Sysfs: fix possible memleak in sysfs_follow_link

There is the possiblity of a memory leak if a page is allocated and if
sysfs_getlink() fails in the sysfs_follow_link.
Signed-off-by: NArmin Kuster <akuster@mvista.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

fs/sysfs/symlink.c

@@ -192,8 +192,11 @@ static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
 	int error = -ENOMEM;
 	unsigned long page = get_zeroed_page(GFP_KERNEL);
-	if (page)
+	if (page) {
 		error = sysfs_getlink(dentry, (char *) page); 
+		if (error < 0)
+			free_page((unsigned long)page);
+	}
 	nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
 	return NULL;
 }