[nginx] svn commit: r4611 - trunk/src/core

[ru at nginx.com]

Author: ru
Date: 2012-04-26 12:58:42 +0000 (Thu, 26 Apr 2012)
New Revision: 4611
URL: http://trac.nginx.org/nginx/changeset/4611/nginx

Log:
Fixed segmentation fault in ngx_resolver_create_name_query().

If name passed for resolution was { 0, NULL } (e.g. as a result
of name server returning CNAME pointing to ".") pointer wrapped
to (void *) -1 resulting in segmentation fault on an attempt to
dereference it.

Reported by Lanshun Zhou.


Modified:
   trunk/src/core/ngx_resolver.c

Modified: trunk/src/core/ngx_resolver.c
===================================================================
--- trunk/src/core/ngx_resolver.c	2012-04-26 11:20:29 UTC (rev 4610)
+++ trunk/src/core/ngx_resolver.c	2012-04-26 12:58:42 UTC (rev 4611)
@@ -1834,6 +1834,10 @@
     p--;
     *p-- = '\0';
 
+    if (ctx->name.len == 0)  {
+        return NGX_DECLINED;
+    }
+
     for (s = ctx->name.data + ctx->name.len - 1; s >= ctx->name.data; s--) {
         if (*s != '.') {
             *p = *s;