Re: [libgpiod] bindings: python: fix segfault when calling Line.request()

[Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>]

wt., 3 gru 2019 o 20:24 Joel Savitz <jsavitz@xxxxxxxxxx> napisał(a):
>
> When Line.request() is called without the required 'consumer=value'
> argument, the module attempts access an empty dictionary object
> resulting in a segfault. This patch avoids such access when the
> dictionary is empty and maintains the current design where the
> LineBulk object is responsible for validation of arguments.
>
> Signed-off-by: Joel Savitz <jsavitz@xxxxxxxxxx>
> ---
>  bindings/python/gpiodmodule.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/bindings/python/gpiodmodule.c b/bindings/python/gpiodmodule.c
> index 2f6ef51..ae7e1cc 100644
> --- a/bindings/python/gpiodmodule.c
> +++ b/bindings/python/gpiodmodule.c
> @@ -434,8 +434,12 @@ static PyObject *gpiod_Line_request(gpiod_LineObject *self,
>         gpiod_LineBulkObject *bulk_obj;
>         int rv;
>
> -       def_val = PyDict_GetItemString(kwds, "default_val");
> -       def_vals = PyDict_GetItemString(kwds, "default_vals");
> +       if (PyDict_Size(kwds) > 0) {
> +               def_val = PyDict_GetItemString(kwds, "default_val");
> +               def_vals = PyDict_GetItemString(kwds, "default_vals");
> +       } else {
> +               def_val = def_vals = NULL;
> +       }
>
>         if (def_val && def_vals) {
>                 PyErr_SetString(PyExc_TypeError,
> --
> 2.23.0
>

Applied to master and 1.4.x stable.

Thanks,
Bartosz