[PATCH 14/14] xfs: Validate the length of on-disk ACLs

[Dave Chinner]

From: Andreas Gruenbacher <agruenba at redhat.com>

Source kernel commit 86a21c79745ca97676cbd47f8608839382cc0448

In xfs_acl_from_disk, instead of trusting that xfs_acl.acl_cnt is correct,
make sure that the length of the attributes is correct as well.  Also, turn
the aclp parameter into a const pointer.

Signed-off-by: Andreas Gruenbacher <agruenba at redhat.com>
Reviewed-by: Dave Chinner <dchinner at redhat.com>
Signed-off-by: Dave Chinner <david at fromorbit.com>
---
 libxfs/xfs_format.h | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/libxfs/xfs_format.h b/libxfs/xfs_format.h
index 7eae0a5..f89b6e0 100644
--- a/libxfs/xfs_format.h
+++ b/libxfs/xfs_format.h
@@ -1502,9 +1502,13 @@ struct xfs_acl {
 						sizeof(struct xfs_acl_entry) \
 		: 25)
 
-#define XFS_ACL_MAX_SIZE(mp) \
+#define XFS_ACL_SIZE(cnt) \
 	(sizeof(struct xfs_acl) + \
-		sizeof(struct xfs_acl_entry) * XFS_ACL_MAX_ENTRIES((mp)))
+		sizeof(struct xfs_acl_entry) * cnt)
+
+#define XFS_ACL_MAX_SIZE(mp) \
+	XFS_ACL_SIZE(XFS_ACL_MAX_ENTRIES((mp)))
+
 
 /* On-disk XFS extended attribute names */
 #define SGI_ACL_FILE		"SGI_ACL_FILE"
-- 
2.5.0