[PATCH] Input: refuse to register absolute devices without absinfo

[PATCH] Input: refuse to register absolute devices without absinfo

[Dmitry Torokhov]

If device is supposed to send absolute events (i.e. EV_ABS bit is set in
dev->evbit) but dev->absinfo is not allocated, then the driver has done
something wrong, and we should not register such device. Otherwise we'll
crash later, when driver tries to send absolute event.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
 drivers/input/input.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/input/input.c b/drivers/input/input.c
index f0d2d45a68e3..4617f2db9e36 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -2095,6 +2095,12 @@ int input_register_device(struct input_dev *dev)
 	const char *path;
 	int error;
 
+	if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
+		dev_err(&dev->dev,
+			"Absolute device without dev->absinfo, refusing to register\n");
+		return -EINVAL;
+	}
+
 	if (dev->devres_managed) {
 		devres = devres_alloc(devm_input_device_unregister,
 				      sizeof(struct input_devres), GFP_KERNEL);
-- 
2.11.0.483.g087da7b7c-goog


-- 
Dmitry

Re: [PATCH] Input: refuse to register absolute devices without absinfo

[Benjamin Tissoires]

On Jan 31 2017 or thereabouts, Dmitry Torokhov wrote:
> If device is supposed to send absolute events (i.e. EV_ABS bit is set in
> dev->evbit) but dev->absinfo is not allocated, then the driver has done
> something wrong, and we should not register such device. Otherwise we'll
> crash later, when driver tries to send absolute event.
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> ---

Looks good to me:
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>

Cheers,
Benjamin

>  drivers/input/input.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index f0d2d45a68e3..4617f2db9e36 100644
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -2095,6 +2095,12 @@ int input_register_device(struct input_dev *dev)
>  	const char *path;
>  	int error;
>  
> +	if (test_bit(EV_ABS, dev->evbit) && !dev->absinfo) {
> +		dev_err(&dev->dev,
> +			"Absolute device without dev->absinfo, refusing to register\n");
> +		return -EINVAL;
> +	}
> +
>  	if (dev->devres_managed) {
>  		devres = devres_alloc(devm_input_device_unregister,
>  				      sizeof(struct input_devres), GFP_KERNEL);
> -- 
> 2.11.0.483.g087da7b7c-goog
> 
> 
> -- 
> Dmitry

Re: [PATCH] Input: refuse to register absolute devices without absinfo

[Jiri Kosina]

On Tue, 31 Jan 2017, Dmitry Torokhov wrote:

> If device is supposed to send absolute events (i.e. EV_ABS bit is set in
> dev->evbit) but dev->absinfo is not allocated, then the driver has done
> something wrong, and we should not register such device. Otherwise we'll
> crash later, when driver tries to send absolute event.
> 
> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Acked-by: Jiri Kosina <jkosina@suse.cz>

Thanks.

-- 
Jiri Kosina
SUSE Labs