[PATCH] check for invalid flags in xfs_attrlist_by_handle

Christoph Hellwig
2008-05-31T07:57:51Z

xfs_attrlist_by_handle should only take the ATTR_ flags for the root
namespaces. The ATTR_KERN* flags may change at anytime and expect special
preconditions that can't be guaranteed for userspace-originating
requests. For example passing down ATTR_KERNNOVAL through
xfs_attrlist_by_handle will hit an assert in debug builds currently.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_ioctl.c 2008-05-28 17:37:02.000000000 +0200
+++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl.c 2008-05-28 17:42:18.000000000 +0200
@@ -470,6 +470,12 @@ xfs_attrlist_by_handle(
if (al_hreq.buflen > XATTR_LIST_MAX)
return -XFS_ERROR(EINVAL);

+ /*
+ * Reject flags, only allow namespaces.
+ */
+ if (al_hreq.flags & ~(ATTR_ROOT|ATTR_TRUST|ATTR_SECURE))
+ return -XFS_ERROR(EINVAL);
+
error = xfs_vget_fsop_handlereq(mp, parinode, &al_hreq.hreq, &inode);
if (error)
goto out;