From: Christoph Hellwig <hch@infradead.org>
Date: Sun, 20 Nov 2011 15:35:32 +0000 (+0000)
Subject: xfs: validate acl count
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=fa8b18ed;p=deliverable%2Flinux.git

xfs: validate acl count

This prevents in-memory corruption and possible panics if the on-disk
ACL is badly corrupted.

Signed-off-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 b6c4b3795c4a..76e4266d2e7e 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -42,6 +42,8 @@ xfs_acl_from_disk(struct xfs_acl *aclp)
 	int count, i;
 
 	count = be32_to_cpu(aclp->acl_cnt);
+	if (count > XFS_ACL_MAX_ENTRIES)
+		return ERR_PTR(-EFSCORRUPTED);
 
 	acl = posix_acl_alloc(count, GFP_KERNEL);
 	if (!acl)