From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758816Ab0BYCOW (ORCPT ); Wed, 24 Feb 2010 21:14:22 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:37258 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758782Ab0BYCOO (ORCPT ); Wed, 24 Feb 2010 21:14:14 -0500 Date: Wed, 24 Feb 2010 18:13:32 -0800 From: Andrew Morton To: Neil Horman Cc: oleg@redhat.com, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, Ingo Molnar , Alan Cox Subject: Re: [PATCH] supress uid comparison test if core output files are pipes Message-Id: <20100224181332.5cdc2454.akpm@linux-foundation.org> In-Reply-To: <20100225013210.GA10527@localhost.localdomain> References: <20100222200851.GD3344@hmsreliant.think-freely.org> <20100224135053.e75800c1.akpm@linux-foundation.org> <20100225013210.GA10527@localhost.localdomain> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 24 Feb 2010 20:32:10 -0500 Neil Horman wrote: > > > diff --git a/fs/exec.c b/fs/exec.c > > > index 6303d18..6af2214 100644 > > > --- a/fs/exec.c > > > +++ b/fs/exec.c > > > @@ -1987,8 +1987,9 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs) > > > /* > > > * Dont allow local users get cute and trick others to coredump > > > * into their pre-created files: > > > + * Note, this is not relevant for pipes > > > */ > > > - if (inode->i_uid != current_fsuid()) > > > + if (!ispipe && (inode->i_uid != current_fsuid())) > > > goto close_fail; > > > if (!cprm.file->f_op) > > > goto close_fail; > > > > hm, this actually appears to fix a regression, added by: > > > In a sense yes. Previously though, Ingos check was both useless for pipes > (since you can't have a user create a pipe that will map to what the coredump > path creates anyway, making this check useless), but it worked anyway, since the > crashing process created the pipe, so the uid check always matched. With the > refactoring andi and I did, thats no longer true, so the check could fail. This > patch just fixes it up by recongnizing that the check isn't needed at all for > pipes Which refactoring? Please identify precisely the patch which this patch fixes up?