[PATCH net] net/mlx5: Only set num_doorbells on a fully initialized SF

[Tariq Toukan <tariqt@nvidia.com>]

From: Cosmin Ratiu <cratiu@nvidia.com>

The validation for the num_doorbells devlink param rejects values
greater than num_channels. For lightweight SFs, this ends up accessing
a NULL priv->eq_table, leading to a crash.

Fix that by rejecting setting num_doorbells on uninitialized SFs.

Fixes: 11bbcfb7668c ("net/mlx5e: Use the 'num_doorbells' devlink param")
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/devlink.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
index b9026cc64383..30a97e48dda7 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/devlink.c
@@ -542,6 +542,12 @@ static int mlx5_devlink_num_doorbells_validate(struct devlink *devlink, u32 id,
 	u32 val32 = val->vu32;
 	u32 max_num_channels;
 
+	if (mlx5_dev_is_lightweight(mdev)) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Setting num_doorbells requires full device initialization; reload the device first");
+		return -EOPNOTSUPP;
+	}
+
 	max_num_channels = mlx5e_get_max_num_channels(mdev);
 	if (val32 > max_num_channels) {
 		NL_SET_ERR_MSG_FMT_MOD(extack,

base-commit: f4377bf85887f57b59abb5479f7660a81ffe4449
-- 
2.44.0