From: Cosmin Ratiu <cratiu@nvidia.com>

PSP is unregistered twice in:
_mlx5e_remove -> mlx5e_psp_unregister
mlx5e_nic_cleanup -> mlx5e_psp_unregister

This leads to a refcount underflow in some conditions:
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 2 PID: 1694 at lib/refcount.c:28 refcount_warn_saturate+0xd8/0xe0
[...]
 mlx5e_psp_unregister+0x26/0x50 [mlx5_core]
 mlx5e_nic_cleanup+0x26/0x90 [mlx5_core]
 mlx5e_remove+0xe6/0x1f0 [mlx5_core]
 auxiliary_bus_remove+0x18/0x30
 device_release_driver_internal+0x194/0x1f0
 bus_remove_device+0xc6/0x130
 device_del+0x159/0x3c0
 mlx5_rescan_drivers_locked+0xbc/0x2a0 [mlx5_core]
[...]

Do not directly remove psp from the _mlx5e_remove path, the PSP cleanup
happens as part of profile cleanup.

Fixes: 89ee2d92f66c ("net/mlx5e: Support PSP offload functionality")
Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 5e17eae81f4b..1545f9c008f4 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -6805,7 +6805,6 @@ static void _mlx5e_remove(struct auxiliary_device *adev)
 	 * is already unregistered before changing to NIC profile.
 	 */
 	if (priv->netdev->reg_state == NETREG_REGISTERED) {
-		mlx5e_psp_unregister(priv);
 		unregister_netdev(priv->netdev);
 		_mlx5e_suspend(adev, false);
 	} else {
-- 
2.31.1

On Mon, Dec 01, 2025 at 05:13:28PM +0200, Tariq Toukan wrote:
> From: Cosmin Ratiu <cratiu@nvidia.com>
> 
> PSP is unregistered twice in:
> _mlx5e_remove -> mlx5e_psp_unregister
> mlx5e_nic_cleanup -> mlx5e_psp_unregister
> 
> This leads to a refcount underflow in some conditions:
> ------------[ cut here ]------------
> refcount_t: underflow; use-after-free.
> WARNING: CPU: 2 PID: 1694 at lib/refcount.c:28 refcount_warn_saturate+0xd8/0xe0
> [...]
>  mlx5e_psp_unregister+0x26/0x50 [mlx5_core]
>  mlx5e_nic_cleanup+0x26/0x90 [mlx5_core]
>  mlx5e_remove+0xe6/0x1f0 [mlx5_core]
>  auxiliary_bus_remove+0x18/0x30
>  device_release_driver_internal+0x194/0x1f0
>  bus_remove_device+0xc6/0x130
>  device_del+0x159/0x3c0
>  mlx5_rescan_drivers_locked+0xbc/0x2a0 [mlx5_core]
> [...]
> 
> Do not directly remove psp from the _mlx5e_remove path, the PSP cleanup
> happens as part of profile cleanup.
> 
> Fixes: 89ee2d92f66c ("net/mlx5e: Support PSP offload functionality")
> Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
> Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com>
> Signed-off-by: Tariq Toukan <tariqt@nvidia.com>

Reviewed-by: Simon Horman <horms@kernel.org>