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 848CAC8300C for ; Wed, 7 Jun 2023 20:20:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232366AbjFGUUF (ORCPT ); Wed, 7 Jun 2023 16:20:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232874AbjFGUTr (ORCPT ); Wed, 7 Jun 2023 16:19:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2900F26BE for ; Wed, 7 Jun 2023 13:19:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C850964380 for ; Wed, 7 Jun 2023 20:18:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DB03AC433EF; Wed, 7 Jun 2023 20:18:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1686169108; bh=k9tHMD1JfXB6FZDsje79FwzK4Ljazuakd2wCOOi5Wj4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sJcpssdpOOo8ucxisXHnCteN1zUNvw3BY+gvYZLojGHON4sXNI/FClzhmM/2JVfiU lJ6hUNzPBD0Klcv+kF4g/xhoTYrOcWhruqq1CrCUjzfUwSCJ9R5kVVtHrIq+qCAPqc cT83IEoeAZAjObiVlLYeqjiW4HKu6V0xpGmYxjtQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wei Chen , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 4.14 18/61] media: dvb-usb: az6027: fix three null-ptr-deref in az6027_i2c_xfer() Date: Wed, 7 Jun 2023 22:15:32 +0200 Message-ID: <20230607200841.500232043@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230607200835.310274198@linuxfoundation.org> References: <20230607200835.310274198@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wei Chen [ Upstream commit 858e97d7956d17a2cb56a9413468704a4d5abfe1 ] In az6027_i2c_xfer, msg is controlled by user. When msg[i].buf is null, commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()") fix the null-ptr-deref bug when msg[i].addr is 0x99. However, null-ptr-deref also happens when msg[i].addr is 0xd0 and 0xc0. We add check on msg[i].len to prevent null-ptr-deref. Link: https://lore.kernel.org/linux-media/20230310165604.3093483-1-harperchen1110@gmail.com Signed-off-by: Wei Chen Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb/az6027.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/media/usb/dvb-usb/az6027.c b/drivers/media/usb/dvb-usb/az6027.c index f2b5ba1d28098..05988c5ce63ca 100644 --- a/drivers/media/usb/dvb-usb/az6027.c +++ b/drivers/media/usb/dvb-usb/az6027.c @@ -991,6 +991,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n /* write/read request */ if (i + 1 < num && (msg[i + 1].flags & I2C_M_RD)) { req = 0xB9; + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } index = (((msg[i].buf[0] << 8) & 0xff00) | (msg[i].buf[1] & 0x00ff)); value = msg[i].addr + (msg[i].len << 8); length = msg[i + 1].len + 6; @@ -1004,6 +1008,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n /* demod 16bit addr */ req = 0xBD; + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } index = (((msg[i].buf[0] << 8) & 0xff00) | (msg[i].buf[1] & 0x00ff)); value = msg[i].addr + (2 << 8); length = msg[i].len - 2; @@ -1029,6 +1037,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n } else { req = 0xBD; + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } index = msg[i].buf[0] & 0x00FF; value = msg[i].addr + (1 << 8); length = msg[i].len - 1; -- 2.39.2