[PATCH 5.12 253/296] gve: Add NULL pointer checks when freeing irqs.

Greg Kroah-Hartman
2021-05-31T16:51:57Z

From: David Awogbemila <awogbemila@google.com>

[ Upstream commit 5218e919c8d06279884aa0baf76778a6817d5b93 ]

When freeing notification blocks, we index priv->msix_vectors.
If we failed to allocate priv->msix_vectors (see abort_with_msix_vectors)
this could lead to a NULL pointer dereference if the driver is unloaded.

Fixes: 893ce44df565 ("gve: Add basic driver framework for Compute Engine Virtual NIC")
Signed-off-by: David Awogbemila <awogbemila@google.com>
Acked-by: Willem de Brujin <willemb@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 | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index 64192942ca53..21a5d058dab4 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -301,20 +301,22 @@ static void gve_free_notify_blocks(struct gve_priv *priv)
{
int i;

- /* 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);
+ 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;
+
+ 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);
priv->ntfy_blocks = NULL;
- free_irq(priv->msix_vectors[priv->mgmt_msix_idx].vector, priv);
pci_disable_msix(priv->pdev);
kvfree(priv->msix_vectors);
priv->msix_vectors = NULL;
--
2.30.2