Commit 0cd273bb authored by Johan Hovold's avatar Johan Hovold Committed by Mauro Carvalho Chehab
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[media] cx231xx-cards: fix NULL-deref at probe



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: e0d3bafd ("V4L/DVB (10954): Add cx231xx USB driver")

Cc: stable <stable@vger.kernel.org>     # 2.6.30
Cc: Sri Deevi <Srinivasa.Deevi@conexant.com>
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent eacb975b
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+40 −5
Original line number Diff line number Diff line
@@ -1425,6 +1425,9 @@ 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;

@@ -1438,7 +1441,12 @@ 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,
@@ -1455,6 +1463,9 @@ 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;
@@ -1471,8 +1482,12 @@ 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);
@@ -1492,6 +1507,9 @@ 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;
@@ -1506,7 +1524,12 @@ 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);
@@ -1675,6 +1698,11 @@ 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;
@@ -1692,7 +1720,14 @@ 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] =