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 95E22EEB565 for ; Sat, 9 Sep 2023 00:49:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232482AbjIIAtR (ORCPT ); Fri, 8 Sep 2023 20:49:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231508AbjIIAtQ (ORCPT ); Fri, 8 Sep 2023 20:49:16 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBC41211F; Fri, 8 Sep 2023 17:48:55 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 802EFC116B0; Sat, 9 Sep 2023 00:41:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694220082; bh=jjzMwEWZKOMTse8iBtBJgqoKd6M6bKScmEB0ZVohEwU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JTUYd7S+ag3hDwGjsQCmgXjNvikNH6Ql/T0ZxHSzx6fuyY+fUP5hQhOdZXnn46Nto THd8DkKBU4HWwxvB6LA6d5tfY/U5BPjeHB7zl8co7U/qSZpBpMZks5pbqTQt0tJpEo eU1PAdcmiYNHiCKHjOrao203Xsm5cb38aobzXtLzO0vGuo9R8mVBZq5kjMkgxYp+87 fXZ+G1Du1dhuLa+Ia3SYSVHfDwuVanO0m1e+WclVX8y+e7vxk4+7sMx+uL1vM9XeGD DyqVaDq/wZpUH/fjTcg3seLZbACgnT9TNE7N/NWLJYovKTdS6/fmpBd+W8/WH9rWT+ mbhqShNCvJUzQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhang Shurong , Hans Verkuil , Sasha Levin , mchehab@kernel.org, yuzhe@nfschina.com, harperchen1110@gmail.com, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 02/12] media: dw2102: Fix null-ptr-deref in dw2102_i2c_transfer() Date: Fri, 8 Sep 2023 20:41:05 -0400 Message-Id: <20230909004115.3581195-2-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230909004115.3581195-1-sashal@kernel.org> References: <20230909004115.3581195-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 4.14.325 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhang Shurong [ Upstream commit 5ae544d94abc8ff77b1b9bf8774def3fa5689b5b ] In dw2102_i2c_transfer, 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 dw2102_i2c_transfer. 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 950e252cb469 ("[media] dw2102: limit messages to buffer size") Signed-off-by: Zhang Shurong Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb/dw2102.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/drivers/media/usb/dvb-usb/dw2102.c b/drivers/media/usb/dvb-usb/dw2102.c index 2c9c4432a0e65..ef22188104718 100644 --- a/drivers/media/usb/dvb-usb/dw2102.c +++ b/drivers/media/usb/dvb-usb/dw2102.c @@ -133,6 +133,10 @@ static int dw2102_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], switch (num) { case 2: + if (msg[0].len < 1) { + num = -EOPNOTSUPP; + break; + } /* read stv0299 register */ value = msg[0].buf[0];/* register */ for (i = 0; i < msg[1].len; i++) { @@ -144,6 +148,10 @@ static int dw2102_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], case 1: switch (msg[0].addr) { case 0x68: + if (msg[0].len < 2) { + num = -EOPNOTSUPP; + break; + } /* write to stv0299 register */ buf6[0] = 0x2a; buf6[1] = msg[0].buf[0]; @@ -153,6 +161,10 @@ static int dw2102_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], break; case 0x60: if (msg[0].flags == 0) { + if (msg[0].len < 4) { + num = -EOPNOTSUPP; + break; + } /* write to tuner pll */ buf6[0] = 0x2c; buf6[1] = 5; @@ -164,6 +176,10 @@ static int dw2102_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], dw210x_op_rw(d->udev, 0xb2, 0, 0, buf6, 7, DW210X_WRITE_MSG); } else { + if (msg[0].len < 1) { + num = -EOPNOTSUPP; + break; + } /* read from tuner */ dw210x_op_rw(d->udev, 0xb5, 0, 0, buf6, 1, DW210X_READ_MSG); @@ -171,12 +187,20 @@ static int dw2102_i2c_transfer(struct i2c_adapter *adap, struct i2c_msg msg[], } break; case (DW2102_RC_QUERY): + if (msg[0].len < 2) { + num = -EOPNOTSUPP; + break; + } dw210x_op_rw(d->udev, 0xb8, 0, 0, buf6, 2, DW210X_READ_MSG); msg[0].buf[0] = buf6[0]; msg[0].buf[1] = buf6[1]; break; case (DW2102_VOLTAGE_CTRL): + if (msg[0].len < 1) { + num = -EOPNOTSUPP; + break; + } buf6[0] = 0x30; buf6[1] = msg[0].buf[0]; dw210x_op_rw(d->udev, 0xb2, 0, 0, -- 2.40.1