Fix potential NULL ptr crash if compiled with DMALLOC

In the unlikely case that we are compiled with -DDMALLOC *and*
malloc() returns NULL, there is an uncaught memset() which would
crash then.  Remove the memset(), as the right the next operation
after check_malloc_return() is a mempcy() which will overwrite
the whole memory block anyway.

Trac: #586

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Message-Id: <20210402173414.14216-1-gert@greenie.muc.de>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21981.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>
(cherry picked from commit e2acfad40c0d79ce7fd431c380d7466d383bcefa)

diff --git a/src/openvpn/buffer.c b/src/openvpn/buffer.c
index b32bc8b2629a185404db37d95dafe08dcc261450..890f31a6cc547bf1f022800ed2275992dc285c87 100644 (file)
--- a/src/openvpn/buffer.c
+++ b/src/openvpn/buffer.c
@@ -709,7 +709,6 @@ string_alloc(const char *str, struct gc_arena *gc)
              */
 #ifdef DMALLOC
             ret = openvpn_dmalloc(file, line, n);
-            memset(ret, 0, n);
 #else
             ret = calloc(1, n);
 #endif