[PATCH mlx5-next] net/mlx5: Check device memory pointer before usage

[Leon Romanovsky <leon@kernel.org>]

From: Stav Aviram <saviram@nvidia.com>

Add a NULL check before accessing device memory to prevent a crash if
dev->dm allocation in mlx5_init_once() fails.

Fixes: c9b9dcb430b3 ("net/mlx5: Move device memory management to mlx5_core")
Signed-off-by: Stav Aviram <saviram@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 drivers/infiniband/hw/mlx5/dm.c                  | 2 +-
 drivers/net/ethernet/mellanox/mlx5/core/lib/dm.c | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/mlx5/dm.c b/drivers/infiniband/hw/mlx5/dm.c
index b4c97fb62abf..9ded2b7c1e31 100644
--- a/drivers/infiniband/hw/mlx5/dm.c
+++ b/drivers/infiniband/hw/mlx5/dm.c
@@ -282,7 +282,7 @@ static struct ib_dm *handle_alloc_dm_memic(struct ib_ucontext *ctx,
 	int err;
 	u64 address;
 
-	if (!MLX5_CAP_DEV_MEM(dm_db->dev, memic))
+	if (!dm_db || !MLX5_CAP_DEV_MEM(dm_db->dev, memic))
 		return ERR_PTR(-EOPNOTSUPP);
 
 	dm = kzalloc(sizeof(*dm), GFP_KERNEL);
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/dm.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/dm.c
index 7c5516b0a844..8115071c34a4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/dm.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/dm.c
@@ -30,7 +30,7 @@ struct mlx5_dm *mlx5_dm_create(struct mlx5_core_dev *dev)
 
 	dm = kzalloc(sizeof(*dm), GFP_KERNEL);
 	if (!dm)
-		return ERR_PTR(-ENOMEM);
+		return NULL;
 
 	spin_lock_init(&dm->lock);
 
@@ -96,7 +96,7 @@ struct mlx5_dm *mlx5_dm_create(struct mlx5_core_dev *dev)
 err_steering:
 	kfree(dm);
 
-	return ERR_PTR(-ENOMEM);
+	return NULL;
 }
 
 void mlx5_dm_cleanup(struct mlx5_core_dev *dev)
-- 
2.50.0