[PATCH 05/10] HID: logitech-dj: validate unnumbered keyboard reports

The HID core invokes raw_event callbacks before validating the report
length.  For an unnumbered keyboard report, logi_dj_raw_event() uses the
second byte as temporary storage while prepending a report ID.  A one-byte
report therefore makes both the initial write and the later restoration
access data beyond the received report.

Reject unnumbered keyboard reports that do not provide the temporary byte.

Commit 47669bec44fe ("HID: asus: refactor the two workqueues and init
sequence") added the same kind of raw_event length validation to hid-asus.

Fixes: 74808f9115ce ("HID: logitech-dj: add support for non unifying receivers")
Cc: stable@vger.kernel.org
Signed-off-by: Jiale Yao <redacted>
---
 drivers/hid/hid-logitech-dj.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-logitech-dj.c b/drivers/hid/hid-logitech-dj.c
index 1d619d2345e1..ce5e0f7218b8 100644
--- a/drivers/hid/hid-logitech-dj.c
+++ b/drivers/hid/hid-logitech-dj.c

@@ -1813,6 +1813,9 @@ static int logi_dj_raw_event(struct hid_device *hdev,
 	if (!hdev->report_enum[HID_INPUT_REPORT].numbered) {
 
 		if (djrcv_dev->unnumbered_application == HID_GD_KEYBOARD) {
+			if (size < 2)
+				return false;
+
 			/*
 			 * For the keyboard, we can reuse the same report by
 			 * using the second byte which is constant in the USB

-- 
2.34.1