Merge branch 'for-6.3/bigben' into for-linus

UAF protection in work struct (Pietro Borrello)

Author: bentiss

drivers/hid/hid-bigbenff.c

@@ -174,6 +174,7 @@ static __u8 pid0902_rdesc_fixed[] = {
 struct bigben_device {
 	struct hid_device *hid;
 	struct hid_report *report;
+	spinlock_t lock;
 	bool removed;
 	u8 led_state;         /* LED1 = 1 .. LED4 = 8 */
 	u8 right_motor_on;    /* right motor off/on 0/1 */
@@ -184,18 +185,39 @@ struct bigben_device {
 	struct work_struct worker;
 };
 
+static inline void bigben_schedule_work(struct bigben_device *bigben)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&bigben->lock, flags);
+	if (!bigben->removed)
+		schedule_work(&bigben->worker);
+	spin_unlock_irqrestore(&bigben->lock, flags);
+}
 
 static void bigben_worker(struct work_struct *work)
 {
 	struct bigben_device *bigben = container_of(work,
 		struct bigben_device, worker);
 	struct hid_field *report_field = bigben->report->field[0];
-
-	if (bigben->removed || !report_field)
+	bool do_work_led = false;
+	bool do_work_ff = false;
+	u8 *buf;
+	u32 len;
+	unsigned long flags;
+
+	buf = hid_alloc_report_buf(bigben->report, GFP_KERNEL);
+	if (!buf)
 		return;
 
+	len = hid_report_len(bigben->report);
+
+	/* LED work */
+	spin_lock_irqsave(&bigben->lock, flags);
+
 	if (bigben->work_led) {
 		bigben->work_led = false;
+		do_work_led = true;
 		report_field->value[0] = 0x01; /* 1 = led message */
 		report_field->value[1] = 0x08; /* reserved value, always 8 */
 		report_field->value[2] = bigben->led_state;
@@ -204,11 +226,22 @@ static void bigben_worker(struct work_struct *work)
 		report_field->value[5] = 0x00; /* padding */
 		report_field->value[6] = 0x00; /* padding */
 		report_field->value[7] = 0x00; /* padding */
-		hid_hw_request(bigben->hid, bigben->report, HID_REQ_SET_REPORT);
+		hid_output_report(bigben->report, buf);
+	}
+
+	spin_unlock_irqrestore(&bigben->lock, flags);
+
+	if (do_work_led) {
+		hid_hw_raw_request(bigben->hid, bigben->report->id, buf, len,
+				   bigben->report->type, HID_REQ_SET_REPORT);
 	}
 
+	/* FF work */
+	spin_lock_irqsave(&bigben->lock, flags);
+
 	if (bigben->work_ff) {
 		bigben->work_ff = false;
+		do_work_ff = true;
 		report_field->value[0] = 0x02; /* 2 = rumble effect message */
 		report_field->value[1] = 0x08; /* reserved value, always 8 */
 		report_field->value[2] = bigben->right_motor_on;
@@ -217,8 +250,17 @@ static void bigben_worker(struct work_struct *work)
 		report_field->value[5] = 0x00; /* padding */
 		report_field->value[6] = 0x00; /* padding */
 		report_field->value[7] = 0x00; /* padding */
-		hid_hw_request(bigben->hid, bigben->report, HID_REQ_SET_REPORT);
+		hid_output_report(bigben->report, buf);
+	}
+
+	spin_unlock_irqrestore(&bigben->lock, flags);
+
+	if (do_work_ff) {
+		hid_hw_raw_request(bigben->hid, bigben->report->id, buf, len,
+				   bigben->report->type, HID_REQ_SET_REPORT);
 	}
+
+	kfree(buf);
 }
 
 static int hid_bigben_play_effect(struct input_dev *dev, void *data,
@@ -228,6 +270,7 @@ static int hid_bigben_play_effect(struct input_dev *dev, void *data,
 	struct bigben_device *bigben = hid_get_drvdata(hid);
 	u8 right_motor_on;
 	u8 left_motor_force;
+	unsigned long flags;
 
 	if (!bigben) {
 		hid_err(hid, "no device data\n");
@@ -242,10 +285,13 @@ static int hid_bigben_play_effect(struct input_dev *dev, void *data,
 
 	if (right_motor_on != bigben->right_motor_on ||
 			left_motor_force != bigben->left_motor_force) {
+		spin_lock_irqsave(&bigben->lock, flags);
 		bigben->right_motor_on   = right_motor_on;
 		bigben->left_motor_force = left_motor_force;
 		bigben->work_ff = true;
-		schedule_work(&bigben->worker);
+		spin_unlock_irqrestore(&bigben->lock, flags);
+
+		bigben_schedule_work(bigben);
 	}
 
 	return 0;
@@ -259,6 +305,7 @@ static void bigben_set_led(struct led_classdev *led,
 	struct bigben_device *bigben = hid_get_drvdata(hid);
 	int n;
 	bool work;
+	unsigned long flags;
 
 	if (!bigben) {
 		hid_err(hid, "no device data\n");
@@ -267,17 +314,19 @@ static void bigben_set_led(struct led_classdev *led,
 
 	for (n = 0; n < NUM_LEDS; n++) {
 		if (led == bigben->leds[n]) {
+			spin_lock_irqsave(&bigben->lock, flags);
 			if (value == LED_OFF) {
 				work = (bigben->led_state & BIT(n));
 				bigben->led_state &= ~BIT(n);
 			} else {
 				work = !(bigben->led_state & BIT(n));
 				bigben->led_state |= BIT(n);
 			}
+			spin_unlock_irqrestore(&bigben->lock, flags);
 
 			if (work) {
 				bigben->work_led = true;
-				schedule_work(&bigben->worker);
+				bigben_schedule_work(bigben);
 			}
 			return;
 		}
@@ -307,8 +356,12 @@ static enum led_brightness bigben_get_led(struct led_classdev *led)
 static void bigben_remove(struct hid_device *hid)
 {
 	struct bigben_device *bigben = hid_get_drvdata(hid);
+	unsigned long flags;
 
+	spin_lock_irqsave(&bigben->lock, flags);
 	bigben->removed = true;
+	spin_unlock_irqrestore(&bigben->lock, flags);
+
 	cancel_work_sync(&bigben->worker);
 	hid_hw_stop(hid);
 }
@@ -318,7 +371,6 @@ static int bigben_probe(struct hid_device *hid,
 {
 	struct bigben_device *bigben;
 	struct hid_input *hidinput;
-	struct list_head *report_list;
 	struct led_classdev *led;
 	char *name;
 	size_t name_sz;
@@ -343,14 +395,12 @@ static int bigben_probe(struct hid_device *hid,
 		return error;
 	}
 
-	report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
-	if (list_empty(report_list)) {
+	bigben->report = hid_validate_values(hid, HID_OUTPUT_REPORT, 0, 0, 8);
+	if (!bigben->report) {
 		hid_err(hid, "no output report found\n");
 		error = -ENODEV;
 		goto error_hw_stop;
 	}
-	bigben->report = list_entry(report_list->next,
-		struct hid_report, list);
 
 	if (list_empty(&hid->inputs)) {
 		hid_err(hid, "no inputs found\n");
@@ -362,6 +412,7 @@ static int bigben_probe(struct hid_device *hid,
 	set_bit(FF_RUMBLE, hidinput->input->ffbit);
 
 	INIT_WORK(&bigben->worker, bigben_worker);
+	spin_lock_init(&bigben->lock);
 
 	error = input_ff_create_memless(hidinput->input, NULL,
 		hid_bigben_play_effect);
@@ -402,7 +453,7 @@ static int bigben_probe(struct hid_device *hid,
 	bigben->left_motor_force = 0;
 	bigben->work_led = true;
 	bigben->work_ff = true;
-	schedule_work(&bigben->worker);
+	bigben_schedule_work(bigben);
 
 	hid_info(hid, "LED and force feedback support for BigBen gamepad\n");