Subject: [V2 net 12/16] net/mlx5: Fix crash during sync firmware reset

From: Saeed Mahameed <[email-masked]>
Date: Mon, 24 Oct 2022 07:12:16 +0100

From: Suresh Devarakonda <[email-masked]>

When setting Bluefield to DPU NIC mode using mlxconfig tool +  sync
firmware reset flow, we run into scenario where the host was not
eswitch manager at the time of mlx5 driver load but becomes eswitch manager
after the sync firmware reset flow. This results in null pointer
access of mpfs structure during mac filter add. This change prevents null
pointer access but mpfs table entries will not be added.

Fixes: 5ec697446f46 ("net/mlx5: Add support for devlink reload action fw activate")
Signed-off-by: Suresh Devarakonda <[email-masked]>
Reviewed-by: Moshe Shemesh <[email-masked]>
Reviewed-by: Bodong Wang <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/lib/mpfs.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/mpfs.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/mpfs.c
index 839a01da110f..8ff16318e32d 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/mpfs.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/mpfs.c
@@ -122,7 +122,7 @@ void mlx5_mpfs_cleanup(struct mlx5_core_dev *dev)
 {
 	struct mlx5_mpfs *mpfs = dev->priv.mpfs;
 
-	if (!MLX5_ESWITCH_MANAGER(dev))
+	if (!mpfs)
 		return;
 
 	WARN_ON(!hlist_empty(mpfs->hash));
@@ -137,7 +137,7 @@ int mlx5_mpfs_add_mac(struct mlx5_core_dev *dev, u8 *mac)
 	int err = 0;
 	u32 index;
 
-	if (!MLX5_ESWITCH_MANAGER(dev))
+	if (!mpfs)
 		return 0;
 
 	mutex_lock(&mpfs->lock);
@@ -185,7 +185,7 @@ int mlx5_mpfs_del_mac(struct mlx5_core_dev *dev, u8 *mac)
 	int err = 0;
 	u32 index;
 
-	if (!MLX5_ESWITCH_MANAGER(dev))
+	if (!mpfs)
 		return 0;
 
 	mutex_lock(&mpfs->lock);
-- 
2.37.3