From: Christoph Hellwig <hch@infradead.org>
Date: Tue, 6 Dec 2011 21:21:05 +0000 (-0500)
Subject: xfs: validate acl count
X-Git-Tag: firefly_0821_release~7541^2~2148
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a980e5dccb3ff8cb8f77ff27264b13837958119d;p=firefly-linux-kernel-4.4.55.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>
Acked-by: Dave Chinner <dchinner@redhat.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 39f4f809bb68..4b9fb915d445 100644
--- a/fs/xfs/linux-2.6/xfs_acl.c
+++ b/fs/xfs/linux-2.6/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)