releases/5.10.73/gve-avoid-freeing-null-pointer.patch

From 7b53330ee5a5e1fb1928c939b8c38ba6c4842db4 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Tue, 5 Oct 2021 19:42:20 -0700
Subject: gve: Avoid freeing NULL pointer

From: Tao Liu <xliutaox@google.com>

[ Upstream commit 922aa9bcac92b3ab6a423526a8e785b35a60b441 ]

Prevent possible crashes when cleaning up after unsuccessful
initializations.

Fixes: 893ce44df5658 ("gve: Add basic driver framework for Compute Engine Virtual NIC")
Signed-off-by: Tao Liu <xliutaox@google.com>
Signed-off-by: Catherine Sully <csully@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/google/gve/gve_main.c | 27 ++++++++++++++--------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index 0b714b606ba1..22b2c6a8d08f 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -71,6 +71,9 @@ static int gve_alloc_counter_array(struct gve_priv *priv)
 
 static void gve_free_counter_array(struct gve_priv *priv)
 {
+	if (!priv->counter_array)
+		return;
+
 	dma_free_coherent(&priv->pdev->dev,
 			  priv->num_event_counters *
 			  sizeof(*priv->counter_array),
@@ -131,6 +134,9 @@ static int gve_alloc_stats_report(struct gve_priv *priv)
 
 static void gve_free_stats_report(struct gve_priv *priv)
 {
+	if (!priv->stats_report)
+		return;
+
 	del_timer_sync(&priv->stats_report_timer);
 	dma_free_coherent(&priv->pdev->dev, priv->stats_report_len,
 			  priv->stats_report, priv->stats_report_bus);
@@ -301,18 +307,19 @@ static void gve_free_notify_blocks(struct gve_priv *priv)
 {
 	int i;
 
-	if (priv->msix_vectors) {
-		/* Free the irqs */
-		for (i = 0; i < priv->num_ntfy_blks; i++) {
-			struct gve_notify_block *block = &priv->ntfy_blocks[i];
-			int msix_idx = i;
+	if (!priv->msix_vectors)
+		return;
 
-			irq_set_affinity_hint(priv->msix_vectors[msix_idx].vector,
-					      NULL);
-			free_irq(priv->msix_vectors[msix_idx].vector, block);
-		}
-		free_irq(priv->msix_vectors[priv->mgmt_msix_idx].vector, priv);
+	/* Free the irqs */
+	for (i = 0; i < priv->num_ntfy_blks; i++) {
+		struct gve_notify_block *block = &priv->ntfy_blocks[i];
+		int msix_idx = i;
+
+		irq_set_affinity_hint(priv->msix_vectors[msix_idx].vector,
+				      NULL);
+		free_irq(priv->msix_vectors[msix_idx].vector, block);
 	}
+	free_irq(priv->msix_vectors[priv->mgmt_msix_idx].vector, priv);
 	dma_free_coherent(&priv->pdev->dev,
 			  priv->num_ntfy_blks * sizeof(*priv->ntfy_blocks),
 			  priv->ntfy_blocks, priv->ntfy_block_bus);
-- 
2.33.0