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=ham 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 3885BC32792 for ; Thu, 3 Oct 2019 16:07:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0627F20865 for ; Thu, 3 Oct 2019 16:07:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118867; bh=2NQHd2QxdKNhEULOQ3m6pk/Bq8wN86OiE8oTa6a2Tsg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ww+nCQOW8XH/3BCtx4yCrG1XS7V8bZ92Awzd2xmKdwoAvgZ4hHaFlddDByVefk5aW gg1ihLqX2EftwQ9vZHxRZYx1IkHkeYTq6GHIV9yU1kfGNy9KfEq/BpWWC5P/WzqDX8 iw9B08aEM3GE4tETlyBCf/TKUUYofy5ImWp5HvO8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732997AbfJCQHq (ORCPT ); Thu, 3 Oct 2019 12:07:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:55580 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732985AbfJCQHm (ORCPT ); Thu, 3 Oct 2019 12:07:42 -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 2CFAF207FF; Thu, 3 Oct 2019 16:07:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570118860; bh=2NQHd2QxdKNhEULOQ3m6pk/Bq8wN86OiE8oTa6a2Tsg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a2U1I/xsaomeD9cC6yZfcvO2wY4LB6gce6NaXiHvtr+pbatyUZJyw7cgVD9URrHJ8 et8I89cz5aXSFjxEtprZrOUjoxq/y+AUiM58jcSWbKpuAoyqbemOToNsZ/Tonkpqnp cGV2HgJ+c+luUqX6lup0e594VL6dVVntHY/ixJe0= 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 4.14 035/185] cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize Date: Thu, 3 Oct 2019 17:51:53 +0200 Message-Id: <20191003154445.452899999@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154437.541662648@linuxfoundation.org> References: <20191003154437.541662648@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -681,8 +681,12 @@ 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)) {