[PATCH 6/6] HID: roccat-ryos: reject short special reports

[Yousef Alhouseen <alhouseenyousef@gmail.com>]

ryos_raw_event() forwards special reports directly to the Roccat
character-device layer, which copies the fixed five-byte report size
registered by this driver. A malformed USB device can send a shorter
report and trigger an out-of-bounds read during that copy.

Only forward complete special reports.

Fixes: 6f3a19360545 ("HID: roccat: add support for Ryos MK keyboards")
Cc: stable@vger.kernel.org
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
---
 drivers/hid/hid-roccat-ryos.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-roccat-ryos.c b/drivers/hid/hid-roccat-ryos.c
index db83f42457da..5087defc7c37 100644
--- a/drivers/hid/hid-roccat-ryos.c
+++ b/drivers/hid/hid-roccat-ryos.c
@@ -189,7 +189,8 @@ static int ryos_raw_event(struct hid_device *hdev,
 			!= RYOS_USB_INTERFACE_PROTOCOL)
 		return 0;
 
-	if (data[0] != RYOS_REPORT_NUMBER_SPECIAL)
+	if (data[0] != RYOS_REPORT_NUMBER_SPECIAL ||
+	    size < sizeof(struct ryos_report_special))
 		return 0;
 
 	if (ryos != NULL && ryos->roccat_claimed)
-- 
2.54.0