net: liquidio: Add missing null pointer checks

The functions send_rx_ctrl_cmd() in both liquidio/lio_main.c and
liquidio/lio_vf_main.c do not check if the call to
octeon_alloc_soft_command() fails and returns a null pointer. Both
functions also return void so errors are not propagated back to the
caller.

Fix these issues by updating both instances of send_rx_ctrl_cmd() to
return an integer rather than void, and have them return -ENOMEM if an
allocation failure occurs. Also update all callers of send_rx_ctrl_cmd()
so that they now check the return value.

Cc: David S. Miller <[e-mail]>
Signed-off-by: Tom Seewald <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/net/ethernet/cavium/liquidio/lio_main.c

···
  * @lio: per-network private data
  * @start_stop: whether to start or stop
  */
-static void send_rx_ctrl_cmd(struct lio *lio, int start_stop)
+static int send_rx_ctrl_cmd(struct lio *lio, int start_stop)
 {
 	struct octeon_soft_command *sc;
 	union octnet_cmd *ncmd;
···
 	int retval;
 
 	if (oct->props[lio->ifidx].rx_on == start_stop)
-		return;
+		return 0;
 
 	sc = (struct octeon_soft_command *)
 		octeon_alloc_soft_command(oct, OCTNET_CMD_SIZE,
 					  16, 0);
+	if (!sc) {
+		netif_info(lio, rx_err, lio->netdev,
+			   "Failed to allocate octeon_soft_command struct\n");
+		return -ENOMEM;
+	}
 
 	ncmd = (union octnet_cmd *)sc->virtdptr;
 
···
 	if (retval == IQ_SEND_FAILED) {
 		netif_info(lio, rx_err, lio->netdev, "Failed to send RX Control message\n");
 		octeon_free_soft_command(oct, sc);
-		return;
 	} else {
 		/* Sleep on a wait queue till the cond flag indicates that the
 		 * response arrived or timed-out.
 		 */
 		retval = wait_for_sc_completion_timeout(oct, sc, 0);
 		if (retval)
-			return;
+			return retval;
 
 		oct->props[lio->ifidx].rx_on = start_stop;
 		WRITE_ONCE(sc->caller_is_done, true);
 	}
+
+	return retval;
 }
 
 /**
···
 	struct octeon_device_priv *oct_priv =
 		(struct octeon_device_priv *)oct->priv;
 	struct napi_struct *napi, *n;
+	int ret = 0;
 
 	if (oct->props[lio->ifidx].napi_enabled == 0) {
 		tasklet_disable(&oct_priv->droq_tasklet);
···
 	netif_info(lio, ifup, lio->netdev, "Interface Open, ready for traffic\n");
 
 	/* tell Octeon to start forwarding packets to host */
-	send_rx_ctrl_cmd(lio, 1);
+	ret = send_rx_ctrl_cmd(lio, 1);
+	if (ret)
+		return ret;
 
 	/* start periodical statistics fetch */
 	INIT_DELAYED_WORK(&lio->stats_wk.work, lio_fetch_stats);
···
 	dev_info(&oct->pci_dev->dev, "%s interface is opened\n",
 		 netdev->name);
 
-	return 0;
+	return ret;
 }
 
 /**
···
 	struct octeon_device_priv *oct_priv =
 		(struct octeon_device_priv *)oct->priv;
 	struct napi_struct *napi, *n;
+	int ret = 0;
 
 	ifstate_reset(lio, LIO_IFSTATE_RUNNING);
 
···
 	lio->link_changes++;
 
 	/* Tell Octeon that nic interface is down. */
-	send_rx_ctrl_cmd(lio, 0);
+	ret = send_rx_ctrl_cmd(lio, 0);
+	if (ret)
+		return ret;
 
 	if (OCTEON_CN23XX_PF(oct)) {
 		if (!oct->msix_on)
···
 
 	dev_info(&oct->pci_dev->dev, "%s interface is stopped\n", netdev->name);
 
-	return 0;
+	return ret;
 }
 
 /**

drivers/net/ethernet/cavium/liquidio/lio_vf_main.c

···
  * @lio: per-network private data
  * @start_stop: whether to start or stop
  */
-static void send_rx_ctrl_cmd(struct lio *lio, int start_stop)
+static int send_rx_ctrl_cmd(struct lio *lio, int start_stop)
 {
 	struct octeon_device *oct = (struct octeon_device *)lio->oct_dev;
 	struct octeon_soft_command *sc;
···
 	int retval;
 
 	if (oct->props[lio->ifidx].rx_on == start_stop)
-		return;
+		return 0;
 
 	sc = (struct octeon_soft_command *)
 		octeon_alloc_soft_command(oct, OCTNET_CMD_SIZE,
 					  16, 0);
+	if (!sc) {
+		netif_info(lio, rx_err, lio->netdev,
+			   "Failed to allocate octeon_soft_command struct\n");
+		return -ENOMEM;
+	}
 
 	ncmd = (union octnet_cmd *)sc->virtdptr;
 
···
 		 */
 		retval = wait_for_sc_completion_timeout(oct, sc, 0);
 		if (retval)
-			return;
+			return retval;
 
 		oct->props[lio->ifidx].rx_on = start_stop;
 		WRITE_ONCE(sc->caller_is_done, true);
 	}
+
+	return retval;
 }
 
 /**
···
 	struct octeon_device_priv *oct_priv =
 		(struct octeon_device_priv *)oct->priv;
 	struct napi_struct *napi, *n;
+	int ret = 0;
 
 	if (!oct->props[lio->ifidx].napi_enabled) {
 		tasklet_disable(&oct_priv->droq_tasklet);
···
 					(LIQUIDIO_NDEV_STATS_POLL_TIME_MS));
 
 	/* tell Octeon to start forwarding packets to host */
-	send_rx_ctrl_cmd(lio, 1);
+	ret = send_rx_ctrl_cmd(lio, 1);
+	if (ret)
+		return ret;
 
 	dev_info(&oct->pci_dev->dev, "%s interface is opened\n", netdev->name);
 
-	return 0;
+	return ret;
 }
 
 /**
···
 	struct octeon_device_priv *oct_priv =
 		(struct octeon_device_priv *)oct->priv;
 	struct napi_struct *napi, *n;
+	int ret = 0;
 
 	/* tell Octeon to stop forwarding packets to host */
-	send_rx_ctrl_cmd(lio, 0);
+	ret = send_rx_ctrl_cmd(lio, 0);
+	if (ret)
+		return ret;
 
 	netif_info(lio, ifdown, lio->netdev, "Stopping interface!\n");
 	/* Inform that netif carrier is down */
···
 
 	dev_info(&oct->pci_dev->dev, "%s interface is stopped\n", netdev->name);
 
-	return 0;
+	return ret;
 }
 
 /**