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=-6.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,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 06913C2BCA1 for ; Sun, 9 Jun 2019 17:04:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D675520843 for ; Sun, 9 Jun 2019 17:04:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099871; bh=/fgqGPPbxUV4uA+bSTZ51Uj7oZtb3BNhtgzicKWlTnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NV2R+tJvAfg8P0KoB9xupKFSqWcJXZvAYKs/Qvs2WrFIACpUeoY+IRYMZ5WdTMB7h Gw8g7grP6dhLtsQN6SuMwxlrreyqSk/If7f+zEb+0vMzyWiLxgHZ/bNDOsELi3HHQx YaYrtGXwqrLBOFZZl7ocrkzgQ+5Vh3m8QFFL4cCE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388596AbfFIREa (ORCPT ); Sun, 9 Jun 2019 13:04:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:43248 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388620AbfFIRE2 (ORCPT ); Sun, 9 Jun 2019 13:04:28 -0400 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 429A820843; Sun, 9 Jun 2019 17:04:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560099867; bh=/fgqGPPbxUV4uA+bSTZ51Uj7oZtb3BNhtgzicKWlTnM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j2al5wakXM8lwfjp04YmlKwevsrqBBBCTjR9LCwSRRYcGgXVexEw5Hm8J/Dx/fI5A d+Z5cDLAhb0j0eIwFrH0JiHW/Wu3hKJ32hTIPve+/n/HAsM5/YaWn73Lh59uy4MIEk ZeNnISLE391NjVJHjPbWvc+dJXzNzPhuSh7EYP7A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , syzbot+71f1e64501a309fcc012@syzkaller.appspotmail.com Subject: [PATCH 4.4 196/241] USB: Fix slab-out-of-bounds write in usb_get_bos_descriptor Date: Sun, 9 Jun 2019 18:42:18 +0200 Message-Id: <20190609164153.632077681@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190609164147.729157653@linuxfoundation.org> References: <20190609164147.729157653@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: 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 CC: Signed-off-by: Greg Kroah-Hartman --- 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 @@ -902,8 +902,8 @@ 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);