Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 20 Feb 2001 08:20:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 20 Feb 2001 08:20:37 -0500 Received: from zikova.cvut.cz ([147.32.235.100]:33799 "EHLO zikova.cvut.cz") by vger.kernel.org with ESMTP id ; Tue, 20 Feb 2001 08:20:26 -0500 From: "Petr Vandrovec" Organization: CC CTU Prague To: Peter Samuelson Date: Tue, 20 Feb 2001 14:19:01 MET-1 MIME-Version: 1.0 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7BIT Subject: Re: [PATCH] new setprocuid syscall CC: linux-kernel@vger.kernel.org X-mailer: Pegasus Mail v3.40 Message-ID: <1605A1153EC8@vcnet.vc.cvut.cz> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 20 Feb 01 at 7:11, Peter Samuelson wrote: > [Alan Cox] > > There is an assumption in the kernel that only the task changes its > > own uid and other related data. > > Fair enough but could you explain the potential problems? And how is > it different from sys_setpriority? Look at what fs/open.c:sys_access does, at least. It switches fsuid/fsgid/capabilities during its execution. sys_setpriority is completely different, no piece of kernel changes that and nothing except schedule() touches that. But {,fs,e}[ug]id are used here and there through whole kernel. Also, changing priority does not remove some access rights from your process, while changing uid/gid does... Petr Vandrovec vandrove@vc.cvut.cz - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/