From patchwork Mon Dec 28 12:50:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 355082 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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_RED, USER_AGENT_GIT autolearn=ham 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 3C447C4332D for ; Mon, 28 Dec 2020 13:35:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F232320719 for ; Mon, 28 Dec 2020 13:35:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389326AbgL1NfZ (ORCPT ); Mon, 28 Dec 2020 08:35:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:35762 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389337AbgL1NfY (ORCPT ); Mon, 28 Dec 2020 08:35:24 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5A7E8206ED; Mon, 28 Dec 2020 13:34:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609162483; bh=FDM1bQrrBwAJ8UlQWbpyLw1SCK+IuHp/9BB247poVos=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aZd6ubNB4yBbLJO74gQf7PTk+ioJ7TFh+Rz/v5O5KYA32m2eGgFNyz8SGMLZh2Vlu gnWZrDW9TSDMeukRrny+D0ZcsGNoZAAFF0hNQrns+JGXkqatjBmc27SAcMXz0cg+ET pUQ7HCHIv39mii/UERQhanO8B/kyI2B6mkpEOPN4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Herbert Xu Subject: [PATCH 4.19 287/346] crypto: ecdh - avoid unaligned accesses in ecdh_set_secret() Date: Mon, 28 Dec 2020 13:50:06 +0100 Message-Id: <20201228124933.649086790@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124919.745526410@linuxfoundation.org> References: <20201228124919.745526410@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Ard Biesheuvel commit 17858b140bf49961b71d4e73f1c3ea9bc8e7dda0 upstream. ecdh_set_secret() casts a void* pointer to a const u64* in order to feed it into ecc_is_key_valid(). This is not generally permitted by the C standard, and leads to actual misalignment faults on ARMv6 cores. In some cases, these are fixed up in software, but this still leads to performance hits that are entirely avoidable. So let's copy the key into the ctx buffer first, which we will do anyway in the common case, and which guarantees correct alignment. Cc: Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/ecdh.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/crypto/ecdh.c +++ b/crypto/ecdh.c @@ -57,12 +57,13 @@ static int ecdh_set_secret(struct crypto return ecc_gen_privkey(ctx->curve_id, ctx->ndigits, ctx->private_key); - if (ecc_is_key_valid(ctx->curve_id, ctx->ndigits, - (const u64 *)params.key, params.key_size) < 0) - return -EINVAL; - memcpy(ctx->private_key, params.key, params.key_size); + if (ecc_is_key_valid(ctx->curve_id, ctx->ndigits, + ctx->private_key, params.key_size) < 0) { + memzero_explicit(ctx->private_key, params.key_size); + return -EINVAL; + } return 0; }