From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752816AbdCMMz2 (ORCPT ); Mon, 13 Mar 2017 08:55:28 -0400 Received: from mail-lf0-f65.google.com ([209.85.215.65]:35819 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750907AbdCMMyg (ORCPT ); Mon, 13 Mar 2017 08:54:36 -0400 From: Johan Hovold To: Mauro Carvalho Chehab Cc: Hans Verkuil , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable , Sri Deevi Subject: [PATCH 3/6] [media] cx231xx-cards: fix NULL-deref at probe Date: Mon, 13 Mar 2017 13:53:56 +0100 Message-Id: <20170313125359.29394-4-johan@kernel.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170313125359.29394-1-johan@kernel.org> References: <20170313125359.29394-1-johan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Make sure to check the number of endpoints to avoid dereferencing a NULL-pointer or accessing memory beyond the endpoint array should a malicious device lack the expected endpoints. Fixes: e0d3bafd0258 ("V4L/DVB (10954): Add cx231xx USB driver") Cc: stable # 2.6.30 Cc: Sri Deevi Signed-off-by: Johan Hovold --- drivers/media/usb/cx231xx/cx231xx-cards.c | 45 +++++++++++++++++++++++++++---- 1 file changed, 40 insertions(+), 5 deletions(-) diff --git a/drivers/media/usb/cx231xx/cx231xx-cards.c b/drivers/media/usb/cx231xx/cx231xx-cards.c index f730fdbc9156..f850267a0095 100644 --- a/drivers/media/usb/cx231xx/cx231xx-cards.c +++ b/drivers/media/usb/cx231xx/cx231xx-cards.c @@ -1426,6 +1426,9 @@ static int cx231xx_init_v4l2(struct cx231xx *dev, uif = udev->actconfig->interface[idx]; + if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) + return -ENODEV; + dev->video_mode.end_point_addr = uif->altsetting[0].endpoint[isoc_pipe].desc.bEndpointAddress; dev->video_mode.num_alt = uif->num_altsetting; @@ -1439,7 +1442,12 @@ static int cx231xx_init_v4l2(struct cx231xx *dev, return -ENOMEM; for (i = 0; i < dev->video_mode.num_alt; i++) { - u16 tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc.wMaxPacketSize); + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) + return -ENODEV; + + tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe].desc.wMaxPacketSize); dev->video_mode.alt_max_pkt_size[i] = (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1); dev_dbg(dev->dev, "Alternate setting %i, max size= %i\n", i, @@ -1456,6 +1464,9 @@ static int cx231xx_init_v4l2(struct cx231xx *dev, } uif = udev->actconfig->interface[idx]; + if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) + return -ENODEV; + dev->vbi_mode.end_point_addr = uif->altsetting[0].endpoint[isoc_pipe].desc. bEndpointAddress; @@ -1472,8 +1483,12 @@ static int cx231xx_init_v4l2(struct cx231xx *dev, return -ENOMEM; for (i = 0; i < dev->vbi_mode.num_alt; i++) { - u16 tmp = - le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe]. + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) + return -ENODEV; + + tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe]. desc.wMaxPacketSize); dev->vbi_mode.alt_max_pkt_size[i] = (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1); @@ -1493,6 +1508,9 @@ static int cx231xx_init_v4l2(struct cx231xx *dev, } uif = udev->actconfig->interface[idx]; + if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) + return -ENODEV; + dev->sliced_cc_mode.end_point_addr = uif->altsetting[0].endpoint[isoc_pipe].desc. bEndpointAddress; @@ -1507,7 +1525,12 @@ static int cx231xx_init_v4l2(struct cx231xx *dev, return -ENOMEM; for (i = 0; i < dev->sliced_cc_mode.num_alt; i++) { - u16 tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe]. + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) + return -ENODEV; + + tmp = le16_to_cpu(uif->altsetting[i].endpoint[isoc_pipe]. desc.wMaxPacketSize); dev->sliced_cc_mode.alt_max_pkt_size[i] = (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1); @@ -1676,6 +1699,11 @@ static int cx231xx_usb_probe(struct usb_interface *interface, } uif = udev->actconfig->interface[idx]; + if (uif->altsetting[0].desc.bNumEndpoints < isoc_pipe + 1) { + retval = -ENODEV; + goto err_video_alt; + } + dev->ts1_mode.end_point_addr = uif->altsetting[0].endpoint[isoc_pipe]. desc.bEndpointAddress; @@ -1693,7 +1721,14 @@ static int cx231xx_usb_probe(struct usb_interface *interface, } for (i = 0; i < dev->ts1_mode.num_alt; i++) { - u16 tmp = le16_to_cpu(uif->altsetting[i]. + u16 tmp; + + if (uif->altsetting[i].desc.bNumEndpoints < isoc_pipe + 1) { + retval = -ENODEV; + goto err_video_alt; + } + + tmp = le16_to_cpu(uif->altsetting[i]. endpoint[isoc_pipe].desc. wMaxPacketSize); dev->ts1_mode.alt_max_pkt_size[i] = -- 2.12.0