From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS22989 209.51.188.0/24 X-Spam-Status: No, score=-4.5 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 4048D1F8C6 for ; Tue, 24 Aug 2021 18:52:12 +0000 (UTC) Received: from localhost ([::1]:34640 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIbWs-0004ek-FS for normalperson@yhbt.net; Tue, 24 Aug 2021 14:52:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:51006) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIbWp-0004eY-04 for bug-gnulib@gnu.org; Tue, 24 Aug 2021 14:52:07 -0400 Received: from zimbra.cs.ucla.edu ([131.179.128.68]:51138) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIbWm-0002oj-92 for bug-gnulib@gnu.org; Tue, 24 Aug 2021 14:52:06 -0400 Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 11A5116005A; Tue, 24 Aug 2021 11:52:02 -0700 (PDT) Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id cQCtwVr7vIL2; Tue, 24 Aug 2021 11:52:01 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 3BCDE1600BE; Tue, 24 Aug 2021 11:52:01 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id uQBhGANw1oXQ; Tue, 24 Aug 2021 11:52:01 -0700 (PDT) Received: from [192.168.1.9] (cpe-172-91-119-151.socal.res.rr.com [172.91.119.151]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 13B6516005A; Tue, 24 Aug 2021 11:52:01 -0700 (PDT) To: Darren Kenny References: <96f2ea78b6ce05f20d2c38fee43ffe87c3ca2664.1624030621.git.darren.kenny@oracle.com> <92b34c53-aa12-fb5e-19fd-fd0c7015bddf@cs.ucla.edu> From: Paul Eggert Organization: UCLA Computer Science Department Subject: Re: [PATCH 1/3] lib/regexec: Fix possible null-dereference Message-ID: <0e3a3c8d-5fa0-825f-3835-4d7e81afb044@cs.ucla.edu> Date: Tue, 24 Aug 2021 11:52:00 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/mixed; boundary="------------736D2D038296607E836CEDD4" Content-Language: en-US Received-SPF: pass client-ip=131.179.128.68; envelope-from=eggert@cs.ucla.edu; helo=zimbra.cs.ucla.edu X-Spam_score_int: -54 X-Spam_score: -5.5 X-Spam_bar: ----- X-Spam_report: (-5.5 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-1.305, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: bug-gnulib@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Gnulib discussion list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Daniel Kiper , bug-gnulib@gnu.org Errors-To: bug-gnulib-bounces+normalperson=yhbt.net@gnu.org Sender: "bug-gnulib" This is a multi-part message in MIME format. --------------736D2D038296607E836CEDD4 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable On 8/24/21 8:11 AM, Darren Kenny wrote: > Is there a specific set of assertions already present that ensure that > the circumstances you outline above are always in place? If by "assertion" you mean using DEBUG_ASSERT to pacify Coverity, I=20 think that the answer is currently "no" but if you apply something like=20 the attached patch then the answer becomes "yes". You'll have to check=20 this though, as Coverity won't give me access to its tools or source code= . If by "assertion" you mean using to verify each of the=20 statements I made, then this is not the sort of thing that one can=20 easily ensure via assertions. It'd be like asking "Is there a specific=20 set of assertions that I can add to 'grep' to ensure that the=20 output of 'grep' is correct?" The answer to that question is "No,=20 there's no practical way to do it." > At present at least, we're not building GRUB with DEBUG, but maybe it i= s > something to consider for Coverity builds. With the attached patch, I hope your Coverity builds can be either with=20 or without DEBUG. --------------736D2D038296607E836CEDD4 Content-Type: text/x-patch; charset=UTF-8; name="coverity3.diff" Content-Transfer-Encoding: quoted-printable Content-Disposition: attachment; filename="coverity3.diff" diff --git a/lib/regexec.c b/lib/regexec.c index 5e4eb497a..bd5b4ea41 100644 --- a/lib/regexec.c +++ b/lib/regexec.c @@ -1675,6 +1675,7 @@ static reg_errcode_t clean_state_log_if_needed (re_match_context_t *mctx, Idx next_state_log_= idx) { Idx top =3D mctx->state_log_top; + DEBUG_ASSERT (mctx->state_log !=3D NULL); =20 if ((next_state_log_idx >=3D mctx->input.bufs_len && mctx->input.bufs_len < mctx->input.len) diff --git a/lib/verify.h b/lib/verify.h index a8ca59b09..3cd71b280 100644 --- a/lib/verify.h +++ b/lib/verify.h @@ -305,6 +305,8 @@ template --enable-gcc-warnings, which compiles with -Dlint. It's nicer when 'assume' silences warnings even with older GCCs. */ # define assume(R) ((R) ? (void) 0 : __builtin_trap ()) +#elif defined __COVERITY__ +# define assume(R) ((R) ? (void) 0 : __coverity_panic__ ()) #else /* Some tools grok NOTREACHED, e.g., Oracle Studio 12.6. */ # define assume(R) ((R) ? (void) 0 : /*NOTREACHED*/ (void) 0) --------------736D2D038296607E836CEDD4--