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=-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=unavailable 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 C5AB5C4332E for ; Mon, 28 Dec 2020 15:38:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9797A229C4 for ; Mon, 28 Dec 2020 15:38:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408499AbgL1Pdl (ORCPT ); Mon, 28 Dec 2020 10:33:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:56000 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404230AbgL1NyX (ORCPT ); Mon, 28 Dec 2020 08:54:23 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 136B3206D4; Mon, 28 Dec 2020 13:54:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609163648; bh=C4Xx29pfeW0Sm72GZwO45w63PsyaxlpmUCXJGWfKUyo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GGfHd7I7CzfQlso2+AFxWg5F+gs2HAMPaTQe+HGAwif19Igg4vMxGTtfmhr1s22s5 dwgR+oeCuoW99LWWFXNCj3fCcZKI2j1v2AU6fZ60ujLuZkjUjkEDlVK6g073MbGkZT q0efK1Vv35b4FRYHdV8tF1p4gxFjdY2przt/kbMA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ard Biesheuvel , Herbert Xu Subject: [PATCH 5.4 359/453] crypto: ecdh - avoid unaligned accesses in ecdh_set_secret() Date: Mon, 28 Dec 2020 13:49:55 +0100 Message-Id: <20201228124954.484259579@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124937.240114599@linuxfoundation.org> References: <20201228124937.240114599@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 @@ -53,12 +53,13 @@ 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; }