[PATCH] chown permission check fix for ATTR_GID

SuSE discovered this problem with chown and ATTR_GID.  Make sure user
is authorized to change the group, CAN-2004-0497.

fs/attr.c

@@ -35,7 +35,8 @@ int inode_change_ok(struct inode *inode, struct iattr *attr)
 
 	/* Make sure caller can chgrp. */
 	if ((ia_valid & ATTR_GID) &&
-	    (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid) &&
+	    (current->fsuid != inode->i_uid ||
+	    (!in_group_p(attr->ia_gid) && attr->ia_gid != inode->i_gid)) &&
 	    !capable(CAP_CHOWN))
 		goto error;