From: Sergey Poznyakoff <gray@gnu.org>
Date: Thu, 20 Dec 2018 15:53:40 +0000 (+0200)
Subject: Fix improper memory access
X-Git-Tag: release_1_31~11
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eae48289c0848c5812644f20dbb1b39fb117a8f6;p=thirdparty%2Ftar.git

Fix improper memory access

Bug reported in
  http://lists.gnu.org/archive/html/bug-tar/2018-12/msg00009.html

* src/transform.c (parse_transform_expr): Check if re is not empty
before accessing its last byte.
---

diff --git a/src/transform.c b/src/transform.c
index 6ef0da6d..bbf20335 100644
--- a/src/transform.c
+++ b/src/transform.c
@@ -273,7 +273,7 @@ parse_transform_expr (const char *expr)
       USAGE_ERROR ((0, 0, _("Invalid transform expression: %s"), errbuf));
     }
 
-  if (str[0] == '^' || str[strlen (str) - 1] == '$')
+  if (str[0] == '^' || (i > 2 && str[i - 3] == '$'))
     tf->transform_type = transform_first;
 
   free (str);