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

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

[Lee Jones]

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@kernel.org>
---
 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

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@kernel.org>
> ---
>  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@google.com>

Thanks for the patch!
—Günther

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

[Lee Jones]

On Tue, 03 Mar 2026, Günther Noack wrote:

> 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@kernel.org>
> > ---
> >  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@google.com>

What are the subsystem preferences in terms of pokes or [RESENDS], please?

I'm happy to submit a [RESEND] if that's required to get this back into view.

-- 
Lee Jones [李琼斯]

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

[Benjamin Tissoires]

On Mar 16 2026, Lee Jones wrote:
> On Tue, 03 Mar 2026, Günther Noack wrote:
> 
> > 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@kernel.org>
> > > ---
> > >  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@google.com>
> 
> What are the subsystem preferences in terms of pokes or [RESENDS], please?

Just send a gently ping like this on the thread, this will make it pop
up in our mailboxes :)

> 
> I'm happy to submit a [RESEND] if that's required to get this back into view.

Nah, no need to send a [RESEND] when the patch is just a couple of weeks
old.

Cheers,
Benjamin

> 
> -- 
> Lee Jones [李琼斯]
> 

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

[Lee Jones]

On Mon, 16 Mar 2026, Benjamin Tissoires wrote:

> On Mar 16 2026, Lee Jones wrote:
> > On Tue, 03 Mar 2026, Günther Noack wrote:
> > 
> > > 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@kernel.org>
> > > > ---
> > > >  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@google.com>
> > 
> > What are the subsystem preferences in terms of pokes or [RESENDS], please?
> 
> Just send a gently ping like this on the thread, this will make it pop
> up in our mailboxes :)
> 
> > 
> > I'm happy to submit a [RESEND] if that's required to get this back into view.
> 
> Nah, no need to send a [RESEND] when the patch is just a couple of weeks
> old.

Understood, thank you.

-- 
Lee Jones [李琼斯]

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

[Benjamin Tissoires]

On Fri, 27 Feb 2026 10:09:38 +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.
> 
> [...]

Applied, thanks!

[1/1] HID: logitech-hidpp: Prevent use-after-free on force feedback initialisation failure
      commit: f7a4c78bfeb320299c1b641500fe7761eadbd101

Best regards,
-- 
Benjamin Tissoires <bentiss@kernel.org>