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=1.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,FSL_HELO_FAKE, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 2CA7CC43142 for ; Mon, 25 Jun 2018 17:14:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D448825EDC for ; Mon, 25 Jun 2018 17:14:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BYBie8Pd" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D448825EDC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934370AbeFYROc (ORCPT ); Mon, 25 Jun 2018 13:14:32 -0400 Received: from mail-pl0-f68.google.com ([209.85.160.68]:45602 "EHLO mail-pl0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933724AbeFYRO3 (ORCPT ); Mon, 25 Jun 2018 13:14:29 -0400 Received: by mail-pl0-f68.google.com with SMTP id o18-v6so6428873pll.12; Mon, 25 Jun 2018 10:14:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=JjuSp3H89JENXPeEO1/EE1PYS+ejPM3/bTrspFvLJdQ=; b=BYBie8Pd2i/Jo3eQYte2AaPX/qLQdeTjRJVEORlYjAFD18qX4zmnTxoHzLPiHr5rpC /0droukld/wGo8eMEeocVaKJlesgFsNGXSXIBAd2b+GvMQnbgvWJd1l3FIo5Zkmhjiph VOzRAS43t2VgZahclqJG4FkBO0+i9bmfmgd5VTMby4rBb7uc+1/Q2DeG4IRfekps0mXm T3sCYggicb4l5+PVzXqKRNAZo7t08UKZ6OXV/sIdqAfqJ2part6NBsGWn9rutCfNenSi FOpJf8eEwhbxeSgFNc6JH8StpYqD1xIM1kjJfmcBOm7g7js0JD8y7K9NseaZFPs7VzkZ pMMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=JjuSp3H89JENXPeEO1/EE1PYS+ejPM3/bTrspFvLJdQ=; b=E+qjCcgb9ELWL8Vl4OsIZSUAbm5fOIM35sOppHYPAuFCel9OzDpum47nLqSYrZ/7uZ yGfMeuFQQ0OqgfVXj+Yr8FhyTr8KQf/EtjAOAlcY2lxh2Tknz5hZTrfMt7kWJVf1SCeN 2mm/RQxNp0xFfxZmMWpxCTCr69FkqujRoh8YHHABJN7lLCrtLyklJmoWMMO0xLY3E48C skHQrJ+icHGzXQxTmoycVH4LqxX1trSRBkrBC634z92/HXgN/eBYERUMV0/PTlIicC99 jJQlXvVKBKK0/EViQJwa54EiS9zfGRVmwrcIF4OBg9kYFvz4BY71DJ+9MO1Ys8DOuMpi rfxw== X-Gm-Message-State: APt69E0M/8HKdACBtRZWJUfzQsXPXQsZ4iRpzQmwxfuktG4FKmtqIlRi WZBQx9uvgW/7/etECc1+lqU= X-Google-Smtp-Source: ADUXVKKBV+mBs37xWxELZaYHvCZpGnvsHNupu/2nXRuGNN/ZVyTHKD+U8QyHhzFHagBo/TQlZmFq+g== X-Received: by 2002:a17:902:600d:: with SMTP id r13-v6mr6180453plj.70.1529946868731; Mon, 25 Jun 2018 10:14:28 -0700 (PDT) Received: from gmail.com ([2620:15c:17:3:dc28:5c82:b905:e8a8]) by smtp.gmail.com with ESMTPSA id 10-v6sm32774531pgb.40.2018.06.25.10.14.27 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 25 Jun 2018 10:14:27 -0700 (PDT) Date: Mon, 25 Jun 2018 10:14:26 -0700 From: Eric Biggers To: David Howells Cc: James Morris , keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Tycho Andersen , Kees Cook , Stephan Mueller , Eric Biggers Subject: Re: [PATCH] dh key: fix rounding up KDF output length Message-ID: <20180625171426.GA180889@gmail.com> References: <20180607191201.97080-1-ebiggers3@gmail.com> <0000000000009c221d056e0cf53a@google.com> <17595.1528472278@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <17595.1528472278@warthog.procyon.org.uk> User-Agent: Mutt/1.10+35 (c786a508) (2018-06-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi David, On Fri, Jun 08, 2018 at 04:37:58PM +0100, David Howells wrote: > Eric Biggers wrote: > > > Commit 383203eff718 ("dh key: get rid of stack allocated array") changed > > kdf_ctr() to assume that the length of key material to derive is a > > multiple of the digest size. The length was supposed to be rounded up > > accordingly. However, the round_up() macro was used which only gives > > the correct result on power-of-2 arguments, whereas not all hash > > algorithms have power-of-2 digest sizes. In some cases this resulted in > > a write past the end of the 'outbuf' buffer. > > > > Fix it by switching to roundup(), which works for non-power-of-2 inputs. > > Applied. Applied to where? When are you planning to send this to Linus? Note that this was a regression from v4.17 to v4.18-rc1. Thanks, - Eric