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=unavailable 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 8657EC10F00 for ; Tue, 12 Mar 2019 18:11:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55EB6205C9 for ; Tue, 12 Mar 2019 18:11:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552414276; bh=bKiqyoYmGVvV5lzX/aq/3CU7xQ9T9ZPyHBc6dc9MhRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ErhykZyLXoxOlWeJZyHY3J3OzEs4Zh89XMh6xF0iyWhfCszf1mPTrSPcc25/z7xUa CZqDcTVWJIPLKC+t42+ahhaFwoMT1Uwi6J3mqV7TJBjOZyJ+Q3Hgf3kmx8kNV/ILtV jfS0d+nRWcyCLUrcHtUlJU3cb42K6VjK9rqmW9nQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727071AbfCLRLm (ORCPT ); Tue, 12 Mar 2019 13:11:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:45120 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727005AbfCLRLe (ORCPT ); Tue, 12 Mar 2019 13:11:34 -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 D2B9521841; Tue, 12 Mar 2019 17:11:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410693; bh=bKiqyoYmGVvV5lzX/aq/3CU7xQ9T9ZPyHBc6dc9MhRI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hgbWpzDh7Xsc85Teepno+OdgPb20wws8N6PcDGGti6/gee9fLk4MLb9040bhLdMOY 0vqiFQ3jobc08DuUCPdyIIFii4ZhUDN8z+SlPZUamxI4zux4cwnZnfPaR4tCVc5wmZ 6a8qfzy6mt2C/xRD0xFAUCcjccFdfom5SAoWo6nk= 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 5.0 01/25] media: uvcvideo: Fix type check leading to overflow Date: Tue, 12 Mar 2019 10:08:39 -0700 Message-Id: <20190312170403.731808196@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190312170403.643852550@linuxfoundation.org> References: <20190312170403.643852550@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 5.0-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 @@ -1106,11 +1106,19 @@ 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,