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 803C9CE79CE for ; Wed, 20 Sep 2023 11:56:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234521AbjITL4h (ORCPT ); Wed, 20 Sep 2023 07:56:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42698 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234847AbjITL4g (ORCPT ); Wed, 20 Sep 2023 07:56:36 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6028AE4 for ; Wed, 20 Sep 2023 04:56:28 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DBCDC433CB; Wed, 20 Sep 2023 11:56:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695210988; bh=0ukN4mCysDcsHb2oM/xtsXrElrDEIOURJRqsJkQXSzk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QqtvgNMelbh1JXlnnEoHcC3QU3OTxmb6q6K4qXoV+2OpDhBnlQOp6g2lk1RZCniBv DNSxedlgxt0pXhfpiVFcFhmkEwTMSvIpIePT9hzumeCjBH8dUihabg7xvwIOgOYy1E J2wNPLcGcYhds8DFvHaKovdqWyIZYiss9pgv+C6g= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhang Shurong , Hans Verkuil , Sasha Levin Subject: [PATCH 6.1 066/139] media: dvb-usb-v2: af9035: Fix null-ptr-deref in af9035_i2c_master_xfer Date: Wed, 20 Sep 2023 13:30:00 +0200 Message-ID: <20230920112838.162420103@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112835.549467415@linuxfoundation.org> References: <20230920112835.549467415@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ 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 [ moved variable declaration to fix build issues in older kernels - gregkh ] Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/dvb-usb-v2/af9035.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/drivers/media/usb/dvb-usb-v2/af9035.c +++ b/drivers/media/usb/dvb-usb-v2/af9035.c @@ -270,6 +270,7 @@ static int af9035_i2c_master_xfer(struct struct dvb_usb_device *d = i2c_get_adapdata(adap); struct state *state = d_to_priv(d); int ret; + u32 reg; if (mutex_lock_interruptible(&d->i2c_mutex) < 0) return -EAGAIN; @@ -322,8 +323,10 @@ static int af9035_i2c_master_xfer(struct 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 | + reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; if (msg[0].addr == state->af9033_i2c_addr[1]) @@ -381,17 +384,16 @@ static int af9035_i2c_master_xfer(struct 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 | + reg = msg[0].buf[0] << 16 | msg[0].buf[1] << 8 | msg[0].buf[2]; 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];