2017-09-12 18:12:17

by Cameron Gutman

Subject: [PATCH] Input: xpad - validate USB endpoint type during probe

We should only see devices with interrupt endpoints. Ignore any other
endpoints that we find, so we don't send try to send them interrupt URBs
and trigger a WARN down in the USB stack.

Reported-by: Andrey Konovalov <[email protected]>
Tested-by: Andrey Konovalov <[email protected]>
Cc: <[email protected]> # c01b5e7464f0 Input: xpad - don't depend on endpoint order
Cc: <[email protected]>
Signed-off-by: Cameron Gutman <[email protected]>
---
To be able to hit any of the LTS kernels, we'll need to also cherry pick
c01b5e7464f0 ("Input: xpad - don't depend on endpoint order"). In hindsight,
this commit also addresses a malicious USB device case, since a device could
purposefully trick us into sending URBs to an endpoint in the wrong direction.
---
drivers/input/joystick/xpad.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
index f8e34ef643c7..d86e59515b9c 100644
--- a/drivers/input/joystick/xpad.c
+++ b/drivers/input/joystick/xpad.c
@@ -1764,10 +1764,12 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
struct usb_endpoint_descriptor *ep =
&intf->cur_altsetting->endpoint[i].desc;

- if (usb_endpoint_dir_in(ep))
- ep_irq_in = ep;
- else
- ep_irq_out = ep;
+ if (usb_endpoint_xfer_int(ep)) {
+ if (usb_endpoint_dir_in(ep))
+ ep_irq_in = ep;
+ else
+ ep_irq_out = ep;
+ }
}

if (!ep_irq_in || !ep_irq_out) {
--
2.14.1

2017-09-12 18:28:50

by Dmitry Torokhov

Subject: Re: [PATCH] Input: xpad - validate USB endpoint type during probe

On Tue, Sep 12, 2017 at 11:12:12AM -0700, Cameron Gutman wrote:
> We should only see devices with interrupt endpoints. Ignore any other
> endpoints that we find, so we don't send try to send them interrupt URBs
> and trigger a WARN down in the USB stack.
>
> Reported-by: Andrey Konovalov <[email protected]>
> Tested-by: Andrey Konovalov <[email protected]>
> Cc: <[email protected]> # c01b5e7464f0 Input: xpad - don't depend on endpoint order
> Cc: <[email protected]>
> Signed-off-by: Cameron Gutman <[email protected]>

Applied, thank you.

> ---
> To be able to hit any of the LTS kernels, we'll need to also cherry pick
> c01b5e7464f0 ("Input: xpad - don't depend on endpoint order"). In hindsight,
> this commit also addresses a malicious USB device case, since a device could
> purposefully trick us into sending URBs to an endpoint in the wrong direction.
> ---
> drivers/input/joystick/xpad.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/joystick/xpad.c b/drivers/input/joystick/xpad.c
> index f8e34ef643c7..d86e59515b9c 100644
> --- a/drivers/input/joystick/xpad.c
> +++ b/drivers/input/joystick/xpad.c
> @@ -1764,10 +1764,12 @@ static int xpad_probe(struct usb_interface *intf, const struct usb_device_id *id
> struct usb_endpoint_descriptor *ep =
> &intf->cur_altsetting->endpoint[i].desc;
>
> - if (usb_endpoint_dir_in(ep))
> - ep_irq_in = ep;
> - else
> - ep_irq_out = ep;
> + if (usb_endpoint_xfer_int(ep)) {
> + if (usb_endpoint_dir_in(ep))
> + ep_irq_in = ep;
> + else
> + ep_irq_out = ep;
> + }
> }
>
> if (!ep_irq_in || !ep_irq_out) {
> --
> 2.14.1

--
Dmitry