Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34B69C43217 for ; Mon, 15 Nov 2021 18:07:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20FDD633A4 for ; Mon, 15 Nov 2021 18:07:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232678AbhKOSKV (ORCPT ); Mon, 15 Nov 2021 13:10:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:50934 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237973AbhKOR23 (ORCPT ); Mon, 15 Nov 2021 12:28:29 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6B4406324B; Mon, 15 Nov 2021 17:16:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636996598; bh=RmlPYkTiq76zSr07PLV9M45bdt/RJ1Lr0AE9kY3UICY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iopCfldm7kdO2LZ62Zz6RRLCjVvXoBzQ8Df+3bcMh/8TPIp8O7eGiXMPY7N46yHkY u57FLwUqbR4/lwkHEsRliuJRoepXpJWVe1+4itcYEiK/mlNd1QdTTKIAVi31kFMJXM SYA1d39FztU9rhxEevRFxtKhsw1reoUYENNTZptE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tom Rix , Tim Harvey , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 5.4 198/355] media: TDA1997x: handle short reads of hdmi info frame. Date: Mon, 15 Nov 2021 18:02:02 +0100 Message-Id: <20211115165320.167133991@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211115165313.549179499@linuxfoundation.org> References: <20211115165313.549179499@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: Tom Rix [ Upstream commit 48d219f9cc667bc6fbc3e3af0b1bfd75db94fce4 ] Static analysis reports this representative problem tda1997x.c:1939: warning: 7th function call argument is an uninitialized value The 7th argument is buffer[0], which is set in the earlier call to io_readn(). When io_readn() call to io_read() fails with the first read, buffer[0] is not set and 0 is returned and stored in len. The later call to hdmi_infoframe_unpack()'s size parameter is the static size of buffer, always 40, so a short read is not caught in hdmi_infoframe_unpacks()'s checking. The variable len should be used instead. Zero initialize buffer to 0 so it is in a known start state. Fixes: 9ac0038db9a7 ("media: i2c: Add TDA1997x HDMI receiver driver") Signed-off-by: Tom Rix Reviewed-by: Tim Harvey Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/i2c/tda1997x.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/media/i2c/tda1997x.c b/drivers/media/i2c/tda1997x.c index 18a2027ba1450..5faffedb0feba 100644 --- a/drivers/media/i2c/tda1997x.c +++ b/drivers/media/i2c/tda1997x.c @@ -1247,13 +1247,13 @@ tda1997x_parse_infoframe(struct tda1997x_state *state, u16 addr) { struct v4l2_subdev *sd = &state->sd; union hdmi_infoframe frame; - u8 buffer[40]; + u8 buffer[40] = { 0 }; u8 reg; int len, err; /* read data */ len = io_readn(sd, addr, sizeof(buffer), buffer); - err = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer)); + err = hdmi_infoframe_unpack(&frame, buffer, len); if (err) { v4l_err(state->client, "failed parsing %d byte infoframe: 0x%04x/0x%02x\n", @@ -1927,13 +1927,13 @@ static int tda1997x_log_infoframe(struct v4l2_subdev *sd, int addr) { struct tda1997x_state *state = to_state(sd); union hdmi_infoframe frame; - u8 buffer[40]; + u8 buffer[40] = { 0 }; int len, err; /* read data */ len = io_readn(sd, addr, sizeof(buffer), buffer); v4l2_dbg(1, debug, sd, "infoframe: addr=%d len=%d\n", addr, len); - err = hdmi_infoframe_unpack(&frame, buffer, sizeof(buffer)); + err = hdmi_infoframe_unpack(&frame, buffer, len); if (err) { v4l_err(state->client, "failed parsing %d byte infoframe: 0x%04x/0x%02x\n", -- 2.33.0