From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752399AbcAFRKw (ORCPT ); Wed, 6 Jan 2016 12:10:52 -0500 Received: from mx2.suse.de ([195.135.220.15]:36725 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752347AbcAFRKs (ORCPT ); Wed, 6 Jan 2016 12:10:48 -0500 Date: Wed, 6 Jan 2016 18:10:44 +0100 From: Borislav Petkov To: Dave Hansen Cc: x86@kernel.org, linux-kernel@vger.kernel.org, dave.hansen@linux.intel.com, hpa@zytor.com, fenghua.yu@intel.com, yu-cheng.yu@intel.com Subject: Re: [PATCH 3/5] x86: simplify early command line parsing Message-ID: <20160106171044.GB20321@pd.tnic> References: <20151222225237.08CDE5F1@viggo.jf.intel.com> <20151222225241.15365E43@viggo.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20151222225241.15365E43@viggo.jf.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 22, 2015 at 02:52:41PM -0800, Dave Hansen wrote: > > From: Dave Hansen > > __cmdline_find_option_bool() tries to account for both > NULL-terminated and non-NULL-terminated strings. It keeps 'pos' > to look for the end of the buffer and also looks for '!c' in a > bunch of places to look for NULL termination. > > But, it also calls strlen(). You can't call strlen on a > non-NULL-terminated string. > > If !strlen(cmdline), then cmdline[0]=='\0'. In that case, we > will go in to the while() loop, set c='\0', hit st_wordstart, > notice !c, and will immediately return 0. > > So, remove the strlen(). It is unnecessary and unsafe. > > Signed-off-by: Dave Hansen > Cc: Borislav Petkov > Cc: H. Peter Anvin > Cc: linux-kernel@vger.kernel.org > Cc: fenghua.yu@intel.com > Cc: yu-cheng.yu@intel.com > --- > > b/arch/x86/lib/cmdline.c | 3 --- > 1 file changed, 3 deletions(-) > > diff -puN arch/x86/lib/cmdline.c~x86-early-command-line-non-term arch/x86/lib/cmdline.c > --- a/arch/x86/lib/cmdline.c~x86-early-command-line-non-term 2015-12-22 11:56:59.454186167 -0800 > +++ b/arch/x86/lib/cmdline.c 2015-12-22 11:56:59.457186302 -0800 > @@ -39,9 +39,6 @@ int cmdline_find_option_bool(const char > if (!cmdline) > return -1; /* No command line */ > > - if (!strlen(cmdline)) > - return 0; > - Patch 1 adds the strlen(), this patch removes it. Please merge both patches. -- Regards/Gruss, Boris. SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg) --