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 82CECEEB581 for ; Sat, 9 Sep 2023 00:40:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346081AbjIIAkv (ORCPT ); Fri, 8 Sep 2023 20:40:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346003AbjIIAj5 (ORCPT ); Fri, 8 Sep 2023 20:39:57 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD5372D49; Fri, 8 Sep 2023 17:39:17 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 166F5C433CB; Sat, 9 Sep 2023 00:39:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694219947; bh=aKfzVcqunrOiIbIPCjM4v1oW4MBSMStv4PkOIThX1iA=; h=From:To:Cc:Subject:Date:From; b=Vu5XIZ2AeTYMhyh7V61W+hkB6Vd7opEsoWhd1mNlYyhc+mN46fmNWeGhW8D0D7sZV 7Gli2OENE1HfAz0fpVVyj1nlMrSLniy+3MIH8M+Fyc8j33JFQpp52uhiJfdNAwHeoH Oo8iqRaBW1VUs3M0G3mlx2GIKuASPSSYEcIXAjZLReEM2xcrmlgtziTjASf8jl/9VM rcCPu1SyMrDHLX+DIkzeCKOpJeyofi/MKVVOvM9p+sVS81dhPVfSANKaBZj3Knvsap AyVFcBS25dJr2HuGB248pEP9nuLeOTz1yIqQKv2A61ADncz8+YfLzjAYFduLHVFEBx n6ScMbrNqsNcA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zhang Shurong , Hans Verkuil , Sasha Levin , crope@iki.fi, mchehab@kernel.org, linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 01/19] media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer Date: Fri, 8 Sep 2023 20:38:45 -0400 Message-Id: <20230909003903.3580394-1-sashal@kernel.org> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.131 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zhang Shurong [ Upstream commit 7bf744f2de0a848fb1d717f5831b03db96feae89 ] In af9035_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 af9035_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()") Signed-off-by: Zhang Shurong Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/usb/dvb-usb-v2/af9035.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/media/usb/dvb-usb-v2/af9035.c b/drivers/media/usb/dvb-usb-v2/af9035.c index 5eef37b00a520..39d9e4f7682c2 100644 --- a/drivers/media/usb/dvb-usb-v2/af9035.c +++ b/drivers/media/usb/dvb-usb-v2/af9035.c @@ -322,6 +322,8 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, ret = -EOPNOTSUPP; } else if ((msg[0].addr == state->af9033_i2c_addr[0]) || (msg[0].addr == state->af9033_i2c_addr[1])) { + if (msg[0].len < 3 || msg[1].len < 1) + return -EOPNOTSUPP; /* demod access via firmware interface */ u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; @@ -381,6 +383,8 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, ret = -EOPNOTSUPP; } else if ((msg[0].addr == state->af9033_i2c_addr[0]) || (msg[0].addr == state->af9033_i2c_addr[1])) { + if (msg[0].len < 3) + return -EOPNOTSUPP; /* demod access via firmware interface */ u32 reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; @@ -388,10 +392,7 @@ static int af9035_i2c_master_xfer(struct i2c_adapter *adap, if (msg[0].addr == state->af9033_i2c_addr[1]) reg |= 0x100000; - ret = (msg[0].len >= 3) ? af9035_wr_regs(d, reg, - &msg[0].buf[3], - msg[0].len - 3) - : -EOPNOTSUPP; + ret = af9035_wr_regs(d, reg, &msg[0].buf[3], msg[0].len - 3); } else { /* I2C write */ u8 buf[MAX_XFER_SIZE]; -- 2.40.1