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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 438B6C352AA for ; Tue, 1 Oct 2019 16:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0A3192168B for ; Tue, 1 Oct 2019 16:57:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569949030; bh=hDT39oXpPfsh9HY8HnQFrhdfgpcobOmZ6jTV4HOfkBs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VkmQqnWzkkooiyhOfKjcK39h3DSMNXJ/yamE61EBQzXJOORL8uk2rzMUaqwTT6KKW 59rFojaMmCk5D9uz+RVOjzp1a+xaJqn1Uwr0eQyjgIupzpPMm/6XhokRRGfxbHLk4X qRMV9Adpu+aB/zEAr4QbD2exFK79DmHOJrlGhXTs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732953AbfJAQ5I (ORCPT ); Tue, 1 Oct 2019 12:57:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:53742 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731527AbfJAQl7 (ORCPT ); Tue, 1 Oct 2019 12:41:59 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F39C921855; Tue, 1 Oct 2019 16:41:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948118; bh=hDT39oXpPfsh9HY8HnQFrhdfgpcobOmZ6jTV4HOfkBs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sO9Vr5EqyIzWNOEqtkahYzonwn+i3I7/pOAeVwikrC3TGhFB+WEe3r4MosqQgcuzZ nquXZeHqrcqox4lz7SM5B9pWMNUOviajxyCMvT2LGFVXM1L8ED3qppj+sWmDDeY1sw BEsO3c4Egk+xxLq04t8ewElEjL7617reOEOb5UTc= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Bj=C3=B8rn=20Mork?= , syzbot+ce366e2b8296e25d84f5@syzkaller.appspotmail.com, Jakub Kicinski , Sasha Levin , linux-usb@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 24/63] cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize Date: Tue, 1 Oct 2019 12:40:46 -0400 Message-Id: <20191001164125.15398-24-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164125.15398-1-sashal@kernel.org> References: <20191001164125.15398-1-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-stable: review X-Patchwork-Hint: Ignore 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: Sasha Levin --- drivers/net/usb/cdc_ncm.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 50c05d0f44cb3..00cab3f43a4ca 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -681,8 +681,12 @@ cdc_ncm_find_endpoints(struct usbnet *dev, struct usb_interface *intf) 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)) { -- 2.20.1