bugfix: segment fault when get header via ngx.req.raw_header with malformed requests.

Co-authored-by: lijunlong@openresty.com

Author: GordonMcKinney

src/ngx_http_lua_headers.c

@@ -167,6 +167,12 @@ ngx_http_lua_ngx_req_raw_header(lua_State *L)
     size = 0;
     b = c->buffer;
 
+    if (mr->request_line.len == 0) {
+        /* return empty string on invalid request */
+        lua_pushlstring(L, "", 0);
+        return 1;
+    }
+
     if (mr->request_line.data[mr->request_line.len] == CR) {
         line_break_len = 2;
 

t/104-req-raw-header.t

@@ -1017,3 +1017,36 @@ client sent invalid header line: "\x20..." while reading client request headers
 [error]
 --- skip_nginx
 3: < 1.21.1
+
+
+
+=== TEST 35: bugfix: invalid http request
+--- log_level: error
+--- http_config
+    lua_package_path "../lua-resty-core/lib/?.lua;;";
+--- config
+    location /t {
+        content_by_lua_block {
+            local sock = ngx.socket.tcp()
+            local ok, err = sock:connect("127.0.0.1", $TEST_NGINX_SERVER_PORT)
+            if not ok then
+                ngx.log(ngx.ERR, "failed to connect to memc: ", err)
+                return
+            end
+            sock:send("\n")
+            sock:close()
+
+            ngx.say("OK")
+        }
+    }
+
+    log_by_lua_block {
+        local h = ngx.req.raw_header()
+    }
+
+--- request
+GET /t
+--- response_body
+OK
+--- no_error_log
+[error]