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=-18.8 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_BLOCKED, 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 1E6BAC433E0 for ; Mon, 11 Jan 2021 13:08:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CEB78227C3 for ; Mon, 11 Jan 2021 13:08:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730659AbhAKNH7 (ORCPT ); Mon, 11 Jan 2021 08:07:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:54744 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730532AbhAKNHL (ORCPT ); Mon, 11 Jan 2021 08:07:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id CD1722251F; Mon, 11 Jan 2021 13:06:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610370390; bh=qUziF+x+vkE7l0Qc0ydsWSwZ/md35vyMtcMMyR3TadA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kXMuAogKNWGrhQWt19FK3ucUaUZkMLOSjn7p1mQaajvCxsRmPiLc5AHUAtnz9oY5/ 0ziPe4dUIRntze1ERJLTtJHfJHBEQOJ44xPVftFJqmB+UrHPcJABlArp/KgBsTYvs7 2hVZ6K9x9BeNMwBF4IkkTOxAWTnLQo0vR1wJIaxQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Machek , Ard Biesheuvel , Herbert Xu Subject: [PATCH 4.14 28/57] crypto: ecdh - avoid buffer overflow in ecdh_set_secret() Date: Mon, 11 Jan 2021 14:01:47 +0100 Message-Id: <20210111130035.076633853@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111130033.715773309@linuxfoundation.org> References: <20210111130033.715773309@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: linux-kernel@vger.kernel.org From: Ard Biesheuvel commit 0aa171e9b267ce7c52d3a3df7bc9c1fc0203dec5 upstream. Pavel reports that commit 17858b140bf4 ("crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()") fixes one problem but introduces another: the unconditional memcpy() introduced by that commit may overflow the target buffer if the source data is invalid, which could be the result of intentional tampering. So check params.key_size explicitly against the size of the target buffer before validating the key further. Fixes: 17858b140bf4 ("crypto: ecdh - avoid unaligned accesses in ecdh_set_secret()") Reported-by: Pavel Machek Cc: Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- crypto/ecdh.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/crypto/ecdh.c +++ b/crypto/ecdh.c @@ -43,7 +43,8 @@ static int ecdh_set_secret(struct crypto struct ecdh params; unsigned int ndigits; - if (crypto_ecdh_decode_key(buf, len, ¶ms) < 0) + if (crypto_ecdh_decode_key(buf, len, ¶ms) < 0 || + params.key_size > sizeof(ctx->private_key)) return -EINVAL; ndigits = ecdh_supported_curve(params.curve_id);