[PATCH 5/6] HID: roccat-konepure: reject short button reports

[Yousef Alhouseen <alhouseenyousef@gmail.com>]

konepure_raw_event() forwards button reports directly to
roccat_report_event(), which copies the fixed eight-byte report size
registered by this driver. A malformed USB device can send a shorter
report and make that copy read beyond the input buffer.

Only forward complete button reports.

Fixes: 8936aa31cd5f ("HID: roccat: add support for Roccat Kone Pure gaming mouse")
Cc: stable@vger.kernel.org
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
---
 drivers/hid/hid-roccat-konepure.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-roccat-konepure.c b/drivers/hid/hid-roccat-konepure.c
index 7f753dfc2a10..d17dee18ac2b 100644
--- a/drivers/hid/hid-roccat-konepure.c
+++ b/drivers/hid/hid-roccat-konepure.c
@@ -181,7 +181,8 @@ static int konepure_raw_event(struct hid_device *hdev,
 			!= USB_INTERFACE_PROTOCOL_MOUSE)
 		return 0;
 
-	if (data[0] != KONEPURE_MOUSE_REPORT_NUMBER_BUTTON)
+	if (data[0] != KONEPURE_MOUSE_REPORT_NUMBER_BUTTON ||
+	    size < sizeof(struct konepure_mouse_report_button))
 		return 0;
 
 	if (konepure != NULL && konepure->roccat_claimed)
-- 
2.54.0