[PATCH net V2 1/3] net/mlx5: LAG, Fix off-by-one in single-FDB error rollback

[Tariq Toukan]

From: Shay Drory <shayd@xxxxxxxxxx>

On failure at index i, the reverse cleanup loop in
mlx5_lag_create_single_fdb() starts from i, so the failed index
itself is rolled back. That can operate on uninitialized state or
double-tear-down a rule the add_one path already self-rolled-back.

Start the rollback from i - 1 so only successfully-installed entries
are undone.

Fixes: ddbb5ddc43ad ("net/mlx5: LAG, Refactor lag logic")
Signed-off-by: Shay Drory <shayd@xxxxxxxxxx>
Reviewed-by: Mark Bloch <mbloch@xxxxxxxxxx>
Signed-off-by: Tariq Toukan <tariqt@xxxxxxxxxx>
---
 drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c b/drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c
index 113866494d16..6b4ad3c53f2f 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lag/shared_fdb.c
@@ -78,7 +78,7 @@ static int mlx5_lag_create_single_fdb_filter(struct mlx5_lag *ldev, u32 filter)
 	}
 	return 0;
 err:
-	mlx5_lag_for_each_reverse(j, i, 0, ldev, filter) {
+	mlx5_lag_for_each_reverse(j, i - 1, 0, ldev, filter) {
 		struct mlx5_eswitch *slave_esw;
 
 		if (j == master_idx)
-- 
2.44.0