From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757172AbYHHCZ3 (ORCPT ); Thu, 7 Aug 2008 22:25:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754458AbYHHCZU (ORCPT ); Thu, 7 Aug 2008 22:25:20 -0400 Received: from zen.handcraftedcomputers.com.au ([203.122.247.90]:2345 "EHLO zen.handcraftedcomputers.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753651AbYHHCZT (ORCPT ); Thu, 7 Aug 2008 22:25:19 -0400 Message-ID: <489BAE70.5080909@handcraftedcomputers.com.au> Date: Fri, 08 Aug 2008 11:54:48 +0930 From: Daryl Tester User-Agent: Thunderbird 2.0.0.16 (X11/20080724) MIME-Version: 1.0 To: Alexey Dobriyan CC: Sven Wegener , lkml Subject: Re: PROBLEM?: "permission denied" when accessing /proc/self/fd/* after setuid References: <489A9357.50105@handcraftedcomputers.com.au> <489B957D.9080206@handcraftedcomputers.com.au> <20080808005049.GA20707@martell.zuzino.mipt.ru> In-Reply-To: <20080808005049.GA20707@martell.zuzino.mipt.ru> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexey Dobriyan wrote: > Something similar was fixed in 2.6.22, but let me check. You're right - from : commit 8948e11f450e6189a79e47d6051c3d5a0b98e3f3 Author: Alexey Dobriyan Date: Tue May 8 00:23:35 2007 -0700 Allow access to /proc/$PID/fd after setuid() /proc/$PID/fd has r-x------ permissions, so if process does setuid(), it will not be able to access /proc/*/fd/. This breaks fstatat() emulation in glibc. open("foo", O_RDONLY|O_DIRECTORY) = 4 setuid32(65534) = 0 stat64("/proc/self/fd/4/bar", 0xbfafb298) = -1 EACCES (Permission denied) However, one of the kernels I tried this on (and failed) was a 2.6.24-19 - is it possible this patch was backed out? Cheers, --dt