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=1.8 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,URIBL_BLOCKED, 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 A986FC43140 for ; Wed, 20 Jun 2018 23:42:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 623EE2083A for ; Wed, 20 Jun 2018 23:42:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Z8F4CXK/" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 623EE2083A 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 S933077AbeFTXmv (ORCPT ); Wed, 20 Jun 2018 19:42:51 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:34983 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932597AbeFTXmg (ORCPT ); Wed, 20 Jun 2018 19:42:36 -0400 Received: by mail-pf0-f194.google.com with SMTP id c22-v6so554057pfi.2; Wed, 20 Jun 2018 16:42:36 -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=th9nn/aCwE+JUnbogInTYjEi2QI03gTSTd0O9iFYQJs=; b=Z8F4CXK//6f+QLKs0imC1c7wH4VTY8JQZ9y+VHjRid7Qw8kHFukrqoFoGWtGgJxHKt AV0FTsIYyKls6bS589GnNCtY+c3KxU6/EDvU7a5dMsHLEQvk2H0zk6pcAuYcqIKseG4N aYY8nV+admPJycsk8UZBKD4xGcJzczwYNLcDN2cdAQ84QRdiKLR+Q0KlyXe3I6Rlb2VH dHkEyb4/pwECzMAxfNmA6VUGjfvqXiZDh9OyMzR6JgS3Gi+ltWfalGAnxwoSzftL62HH SLqKai+E6sC/ilRk70skWc7vbGBj9ClrPfdr6Um1p/KPGB0IQNYsQdHHTvZU3Q6HCcYg SVRQ== 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=th9nn/aCwE+JUnbogInTYjEi2QI03gTSTd0O9iFYQJs=; b=hYhk4LANL9ChLKfs9ToJiItd/l+O6sqQqu+KMRxGf7BAzi5rNlljk+qWDpEvaOXaBV qb4KJBFigUhsDl4fnDua9u3A5JKDswQKReM3uBSVDWtYDGknxMmq25ZpJvqtbyhXUNy9 dsCi5mU1hPbE4b9/sQUbEaarZi6bEA3zBMcHUV38ImnJyFagwxrykuWUHZ1ksIk4mh7k yIGa3MiFS/61EYIV2fL3lMQ/Q5kxrjrFzIq63P7chyEWBuIUvDXDKrw49CArRL7bFRb8 nSEND/7TiEy8dl1memm+keFfEUA1tJRi9vgifQW7ja+rK6wGUK3ex25UC0b+nue33n+Z 3e6Q== X-Gm-Message-State: APt69E3FMgNgmpW+JQI2ErkuHCLTEFaHMDIFe2vIxohl5MMLGcKMXn2N 8Ad4aYWUpkc2/vgVo9OfebV82uoHP/w= X-Google-Smtp-Source: ADUXVKLNzMJWWOH2iD0f23nlI3U7ocL8XJ7psfBRU2zAPsAgX8KYyM2A1ysqypixz64FfhSsnOujsg== X-Received: by 2002:a62:50d6:: with SMTP id g83-v6mr24762185pfj.31.1529538155913; Wed, 20 Jun 2018 16:42:35 -0700 (PDT) Received: from gmail.com ([2620:15c:17:3:dc28:5c82:b905:e8a8]) by smtp.gmail.com with ESMTPSA id c17-v6sm5478420pgw.11.2018.06.20.16.42.35 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 20 Jun 2018 16:42:35 -0700 (PDT) Date: Wed, 20 Jun 2018 16:42:33 -0700 From: Eric Biggers To: Kees Cook Cc: Herbert Xu , Giovanni Cabiddu , Arnd Bergmann , Eric Biggers , Mike Snitzer , "Gustavo A. R. Silva" , qat-linux@intel.com, linux-kernel@vger.kernel.org, dm-devel@redhat.com, linux-crypto@vger.kernel.org, Lars Persson , Tim Chen , "David S. Miller" , Alasdair Kergon , Rabin Vincent Subject: Re: [dm-devel] [PATCH 06/11] crypto: cbc: Remove VLA usage Message-ID: <20180620234233.GD111712@gmail.com> References: <20180620190408.45104-1-keescook@chromium.org> <20180620190408.45104-7-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180620190408.45104-7-keescook@chromium.org> User-Agent: Mutt/1.10+28 (db52f11e) (2018-06-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 20, 2018 at 12:04:03PM -0700, Kees Cook wrote: > In the quest to remove all stack VLA usage from the kernel[1], this > uses the upper bounds on blocksize. > > [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com > > Signed-off-by: Kees Cook > --- > include/crypto/cbc.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/crypto/cbc.h b/include/crypto/cbc.h > index f5b8bfc22e6d..260096bcf99b 100644 > --- a/include/crypto/cbc.h > +++ b/include/crypto/cbc.h > @@ -113,7 +113,7 @@ static inline int crypto_cbc_decrypt_inplace( > unsigned int bsize = crypto_skcipher_blocksize(tfm); > unsigned int nbytes = walk->nbytes; > u8 *src = walk->src.virt.addr; > - u8 last_iv[bsize]; > + u8 last_iv[CRYPTO_ALG_MAX_BLOCKSIZE]; > Why not MAX_CIPHER_BLOCKSIZE? - Eric