[PATCH 5.13 243/300] net/mlx5e: Fix possible use-after-free deleting fdb rule

Greg Kroah-Hartman
2021-09-13T14:14:33Z

From: Roi Dayan <roid@nvidia.com>

[ Upstream commit 9a5f9cc794e17cf6ed2a5bb215d2e8b6832db444 ]

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 <roid@nvidia.com>
Reviewed-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 490131e06efb..aa4dc7d624f8 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
@@ -143,7 +143,7 @@ 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;
@@ -184,7 +184,7 @@ 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;
--
2.30.2