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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0701EC433FE for ; Mon, 24 Jan 2022 19:16:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345278AbiAXTQc (ORCPT ); Mon, 24 Jan 2022 14:16:32 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:38460 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241161AbiAXTMr (ORCPT ); Mon, 24 Jan 2022 14:12:47 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A39B4B8122A; Mon, 24 Jan 2022 19:12:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F37CC340E5; Mon, 24 Jan 2022 19:12:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643051564; bh=uNGaLj2lMbEPT6PmZ400m7tw1ykXSU1lTSsCwt5jZ6Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ftgVtF6+EkelGP8WvfEEwhKl2gFNPZVP/kSJo/OsI1cUev/4cgox33EQ/ipTAMp+2 2vNg33DMRocvNeisuqm1QZTvAvbrKFrlaqJU8Ap3M4h4aKh9ZndvB0021Ye6KKgKKd rJyt1Og0LIQ4dli4qXzzVQqpc/GdlRBQs3rre8Qg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Johan Hovold , Kieran Bingham , Laurent Pinchart , Mauro Carvalho Chehab Subject: [PATCH 4.19 016/239] media: uvcvideo: fix division by zero at stream start Date: Mon, 24 Jan 2022 19:40:54 +0100 Message-Id: <20220124183943.630073909@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220124183943.102762895@linuxfoundation.org> References: <20220124183943.102762895@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Johan Hovold commit 8aa637bf6d70d2fb2ad4d708d8b9dd02b1c095df upstream. Add the missing bulk-endpoint max-packet sanity check to uvc_video_start_transfer() to avoid division by zero in uvc_alloc_urb_buffers() in case a malicious device has broken descriptors (or when doing descriptor fuzz testing). Note that USB core will reject URBs submitted for endpoints with zero wMaxPacketSize but that drivers doing packet-size calculations still need to handle this (cf. commit 2548288b4fb0 ("USB: Fix: Don't skip endpoint descriptors with maxpacket=0")). Fixes: c0efd232929c ("V4L/DVB (8145a): USB Video Class driver") Cc: stable@vger.kernel.org # 2.6.26 Signed-off-by: Johan Hovold Reviewed-by: Kieran Bingham Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/usb/uvc/uvc_video.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/media/usb/uvc/uvc_video.c +++ b/drivers/media/usb/uvc/uvc_video.c @@ -1854,6 +1854,10 @@ static int uvc_init_video(struct uvc_str if (ep == NULL) return -EIO; + /* Reject broken descriptors. */ + if (usb_endpoint_maxp(&ep->desc) == 0) + return -EIO; + ret = uvc_init_video_bulk(stream, ep, gfp_flags); }