Subject: [net 3/6] net/mlx5e: Fix possible use-after-free deleting fdb rule

From: Saeed Mahameed <[email-masked]>
Date: Thu, 26 Aug 2021 15:18:07 -0700

From: Roi Dayan <[email-masked]>

After neigh-update-add failure we are still with a slow path rule but
the driver always assume the rule is an fdb rule.
Fix neigh-update-del by checking slow path tc flag on the flow.
Also fix neigh-update-add for when neigh-update-del fails the same.

Fixes: 5dbe906ff1d5 ("net/mlx5e: Use a slow path rule instead if vxlan neighbour isn't available")
Signed-off-by: Roi Dayan <[email-masked]>
Reviewed-by: Paul Blakey <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
index 2e846b741280..1c44c6c345f5 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_encap.c
@@ -147,7 +147,7 @@ void mlx5e_tc_encap_flows_add(struct mlx5e_priv *priv,
 	mlx5e_rep_queue_neigh_stats_work(priv);
 
 	list_for_each_entry(flow, flow_list, tmp_list) {
-		if (!mlx5e_is_offloaded_flow(flow))
+		if (!mlx5e_is_offloaded_flow(flow) || !flow_flag_test(flow, SLOW))
 			continue;
 		attr = flow->attr;
 		esw_attr = attr->esw_attr;
@@ -188,7 +188,7 @@ void mlx5e_tc_encap_flows_del(struct mlx5e_priv *priv,
 	int err;
 
 	list_for_each_entry(flow, flow_list, tmp_list) {
-		if (!mlx5e_is_offloaded_flow(flow))
+		if (!mlx5e_is_offloaded_flow(flow) || flow_flag_test(flow, SLOW))
 			continue;
 		attr = flow->attr;
 		esw_attr = attr->esw_attr;
-- 
2.31.1