From: Christoph Hellwig <hch@infradead.org>
Date: Sun, 20 Nov 2011 15:35:32 +0000 (+0000)
Subject: xfs: validate acl count
X-Git-Tag: v2.6.32.54~2
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=9ee3e4ab17e3670a46b24502394eb24d68a85f9b;p=linux-pvops.git

xfs: validate acl count

commit fa8b18edd752a8b4e9d1ee2cd615b82c93cf8bba upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/fs/xfs/linux-2.6/xfs_acl.c b/fs/xfs/linux-2.6/xfs_acl.c
index 4c7b14503716..03aec610b3fc 100644
--- a/fs/xfs/linux-2.6/xfs_acl.c
+++ b/fs/xfs/linux-2.6/xfs_acl.c
@@ -40,6 +40,8 @@ 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)