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 635DDC7EE2C for ; Thu, 25 May 2023 18:57:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243463AbjEYS5W (ORCPT ); Thu, 25 May 2023 14:57:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243298AbjEYSzD (ORCPT ); Thu, 25 May 2023 14:55:03 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BCAB468B; Thu, 25 May 2023 11:46:44 -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 D6FF06498F; Thu, 25 May 2023 18:44:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93A63C4339B; Thu, 25 May 2023 18:44:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1685040253; bh=mZDtEH9Zmy+aDkPrJKTdtSRKrMzyB2JQlpEDhjhEops=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Yby0HW/CL3A8MXSwtyiDg/BLloE5K+fY7Ra8IrpAmRBEBlaxirnk0XHzLdyzja+gQ kuTEtBujjTk2as/P6bDQEJuIXoBs3rQK2mMR7oD/1Dn9bKVRFss0eWCeqD0OFVOGpi sF/fmzcEpCFtyrTqfvIz54syqvR6QYvQhhaQ4TUW70fLKU4ncJboaAt+/UUvBCfSym h0BZV4gvfBuD34tYsPRwgVLqGivZbTGHZZ5/ynKiSyA+OcLnZfz4+XJWJxMQRLftnW +kxTxEgzrKZBzX+pPdF2BACfYrImDBLo5XF21AFjNIcuDvT0tXgZi2HtJA/P2+Ktm1 oaUmLSBZewibg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wei Chen , Mauro Carvalho Chehab , Sasha Levin , crope@iki.fi, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 07/27] media: dvb-usb-v2: ce6230: fix null-ptr-deref in ce6230_i2c_master_xfer() Date: Thu, 25 May 2023 14:43:33 -0400 Message-Id: <20230525184356.1974216-7-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230525184356.1974216-1-sashal@kernel.org> References: <20230525184356.1974216-1-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: Wei Chen [ Upstream commit dff919090155fb22679869e8469168f270dcd97f ] In ce6230_i2c_master_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 ce6230_i2c_master_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/20230313092751.209496-1-harperchen1110@gmail.com Signed-off-by: Wei Chen Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb-v2/ce6230.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/media/usb/dvb-usb-v2/ce6230.c b/drivers/media/usb/dvb-usb-v2/ce6230.c index e596031a708d0..80a07aab3b4b0 100644 --- a/drivers/media/usb/dvb-usb-v2/ce6230.c +++ b/drivers/media/usb/dvb-usb-v2/ce6230.c @@ -111,6 +111,10 @@ static int ce6230_i2c_master_xfer(struct i2c_adapter *adap, if (num > i + 1 && (msg[i+1].flags & I2C_M_RD)) { if (msg[i].addr == ce6230_zl10353_config.demod_address) { + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } req.cmd = DEMOD_READ; req.value = msg[i].addr >> 1; req.index = msg[i].buf[0]; @@ -127,6 +131,10 @@ static int ce6230_i2c_master_xfer(struct i2c_adapter *adap, } else { if (msg[i].addr == ce6230_zl10353_config.demod_address) { + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } req.cmd = DEMOD_WRITE; req.value = msg[i].addr >> 1; req.index = msg[i].buf[0]; -- 2.39.2