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 1BCB4C433E6 for ; Mon, 11 Jan 2021 13:28:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D180B22515 for ; Mon, 11 Jan 2021 13:28:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732445AbhAKN2E (ORCPT ); Mon, 11 Jan 2021 08:28:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:34996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732381AbhAKNQW (ORCPT ); Mon, 11 Jan 2021 08:16:22 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6561222A83; Mon, 11 Jan 2021 13:15:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610370941; bh=dCWYoSgP0H6MmMbGD2bGUmY/0stEmMVXnyrvmkctCRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MMecgBSvY/HsU7BP0ag+6J40K8o4QZS603XPH6i750raB2pNjiFf+MhIMi1c/4oi8 ANDhfOiD1RqQ0HCwAxXNdbB4jn08MT2/61gCK++6Q4E51gvblSomwi6/WZ4PHs9+ZT mbHBwTRN+JYKJS0moc5f0neJZHBzYRY2XCo9+oeU= 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 5.10 072/145] crypto: ecdh - avoid buffer overflow in ecdh_set_secret() Date: Mon, 11 Jan 2021 14:01:36 +0100 Message-Id: <20210111130051.997090771@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210111130048.499958175@linuxfoundation.org> References: <20210111130048.499958175@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 @@ -39,7 +39,8 @@ 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);