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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 84B1CC4360C for ; Wed, 2 Oct 2019 19:12:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 62197207FF for ; Wed, 2 Oct 2019 19:12:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729156AbfJBTIK (ORCPT ); Wed, 2 Oct 2019 15:08:10 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35200 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728763AbfJBTIH (ORCPT ); Wed, 2 Oct 2019 15:08:07 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iFjyn-00035B-4k; Wed, 02 Oct 2019 20:08:05 +0100 Received: from ben by deadeye with local (Exim 4.92.1) (envelope-from ) id 1iFjym-0003aF-Ul; Wed, 02 Oct 2019 20:08:04 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Greg Kroah-Hartman" , "Alan Stern" Date: Wed, 02 Oct 2019 20:06:51 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 06/87] USB: Fix slab-out-of-bounds write in usb_get_bos_descriptor In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.75-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit a03ff54460817c76105f81f3aa8ef655759ccc9a upstream. The syzkaller USB fuzzer found a slab-out-of-bounds write bug in the USB core, caused by a failure to check the actual size of a BOS descriptor. This patch adds a check to make sure the descriptor is at least as large as it is supposed to be, so that the code doesn't inadvertently access memory beyond the end of the allocated region when assigning to dev->bos->desc->bNumDeviceCaps later on. Signed-off-by: Alan Stern Reported-and-tested-by: syzbot+71f1e64501a309fcc012@syzkaller.appspotmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- drivers/usb/core/config.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -897,8 +897,8 @@ int usb_get_bos_descriptor(struct usb_de /* Get BOS descriptor */ ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE); - if (ret < USB_DT_BOS_SIZE) { - dev_err(ddev, "unable to get BOS descriptor\n"); + if (ret < USB_DT_BOS_SIZE || bos->bLength < USB_DT_BOS_SIZE) { + dev_err(ddev, "unable to get BOS descriptor or descriptor too short\n"); if (ret >= 0) ret = -ENOMSG; kfree(bos);