From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261175AbULWMgs (ORCPT ); Thu, 23 Dec 2004 07:36:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261184AbULWMgs (ORCPT ); Thu, 23 Dec 2004 07:36:48 -0500 Received: from clock-tower.bc.nu ([81.2.110.250]:39825 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S261175AbULWMgo (ORCPT ); Thu, 23 Dec 2004 07:36:44 -0500 Subject: Re: [PATCH 2.4] Fix rlimit check in precheck_file_write() From: Alan Cox To: Jason Uhlenkott Cc: Linux Kernel Mailing List In-Reply-To: <20041222215759.GA217560@dragonfly.engr.sgi.com> References: <20041222215759.GA217560@dragonfly.engr.sgi.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1103801367.13188.5.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Thu, 23 Dec 2004 11:29:33 +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mer, 2004-12-22 at 21:57, Jason Uhlenkott wrote: > Remove a broken assumption that rlimits are 32 bits which can cause > nasty things to happen on 64-bit machines if we try to write past the > 2^32-1th character of a file and a larger file size limit exists. > > Signed-off-by: Jason Uhlenkott > > --- linux-2.4.29-pre3.orig/mm/filemap.c 2004-11-17 03:54:22.000000000 -0800 > +++ linux-2.4.29-pre3/mm/filemap.c 2004-12-22 13:41:46.000000000 -0800 > @@ -3088,9 +3088,9 @@ > send_sig(SIGXFSZ, current, 0); > goto out; > } > - if (pos > 0xFFFFFFFFULL || *count > limit - (u32)pos) { > + if (*count > limit - pos) { > /* send_sig(SIGXFSZ, current, 0); */ > - *count = limit - (u32)pos; > + *count = limit - pos; > } Are you sure this is safe for all conceivable 32bit cases as well as your 64bit one ? I don't think it is looking at the overflow cases in the if that you removed checking of. Alan