From patchwork Tue Aug 7 21:18:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10559209 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-2.web.codeaurora.org (Postfix) with ESMTP id 855FA1390 for ; Tue, 7 Aug 2018 21:19:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 75E752A5F7 for ; Tue, 7 Aug 2018 21:19:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6A3B02A5FB; Tue, 7 Aug 2018 21:19:09 +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=ham 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 168E92A5F7 for ; Tue, 7 Aug 2018 21:19:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727240AbeHGXfO (ORCPT ); Tue, 7 Aug 2018 19:35:14 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:40188 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727169AbeHGXfN (ORCPT ); Tue, 7 Aug 2018 19:35:13 -0400 Received: by mail-pg1-f196.google.com with SMTP id x5-v6so33651pgp.7 for ; Tue, 07 Aug 2018 14:18:55 -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=MolSfpaKz70ZU2b1072Jk1SbatLRIM91vChMXrA2xIqNwfxBezcEU2kqo4c2Wno5rh 6QwpE0T2sBrl+rxI8Nxqt0spLN6nEyODTgD28prp0sGMxIV2Mb49rWrW9A0Iz20U3/tm I6ZgxWs75yLRyZGwq2XZx2PttDL0r6w0zlggU= 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=eEbSKL6IQRRqgU+U1H1P+xG1/azka5yFceRPE7eFvnj8vOkubYPt1wE5pM0eqPPr2d KX1KPCAAXYG9KEHZ//kc+kNevlDnfo3SkyF3KfM9oWaiolCfgJbv7DI3PEcSyM2iBeTn X88h/koPkCOAoeqWSlx0HSHh8Z+sPHX6MScK6MqdOp8uSzbS9JC6r9NJehG/zdPyI9VY dXytltx3KGwtB/I4QI/XBrffEBkDQJrNq0Qzf6pI2q16hDdkCZsBnh4uwxtxd/qjOpeH uO28Cn3kDOjSYXGJCyuwRTwWkvS6wsHVyG2kwOHyAPuFJ1RPCYDIS1VkSeR2nnbghpX9 rEtA== X-Gm-Message-State: AOUpUlHkRSKppWfzmVaeGMfecqYXJ5LQiI3eo4GyFNKLICep5gmZNK5x 45MrcLNqwVCuQlYQUVPXqUoFMg== X-Google-Smtp-Source: AA+uWPyFXh2Ih2BWYqPM8DkJ+vqdAAp3AfsudSnI3WJ1RwOCXImn5IqCJVa14q7zc2+GF1suv4yY6g== X-Received: by 2002:a62:8559:: with SMTP id u86-v6mr105034pfd.32.1533676735035; Tue, 07 Aug 2018 14:18:55 -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 b68-v6sm422503pfd.74.2018.08.07.14.18.49 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 07 Aug 2018 14:18:51 -0700 (PDT) From: Kees Cook To: Herbert Xu Cc: Kees Cook , Eric Biggers , Ard Biesheuvel , Giovanni Cabiddu , Alasdair Kergon , Mike Snitzer , Tudor-Dan Ambarus , Andrew Morton , Thomas Gleixner , Geert Uytterhoeven , Arnd Bergmann , Will Deacon , Rasmus Villemoes , David Woodhouse , Matthew Wilcox , "David S. Miller" , "Gustavo A. R. Silva" , linux-crypto@vger.kernel.org, dm-devel@redhat.com, qat-linux@intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v8 9/9] crypto: skcipher: Remove VLA usage for SKCIPHER_REQUEST_ON_STACK Date: Tue, 7 Aug 2018 14:18:43 -0700 Message-Id: <20180807211843.47586-10-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180807211843.47586-1-keescook@chromium.org> References: <20180807211843.47586-1-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 /**