diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index f736c8895089..efa8b620fee8 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -482,12 +482,12 @@ static void acm_read_bulk_callback(struct urb *urb)
 	struct acm *acm = rb->instance;
 	unsigned long flags;
 	int status = urb->status;
+	bool stopped = false;
+	bool stalled = false;
 
 	dev_vdbg(&acm->data->dev, "got urb %d, len %d, status %d\n",
 		rb->index, urb->actual_length, status);
 
-	set_bit(rb->index, &acm->read_urbs_free);
-
 	if (!acm->dev) {
 		dev_dbg(&acm->data->dev, "%s - disconnected\n", __func__);
 		return;
@@ -500,15 +500,16 @@ static void acm_read_bulk_callback(struct urb *urb)
 		break;
 	case -EPIPE:
 		set_bit(EVENT_RX_STALL, &acm->flags);
-		schedule_work(&acm->work);
-		return;
+		stalled = true;
+		break;
 	case -ENOENT:
 	case -ECONNRESET:
 	case -ESHUTDOWN:
 		dev_dbg(&acm->data->dev,
 			"%s - urb shutting down with status: %d\n",
 			__func__, status);
-		return;
+		stopped = true;
+		break;
 	default:
 		dev_dbg(&acm->data->dev,
 			"%s - nonzero urb status received: %d\n",
@@ -517,10 +518,24 @@ static void acm_read_bulk_callback(struct urb *urb)
 	}
 
 	/*
-	 * Unthrottle may run on another CPU which needs to see events
-	 * in the same order. Submission has an implict barrier
+	 * Make sure URB processing is done before marking as free to avoid
+	 * racing with unthrottle() on another CPU. Matches the barriers
+	 * implied by the test_and_clear_bit() in acm_submit_read_urb().
 	 */
 	smp_mb__before_atomic();
+	set_bit(rb->index, &acm->read_urbs_free);
+	/*
+	 * Make sure URB is marked as free before checking the throttled flag
+	 * to avoid racing with unthrottle() on another CPU. Matches the
+	 * smp_mb() in unthrottle().
+	 */
+	smp_mb__after_atomic();
+
+	if (stopped || stalled) {
+		if (stalled)
+			schedule_work(&acm->work);
+		return;
+	}
 
 	/* throttle device if requested by tty */
 	spin_lock_irqsave(&acm->read_lock, flags);
@@ -854,6 +869,9 @@ static void acm_tty_unthrottle(struct tty_struct *tty)
 	acm->throttle_req = 0;
 	spin_unlock_irq(&acm->read_lock);
 
+	/* Matches the smp_mb__after_atomic() in acm_read_bulk_callback(). */
+	smp_mb();
+
 	if (was_throttled)
 		acm_submit_read_urbs(acm, GFP_KERNEL);
 }