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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E3ABC433FE for ; Mon, 1 Nov 2021 09:22:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 53721611CE for ; Mon, 1 Nov 2021 09:22:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232524AbhKAJZA (ORCPT ); Mon, 1 Nov 2021 05:25:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:58178 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232230AbhKAJXO (ORCPT ); Mon, 1 Nov 2021 05:23:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B8277610E8; Mon, 1 Nov 2021 09:20:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1635758420; bh=OWoe9ut4MvezTUhqlVNY5lcC0+n5MbCV6mfVfXZwDn8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jbHrU7fAwCv4G6UlUyoVJ6hOulaoXSowVkrjONU5DRsLl5mYUyMZIKhAL5oYal++b /A5hxLroNR1TSC4gAI3yv3VHyujt1XF3wyQ2KMGFQ1vuLiKzxuQNtxN77SQzV3tRTL 3wsSxmR3sGbtDlwfCOOkR79mGrow6fiFKjIyjZjA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Woojung.Huh@microchip.com" , Johan Hovold , "David S. Miller" Subject: [PATCH 4.14 16/25] net: lan78xx: fix division by zero in send path Date: Mon, 1 Nov 2021 10:17:28 +0100 Message-Id: <20211101082450.882639596@linuxfoundation.org> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211101082447.070493993@linuxfoundation.org> References: <20211101082447.070493993@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 db6c3c064f5d55fa9969f33eafca3cdbefbb3541 upstream. Add the missing endpoint max-packet sanity check to probe() to avoid division by zero in lan78xx_tx_bh() in case a malicious device has broken descriptors (or when doing descriptor fuzz testing). 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: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver") Cc: stable@vger.kernel.org # 4.3 Cc: Woojung.Huh@microchip.com Signed-off-by: Johan Hovold Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/lan78xx.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/net/usb/lan78xx.c +++ b/drivers/net/usb/lan78xx.c @@ -3615,6 +3615,12 @@ static int lan78xx_probe(struct usb_inte dev->maxpacket = usb_maxpacket(dev->udev, dev->pipe_out, 1); + /* Reject broken descriptors. */ + if (dev->maxpacket == 0) { + ret = -ENODEV; + goto out4; + } + /* driver requires remote-wakeup capability during autosuspend. */ intf->needs_remote_wakeup = 1;