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 9EF37ECE58A for ; Tue, 1 Oct 2019 16:40:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E27C2190F for ; Tue, 1 Oct 2019 16:40:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948008; bh=hDT39oXpPfsh9HY8HnQFrhdfgpcobOmZ6jTV4HOfkBs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0Ja9OxKd4Zjb5FrYzgePPjACeLB31mAtaAUkMjAO/PssyBi2TcrBf47lSR0V1Ecro tQWlJz36Ycqhba3WA0KwZ0OXG+7gH50/XNiL3CWr/ssPWPU0idkKIv6O9GcvmpQ9G2 m7Ibwjbc+gK93h4ZirRfunewdqPiadKhcIwi5Jgs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729600AbfJAQkH (ORCPT ); Tue, 1 Oct 2019 12:40:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:51170 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729331AbfJAQkB (ORCPT ); Tue, 1 Oct 2019 12:40:01 -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 EE76B21A4A; Tue, 1 Oct 2019 16:39:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948000; bh=hDT39oXpPfsh9HY8HnQFrhdfgpcobOmZ6jTV4HOfkBs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ydxD+RhnwDsr/x1iwnT+H4gBQ3CZFOy6h3h5I92R/SF5iF7pNdeDM8Ny+6rQgNNrz Cj8zgotM7H4TLPmjaOZhFCLXq4hfExioi7fzC+oztL7d7u6L6cJ91KmFgR4sQR08jO GCTgmrsU3ebNDVoIpq2iMXFQCzarT7NRqRvDz1jw= 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 5.3 26/71] cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize Date: Tue, 1 Oct 2019 12:38:36 -0400 Message-Id: <20191001163922.14735-26-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001163922.14735-1-sashal@kernel.org> References: <20191001163922.14735-1-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