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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 2235AC636CE for ; Thu, 15 Jul 2021 18:58:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DECB60D07 for ; Thu, 15 Jul 2021 18:58:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241935AbhGOTBN (ORCPT ); Thu, 15 Jul 2021 15:01:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:60992 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241332AbhGOS6w (ORCPT ); Thu, 15 Jul 2021 14:58:52 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 747C0613C4; Thu, 15 Jul 2021 18:55:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626375356; bh=Rq6Vllx5aizCaYRvGFri4AYkM3uXqJdalDaJzcbLmwY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2gwth65YQ8yxzPA51s9qu+nlm/z8X5FQMn9OrriEA3a/gJ25bSIOOw6MIfEQUk6c4 Dhl5bHlFchLZkYTn2C6uaSM2vaEIW6gJVx2tMBkzRQAeNC3QeVo1gyklIQ1sHMsvSt nZb7/qzzC7KmHnZ25Tsl5WbuSv84MrgNjTJgSN9o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Alex Deucher , Sasha Levin Subject: [PATCH 5.12 051/242] drm/amd/display: Avoid HDCP over-read and corruption Date: Thu, 15 Jul 2021 20:36:53 +0200 Message-Id: <20210715182601.283161448@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210715182551.731989182@linuxfoundation.org> References: <20210715182551.731989182@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: Kees Cook [ Upstream commit 06888d571b513cbfc0b41949948def6cb81021b2 ] Instead of reading the desired 5 bytes of the actual target field, the code was reading 8. This could result in a corrupted value if the trailing 3 bytes were non-zero, so instead use an appropriately sized and zero-initialized bounce buffer, and read only 5 bytes before casting to u64. Signed-off-by: Kees Cook Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c index 73ca49f05bd3..eb56526ec32c 100644 --- a/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c +++ b/drivers/gpu/drm/amd/display/modules/hdcp/hdcp1_execution.c @@ -29,8 +29,10 @@ static inline enum mod_hdcp_status validate_bksv(struct mod_hdcp *hdcp) { uint64_t n = 0; uint8_t count = 0; + u8 bksv[sizeof(n)] = { }; - memcpy(&n, hdcp->auth.msg.hdcp1.bksv, sizeof(uint64_t)); + memcpy(bksv, hdcp->auth.msg.hdcp1.bksv, sizeof(hdcp->auth.msg.hdcp1.bksv)); + n = *(uint64_t *)bksv; while (n) { count++; -- 2.30.2