[lingpiod][PATCH] bindings: python: fix uninitialized default_vals being passed to gpiod_LineBulk_request()

[lingpiod][PATCH] bindings: python: fix uninitialized default_vals being passed to gpiod_LineBulk_request()

[Kent Gibson]

If "default_vals" is not provided in the kwds then default_vals are
passed uninitialized to gpiod_line_request_bulk(), so rename the
existing default_vals to vals and introduce a new default_vals that
points to vals, or NULL if no defaults have been passed.

Fixes: 96c524c4951c (bindings: implement python bindings)
Reported-by: Pedro Botella <pbotella@gmail.com>
Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
 bindings/python/gpiodmodule.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/bindings/python/gpiodmodule.c b/bindings/python/gpiodmodule.c
index fee4c32..832787d 100644
--- a/bindings/python/gpiodmodule.c
+++ b/bindings/python/gpiodmodule.c
@@ -1327,12 +1327,13 @@ static PyObject *gpiod_LineBulk_request(gpiod_LineBulkObject *self,
 				  NULL };
 
 	int rv, type = gpiod_LINE_REQ_DIR_AS_IS, flags = 0,
-	    default_vals[GPIOD_LINE_BULK_MAX_LINES], val;
+	    vals[GPIOD_LINE_BULK_MAX_LINES], val;
 	PyObject *def_vals_obj = NULL, *iter, *next;
 	struct gpiod_line_request_config conf;
 	struct gpiod_line_bulk bulk;
 	Py_ssize_t num_def_vals;
 	char *consumer = NULL;
+	const int *default_vals = NULL;
 	Py_ssize_t i;
 
 	if (gpiod_LineBulkOwnerIsClosed(self))
@@ -1348,7 +1349,7 @@ static PyObject *gpiod_LineBulk_request(gpiod_LineBulkObject *self,
 	gpiod_MakeRequestConfig(&conf, consumer, type, flags);
 
 	if (def_vals_obj) {
-		memset(default_vals, 0, sizeof(default_vals));
+		memset(vals, 0, sizeof(vals));
 
 		num_def_vals = PyObject_Size(def_vals_obj);
 		if (num_def_vals != self->num_lines) {
@@ -1375,8 +1376,9 @@ static PyObject *gpiod_LineBulk_request(gpiod_LineBulkObject *self,
 				return NULL;
 			}
 
-			default_vals[i] = !!val;
+			vals[i] = !!val;
 		}
+		default_vals = vals;
 	}
 
 	Py_BEGIN_ALLOW_THREADS;
-- 
2.30.0

Re: [lingpiod][PATCH] bindings: python: fix uninitialized default_vals being passed to gpiod_LineBulk_request()

[Bartosz Golaszewski]

On Mon, Feb 15, 2021 at 1:51 PM Kent Gibson <warthog618@gmail.com> wrote:
>
> If "default_vals" is not provided in the kwds then default_vals are
> passed uninitialized to gpiod_line_request_bulk(), so rename the
> existing default_vals to vals and introduce a new default_vals that
> points to vals, or NULL if no defaults have been passed.
>
> Fixes: 96c524c4951c (bindings: implement python bindings)
> Reported-by: Pedro Botella <pbotella@gmail.com>
> Signed-off-by: Kent Gibson <warthog618@gmail.com>
> ---
>  bindings/python/gpiodmodule.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/bindings/python/gpiodmodule.c b/bindings/python/gpiodmodule.c
> index fee4c32..832787d 100644
> --- a/bindings/python/gpiodmodule.c
> +++ b/bindings/python/gpiodmodule.c
> @@ -1327,12 +1327,13 @@ static PyObject *gpiod_LineBulk_request(gpiod_LineBulkObject *self,
>                                   NULL };
>
>         int rv, type = gpiod_LINE_REQ_DIR_AS_IS, flags = 0,
> -           default_vals[GPIOD_LINE_BULK_MAX_LINES], val;
> +           vals[GPIOD_LINE_BULK_MAX_LINES], val;
>         PyObject *def_vals_obj = NULL, *iter, *next;
>         struct gpiod_line_request_config conf;
>         struct gpiod_line_bulk bulk;
>         Py_ssize_t num_def_vals;
>         char *consumer = NULL;
> +       const int *default_vals = NULL;
>         Py_ssize_t i;
>
>         if (gpiod_LineBulkOwnerIsClosed(self))
> @@ -1348,7 +1349,7 @@ static PyObject *gpiod_LineBulk_request(gpiod_LineBulkObject *self,
>         gpiod_MakeRequestConfig(&conf, consumer, type, flags);
>
>         if (def_vals_obj) {
> -               memset(default_vals, 0, sizeof(default_vals));
> +               memset(vals, 0, sizeof(vals));
>
>                 num_def_vals = PyObject_Size(def_vals_obj);
>                 if (num_def_vals != self->num_lines) {
> @@ -1375,8 +1376,9 @@ static PyObject *gpiod_LineBulk_request(gpiod_LineBulkObject *self,
>                                 return NULL;
>                         }
>
> -                       default_vals[i] = !!val;
> +                       vals[i] = !!val;
>                 }
> +               default_vals = vals;
>         }
>
>         Py_BEGIN_ALLOW_THREADS;
> --
> 2.30.0
>

Applied, thanks!

Bartosz