[PATCH 3/3]posix acl:Add an acl check

["Liuweni" <qingshenlwy@gmail.com>]

In this function, the parameter of acl will be called by FOREACH_ACL_ENTRY(macro) 
without null point check. I add a Null point check to it. 

---
Signed-off-by: Liuwenyi <qingshenlwy@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 39df95a..6d81a13 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -213,6 +213,9 @@ posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want)
 	const struct posix_acl_entry *pa, *pe, *mask_obj;
 	int found = 0;
 
+	if (!acl)
+		return -EINVAL;
+
 	FOREACH_ACL_ENTRY(pa, acl, pe) {
                 switch(pa->e_tag) {
                         case ACL_USER_OBJ:

 				
--------------
Best Regards,
Liuweni
2009-12-17