[PATCH v2 3/3] HID: rapoo: fix missing hid_is_usb() check

[Jann Horn]

to_usb_interface() can only be used on a hid_device whose parent is really
USB; uhid can create devices that identify as being on BUS_USB, but don't
actually have a USB parent.
Fix the use of to_usb_interface() without a hid_is_usb() check.

Add a dependency on USB_HID for hid_is_usb(), as other HID drivers do; the
alternative would be to provide a simple stub implementation on !USB_HID
builds.

I have verified that it is currently possible to trigger a kernel splat due
to this bug in an ASAN build, and that this commit fixes the issue.

Fixes: b3b1c68fb726 ("HID: rapoo: Add support for side buttons on RAPOO 0x2015 mouse")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
---
 drivers/hid/Kconfig     | 1 +
 drivers/hid/hid-rapoo.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index f9bcaeb66385..48934c4f3c45 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -1048,6 +1048,7 @@ config HID_PXRC
 
 config HID_RAPOO
 	tristate "Rapoo non-fully HID-compliant devices"
+	depends on USB_HID
 	help
 	Support for Rapoo devices that are not fully compliant with the
 	HID standard.
diff --git a/drivers/hid/hid-rapoo.c b/drivers/hid/hid-rapoo.c
index 4c81f3086de4..5c9c396fabf7 100644
--- a/drivers/hid/hid-rapoo.c
+++ b/drivers/hid/hid-rapoo.c
@@ -36,7 +36,7 @@ static int rapoo_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		return ret;
 	}
 
-	if (hdev->bus == BUS_USB) {
+	if (hid_is_usb(hdev)) {
 		struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
 
 		if (intf->cur_altsetting->desc.bInterfaceNumber != 1)

-- 
2.55.0.rc0.799.gd6f94ed593-goog