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 462D2C7EE2C for ; Thu, 25 May 2023 18:40:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241901AbjEYSk4 (ORCPT ); Thu, 25 May 2023 14:40:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242111AbjEYSjL (ORCPT ); Thu, 25 May 2023 14:39:11 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F209A1FCD; Thu, 25 May 2023 11:37:09 -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 0C68D6491B; Thu, 25 May 2023 18:37:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BB825C4339E; Thu, 25 May 2023 18:37:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685039826; bh=jKrNuBwFBASeoYEA5DGc1XNcj2STVtp2XXCpYrs7yV0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Qxm99LEC6Y7SSXf7mXH/ujAWV3aruuSsBgPVWDODSWrCL8pxMCy+YJy4o/4FVoCR7 t9qQCPZQBfapOxPO1AVevBmZv/pPtcqQs5btGAnRR83+U0vqCyXUHxO7YGEBMuKFmt VSHnGyH0AwYj3KFk0Jincz+mvvD2qYx5Y23WNjHoG59CJuivtnZlxOIWjTG63xD/dy 2NwXpT/skjwxt1Os1N2t5tgc+qni4SAco+7ADFobE7GpwvmMlZe8K5IkqvD4vn3UEL 9xbwutX5KazZAZoFdOLn/7GDpZaBoG7UKh4zD8Sen912C1VWR1nuJnfqq1Egksoyoq GLmiCgaBQMybw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhang Shurong , Mauro Carvalho Chehab , Sasha Levin , crope@iki.fi, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 15/57] media: dvb-usb-v2: rtl28xxu: fix null-ptr-deref in rtl28xxu_i2c_xfer Date: Thu, 25 May 2023 14:35:25 -0400 Message-Id: <20230525183607.1793983-15-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230525183607.1793983-1-sashal@kernel.org> References: <20230525183607.1793983-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zhang Shurong [ Upstream commit aa4a447b81b84f69c1a89ad899df157f386d7636 ] In rtl28xxu_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 rtl28xxu_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()") Link: https://lore.kernel.org/linux-media/tencent_3623572106754AC2F266B316798B0F6CCA05@qq.com Signed-off-by: Zhang Shurong Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb-v2/rtl28xxu.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c index 795a012d40200..f7884bb56fccf 100644 --- a/drivers/media/usb/dvb-usb-v2/rtl28xxu.c +++ b/drivers/media/usb/dvb-usb-v2/rtl28xxu.c @@ -176,6 +176,10 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = -EOPNOTSUPP; goto err_mutex_unlock; } else if (msg[0].addr == 0x10) { + if (msg[0].len < 1 || msg[1].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 1 - integrated demod */ if (msg[0].buf[0] == 0x00) { /* return demod page from driver cache */ @@ -189,6 +193,10 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = rtl28xxu_ctrl_msg(d, &req); } } else if (msg[0].len < 2) { + if (msg[0].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 2 - old I2C */ req.value = (msg[0].buf[0] << 8) | (msg[0].addr << 1); req.index = CMD_I2C_RD; @@ -217,8 +225,16 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = -EOPNOTSUPP; goto err_mutex_unlock; } else if (msg[0].addr == 0x10) { + if (msg[0].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 1 - integrated demod */ if (msg[0].buf[0] == 0x00) { + if (msg[0].len < 2) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* save demod page for later demod access */ dev->page = msg[0].buf[1]; ret = 0; @@ -231,6 +247,10 @@ static int rtl28xxu_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], ret = rtl28xxu_ctrl_msg(d, &req); } } else if ((msg[0].len < 23) && (!dev->new_i2c_write)) { + if (msg[0].len < 1) { + ret = -EOPNOTSUPP; + goto err_mutex_unlock; + } /* method 2 - old I2C */ req.value = (msg[0].buf[0] << 8) | (msg[0].addr << 1); req.index = CMD_I2C_WR; -- 2.39.2