Re: [PATCH v2 1/3] HID: logitech-dj: check report length

[Benjamin Tissoires]

On Tue, Dec 16, 2014 at 10:55 AM, Peter Wu <peter@xxxxxxxxxxxxx> wrote:
> Malicious USB devices can send bogus reports smaller than the expected
> buffer size. Ensure that the length is valid to avoid reading out of
> bounds.
>
> Signed-off-by: Peter Wu <peter@xxxxxxxxxxxxx>
> ---
>  v1: patch 2/3 HID: logitech-{dj,hidpp}: check report length
>  v2: splitted original report length check patch
> ---

Reviewed-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

Cheers,
Benjamin

>  drivers/hid/hid-logitech-dj.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
> index c917ab6..5bc6d80 100644
> --- a/drivers/hid/hid-logitech-dj.c
> +++ b/drivers/hid/hid-logitech-dj.c
> @@ -962,10 +962,24 @@ static int logi_dj_raw_event(struct hid_device *hdev,
>
>         switch (data[0]) {
>         case REPORT_ID_DJ_SHORT:
> +               if (size != DJREPORT_SHORT_LENGTH) {
> +                       dev_err(&hdev->dev, "DJ report of bad size (%d)", size);
> +                       return false;
> +               }
>                 return logi_dj_dj_event(hdev, report, data, size);
>         case REPORT_ID_HIDPP_SHORT:
> -               /* intentional fallthrough */
> +               if (size != HIDPP_REPORT_SHORT_LENGTH) {
> +                       dev_err(&hdev->dev,
> +                               "Short HID++ report of bad size (%d)", size);
> +                       return false;
> +               }
> +               return logi_dj_hidpp_event(hdev, report, data, size);
>         case REPORT_ID_HIDPP_LONG:
> +               if (size != HIDPP_REPORT_LONG_LENGTH) {
> +                       dev_err(&hdev->dev,
> +                               "Long HID++ report of bad size (%d)", size);
> +                       return false;
> +               }
>                 return logi_dj_hidpp_event(hdev, report, data, size);
>         }
>
> --
> 2.1.3
>
> --
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