can: hi311x: fix null pointer dereference when resuming from sleep before interface was enabled

This issue is similar to the vulnerability in the `mcp251x` driver,
which was fixed in commit 03c4271 ("can: mcp251x: fix resume from
sleep before interface was brought up").

In the `hi311x` driver, when the device resumes from sleep, the driver
schedules `priv->restart_work`. However, if the network interface was
not previously enabled, the `priv->wq` (workqueue) is not allocated and
initialized, leading to a null pointer dereference.

To fix this, we move the allocation and initialization of the workqueue
from the `hi3110_open` function to the `hi3110_can_probe` function.
This ensures that the workqueue is properly initialized before it is
used during device resume. And added logic to destroy the workqueue
in the error handling paths of `hi3110_can_probe` and in the
`hi3110_can_remove` function to prevent resource leaks.

Signed-off-by: Chen Yufeng <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: Chen Yufeng

drivers/net/can/spi/hi311x.c

@@ -545,8 +545,6 @@ static int hi3110_stop(struct net_device *net)
 
 	priv->force_quit = 1;
 	free_irq(spi->irq, priv);
-	destroy_workqueue(priv->wq);
-	priv->wq = NULL;
 
 	mutex_lock(&priv->hi3110_lock);
 
@@ -770,34 +768,23 @@ static int hi3110_open(struct net_device *net)
 		goto out_close;
 	}
 
-	priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
-				   0);
-	if (!priv->wq) {
-		ret = -ENOMEM;
-		goto out_free_irq;
-	}
-	INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
-	INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
-
 	ret = hi3110_hw_reset(spi);
 	if (ret)
-		goto out_free_wq;
+		goto out_free_irq;
 
 	ret = hi3110_setup(net);
 	if (ret)
-		goto out_free_wq;
+		goto out_free_irq;
 
 	ret = hi3110_set_normal_mode(spi);
 	if (ret)
-		goto out_free_wq;
+		goto out_free_irq;
 
 	netif_wake_queue(net);
 	mutex_unlock(&priv->hi3110_lock);
 
 	return 0;
 
- out_free_wq:
-	destroy_workqueue(priv->wq);
  out_free_irq:
 	free_irq(spi->irq, priv);
 	hi3110_hw_sleep(spi);
@@ -908,6 +895,15 @@ static int hi3110_can_probe(struct spi_device *spi)
 	if (ret)
 		goto out_clk;
 
+	priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
+				   0);
+	if (!priv->wq) {
+		ret = -ENOMEM;
+		goto out_clk;
+	}
+	INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
+	INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
+
 	priv->spi = spi;
 	mutex_init(&priv->hi3110_lock);
 
@@ -943,6 +939,8 @@ static int hi3110_can_probe(struct spi_device *spi)
 	return 0;
 
  error_probe:
+	destroy_workqueue(priv->wq);
+	priv->wq = NULL;
 	hi3110_power_enable(priv->power, 0);
 
  out_clk:
@@ -963,6 +961,9 @@ static void hi3110_can_remove(struct spi_device *spi)
 
 	hi3110_power_enable(priv->power, 0);
 
+	destroy_workqueue(priv->wq);
+	priv->wq = NULL;
+
 	clk_disable_unprepare(priv->clk);
 
 	free_candev(net);