[PATCH] hwmon: (gigabyte_waterforce) reject short input reports

[Jiale Yao]

The HID driver raw_event callback runs before HID core validates the
received report length.  waterforce_raw_event() reads the command bytes
and then accesses fixed offsets for firmware or status data without any
length checks.  A truncated report can therefore cause out-of-bounds reads
and update hwmon state with data beyond the received report.

Require both command bytes before identifying a report, then check the
minimum length needed by the firmware and status paths before accessing
their payloads.  Commit 47669bec44fe ("HID: asus: refactor the two
workqueues and init sequence") added equivalent raw-event length
validation to hid-asus.

Fixes: 42ac68e3d4ba ("hwmon: Add driver for Gigabyte AORUS Waterforce AIO coolers")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/hwmon/gigabyte_waterforce.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/hwmon/gigabyte_waterforce.c b/drivers/hwmon/gigabyte_waterforce.c
index 4eea05f8b569..9499cb274cbd 100644
--- a/drivers/hwmon/gigabyte_waterforce.c
+++ b/drivers/hwmon/gigabyte_waterforce.c
@@ -257,8 +257,14 @@ static int waterforce_raw_event(struct hid_device *hdev, struct hid_report *repo
 {
 	struct waterforce_data *priv = hid_get_drvdata(hdev);
 
+	if (size < sizeof(get_status_cmd))
+		return 0;
+
 	if (data[0] == get_firmware_ver_cmd[0] && data[1] == get_firmware_ver_cmd[1]) {
 		/* Received a firmware version report */
+		if (size <= FIRMWARE_VER_START_OFFSET_2)
+			return 0;
+
 		priv->firmware_version =
 		    data[FIRMWARE_VER_START_OFFSET_1] * 10 + data[FIRMWARE_VER_START_OFFSET_2];
 
@@ -269,6 +275,8 @@ static int waterforce_raw_event(struct hid_device *hdev, struct hid_report *repo
 
 	if (data[0] != get_status_cmd[0] || data[1] != get_status_cmd[1])
 		return 0;
+	if (size <= WATERFORCE_TEMP_SENSOR)
+		return 0;
 
 	priv->temp_input[0] = data[WATERFORCE_TEMP_SENSOR] * 1000;
 	priv->speed_input[0] = get_unaligned_le16(data + WATERFORCE_FAN_SPEED);
-- 
2.34.1