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

[Liuwenyi]

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