Fixed segfault in ngx_http_find_virtual_server() within xquic module

[morf]

A segfault was corrected when calling ngx_http_find_virtual_server in the xquic module. The issue originated from c->data being taken as ngx_http_connection_t while regular expressions were in use. However, for http3 connections, c->data is a pointer to ngx_http_xquic_connection_t

[drawing]

Can you show the configuration when segfault occurs?

[morf]

nginx.conf (with two servers for run regexp in ngx_http_find_virtual_server):

worker_processes 1;
daemon off;
master_process off;

error_log /dev/stdout debug;

http {

    xquic_ssl_certificate /path-to/nginx-selfsigned.crt;
    xquic_ssl_certificate_key /path-to/nginx-selfsigned.key;

    xquic_log_file /dev/stdout;
    xquic_log_level debug;

    server {
        listen 8081 reuseport xquic;
        server_name "~^test\.com$";

        location / {
            return 200 "ok\n";
        }
    }

    server {
        listen 8081 xquic;
        server_name "~^test2\.com$";

        location / {
            return 200 "ok\n";
        }
    }
}

events { }

run:

gdb --arg ./objs/nginx -p /tmp/ -c /path-to/nginx.conf

command:

curl -k -v --resolve test.com:8081:127.0.0.1 --http3-only 'https://test.com:8081'

segfault:

2023/07/20 21:30:13 [warn] 8095#0: |xquic|lib[debug] |scid:a96fcd03d7d27c468579261d|xqc_h3_stream_process_bidi|xqc_h3_stream_process_bidi|10|1||
2023/07/20 21:30:13 [debug] 8095#0: |xquic|xqc_http_v3_request_create_notify|
2023/07/20 21:30:13 [debug] 8095#0: |xquic|xqc_http_v3_request_create_notify in connection|0000AAAB00974120|

Program received signal SIGSEGV, Segmentation fault.
ngx_http_v3_create_stream (stream_id=0, h3c=0xaaab00974120) at /path/tengine/modules/ngx_http_xquic_module/ngx_http_v3_stream.c:112
112         ngx_memzero(rev, sizeof(ngx_event_t));
(gdb)

problem code:

tengine/src/http/ngx_http_request.c

Line 2505 in 11f2eb4

hc = c->data;