From: Miklos Szeredi <mszeredi@suse.cz>
Date: Mon, 18 Feb 2013 15:24:11 +0000 (+0100)
Subject: fuse_opt_parse(): fix memory leak
X-Git-Tag: fuse-3.0.0pre0~132
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a38722be2ba63466431616a0756981697d29fa23;p=qemu-gpiodev%2Flibfuse.git

fuse_opt_parse(): fix memory leak

when storing a newly allocated string for format "%s", free the previous value
stored at that location.

Reported by Marco Schuster
---

diff --git a/ChangeLog b/ChangeLog
index 502a9bb..9a775bb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2013-02-18  Miklos Szeredi <miklos@szeredi.hu>
+
+	* fuse_opt_parse(): when storing a newly allocated string for
+	format "%s", free the previous value stored at that location.
+	Reported by Marco Schuster
+
 2013-02-07  Miklos Szeredi <miklos@szeredi.hu>
 
 	* libfuse: add readdirplus support in fuse_lowlevel_ops.  Patch by
diff --git a/include/fuse_opt.h b/include/fuse_opt.h
index add0a30..20653b1 100644
--- a/include/fuse_opt.h
+++ b/include/fuse_opt.h
@@ -70,8 +70,9 @@ extern "C" {
  *
  * 6) "-x %s", etc.  Combination of 4) and 5)
  *
- * If the format is "%s", memory is allocated for the string unlike
- * with scanf().
+ * If the format is "%s", memory is allocated for the string unlike with
+ * scanf().  The previous value (if non-NULL) stored at the this location is
+ * freed.
  */
 struct fuse_opt {
 	/** Matching template and optional parameter formatting */
diff --git a/lib/fuse_opt.c b/lib/fuse_opt.c
index 93efd29..15f9e21 100644
--- a/lib/fuse_opt.c
+++ b/lib/fuse_opt.c
@@ -204,11 +204,13 @@ static int process_opt_param(void *var, const char *format, const char *param,
 {
 	assert(format[0] == '%');
 	if (format[1] == 's') {
+		char **s = var;
 		char *copy = strdup(param);
 		if (!copy)
 			return alloc_failed();
 
-		*(char **) var = copy;
+		free(*s);
+		*s = copy;
 	} else {
 		if (sscanf(param, format, var) != 1) {
 			fprintf(stderr, "fuse: invalid parameter in option `%s'\n", arg);