From: Xi Wang <xi.wang@gmail.com>
Date: Mon, 12 Dec 2011 21:55:52 +0000 (+0000)
Subject: xfs: fix acl count validation in xfs_acl_from_disk()
X-Git-Tag: firefly_0821_release~3680^2~3803^2~3
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=093019cf1b18dd31b2c3b77acce4e000e2cbc9ce;p=firefly-linux-kernel-4.4.55.git

xfs: fix acl count validation in xfs_acl_from_disk()

Commit fa8b18ed didn't prevent the integer overflow and possible
memory corruption.  "count" can go negative and bypass the check.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
---

diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index 76e4266d2e7e..ac702a6eab9b 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -39,7 +39,7 @@ xfs_acl_from_disk(struct xfs_acl *aclp)
 	struct posix_acl_entry *acl_e;
 	struct posix_acl *acl;
 	struct xfs_acl_entry *ace;
-	int count, i;
+	unsigned int count, i;
 
 	count = be32_to_cpu(aclp->acl_cnt);
 	if (count > XFS_ACL_MAX_ENTRIES)