From patchwork Mon Jun 25 21:10:24 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10487297 X-Patchwork-Delegate: snitzer@redhat.com 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 4EE186038C for ; Mon, 25 Jun 2018 21:11:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3CCB3286EC for ; Mon, 25 Jun 2018 21:11:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 312D4286F7; Mon, 25 Jun 2018 21:11:06 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9A53E286DF for ; Mon, 25 Jun 2018 21:11:05 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AF4D0C058CA5; Mon, 25 Jun 2018 21:11:04 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7209E26DF0; Mon, 25 Jun 2018 21:11:04 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 16B8318037F4; Mon, 25 Jun 2018 21:11:04 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id w5PLAqtV027002 for ; Mon, 25 Jun 2018 17:10:52 -0400 Received: by smtp.corp.redhat.com (Postfix) id 40B897D497; Mon, 25 Jun 2018 21:10:52 +0000 (UTC) Delivered-To: dm-devel@redhat.com Received: from mx1.redhat.com (ext-mx06.extmail.prod.ext.phx2.redhat.com [10.5.110.30]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 339D37CAEF for ; Mon, 25 Jun 2018 21:10:49 +0000 (UTC) Received: from mail-pg0-f65.google.com (mail-pg0-f65.google.com [74.125.83.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 3BC0D356DB for ; Mon, 25 Jun 2018 21:10:48 +0000 (UTC) Received: by mail-pg0-f65.google.com with SMTP id i7-v6so6613197pgp.2 for ; Mon, 25 Jun 2018 14:10:48 -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=PbwSt8IMbUmiAnJPK0uuLHHvB9/qjp0V2xYcxgegYD4=; b=fr1CduVB1/5v34K7SXFRFl6hAA7+DVm9T9LIogF23zAtTG8UycUcMgyFrngt2RxvTG y2jf0UStdogBGrCfnVMBFs/Z3beLSja8yXnIP4yybArIQITX0uTsHmMHGxvHKeePOKrm WFWe2xq2vruI4yXXAAkLgvPplNEn6AdKv/aNM= 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=PbwSt8IMbUmiAnJPK0uuLHHvB9/qjp0V2xYcxgegYD4=; b=FOoK4lyREc/SwAngk21vlwafOeRHGasVnqxFmzFlQhBsiXhi0SOOm/tUgl8VT3QbtS iVHElh8H5rzSMv3KJeDjmeISVUUdMYpdUpOn5IRxkg/Yz7kk0PoMOzz+hFSZ66nuJaLW EbIt+N7oWTu0XKnUQyGpq1hq2Oyo3RjKWqlRdT9lJlZbxCvMR71aPLxixKQ0y268xYC7 XwH4aucNbUhgqQ11rgh4T/GXff/RR4t5/5wHEhN6ZjrqJcJmeblx2Rfm4+wa6QTpAw/B Ip97FG03qeI6nkKuQEHXoSAdeJiYyhbXKBTvSuO1x5qBDHBvgGRSFuErWMENX3FhEmc7 SI8A== X-Gm-Message-State: APt69E0Dhqw5D7YjQaW+0iTBTtRi4BQMvpzOKBmPKmur6aoR7vkKAkhH VZFJRRb7+PPEMl8a4KLxd7wsDQ== X-Google-Smtp-Source: ADUXVKIbl8p2B4qPAzrO4KEvhKjTIYF6iVPudD4v5zCedSeguJ4Pt9x4EKPN8yiOa+CKRu/5awxvAQ== X-Received: by 2002:a62:6406:: with SMTP id y6-v6mr14571609pfb.204.1529961047692; Mon, 25 Jun 2018 14:10:47 -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 c12-v6sm22800661pfi.177.2018.06.25.14.10.39 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 25 Jun 2018 14:10:41 -0700 (PDT) From: Kees Cook To: Herbert Xu Date: Mon, 25 Jun 2018 14:10:24 -0700 Message-Id: <20180625211026.15819-10-keescook@chromium.org> In-Reply-To: <20180625211026.15819-1-keescook@chromium.org> References: <20180625211026.15819-1-keescook@chromium.org> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 25 Jun 2018 21:10:48 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 25 Jun 2018 21:10:48 +0000 (UTC) for IP:'74.125.83.65' DOMAIN:'mail-pg0-f65.google.com' HELO:'mail-pg0-f65.google.com' FROM:'keescook@chromium.org' RCPT:'' X-RedHat-Spam-Score: -0.131 (DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_PASS) 74.125.83.65 mail-pg0-f65.google.com 74.125.83.65 mail-pg0-f65.google.com X-Scanned-By: MIMEDefang 2.78 on 10.5.110.30 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-loop: dm-devel@redhat.com Cc: Giovanni Cabiddu , Kees Cook , Arnd Bergmann , "Gustavo A. R. Silva" , Mike Snitzer , Eric Biggers , 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: [dm-devel] [PATCH v2 09/11] crypto: shash: Remove VLA usage in unaligned hashing X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Mon, 25 Jun 2018 21:11:05 +0000 (UTC) X-Virus-Scanned: ClamAV using ClamSMTP In the quest to remove all stack VLA usage from the kernel[1], this uses the newly defined max alignment to perform unaligned hashing to avoid VLAs, and drops the helper function while adding sanity checks on the resulting buffer sizes. Additionally, the __aligned_largest macro is removed since this helper was the only user. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Cc: Herbert Xu Cc: "David S. Miller" Cc: linux-crypto@vger.kernel.org Signed-off-by: Kees Cook --- crypto/shash.c | 19 ++++++++----------- include/linux/compiler-gcc.h | 1 - 2 files changed, 8 insertions(+), 12 deletions(-) diff --git a/crypto/shash.c b/crypto/shash.c index ab6902c6dae7..8081c5e03770 100644 --- a/crypto/shash.c +++ b/crypto/shash.c @@ -73,13 +73,6 @@ int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key, } EXPORT_SYMBOL_GPL(crypto_shash_setkey); -static inline unsigned int shash_align_buffer_size(unsigned len, - unsigned long mask) -{ - typedef u8 __aligned_largest u8_aligned; - return len + (mask & ~(__alignof__(u8_aligned) - 1)); -} - static int shash_update_unaligned(struct shash_desc *desc, const u8 *data, unsigned int len) { @@ -88,11 +81,13 @@ static int shash_update_unaligned(struct shash_desc *desc, const u8 *data, unsigned long alignmask = crypto_shash_alignmask(tfm); unsigned int unaligned_len = alignmask + 1 - ((unsigned long)data & alignmask); - u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)] - __aligned_largest; + u8 ubuf[MAX_ALGAPI_ALIGNMASK + 1]; u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1); int err; + if (WARN_ON(buf + unaligned_len > ubuf + sizeof(ubuf))) + return -EINVAL; + if (unaligned_len > len) unaligned_len = len; @@ -124,11 +119,13 @@ static int shash_final_unaligned(struct shash_desc *desc, u8 *out) unsigned long alignmask = crypto_shash_alignmask(tfm); struct shash_alg *shash = crypto_shash_alg(tfm); unsigned int ds = crypto_shash_digestsize(tfm); - u8 ubuf[shash_align_buffer_size(ds, alignmask)] - __aligned_largest; + u8 ubuf[SHASH_MAX_DIGESTSIZE]; u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1); int err; + if (WARN_ON(buf + ds > ubuf + sizeof(ubuf))) + return -EINVAL; + err = shash->final(desc, buf); if (err) goto out; diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index f1a7492a5cc8..1f1cdef36a82 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -125,7 +125,6 @@ */ #define __pure __attribute__((pure)) #define __aligned(x) __attribute__((aligned(x))) -#define __aligned_largest __attribute__((aligned)) #define __printf(a, b) __attribute__((format(printf, a, b))) #define __scanf(a, b) __attribute__((format(scanf, a, b))) #define __attribute_const__ __attribute__((__const__))