Re: [PATCH 1/1] HID: logitech-hidpp: Prevent use-after-free on force feedback initialisation failure

[Günther Noack]

On Fri, Feb 27, 2026 at 10:09:38AM +0000, Lee Jones wrote:
> Presently, if the force feedback initialisation fails when probing the
> Logitech G920 Driving Force Racing Wheel for Xbox One, an error number
> will be returned and propagated before the userspace infrastructure
> (sysfs and /dev/input) has been torn down.  If userspace ignores the
> errors and continues to use its references to these dangling entities, a
> UAF will promptly follow.
> 
> We have 2 options; continue to return the error, but ensure that all of
> the infrastructure is torn down accordingly or continue to treat this
> condition as a warning by emitting the message but returning success.
> It is thought that the original author's intention was to emit the
> warning but keep the device functional, less the force feedback feature,
> so let's go with that.
> 
> Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
> ---
>  drivers/hid/hid-logitech-hidpp.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
> index e871f1729d4b..eee9ab6a2fc4 100644
> --- a/drivers/hid/hid-logitech-hidpp.c
> +++ b/drivers/hid/hid-logitech-hidpp.c
> @@ -4487,10 +4487,12 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
>  		if (!ret)
>  			ret = hidpp_ff_init(hidpp, &data);
>  
> -		if (ret)
> +		if (ret) {
>  			hid_warn(hidpp->hid_dev,
>  		     "Unable to initialize force feedback support, errno %d\n",
>  				 ret);
> +			ret = 0;
> +		}
>  	}
>  
>  	/*
> -- 
> 2.53.0.473.g4a7958ca14-goog
> 

Reviewed-by: Günther Noack <gnoack@xxxxxxxxxx>

Thanks for the patch!
—Günther