xfs: Sanity check flags of Q_XQUOTARM call

commit 3dd4d40b upstream.

Flags passed to Q_XQUOTARM were not sanity checked for invalid values.
Fix that.

Fixes: 9da93f9b ("xfs: fix Q_XQUOTARM ioctl")
Reported-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/xfs/xfs_quotaops.c

@@ -202,6 +202,9 @@ xfs_fs_rm_xquota(
 	if (XFS_IS_QUOTA_ON(mp))
 		return -EINVAL;
 
+	if (uflags & ~(FS_USER_QUOTA | FS_GROUP_QUOTA | FS_PROJ_QUOTA))
+		return -EINVAL;
+
 	if (uflags & FS_USER_QUOTA)
 		flags |= XFS_DQ_USER;
 	if (uflags & FS_GROUP_QUOTA)