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 90385C17445 for ; Mon, 11 Nov 2019 18:35:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5F3C5214E0 for ; Mon, 11 Nov 2019 18:35:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573497344; bh=C5xQkwwGDricWqdA8SR940TB54ZWtqNg32onbdI9kCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aO2Ye4EPOHhd9lSDyyHE4g0ph1dcTMlzLwvJqrIKf5OLY+Csea7WlNkpf1jHxNEcq 1O+UWTZevS8PZ6C+eP8gKWFHyk732ZtI/zCkFfQzcFiw09VK+b+EazEf3SSvENpeSA ioMT52C65P3WtWkqYOobFDD4SJ56BcJuPHcvswTE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728581AbfKKSfm (ORCPT ); Mon, 11 Nov 2019 13:35:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:53588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727417AbfKKSfi (ORCPT ); Mon, 11 Nov 2019 13:35:38 -0500 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 4D9FB21783; Mon, 11 Nov 2019 18:35:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573497337; bh=C5xQkwwGDricWqdA8SR940TB54ZWtqNg32onbdI9kCY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CWzX311XaB38ezuKJHWuffEVeNYMZu4IcnenIoRRyfczWmIQwRdnkX1zvZIQzUffT aucLJZK778GfcuD1xo1qnJD2pshL3xhi+iynQDMuZ940GgBLufqtsqMnXxYlq9jbED M7X0BLaJLI1dt/pSRkOOpV+hnjoU/1obGFrxFM0I= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oliver Neukum , "David S. Miller" , syzbot+0631d878823ce2411636@syzkaller.appspotmail.com Subject: [PATCH 4.14 002/105] CDC-NCM: handle incomplete transfer of MTU Date: Mon, 11 Nov 2019 19:27:32 +0100 Message-Id: <20191111181422.777911819@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191111181421.390326245@linuxfoundation.org> References: <20191111181421.390326245@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: Oliver Neukum [ Upstream commit 332f989a3b0041b810836c5c3747e59aad7e9d0b ] A malicious device may give half an answer when asked for its MTU. The driver will proceed after this with a garbage MTU. Anything but a complete answer must be treated as an error. V2: used sizeof as request by Alexander Reported-and-tested-by: syzbot+0631d878823ce2411636@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/cdc_ncm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -578,8 +578,8 @@ static void cdc_ncm_set_dgram_size(struc /* read current mtu value from device */ err = usbnet_read_cmd(dev, USB_CDC_GET_MAX_DATAGRAM_SIZE, USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE, - 0, iface_no, &max_datagram_size, 2); - if (err < 0) { + 0, iface_no, &max_datagram_size, sizeof(max_datagram_size)); + if (err < sizeof(max_datagram_size)) { dev_dbg(&dev->intf->dev, "GET_MAX_DATAGRAM_SIZE failed\n"); goto out; } @@ -590,7 +590,7 @@ static void cdc_ncm_set_dgram_size(struc max_datagram_size = cpu_to_le16(ctx->max_datagram_size); err = usbnet_write_cmd(dev, USB_CDC_SET_MAX_DATAGRAM_SIZE, USB_TYPE_CLASS | USB_DIR_OUT | USB_RECIP_INTERFACE, - 0, iface_no, &max_datagram_size, 2); + 0, iface_no, &max_datagram_size, sizeof(max_datagram_size)); if (err < 0) dev_dbg(&dev->intf->dev, "SET_MAX_DATAGRAM_SIZE failed\n");