| Message ID | 20210404080432.4322-4-hdegoede@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | HID: lenovo: LED fixes and Thinkpad X1 Tablet kbd support | expand |
diff --git a/drivers/hid/hid-lenovo.c b/drivers/hid/hid-lenovo.c index ee175ab54281..b2596ed37880 100644 --- a/drivers/hid/hid-lenovo.c +++ b/drivers/hid/hid-lenovo.c @@ -508,6 +508,9 @@ static int lenovo_event_cptkbd(struct hid_device *hdev, static int lenovo_event(struct hid_device *hdev, struct hid_field *field, struct hid_usage *usage, __s32 value) { + if (!hid_get_drvdata(hdev)) + return 0; + switch (hdev->product) { case USB_DEVICE_ID_LENOVO_CUSBKBD: case USB_DEVICE_ID_LENOVO_CBTKBD:
The HID lenovo probe function only attaches drvdata to one of the USB interfaces, but lenovo_event() will get called for all USB interfaces to which hid-lenovo is bound. This allows a malicious device to fake being a device handled by hid-lenovo, which generates events for which lenovo_event() has special handling (and thus dereferences hid_get_drvdata()) on another interface triggering a NULL pointer exception. Add a check for hid_get_drvdata() returning NULL, avoiding this possible NULL pointer exception. Fixes: bc04b37ea0ec ("HID: lenovo: Add ThinkPad 10 Ultrabook Keyboard support") Reviewed-by: Marek Behún <kabel@kernel.org> Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/hid/hid-lenovo.c | 3 +++ 1 file changed, 3 insertions(+)