2017-11-05 03:56:15

by Gustavo A. R. Silva

[permalink] [raw]
Subject: [PATCH] net/mlx5e/core/en_fs: fix pointer dereference after free in mlx5e_execute_l2_action

hn is being kfree'd in mlx5e_del_l2_from_hash and then dereferenced
by accessing hn->ai.addr

Fix this by copying the MAC address into a local variable for its safe use
in all possible execution paths within function mlx5e_execute_l2_action.

Addresses-Coverity-ID: 1417789
Fixes: eeb66cdb6826 ("net/mlx5: Separate between E-Switch and MPFS")
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/net/ethernet/mellanox/mlx5/core/en_fs.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_fs.c b/drivers/net/ethernet/mellanox/mlx5/core/en_fs.c
index 850cdc9..4837045 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_fs.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_fs.c
@@ -365,21 +365,24 @@ static void mlx5e_execute_l2_action(struct mlx5e_priv *priv,
struct mlx5e_l2_hash_node *hn)
{
u8 action = hn->action;
+ u8 mac_addr[ETH_ALEN];
int l2_err = 0;

+ ether_addr_copy(mac_addr, hn->ai.addr);
+
switch (action) {
case MLX5E_ACTION_ADD:
mlx5e_add_l2_flow_rule(priv, &hn->ai, MLX5E_FULLMATCH);
- if (!is_multicast_ether_addr(hn->ai.addr)) {
- l2_err = mlx5_mpfs_add_mac(priv->mdev, hn->ai.addr);
+ if (!is_multicast_ether_addr(mac_addr)) {
+ l2_err = mlx5_mpfs_add_mac(priv->mdev, mac_addr);
hn->mpfs = !l2_err;
}
hn->action = MLX5E_ACTION_NONE;
break;

case MLX5E_ACTION_DEL:
- if (!is_multicast_ether_addr(hn->ai.addr) && hn->mpfs)
- l2_err = mlx5_mpfs_del_mac(priv->mdev, hn->ai.addr);
+ if (!is_multicast_ether_addr(mac_addr) && hn->mpfs)
+ l2_err = mlx5_mpfs_del_mac(priv->mdev, mac_addr);
mlx5e_del_l2_flow_rule(priv, &hn->ai);
mlx5e_del_l2_from_hash(hn);
break;
@@ -387,7 +390,7 @@ static void mlx5e_execute_l2_action(struct mlx5e_priv *priv,

if (l2_err)
netdev_warn(priv->netdev, "MPFS, failed to %s mac %pM, err(%d)\n",
- action == MLX5E_ACTION_ADD ? "add" : "del", hn->ai.addr, l2_err);
+ action == MLX5E_ACTION_ADD ? "add" : "del", mac_addr, l2_err);
}

static void mlx5e_sync_netdev_addr(struct mlx5e_priv *priv)
--
2.7.4


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