From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 956AAC433DF for ; Sun, 2 Aug 2020 18:29:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA6462065E for ; Sun, 2 Aug 2020 18:29:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=chronox.de header.i=@chronox.de header.b="A1AEdXZU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726163AbgHBS3O (ORCPT ); Sun, 2 Aug 2020 14:29:14 -0400 Received: from mo4-p00-ob.smtp.rzone.de ([85.215.255.22]:10294 "EHLO mo4-p00-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725917AbgHBS3N (ORCPT ); Sun, 2 Aug 2020 14:29:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1596392949; s=strato-dkim-0002; d=chronox.de; h=References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: X-RZG-CLASS-ID:X-RZG-AUTH:From:Subject:Sender; bh=2NEjcRTj85kAAf1x/mTVx2JMX5a/v0WFkm/vzxr7gAQ=; b=A1AEdXZUxXsG+UW8F4PX+i3A7jEXyHI39SsBLIzsv9lTVr4oXF1w3XVJ0Aqk4ONuIY Q2boyUqpWwNvmiKhzZeShfm1APrWvOdPr7PY20m1ODZQtLyZCxqr4ecTD2Oz5luTjYEq 97M/craFyHfML1DxkYGZmVOTahbYhRq3xyAgXt6W3ntNrfc9M/rOoiYJkqQfqLKZrNon MQtUk7VqGbhcPj/UjUqh7AO2Cki4lIYMaU50Rij4OH5dre0cVCidygjO+fuUtwvpWbP/ bdIP/hWrZBQMBDdrHLVdakM3ZBZ1/Jt83C67rbbTKTCteE9flxothRnPH4ERlqOPRy+i tgHg== X-RZG-AUTH: ":P2ERcEykfu11Y98lp/T7+hdri+uKZK8TKWEqNyiHySGSa9k9xmwdNnzGHXPZJPSfIqEh" X-RZG-CLASS-ID: mo00 Received: from tauon.chronox.de by smtp.strato.de (RZmta 46.10.5 DYNA|AUTH) with ESMTPSA id y0546bw72IT6VJ4 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Sun, 2 Aug 2020 20:29:06 +0200 (CEST) From: Stephan Mueller To: herbert@gondor.apana.org.au, davem@davemloft.net, trix@redhat.com Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Tom Rix Subject: Re: [PATCH] crypto: drbg: check blocklen is non zero Date: Sun, 02 Aug 2020 20:29:05 +0200 Message-ID: <9904643.2WqB4rESCP@tauon.chronox.de> In-Reply-To: <20200802171247.16558-1-trix@redhat.com> References: <20200802171247.16558-1-trix@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Am Sonntag, 2. August 2020, 19:12:47 CEST schrieb trix@redhat.com: Hi Tom, > From: Tom Rix > > Clang static analysis reports this error > > crypto/drbg.c:441:40: warning: Division by zero > padlen = (inputlen + sizeof(L_N) + 1) % (drbg_blocklen(drbg)); > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~ > > When drbg_bocklen fails it returns 0. > > if (drbg && drbg->core) > return drbg->core->blocklen_bytes; > return 0; > > In many places in drbg_ctr_df drbg_bocklen is assumed to be non zero. > So turn the assumption into a check. > > Fixes: 541af946fe13 ("crypto: drbg - SP800-90A Deterministic Random Bit > Generator") > > Signed-off-by: Tom Rix Thank you. Reviewed-by: Stephan Mueller Ciao Stephan