net/mlx5e: Fix free peer_flow when refcount is 0

commit eb252c3a24fc5856fa62140c2f8269ddce6ce4e5 upstream.

It could be neigh update flow took a refcount on peer flow so
sometimes we cannot release peer flow even if parent flow is
being freed now.

Fixes: 5a7e5bcb663d ("net/mlx5e: Extend tc flow struct with reference counter")
Signed-off-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Eli Britstein <elibr@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
index 947122c..96711e3 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
@@ -1615,8 +1615,11 @@ static void __mlx5e_tc_del_fdb_peer_flow(struct mlx5e_tc_flow *flow)
 
        flow_flag_clear(flow, DUP);
 
-       mlx5e_tc_del_fdb_flow(flow->peer_flow->priv, flow->peer_flow);
-       kfree(flow->peer_flow);
+       if (refcount_dec_and_test(&flow->peer_flow->refcnt)) {
+               mlx5e_tc_del_fdb_flow(flow->peer_flow->priv, flow->peer_flow);
+               kfree(flow->peer_flow);
+       }
+
        flow->peer_flow = NULL;
 }