[PATCH net 3/5] net/mlx5e: Fix NULL pointer dereference in ioctl module EEPROM query

[Mark Bloch <mbloch@nvidia.com>]

From: Gal Pressman <gal@nvidia.com>

The mlx5_query_mcia() function unconditionally dereferences the status
pointer to store the MCIA register status value.
However, mlx5e_get_module_id() passes NULL since it doesn't need the
status value.

Add a NULL check before dereferencing the status pointer to prevent a
NULL pointer dereference.

Fixes: 2e4c44b12f4d ("net/mlx5: Refactor EEPROM query error handling to return status separately")
Signed-off-by: Gal Pressman <gal@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/port.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/port.c b/drivers/net/ethernet/mellanox/mlx5/core/port.c
index 85a9e534f442..8f36454dd196 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/port.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/port.c
@@ -393,9 +393,11 @@ static int mlx5_query_mcia(struct mlx5_core_dev *dev,
 	if (err)
 		return err;
 
-	*status = MLX5_GET(mcia_reg, out, status);
-	if (*status)
+	if (MLX5_GET(mcia_reg, out, status)) {
+		if (status)
+			*status = MLX5_GET(mcia_reg, out, status);
 		return -EIO;
+	}
 
 	ptr = MLX5_ADDR_OF(mcia_reg, out, dword_0);
 	memcpy(data, ptr, size);
-- 
2.34.1