# HG changeset patch
# User Sergey Kandaurov <pluknet@nginx.com>
# Date 1588954756 -10800
# Node ID 028b16e2798f8ec4c6a3d042a6ac8a07f7262690
# Parent  716eddd74bc2831537f5b3f7ecd16ad3e516d043
Variables: fixed buffer over-read when evaluating "$arg_".

diff --git a/src/http/ngx_http_variables.c b/src/http/ngx_http_variables.c
--- a/src/http/ngx_http_variables.c
+++ b/src/http/ngx_http_variables.c
@@ -1075,7 +1075,7 @@ ngx_http_variable_argument(ngx_http_requ
     len = name->len - (sizeof("arg_") - 1);
     arg = name->data + sizeof("arg_") - 1;
 
-    if (ngx_http_arg(r, arg, len, &value) != NGX_OK) {
+    if (len == 0 || ngx_http_arg(r, arg, len, &value) != NGX_OK) {
         v->not_found = 1;
         return NGX_OK;
     }