From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757119AbYEOUWa (ORCPT ); Thu, 15 May 2008 16:22:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751669AbYEOUWR (ORCPT ); Thu, 15 May 2008 16:22:17 -0400 Received: from wa-out-1112.google.com ([209.85.146.182]:48789 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751546AbYEOUWP (ORCPT ); Thu, 15 May 2008 16:22:15 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=Y6AnijYV6Zdgh6kANJVdqh5zTNuG7uqrh1VSWo6pOf6gUEN4bbdRDB8vfn0QfYYhyxIKWmqIGVm0bxw77wapLyBLk59NVAPYvTNPG8Ie9A8Z2VRqYrUNebHlZRLPsiXD2kTfVf1FO+EzIQu06MqEB4MxkMY4JONfRa569V4IbPU= Message-ID: Date: Fri, 16 May 2008 00:22:14 +0400 From: "Cyrill Gorcunov" To: "Geert Uytterhoeven" , "Andrew Morton" , "Linus Torvalds" , "Roman Zippel" , "Andreas Schwab" , LKML , "Linux/m68k" Subject: Re: [PATCH] init - fix building bug and potential buffer overflow In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20080514154402.GF6902@cvg> <20080515105803.7c9ab8c7.akpm@linux-foundation.org> <20080515180528.GC7481@cvg> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Could you please make an update to the patch? I can make it only tomorrow evening (ie not that fast) On 5/15/08, Geert Uytterhoeven wrote: > On Thu, 15 May 2008, Cyrill Gorcunov wrote: >> [Andrew Morton - Thu, May 15, 2008 at 10:58:03AM -0700] >> | On Wed, 14 May 2008 19:44:02 +0400 Cyrill Gorcunov >> wrote: >> | >> | > This patch does fix build bug on m68k wich does not have strncat in >> straight way. >> | > >> | > What is more important - my previous patch >> | > >> | > commit e662e1cfd434aa234b72fbc781f1d70211cb785b >> | > Author: Cyrill Gorcunov >> | > Date: Mon May 12 14:02:22 2008 -0700 >> | > >> | > init: don't lose initcall return values >> | > >> | > has introduced potential buffer overflow by wrong calculation >> | > of string accumulator size. >> | > >> | > Many thanks Andreas Schwab and Geert Uytterhoeven for helping >> | > to catch and fix the bug. >> | > >> | > Signed-off-by: Cyrill Gorcunov >> | > --- >> | > >> | > Index: linux-2.6.git/init/main.c >> | > =================================================================== >> | > --- linux-2.6.git.orig/init/main.c 2008-05-14 17:55:10.000000000 +0400 >> | > +++ linux-2.6.git/init/main.c 2008-05-14 19:11:18.000000000 +0400 >> | > @@ -702,7 +702,7 @@ static void __init do_initcalls(void) >> | > >> | > for (call = __initcall_start; call < __initcall_end; call++) { >> | > ktime_t t0, t1, delta; >> | > - char msgbuf[40]; >> | > + char msgbuf[64]; >> | > int result; >> | > >> | > if (initcall_debug) { >> | > @@ -729,11 +729,11 @@ static void __init do_initcalls(void) >> | > sprintf(msgbuf, "error code %d ", result); >> | > >> | > if (preempt_count() != count) { >> | > - strncat(msgbuf, "preemption imbalance ", sizeof(msgbuf)); >> | > + strcat(msgbuf, "preemption imbalance "); >> | > preempt_count() = count; >> | > } >> | > if (irqs_disabled()) { >> | > - strncat(msgbuf, "disabled interrupts ", sizeof(msgbuf)); >> | > + strcat(msgbuf, "disabled interrupts "); >> | > local_irq_enable(); >> | > } >> | > if (msgbuf[0]) { >> | >> | umm, why can't m68k call strncat() from init/main.c?? >> | >> >> there some problem with headers iirc, we have to declare it first or >> use some gcc option (as Adrian suggested). Actually I would prefer to use > > gcc turns the strncat() into an implicit call to strlen() and some form > of expanded memcpy(). E.g. > > > if (preempt_count() != count) { > strncat(msgbuf, "preemption imbalance ", sizeof(msgbuf)); > preempt_count() = count; > } > > becomes > > cmp.l 884(%a2),%d6 | .thread.info.preempt_count, > count > jeq .L61 | > move.l %d7,-(%sp) | tmp76, > jbsr strlen | > addq.l #4,%sp |, > move.l %d7,%a0 | tmp76, tmp80 > add.l %d0,%a0 |, tmp80 > move.l #1886545253,(%a0)+ |, > move.l #1836086377,(%a0)+ |, > move.l #1869488233,(%a0)+ |, > move.l #1835164012,(%a0)+ |, > move.l #1634624357,(%a0)+ |, > move.w #8192,(%a0) |,* D.28541 > move.l %d6,884(%a2) | count, > .thread.info.preempt_count > .L61: > > All other explicit calls to strlen() are inlined, as per > include/asm-m68k/string.h. > >> strlcat there but it seems it would fail to build too. Originally I've >> messed >> strlcat with strncat :( > > Actually it build and runs fine after s/strncat/strlcat/... > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- > geert@linux-m68k.org > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like > that. > -- Linus Torvalds >