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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74B2EEEB565 for ; Sat, 9 Sep 2023 00:44:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346100AbjIIAoQ (ORCPT ); Fri, 8 Sep 2023 20:44:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346199AbjIIAni (ORCPT ); Fri, 8 Sep 2023 20:43:38 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76ABEE45; Fri, 8 Sep 2023 17:41:03 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8666C116A5; Sat, 9 Sep 2023 00:40:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694220054; bh=zYyaHrFEtEHKe5etRnxtlFJFqe1gKZN9do1KTfD6Etg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qmG2BH8HRa62R0IW4fPSzHBEyiw2eVW4ymFYtwUw6AlAyBkl5OI9zYaKz+TAcwCvK 76d6Cc9LXiH0xeFMnHsXRRri12Zc4Dv1U5bUO3A7W+KXBCCSs8fWL3u/yJ4fRlfWUz 6XY/riWV93A3oE65dGGZrsXNAsbwG7gDQHNXu6wQZiU7XoJ4l4hvxnm8c/Izs4GZTr bjjRc7e3zwUvktA0Udx/72wnB/qEB2oeOiTCK/HNEvpi1E9Bmb8IBwbkPV6J/6WdOJ xnj542I6e83Mai2hm+HPMGm/GuieQOBPElzgBp5TTU8vtQeO6XDJcGri2gkg5YVX6F fb58B/abk5+CQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhang Shurong , Hans Verkuil , Sasha Levin , mchehab@kernel.org, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 03/14] media: af9005: Fix null-ptr-deref in af9005_i2c_xfer Date: Fri, 8 Sep 2023 20:40:34 -0400 Message-Id: <20230909004045.3581014-3-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230909004045.3581014-1-sashal@kernel.org> References: <20230909004045.3581014-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.19.294 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhang Shurong [ Upstream commit f4ee84f27625ce1fdf41e8483fa0561a1b837d10 ] In af9005_i2c_xfer, msg is controlled by user. When msg[i].buf is null and msg[i].len is zero, former checks on msg[i].buf would be passed. Malicious data finally reach af9005_i2c_xfer. If accessing msg[i].buf[0] without sanity check, null ptr deref would happen. We add check on msg[i].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()") Signed-off-by: Zhang Shurong Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb/af9005.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/media/usb/dvb-usb/af9005.c b/drivers/media/usb/dvb-usb/af9005.c index d2737460c9d3b..60acaaf8b892f 100644 --- a/drivers/media/usb/dvb-usb/af9005.c +++ b/drivers/media/usb/dvb-usb/af9005.c @@ -431,6 +431,10 @@ static int af9005_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], if (ret == 0) ret = 2; } else { + if (msg[0].len < 2) { + ret = -EOPNOTSUPP; + goto unlock; + } /* write one or more registers */ reg = msg[0].buf[0]; addr = msg[0].addr; @@ -440,6 +444,7 @@ static int af9005_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = 1; } +unlock: mutex_unlock(&d->i2c_mutex); return ret; } -- 2.40.1