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=-13.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 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 68A5FC5DF62 for ; Wed, 6 Nov 2019 12:39:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B7D3217F4 for ; Wed, 6 Nov 2019 12:39:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731601AbfKFMjf (ORCPT ); Wed, 6 Nov 2019 07:39:35 -0500 Received: from mx2.suse.de ([195.135.220.15]:56464 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727652AbfKFMjf (ORCPT ); Wed, 6 Nov 2019 07:39:35 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6E0A0B1DF; Wed, 6 Nov 2019 12:39:33 +0000 (UTC) Message-ID: <1573043012.3090.24.camel@suse.com> Subject: Re: KMSAN: uninit-value in cdc_ncm_set_dgram_size From: Oliver Neukum To: syzbot , netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Date: Wed, 06 Nov 2019 13:23:32 +0100 In-Reply-To: <00000000000013c4c1059625a655@google.com> References: <00000000000013c4c1059625a655@google.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Am Mittwoch, den 30.10.2019, 12:22 -0700 schrieb syzbot: > Hello, > > syzbot found the following crash on: > > HEAD commit: 96c6c319 net: kasan: kmsan: support CONFIG_GENERIC_CSUM on.. #syz test: https://github.com/google/kmsan.git 96c6c319 >From 23a6624cf7d8e146c35f2eec135d6c22e24f9a2e Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Tue, 5 Nov 2019 12:04:44 +0100 Subject: [PATCH] CDC-NCM: handle incomplete transfer of MTU 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-by: syzbot+0631d878823ce2411636@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum --- drivers/net/usb/cdc_ncm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 00cab3f43a4c..a245597a3902 100644 --- 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(struct usbnet *dev, int new_size) /* 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(struct usbnet *dev, int new_size) 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"); -- 2.16.4