.0+0x6b/0x480 [ 47.399273][ T7180] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.404892][ T7180] tcp_event_data_recv+0x68f/0x990 [ 47.409997][ T7180] tcp_rcv_established+0xbfe/0xf50 [ 47.415112][ T7180] ? ipv4_dst_check+0xc6/0xf0 [ 47.419777][ T7180] tcp_v4_do_rcv+0x381/0x4e0 [ 47.424371][ T7180] __release_sock+0x135/0x1e0 [ 47.429217][ T7180] release_sock+0x61/0x160 [ 47.433644][ T7180] tcp_recvmsg+0x63b/0x1a30 [ 47.438140][ T7180] inet_recvmsg+0xbb/0x250 [ 47.442537][ T7180] ? __tsan_read8+0x2c/0x30 [ 47.447105][ T7180] ? inet_sendpage+0x100/0x100 [ 47.451860][ T7180] sock_recvmsg+0x92/0xb0 [ 47.456181][ T7180] sock_read_iter+0x15f/0x1e0 [ 47.460868][ T7180] new_sync_read+0x389/0x4f0 [ 47.465448][ T7180] __vfs_read+0xb1/0xc0 [ 47.469584][ T7180] vfs_read+0x143/0x2c0 [ 47.473720][ T7180] ksys_read+0xd5/0x1b0 [ 47.477869][ T7180] __x64_sys_read+0x4c/0x60 [ 47.482354][ T7180] do_syscall_64+0xcc/0x370 [ 47.486849][ T7180] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.492723][ T7180] RIP: 0033:0x47c530 [ 47.496684][ T7180] 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 [ 47.516445][ T7180] RSP: 002b:000000c4204fb7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.524830][ T7180] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.532784][ T7180] RDX: 0000000000001000 RSI: 000000c4203cc000 RDI: 0000000000000003 [ 47.540740][ T7180] RBP: 000000c4204fb830 R08: 0000000000000000 R09: 0000000000000000 [ 47.548698][ T7180] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 47.556659][ T7180] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.565976][ T7180] Kernel Offset: disabled [ 47.570303][ T7180] Rebooting in 86400 seconds..