[PATCHv2 01/12]posix_acl: Add the check items

[Liuwenyi <qingshenlwy@gmail.com>]

Add the acl validation check-items
to fix the null pointer error and PTR_ERR error.

Thanks for Matthew Wilcox's sguuestion.

---
Signed-off-by: Liuwenyi <qingshenlwy@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: James Morris <jmorris@namei.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Frank Filz <ffilzlnx@us.ibm.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Tiger Yang <tiger.yang@oracle.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Eric Sandeen <sandeen@sandeen.net>
Cc: xfs-masters@oss.sgi.com
Cc: xfs@oss.sgi.com
Cc: reiserfs-devel@vger.kernel.org
Cc: ocfs2-devel@oss.oracle.com
Cc: linux-nfs@vger.kernel.org
Cc: linux-ext4@vger.kernel.org
Cc: linux-btrfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: cluster-devel@redhat.com
Cc: linux-mtd@lists.infradead.org

--
diff --git a/fs/posix_acl.c b/fs/posix_acl.c
index 39df95a..d4bacb9 100644
--- a/fs/posix_acl.c
+++ b/fs/posix_acl.c
@@ -76,6 +76,12 @@ posix_acl_valid(const struct posix_acl *acl)
unsigned int id = 0; /* keep gcc happy */
int needs_mask = 0;

+ if (!acl)
+ return -EINVAL;
+
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+
FOREACH_ACL_ENTRY(pa, acl, pe) {
if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE))
return -EINVAL;

-- 
Best Regards,
Liuwenyi