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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F932C10F14 for ; Thu, 3 Oct 2019 17:39:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CB74215EA for ; Thu, 3 Oct 2019 17:39:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570124379; bh=hcfejRqgJw0E5uY7PyDrh38sjgIodIs3+rjUHtxGkrQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=cKrkyPPBRrEfVqK4DYeApLhV73w3f320vOSnmsZVc06P96yvbOj/mecZFdUkmY39d KANXAB2X/otfTJuH0D6yTwyOO2TA0kLc5A3jus1jjlED/iqLkV8USBWgE/uHIguzTg tfvJzHP39AyXPzye/D8XKFIH2xuIR59XhxxnbfcA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731730AbfJCQBR (ORCPT ); Thu, 3 Oct 2019 12:01:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:45476 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727024AbfJCQBR (ORCPT ); Thu, 3 Oct 2019 12:01:17 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2D77E207FF; Thu, 3 Oct 2019 16:01:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118476; bh=hcfejRqgJw0E5uY7PyDrh38sjgIodIs3+rjUHtxGkrQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LYy2LvuZ+IDyQ+zj5YQtCJKjE7I7F2Z6f1lafnTSfn7bQAyWlz/thGwfSf0E0Jo1N 9FLpKry8m6upgso1dPYOD0kJHCo7PcceyajndyZb31624xk1YKPnfwg66m5NP8+f5+ nsXJ9/vu16i04Siphi/zlsnIneBKk2lNcF8BxJaw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+ce366e2b8296e25d84f5@syzkaller.appspotmail.com, =?UTF-8?q?Bj=C3=B8rn=20Mork?= , Jakub Kicinski Subject: [PATCH 4.9 024/129] cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize Date: Thu, 3 Oct 2019 17:52:27 +0200 Message-Id: <20191003154330.064190039@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154318.081116689@linuxfoundation.org> References: <20191003154318.081116689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Bjørn Mork [ Upstream commit 3fe4b3351301660653a2bc73f2226da0ebd2b95e ] Endpoints with zero wMaxPacketSize are not usable for transferring data. Ignore such endpoints when looking for valid in, out and status pipes, to make the driver more robust against invalid and meaningless descriptors. The wMaxPacketSize of the out pipe is used as divisor. So this change fixes a divide-by-zero bug. Reported-by: syzbot+ce366e2b8296e25d84f5@syzkaller.appspotmail.com Signed-off-by: Bjørn Mork Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/cdc_ncm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -679,8 +679,12 @@ cdc_ncm_find_endpoints(struct usbnet *de u8 ep; for (ep = 0; ep < intf->cur_altsetting->desc.bNumEndpoints; ep++) { - e = intf->cur_altsetting->endpoint + ep; + + /* ignore endpoints which cannot transfer data */ + if (!usb_endpoint_maxp(&e->desc)) + continue; + switch (e->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) { case USB_ENDPOINT_XFER_INT: if (usb_endpoint_dir_in(&e->desc)) {