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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,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 2BA93C10F00 for ; Tue, 12 Mar 2019 17:17:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F21792171F for ; Tue, 12 Mar 2019 17:17:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552411039; bh=8xSJeDtXk9xVdngmmovu5aR1EOhcq5cKKEiUr6uN82Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jPSXNNosyhi5PJc4iyNf7w4rJ+W7PNCFiFvxJ0t7oX1IAwiMtQ2jIKb/UwTt7wJ8u RJlLqEEU4fYqUUfWp6xk9yyUD3UdPJidX0lEmRcExT3X1BbNcAv567vn10SWbo6TGV OWaqGn1NkKCdEQQyWqXRVJdbFLJZm9RSV2JE7h3g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729533AbfCLRRR (ORCPT ); Tue, 12 Mar 2019 13:17:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:57778 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729019AbfCLRQJ (ORCPT ); Tue, 12 Mar 2019 13:16:09 -0400 Received: from localhost (unknown [104.133.8.98]) (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 0E5812183F; Tue, 12 Mar 2019 17:16:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410969; bh=8xSJeDtXk9xVdngmmovu5aR1EOhcq5cKKEiUr6uN82Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=igCYS+rXpXKu9lO28oKMI/bXSu4jJXHj0Em0jWMHAx++AkfPaXs6B0LCEAs1TG5mf ulcWBp3fXBWqS/k3M1mAkp9GIA6lTD/0qhasybROg5hgevQsq7eV6bdo9tromwJKAS gviifcxvmaoE6Vn5pq2QUZ8YdMQ9VnKoRZskkFh0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot , Alistair Strachan , Laurent Pinchart , Mauro Carvalho Chehab Subject: [PATCH 4.14 043/135] media: uvcvideo: Fix type check leading to overflow Date: Tue, 12 Mar 2019 10:08:10 -0700 Message-Id: <20190312170345.095097787@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190312170341.127810985@linuxfoundation.org> References: <20190312170341.127810985@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alistair Strachan commit 47bb117911b051bbc90764a8bff96543cbd2005f upstream. When initially testing the Camera Terminal Descriptor wTerminalType field (buffer[4]), no mask is used. Later in the function, the MSB is overloaded to store the descriptor subtype, and so a mask of 0x7fff is used to check the type. If a descriptor is specially crafted to set this overloaded bit in the original wTerminalType field, the initial type check will fail (falling through, without adjusting the buffer size), but the later type checks will pass, assuming the buffer has been made suitably large, causing an overflow. Avoid this problem by checking for the MSB in the wTerminalType field. If the bit is set, assume the descriptor is bad, and abort parsing it. Originally reported here: https://groups.google.com/forum/#!topic/syzkaller/Ot1fOE6v1d8 A similar (non-compiling) patch was provided at that time. Reported-by: syzbot Signed-off-by: Alistair Strachan Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/uvc/uvc_driver.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) --- a/drivers/media/usb/uvc/uvc_driver.c +++ b/drivers/media/usb/uvc/uvc_driver.c @@ -1054,11 +1054,19 @@ static int uvc_parse_standard_control(st return -EINVAL; } - /* Make sure the terminal type MSB is not null, otherwise it - * could be confused with a unit. + /* + * Reject invalid terminal types that would cause issues: + * + * - The high byte must be non-zero, otherwise it would be + * confused with a unit. + * + * - Bit 15 must be 0, as we use it internally as a terminal + * direction flag. + * + * Other unknown types are accepted. */ type = get_unaligned_le16(&buffer[4]); - if ((type & 0xff00) == 0) { + if ((type & 0x7f00) == 0 || (type & 0x8000) != 0) { uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol " "interface %d INPUT_TERMINAL %d has invalid " "type 0x%04x, skipping\n", udev->devnum,