From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 21 Sep 2001 15:26:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 21 Sep 2001 15:26:14 -0400 Received: from mueller.uncooperative.org ([216.254.102.19]:53773 "EHLO mueller.datastacks.com") by vger.kernel.org with ESMTP id ; Fri, 21 Sep 2001 15:26:01 -0400 Date: Fri, 21 Sep 2001 15:26:26 -0400 From: Crutcher Dunnavant To: linux-kernel@vger.kernel.org Subject: Re: [PATCH] 2.4 vsnprintf fix. Message-ID: <20010921152626.A8188@mueller.datastacks.com> Mail-Followup-To: linux-kernel@vger.kernel.org In-Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from rusty@rustcorp.com.au on Thu, Sep 20, 2001 at 09:29:05PM +1000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org ++ 20/09/01 21:29 +1000 - Rusty Russell: > Following patch fixes calling vsnprintf with (NULL, 0) to get the > length of the string. The problem is that the end ptr is set to > 0xFFFFFFFF in this case, causing a write into address 0 as start < > end. Doh! Egg on face. Between this and the sysrq bugs, I'm thinking of going into dance instead of hacking anymore. Sorry about this, it is a basic mistake (right up there with going up against a scicilian when death is on the line.) > > Cheers, > Rusty. > -- > Premature optmztion is rt of all evl. --DK > > --- working-pmac-module/lib/vsprintf.c.~1~ Mon Sep 17 08:53:56 2001 > +++ working-pmac-module/lib/vsprintf.c Thu Sep 20 21:26:05 2001 > @@ -246,6 +246,8 @@ > /* 'z' support added 23/7/1999 S.H. */ > /* 'z' changed to 'Z' --davidm 1/25/99 */ > > + /* buf = NULL, size = 0 is common for getting length */ > + if (size == 0) buf = (void *)1; > str = buf; > end = buf + size - 1; > - > 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/ -- Crutcher GCS d--- s+:>+:- a-- C++++$ UL++++$ L+++$>++++ !E PS+++ PE Y+ PGP+>++++ R-(+++) !tv(+++) b+(++++) G+ e>++++ h+>++ r* y+>*$