CVS commit: src/lib/libc/stdlib

[Matthias Scheler]

Module Name:    src
Committed By:   tron
Date:           Sat Oct  2 16:56:03 UTC 2010

Modified Files:
        src/lib/libc/stdlib: putenv.c setenv.c

Log Message:
Restore binary compatibility with application which use putenv(3) on
contant strings (e.g. postdrop(1)):
- Don't write to the environment string passed to putenv(3).
- Don't overwrite the value of an existing in setenv(3) unless the memory
  was actually allocated by setenv(3).


To generate a diff of this commit:
cvs rdiff -u -r1.14 -r1.15 src/lib/libc/stdlib/putenv.c
cvs rdiff -u -r1.39 -r1.40 src/lib/libc/stdlib/setenv.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/lib/libc/stdlib/putenv.c
diff -u src/lib/libc/stdlib/putenv.c:1.14 src/lib/libc/stdlib/putenv.c:1.15
--- src/lib/libc/stdlib/putenv.c:1.14	Sat Oct  2 10:05:55 2010
+++ src/lib/libc/stdlib/putenv.c	Sat Oct  2 16:56:03 2010
@@ -1,4 +1,4 @@
-/*	$NetBSD: putenv.c,v 1.14 2010/10/02 10:05:55 tron Exp $	*/
+/*	$NetBSD: putenv.c,v 1.15 2010/10/02 16:56:03 tron Exp $	*/
 
 /*-
  * Copyright (c) 1988, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)putenv.c	8.2 (Berkeley) 3/27/94";
 #else
-__RCSID("$NetBSD: putenv.c,v 1.14 2010/10/02 10:05:55 tron Exp $");
+__RCSID("$NetBSD: putenv.c,v 1.15 2010/10/02 16:56:03 tron Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -54,7 +54,8 @@
 int
 putenv(char *str)
 {
-	char *p, *equal;
+	char *name, *equal, *p;
+	size_t namelen;
 	int offset;
 
 	_DIAGASSERT(str != NULL);
@@ -62,12 +63,19 @@
 	if ((equal = strchr(str, '=')) == NULL)
 		return -1;
 
-	if (rwlock_wrlock(&__environ_lock) != 0)
+	namelen = equal - str;
+	if ((name = malloc(namelen + 1)) == NULL)
 		return -1;
+	(void)memcpy(name, str, namelen);
+	name[namelen] = '\0';
 
-	*equal = '\0';
-	p = __findenv(str, &offset);
-	*equal = '=';
+	if (rwlock_wrlock(&__environ_lock) != 0) {
+		free(name);
+		return -1;
+	}
+
+	p = __findenv(name, &offset);
+	free(name);
 
 	if (__allocenv(offset) == -1)
 		goto bad;

Index: src/lib/libc/stdlib/setenv.c
diff -u src/lib/libc/stdlib/setenv.c:1.39 src/lib/libc/stdlib/setenv.c:1.40
--- src/lib/libc/stdlib/setenv.c:1.39	Fri Oct  1 20:11:32 2010
+++ src/lib/libc/stdlib/setenv.c	Sat Oct  2 16:56:03 2010
@@ -1,4 +1,4 @@
-/*	$NetBSD: setenv.c,v 1.39 2010/10/01 20:11:32 christos Exp $	*/
+/*	$NetBSD: setenv.c,v 1.40 2010/10/02 16:56:03 tron Exp $	*/
 
 /*
  * Copyright (c) 1987, 1993
@@ -34,7 +34,7 @@
 #if 0
 static char sccsid[] = "@(#)setenv.c	8.1 (Berkeley) 6/4/93";
 #else
-__RCSID("$NetBSD: setenv.c,v 1.39 2010/10/01 20:11:32 christos Exp $");
+__RCSID("$NetBSD: setenv.c,v 1.40 2010/10/02 16:56:03 tron Exp $");
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -83,8 +83,15 @@
 	if (c != NULL) {
 		if (!rewrite)
 			goto good;
-		if (strlen(c) >= l_value)	/* old is enough; copy over */
+		/*
+		 * Check whether the buffer was allocated via setenv(3) and
+		 * whether there is enough space. If so simply overwrite the
+		 * existing value.
+		 */
+		if (environ[offset] == __environ_malloced[offset] &&
+		    strlen(c) >= l_value) {
 			goto copy;
+		}
 	}
 	for (cc = name; *cc && *cc != '='; ++cc)	/* no `=' in name */
 		continue;