From patchwork Wed Jul 11 20:36:19 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10520427 X-Patchwork-Delegate: herbert@gondor.apana.org.au Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3E90B600CA for ; Wed, 11 Jul 2018 20:36:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 21C252961A for ; Wed, 11 Jul 2018 20:36:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1645F294FA; Wed, 11 Jul 2018 20:36:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B70F42955E for ; Wed, 11 Jul 2018 20:36:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390346AbeGKUml (ORCPT ); Wed, 11 Jul 2018 16:42:41 -0400 Received: from mail-pf0-f193.google.com ([209.85.192.193]:46514 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390335AbeGKUml (ORCPT ); Wed, 11 Jul 2018 16:42:41 -0400 Received: by mail-pf0-f193.google.com with SMTP id l123-v6so19127249pfl.13 for ; Wed, 11 Jul 2018 13:36:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=xi1UiijgPtH3bEbgxLJTLT+H3zXPa7fDlbmxyBVC5QY=; b=NW7U48sxDmiQ8pX3SOZwI10vZPpyQfhJ8ZJnnQ8uq01C90eDMBj7PF5fD4x3CKbq0O mbHK7+YNxptMgbhT+7AVUTsCVwDVMMGY60UlXO4i9/K08LQUXWOMmxBpWdGQJEYL/qFf NtoDQJxE7XXbFzlPV+gXyCQRuqWcZWbFVgcbI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=xi1UiijgPtH3bEbgxLJTLT+H3zXPa7fDlbmxyBVC5QY=; b=FfS4zp++0Xf4Nujqc4WXAx7iGk5z7fjaGbmmYHKWoLLP2yLJTt/gJrlluKysucM93H LxDPj9qoVHVogB/lVQbzE3vF4q58WryP7IOWSySPcq1LcUMCNdiPN0bgAWCFgg4OPU/d k0riNzCCN7g1ji66St7zWbAXpSdJg8FaLIixtDGbiWUUxF+QoaEXtB2+7k5SjW3pV9cJ lITbcaJCwvAhMHubkEIWp/AT7tsEMQVrPHqzDKVbI8RZ1/Ad9G8EqEJKOqlVvOCwR9P1 KraBzHiDhrWutCX8LT7+9bG65yp100A2zRGPseIpMl3V3tgX6hhBD+PW+qCD97/6weLQ gybw== X-Gm-Message-State: AOUpUlGheOo15Tb+Tq8Gb3yv2XcpR9CEiZc6SZ/oCwrgATrR9fPkV+8O WbbsKHQNeQQ70cHdH277IrZuqsSWUbE= X-Google-Smtp-Source: AAOMgpe9F+WEAHsUt3SKq15qbyYR7eQihyh2YUrdzo9zjliNQNvEaQUYGfMn9T00d1rfx2YP/3AoQA== X-Received: by 2002:a63:7847:: with SMTP id t68-v6mr116587pgc.329.1531341397477; Wed, 11 Jul 2018 13:36:37 -0700 (PDT) Received: from www.outflux.net (173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133]) by smtp.gmail.com with ESMTPSA id z76-v6sm915707pgz.16.2018.07.11.13.36.28 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 11 Jul 2018 13:36:35 -0700 (PDT) From: Kees Cook To: Herbert Xu Cc: Kees Cook , "Gustavo A. R. Silva" , Arnd Bergmann , Eric Biggers , Alasdair Kergon , Giovanni Cabiddu , Lars Persson , Mike Snitzer , Rabin Vincent , Tim Chen , "David S. Miller" , Masahiro Yamada , linux-crypto@vger.kernel.org, qat-linux@intel.com, dm-devel@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH v4 14/14] crypto: skcipher: Remove VLA usage for SKCIPHER_REQUEST_ON_STACK Date: Wed, 11 Jul 2018 13:36:19 -0700 Message-Id: <20180711203619.1020-15-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180711203619.1020-1-keescook@chromium.org> References: <20180711203619.1020-1-keescook@chromium.org> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In the quest to remove all stack VLA usage from the kernel[1], this caps the skcipher request size similar to other limits and adds a sanity check at registration. Looking at instrumented tcrypt output, the largest is for lrw: crypt: testing lrw(aes) crypto_skcipher_set_reqsize: 8 crypto_skcipher_set_reqsize: 88 crypto_skcipher_set_reqsize: 472 [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by: Kees Cook --- include/crypto/internal/skcipher.h | 1 + include/crypto/skcipher.h | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/include/crypto/internal/skcipher.h b/include/crypto/internal/skcipher.h index e42f7063f245..5035482cbe68 100644 --- a/include/crypto/internal/skcipher.h +++ b/include/crypto/internal/skcipher.h @@ -130,6 +130,7 @@ static inline struct crypto_skcipher *crypto_spawn_skcipher( static inline void crypto_skcipher_set_reqsize( struct crypto_skcipher *skcipher, unsigned int reqsize) { + BUG_ON(reqsize > SKCIPHER_MAX_REQSIZE); skcipher->reqsize = reqsize; } diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h index 2f327f090c3e..c48e194438cf 100644 --- a/include/crypto/skcipher.h +++ b/include/crypto/skcipher.h @@ -139,9 +139,11 @@ struct skcipher_alg { struct crypto_alg base; }; +#define SKCIPHER_MAX_REQSIZE 472 + #define SKCIPHER_REQUEST_ON_STACK(name, tfm) \ char __##name##_desc[sizeof(struct skcipher_request) + \ - crypto_skcipher_reqsize(tfm)] CRYPTO_MINALIGN_ATTR; \ + SKCIPHER_MAX_REQSIZE] CRYPTO_MINALIGN_ATTR; \ struct skcipher_request *name = (void *)__##name##_desc /**