From 38a50c517836b12720b963c498e303d677ec434c Mon Sep 17 00:00:00 2001
Message-Id: <38a50c517836b12720b963c498e303d677ec434c@dist-git>
From: Martin Kletzander <mkletzan@redhat.com>
Date: Wed, 31 Jan 2018 16:32:23 +0100
Subject: [PATCH] util: Fix leak in virStringTrimOptionalNewline

https://bugzilla.redhat.com/show_bug.cgi?id=1289368

Do not access any data if strlen() == 0.

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
(cherry picked from commit ea7b2a6d04f5c354b1cda941362ba8ac42e92278)
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
---
 src/util/virstring.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/util/virstring.c b/src/util/virstring.c
index eac4774b53..b2ebce27ff 100644
--- a/src/util/virstring.c
+++ b/src/util/virstring.c
@@ -1394,9 +1394,13 @@ virStringEncodeBase64(const uint8_t *buf, size_t buflen)
  */
 void virStringTrimOptionalNewline(char *str)
 {
-    char *tmp = str + strlen(str) - 1;
-    if (*tmp == '\n')
-        *tmp = '\0';
+    size_t len = strlen(str);
+
+    if (!len)
+        return;
+
+    if (str[len - 1] == '\n')
+        str[len - 1] = '\0';
 }
 
 
-- 
2.16.1