[nginx] Proxy: fixed possible uninitialized memory access.

[Valentin Bartenev]

details:   http://hg.nginx.org/nginx/rev/fbfdf8017748
branches:  
changeset: 5676:fbfdf8017748
user:      Valentin Bartenev <vbart at nginx.com>
date:      Mon Nov 18 03:06:45 2013 +0400
description:
Proxy: fixed possible uninitialized memory access.

The ngx_http_proxy_rewrite_cookie() function expects the value of the
"Set-Cookie" header to be null-terminated, and for headers obtained
from proxied server it is usually true.

Now the ngx_http_proxy_rewrite() function preserves the null character
while rewriting headers.

This fixes accessing memory outside of rewritten value if both the
"proxy_cookie_path" and "proxy_cookie_domain" directives are used in
the same location.

diffstat:

 src/http/modules/ngx_http_proxy_module.c |  6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

diffs (30 lines):

diff -r 1710bf72243e -r fbfdf8017748 src/http/modules/ngx_http_proxy_module.c
--- a/src/http/modules/ngx_http_proxy_module.c	Thu Apr 24 20:50:10 2014 +0400
+++ b/src/http/modules/ngx_http_proxy_module.c	Mon Nov 18 03:06:45 2013 +0400
@@ -2365,7 +2365,7 @@ ngx_http_proxy_rewrite(ngx_http_request_
 
     if (replacement->len > len) {
 
-        data = ngx_pnalloc(r->pool, new_len);
+        data = ngx_pnalloc(r->pool, new_len + 1);
         if (data == NULL) {
             return NGX_ERROR;
         }
@@ -2374,7 +2374,7 @@ ngx_http_proxy_rewrite(ngx_http_request_
         p = ngx_copy(p, replacement->data, replacement->len);
 
         ngx_memcpy(p, h->value.data + prefix + len,
-                   h->value.len - len - prefix);
+                   h->value.len - len - prefix + 1);
 
         h->value.data = data;
 
@@ -2383,7 +2383,7 @@ ngx_http_proxy_rewrite(ngx_http_request_
                      replacement->len);
 
         ngx_memmove(p, h->value.data + prefix + len,
-                    h->value.len - len - prefix);
+                    h->value.len - len - prefix + 1);
     }
 
     h->value.len = new_len;