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 819F2C4332F for ; Wed, 24 Nov 2021 12:35:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344624AbhKXMib (ORCPT ); Wed, 24 Nov 2021 07:38:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:52032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243359AbhKXMbc (ORCPT ); Wed, 24 Nov 2021 07:31:32 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4C42161151; Wed, 24 Nov 2021 12:19:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1637756386; bh=gG2A73eHaLzf28OVdDyxSEVi7UA03PQtGCK3zRd+aHo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=n1aUJFuJQX4F6Av1L9A2p+Yepe75xyRAdQnFVzqefYSTn0nz9dj2MNYzeKQzygPpy dgtWqYfsArpSr1hMBWFl34kW18Y/b0228wExRWubJP766Jb+Gw2JdEUR5eTmOY2ysb Te9U2Y4TPHeizCrncbGJO7vp8/9uR4CQtMnYK7y0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Amitkumar Karwar , Johan Hovold , Brian Norris , Kalle Valo Subject: [PATCH 4.14 036/251] mwifiex: fix division by zero in fw download path Date: Wed, 24 Nov 2021 12:54:38 +0100 Message-Id: <20211124115711.497881205@linuxfoundation.org> X-Mailer: git-send-email 2.34.0 In-Reply-To: <20211124115710.214900256@linuxfoundation.org> References: <20211124115710.214900256@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 89f8765a11d8df49296d92c404067f9b5c58ee26 upstream. Add the missing endpoint sanity checks to probe() to avoid division by zero in mwifiex_write_data_sync() in case a malicious device has broken descriptors (or when doing descriptor fuzz testing). Only add checks for the firmware-download boot stage, which require both command endpoints, for now. The driver looks like it will handle a missing endpoint during normal operation without oopsing, albeit not very gracefully as it will try to submit URBs to the default pipe and fail. Note that USB core will reject URBs submitted for endpoints with zero wMaxPacketSize but that drivers doing packet-size calculations still need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip endpoint descriptors with maxpacket=0")). Fixes: 4daffe354366 ("mwifiex: add support for Marvell USB8797 chipset") Cc: stable@vger.kernel.org # 3.5 Cc: Amitkumar Karwar Signed-off-by: Johan Hovold Reviewed-by: Brian Norris Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20211027080819.6675-4-johan@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/marvell/mwifiex/usb.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) --- a/drivers/net/wireless/marvell/mwifiex/usb.c +++ b/drivers/net/wireless/marvell/mwifiex/usb.c @@ -491,6 +491,22 @@ static int mwifiex_usb_probe(struct usb_ } } + switch (card->usb_boot_state) { + case USB8XXX_FW_DNLD: + /* Reject broken descriptors. */ + if (!card->rx_cmd_ep || !card->tx_cmd_ep) + return -ENODEV; + if (card->bulk_out_maxpktsize == 0) + return -ENODEV; + break; + case USB8XXX_FW_READY: + /* Assume the driver can handle missing endpoints for now. */ + break; + default: + WARN_ON(1); + return -ENODEV; + } + usb_set_intfdata(intf, card); ret = mwifiex_add_card(card, &card->fw_done, &usb_ops,