[PATCH 3/6] HID: roccat-pyra: reject short button reports

[Yousef Alhouseen <alhouseenyousef@gmail.com>]

The Pyra raw-event path treats every button report as a complete
five-byte structure. A malformed USB device can send a shorter report
and make profile tracking or character-device event construction read
beyond the received input buffer.

Ignore incomplete button reports before calling either helper.

Fixes: cb7cf3da0daa ("HID: roccat: add driver for Roccat Pyra mouse")
Cc: stable@vger.kernel.org
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
---
 drivers/hid/hid-roccat-pyra.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/hid/hid-roccat-pyra.c b/drivers/hid/hid-roccat-pyra.c
index 0d515995bb9d..df8949c17ce3 100644
--- a/drivers/hid/hid-roccat-pyra.c
+++ b/drivers/hid/hid-roccat-pyra.c
@@ -557,6 +557,10 @@ static int pyra_raw_event(struct hid_device *hdev, struct hid_report *report,
 	if (pyra == NULL)
 		return 0;
 
+	if (data[0] == PYRA_MOUSE_REPORT_NUMBER_BUTTON &&
+	    size < sizeof(struct pyra_mouse_event_button))
+		return 0;
+
 	pyra_keep_values_up_to_date(pyra, data);
 
 	if (pyra->roccat_claimed)
-- 
2.54.0