[PATCH 0/2] hwmon: Fix ASUS ROG Ryujin HID report handling

[PATCH 0/2] hwmon: Fix ASUS ROG Ryujin HID report handling

[Arie Miller]

A Sashiko review found two pre-existing issues in the ASUS ROG Ryujin
driver: missing HID report length validation and a race between completion
updates and reinitialization.

Reject undersized reports and serialize both paths with the existing
spinlock.

Tested on an ASUS ROG Ryujin III EVA using a DKMS-built module with 16,000
concurrent hwmon reads and 50 liquidctl status requests over hidraw. No
failures, timeouts, lock warnings, or HID errors were observed.

Arie Miller (2):
  hwmon: (asus_rog_ryujin) Validate HID report lengths
  hwmon: (asus_rog_ryujin) Synchronize HID command and report handling

 drivers/hwmon/asus_rog_ryujin.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

-- 
2.55.0

[PATCH 1/2] hwmon: (asus_rog_ryujin) Validate HID report lengths

[Arie Miller]

rog_ryujin_raw_event() parses response headers and payload fields without
first checking that they are present in the received report. A short report
can therefore make the driver consume uninitialized bytes from the HID
transport buffer and expose them as sensor values through sysfs.

Validate the response header and the fields used by each response type
before parsing them.

Fixes: ed3e03790c5c ("hwmon: Add driver for ASUS ROG RYUJIN II 360 AIO cooler")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-hwmon/20260812104617.858D01F000E9@smtp.kernel.org/
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6-sol sparse
Signed-off-by: Arie Miller <renari@arimil.com>
---
 drivers/hwmon/asus_rog_ryujin.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/asus_rog_ryujin.c b/drivers/hwmon/asus_rog_ryujin.c
index 702edb831394..f4d99c510369 100644
--- a/drivers/hwmon/asus_rog_ryujin.c
+++ b/drivers/hwmon/asus_rog_ryujin.c
@@ -422,10 +422,15 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 {
 	struct rog_ryujin_data *priv = hid_get_drvdata(hdev);
 
-	if (data[0] != RYUJIN_CMD_PREFIX)
+	if (size < 2 || data[0] != RYUJIN_CMD_PREFIX)
 		return 0;
 
 	if (data[1] == RYUJIN_GET_COOLER_STATUS_CMD_RESPONSE) {
+		if (size <= priv->info->temp_offset + 1 ||
+		    size <= priv->info->pump_speed_offset + 1 ||
+		    size <= priv->info->fan_speed_offset + 1)
+			return 0;
+
 		/* Received coolant temp and speeds of pump and internal fan */
 		priv->temp_input[0] = data[priv->info->temp_offset] * 1000 +
 			data[priv->info->temp_offset + 1] * 100;
@@ -437,6 +442,9 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 		if (!completion_done(&priv->cooler_status_received))
 			complete_all(&priv->cooler_status_received);
 	} else if (data[1] == RYUJIN_GET_CONTROLLER_SPEED_CMD_RESPONSE) {
+		if (size <= RYUJIN_CONTROLLER_SPEED_3 + 1)
+			return 0;
+
 		/* Received speeds of four fans attached to the controller */
 		priv->speed_input[2] = get_unaligned_le16(data + RYUJIN_CONTROLLER_SPEED_1);
 		priv->speed_input[3] = get_unaligned_le16(data + RYUJIN_CONTROLLER_SPEED_2);
@@ -446,6 +454,9 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 		if (!completion_done(&priv->controller_status_received))
 			complete_all(&priv->controller_status_received);
 	} else if (data[1] == RYUJIN_GET_COOLER_DUTY_CMD_RESPONSE) {
+		if (size <= RYUJIN_INTERNAL_FAN_DUTY)
+			return 0;
+
 		/* Received report for pump and internal fan duties (in %) */
 		if (data[RYUJIN_PUMP_DUTY] == 0 && data[RYUJIN_INTERNAL_FAN_DUTY] == 0) {
 			/*
@@ -472,6 +483,9 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 		if (!completion_done(&priv->cooler_duty_received))
 			complete_all(&priv->cooler_duty_received);
 	} else if (data[1] == RYUJIN_GET_CONTROLLER_DUTY_CMD_RESPONSE) {
+		if (size <= RYUJIN_CONTROLLER_DUTY)
+			return 0;
+
 		/* Received report for controller duty for fans (in PWM) */
 		if (data[RYUJIN_CONTROLLER_DUTY] == 0) {
 			/*
-- 
2.55.0

[PATCH 2/2] hwmon: (asus_rog_ryujin) Synchronize HID command and report handling

[Arie Miller]

rog_ryujin_execute_cmd() holds status_report_request_lock while
reinitializing a completion, intending to exclude raw-event handling.
However, rog_ryujin_raw_event() does not acquire the lock when it updates
the completion. A response can therefore race with reinit_completion() and
be lost, leaving the command to time out.

Hold the lock while parsing reports and updating their completions. Use the
irqsave variants in both paths because raw-event handling may run in
interrupt context.

Fixes: ed3e03790c5c ("hwmon: Add driver for ASUS ROG RYUJIN II 360 AIO cooler")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-hwmon/20260812104617.858D01F000E9@smtp.kernel.org/
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.6-sol sparse
Signed-off-by: Arie Miller <renari@arimil.com>
---
 drivers/hwmon/asus_rog_ryujin.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/hwmon/asus_rog_ryujin.c b/drivers/hwmon/asus_rog_ryujin.c
index f4d99c510369..e297557ca346 100644
--- a/drivers/hwmon/asus_rog_ryujin.c
+++ b/drivers/hwmon/asus_rog_ryujin.c
@@ -184,6 +184,7 @@ static int rog_ryujin_write_expanded(struct rog_ryujin_data *priv, const u8 *cmd
 static int rog_ryujin_execute_cmd(struct rog_ryujin_data *priv, const u8 *cmd, int cmd_length,
 				  struct completion *status_completion)
 {
+	unsigned long flags;
 	int ret;
 
 	/*
@@ -191,9 +192,9 @@ static int rog_ryujin_execute_cmd(struct rog_ryujin_data *priv, const u8 *cmd, i
 	 * completion. Reinit is done because hidraw could have triggered
 	 * the raw event parsing and marked the passed in completion as done.
 	 */
-	spin_lock_bh(&priv->status_report_request_lock);
+	spin_lock_irqsave(&priv->status_report_request_lock, flags);
 	reinit_completion(status_completion);
-	spin_unlock_bh(&priv->status_report_request_lock);
+	spin_unlock_irqrestore(&priv->status_report_request_lock, flags);
 
 	/* Send command for getting data */
 	ret = rog_ryujin_write_expanded(priv, cmd, cmd_length);
@@ -421,15 +422,18 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 				int size)
 {
 	struct rog_ryujin_data *priv = hid_get_drvdata(hdev);
+	unsigned long flags;
 
 	if (size < 2 || data[0] != RYUJIN_CMD_PREFIX)
 		return 0;
 
+	spin_lock_irqsave(&priv->status_report_request_lock, flags);
+
 	if (data[1] == RYUJIN_GET_COOLER_STATUS_CMD_RESPONSE) {
 		if (size <= priv->info->temp_offset + 1 ||
 		    size <= priv->info->pump_speed_offset + 1 ||
 		    size <= priv->info->fan_speed_offset + 1)
-			return 0;
+			goto unlock;
 
 		/* Received coolant temp and speeds of pump and internal fan */
 		priv->temp_input[0] = data[priv->info->temp_offset] * 1000 +
@@ -443,7 +447,7 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 			complete_all(&priv->cooler_status_received);
 	} else if (data[1] == RYUJIN_GET_CONTROLLER_SPEED_CMD_RESPONSE) {
 		if (size <= RYUJIN_CONTROLLER_SPEED_3 + 1)
-			return 0;
+			goto unlock;
 
 		/* Received speeds of four fans attached to the controller */
 		priv->speed_input[2] = get_unaligned_le16(data + RYUJIN_CONTROLLER_SPEED_1);
@@ -455,7 +459,7 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 			complete_all(&priv->controller_status_received);
 	} else if (data[1] == RYUJIN_GET_COOLER_DUTY_CMD_RESPONSE) {
 		if (size <= RYUJIN_INTERNAL_FAN_DUTY)
-			return 0;
+			goto unlock;
 
 		/* Received report for pump and internal fan duties (in %) */
 		if (data[RYUJIN_PUMP_DUTY] == 0 && data[RYUJIN_INTERNAL_FAN_DUTY] == 0) {
@@ -474,7 +478,7 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 				 * We're expecting a report, so parse it.
 				 */
 				goto read_cooler_duty;
-			return 0;
+			goto unlock;
 		}
 read_cooler_duty:
 		priv->duty_input[0] = rog_ryujin_percent_to_pwm(data[RYUJIN_PUMP_DUTY]);
@@ -484,7 +488,7 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 			complete_all(&priv->cooler_duty_received);
 	} else if (data[1] == RYUJIN_GET_CONTROLLER_DUTY_CMD_RESPONSE) {
 		if (size <= RYUJIN_CONTROLLER_DUTY)
-			return 0;
+			goto unlock;
 
 		/* Received report for controller duty for fans (in PWM) */
 		if (data[RYUJIN_CONTROLLER_DUTY] == 0) {
@@ -503,7 +507,7 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 				 * We're expecting a report, so parse it.
 				 */
 				goto read_controller_duty;
-			return 0;
+			goto unlock;
 		}
 read_controller_duty:
 		priv->duty_input[2] = data[RYUJIN_CONTROLLER_DUTY];
@@ -512,6 +516,8 @@ static int rog_ryujin_raw_event(struct hid_device *hdev, struct hid_report *repo
 			complete_all(&priv->controller_duty_received);
 	}
 
+unlock:
+	spin_unlock_irqrestore(&priv->status_report_request_lock, flags);
 	return 0;
 }
 
-- 
2.55.0