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=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 0254FC352AA for ; Tue, 1 Oct 2019 17:02:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD5BE2054F for ; Tue, 1 Oct 2019 17:02:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569949364; bh=hDT39oXpPfsh9HY8HnQFrhdfgpcobOmZ6jTV4HOfkBs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sAS6e0KkG5wWsTnd01jtYncWMrsJUOI52IcmV+Q/TBJxlv+B22eBu1cdfUeBYNv20 NeePUjlwCAfHuhhKrX4kpXkPR65LHUQSSE7ImtlHhSPUksapNwzQ5qnEeYwYaaVVPJ PkN13FFVrrxsxGl9r9jTd1Fexbl+YHyBkw5zS0yg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729417AbfJAQkC (ORCPT ); Tue, 1 Oct 2019 12:40:02 -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: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@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