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Commit 62de7d99 authored by Mauro Carvalho Chehab's avatar Mauro Carvalho Chehab
Browse files

[media] usbtv: don't do DMA on stack 



As reported by smatch:
	drivers/media/usb/usbtv/usbtv-video.c:716 usbtv_s_ctrl() error: doing dma on the stack (data)
	drivers/media/usb/usbtv/usbtv-video.c:758 usbtv_s_ctrl() error: doing dma on the stack (data)

We should not do it, as it won't work on Kernels 4.9 and upper.
So, alloc a buffer for it.

Fixes: c53a846c ("[media] usbtv: add video controls")
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent c53a846c

drivers/media/usb/usbtv/usbtv-video.c

+13 −5
Original line number Diff line number Diff line
@@ -704,10 +704,14 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) 
{

	struct usbtv *usbtv = container_of(ctrl->handler, struct usbtv,

								ctrl);

	u8 data[3];

	u8 *data;

	u16 index, size;

	int ret;



	data = kmalloc(3, GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	/*

	 * Read in the current brightness/contrast registers. We need them

	 * both, because the values are for some reason interleaved.
@@ -717,6 +721,8 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) 
			usb_sndctrlpipe(usbtv->udev, 0), USBTV_CONTROL_REG,

			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,

			0, USBTV_BASE + 0x0244, (void *)data, 3, 0);

		if (ret < 0)

			goto error;

	}



	switch (ctrl->id) {
@@ -752,6 +758,7 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) 
		}

		break;

	default:

		kfree(data);

		return -EINVAL;

	}
@@ -759,12 +766,13 @@ static int usbtv_s_ctrl(struct v4l2_ctrl *ctrl) 
			USBTV_CONTROL_REG,

			USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,

			0, index, (void *)data, size, 0);

	if (ret < 0) {



error:

	if (ret < 0)

		dev_warn(usbtv->dev, "Failed to submit a control request.\n");

		return ret;

	}



	return 0;

	kfree(data);

	return ret;

}



static const struct v4l2_ctrl_ops usbtv_ctrl_ops = {