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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3AF9C433FE for ; Wed, 10 Nov 2021 18:47:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B81DE61288 for ; Wed, 10 Nov 2021 18:47:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233428AbhKJStx (ORCPT ); Wed, 10 Nov 2021 13:49:53 -0500 Received: from mail.kernel.org ([198.145.29.99]:47364 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232818AbhKJSsh (ORCPT ); Wed, 10 Nov 2021 13:48:37 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C975E61279; Wed, 10 Nov 2021 18:45:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1636569949; bh=aUxJBoVf4Th1jRRTCdRJlx38T/xtmE2lG68lokh+Y/Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KwuY2P5JcjcxES7EXrwZIL9x6ig+qIBLuPEiF+ndU58/xljKjQp7dAF0mfwvFzOnb 2+ckCyfUuuZXTcxSFv25UZZR0n7wXiSyOB2nV5TPXxcbrs+NxEV1uuMx4CrSBr8Fyk rAY578Hw8NOF1jPjw80/zI6NZdRmMgigS65B+45E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Luca Ellero , Ian Abbott , Johan Hovold Subject: [PATCH 4.14 16/22] comedi: ni_usb6501: fix NULL-deref in command paths Date: Wed, 10 Nov 2021 19:43:36 +0100 Message-Id: <20211110182003.189019495@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211110182002.666244094@linuxfoundation.org> References: <20211110182002.666244094@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johan Hovold commit 907767da8f3a925b060c740e0b5c92ea7dbec440 upstream. The driver uses endpoint-sized USB transfer buffers but had no sanity checks on the sizes. This can lead to zero-size-pointer dereferences or overflowed transfer buffers in ni6501_port_command() and ni6501_counter_command() if a (malicious) device has smaller max-packet sizes than expected (or when doing descriptor fuzz testing). Add the missing sanity checks to probe(). Fixes: a03bb00e50ab ("staging: comedi: add NI USB-6501 support") Cc: stable@vger.kernel.org # 3.18 Cc: Luca Ellero Reviewed-by: Ian Abbott Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20211027093529.30896-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/ni_usb6501.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/staging/comedi/drivers/ni_usb6501.c +++ b/drivers/staging/comedi/drivers/ni_usb6501.c @@ -153,6 +153,10 @@ static const u8 READ_COUNTER_RESPONSE[] 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00}; +/* Largest supported packets */ +static const size_t TX_MAX_SIZE = sizeof(SET_PORT_DIR_REQUEST); +static const size_t RX_MAX_SIZE = sizeof(READ_PORT_RESPONSE); + enum commands { READ_PORT, WRITE_PORT, @@ -510,6 +514,12 @@ static int ni6501_find_endpoints(struct if (!devpriv->ep_rx || !devpriv->ep_tx) return -ENODEV; + if (usb_endpoint_maxp(devpriv->ep_rx) < RX_MAX_SIZE) + return -ENODEV; + + if (usb_endpoint_maxp(devpriv->ep_tx) < TX_MAX_SIZE) + return -ENODEV; + return 0; }