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 A2810C433E1 for ; Fri, 21 Aug 2020 17:25:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 80F23207DE for ; Fri, 21 Aug 2020 17:25:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598030748; bh=Oq7KjuIEGAsnarIYTg82Iav+HRMBExE8AuCjNT05MZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=k+2gw+5+SkLsEoRQUR6jhoX+ZWPDrZ35zPLfWxSnaFECEL8dSKRFESU63SOPNWa8i MEvbwuH/ujXFxsZkh1pFJDTd4hFFdvxBbASlIvKK9sts0/dX92VpXgMggkBMlRhrTD kRRL/BIuAZ4O3xKKiPqh41boMHJZuEBaLWzhNdgo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729205AbgHURZe (ORCPT ); Fri, 21 Aug 2020 13:25:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:48002 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726749AbgHUQPW (ORCPT ); Fri, 21 Aug 2020 12:15:22 -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 ADBE622B43; Fri, 21 Aug 2020 16:15:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598026520; bh=Oq7KjuIEGAsnarIYTg82Iav+HRMBExE8AuCjNT05MZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rVSHuL6Kjgpv+y5tN7wmfq052r5B/ql3ZOXlYpr9w08m7JBAPWcTnPvDLfLQ6wKWH SJKa8fyhoWW9cuTYhMs9fgjUrbRvQN5Oat3LBh+vr8n562eQ8FDgNZ1zxF0n4OYhxm 8zNEtnGDy/ohogCnJjAhGAkldyDP6ldAA7RqY0ko= 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 Subject: [PATCH AUTOSEL 5.8 44/62] cec-api: prevent leaking memory through hole in structure Date: Fri, 21 Aug 2020 12:14:05 -0400 Message-Id: <20200821161423.347071-44-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200821161423.347071-1-sashal@kernel.org> References: <20200821161423.347071-1-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/media/cec/core/cec-api.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/media/cec/core/cec-api.c b/drivers/media/cec/core/cec-api.c index 17d1cb2e5f976..f922a2196b2b7 100644 --- a/drivers/media/cec/core/cec-api.c +++ b/drivers/media/cec/core/cec-api.c @@ -147,7 +147,13 @@ 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