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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 E987BC433DF for ; Fri, 21 Aug 2020 16:24:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC0B820578 for ; Fri, 21 Aug 2020 16:24:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598027044; bh=8kd2JWfylGbyX5junfsVFBIFiC5m0s7OyUEiuP3YRFk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=BivIA3HsT9MnBwMj6bGEQ/W1xRZbm9N0r4LvQweA3ICqmQltIqd+D2GLSAcNbYCQ8 AXyj/43b7VaQQbXqbNiZB9cpq15iX0DV/o3Hq1AqpAvKJ/JMP5p7qufQgyXqMWJRaV fHMZQf/7GamAmUT79u1waf/spGPn2NFT9M13c7OE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728584AbgHUQYC (ORCPT ); Fri, 21 Aug 2020 12:24:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:49882 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728146AbgHUQUu (ORCPT ); Fri, 21 Aug 2020 12:20:50 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8A95E22D2C; Fri, 21 Aug 2020 16:20:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598026804; bh=8kd2JWfylGbyX5junfsVFBIFiC5m0s7OyUEiuP3YRFk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gZ9jFDVwmCaXZXBb1deWpdSWZD/rmKF3B0u5K+8t27bEnrGEBC/0b7WR02YtYXraX JEqLUQIc9Vl3MZ8XCEEocpfmJLE4rLt6SUT6DGNsEpjBZig3QuROsnky397fnFuVCN p0GSoNUJ3zErU0aKjkBgbdBqvCkDVCL28GZvjCEs= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin , linux-media@vger.kernel.org, devel@driverdev.osuosl.org Subject: [PATCH AUTOSEL 4.9 19/26] cec-api: prevent leaking memory through hole in structure Date: Fri, 21 Aug 2020 12:19:30 -0400 Message-Id: <20200821161938.349246-19-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200821161938.349246-1-sashal@kernel.org> References: <20200821161938.349246-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hans Verkuil [ Upstream commit 6c42227c3467549ddc65efe99c869021d2f4a570 ] Fix this smatch warning: drivers/media/cec/core/cec-api.c:156 cec_adap_g_log_addrs() warn: check that 'log_addrs' doesn't leak information (struct has a hole after 'features') Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/staging/media/cec/cec-api.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/staging/media/cec/cec-api.c b/drivers/staging/media/cec/cec-api.c index e274e2f223986..264bb7d1efcb8 100644 --- a/drivers/staging/media/cec/cec-api.c +++ b/drivers/staging/media/cec/cec-api.c @@ -141,7 +141,13 @@ static long cec_adap_g_log_addrs(struct cec_adapter *adap, struct cec_log_addrs log_addrs; mutex_lock(&adap->lock); - log_addrs = adap->log_addrs; + /* + * We use memcpy here instead of assignment since there is a + * hole at the end of struct cec_log_addrs that an assignment + * might ignore. So when we do copy_to_user() we could leak + * one byte of memory. + */ + memcpy(&log_addrs, &adap->log_addrs, sizeof(log_addrs)); if (!adap->is_configured) memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID, sizeof(log_addrs.log_addr)); -- 2.25.1