Unify calloc (its the same thing regardless of the underlying

malloc implementation).  Fix problem reported to bugtraq about
problems with integer overflow that can occur during the
computation of the memory region size by calloc (and similar
functions) which could result in a subsequent buffer overflow.
 -Erik

1 files changed, 32 insertions, 17 deletions

diff --git a/libc/stdlib/malloc-930716/calloc.c b/libc/stdlib/malloc-930716/calloc.c
index 55d22ac11..e97db496d 100644
--- a/libc/stdlib/malloc-930716/calloc.c
+++ b/libc/stdlib/malloc-930716/calloc.c
@@ -1,24 +1,39 @@
-/* calloc.c - C standard library routine.
-   Copyright (c) 1989, 1993  Michael J. Haertel
-   You may redistribute this library under the terms of the
-   GNU Library General Public License (version 2 or any later
-   version) as published by the Free Software Foundation.
-   THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT ANY EXPRESS OR IMPLIED
-   WARRANTY.  IN PARTICULAR, THE AUTHOR MAKES NO REPRESENTATION OR
-   WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY OF THIS
-   SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE. */
+/* vi: set sw=4 ts=4: */
+/* calloc for uClibc
+ *
+ * Copyright (C) 2002 by Erik Andersen <andersen@uclibc.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Library General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Library General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
 
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 
-/* Allocate space for the given number of elements of the given
-   size, initializing the whole region to binary zeroes. */
-void * calloc(size_t nelem, size_t size)
+void * calloc(size_t nmemb, size_t lsize)
 {
-    void *result;
+	void *result;
+	size_t size=lsize * nmemb;
 
-    result = malloc(size * nelem);
-    if (result)
-	memset(result, 0, nelem * size);
-    return result;
+	/* guard vs integer overflow */
+	if (lsize != (size / nmemb)) {
+		__set_errno(ENOMEM);
+		return NULL;
+	}
+	if ((result=malloc(size))) {
+		memset(result, 0, size);
+	}
+	return result;
 }