From 4f0d91ba72811fd5dd577bcdccd7fed649aae62c Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 30 Sep 2025 15:25:01 +0300 Subject: [PATCH] net/mlx4: prevent potential use after free in mlx4_en_do_uc_filter() Print "entry->mac" before freeing "entry". The "entry" pointer is freed with kfree_rcu() so it's unlikely that we would trigger this in real life, but it's safer to re-order it. Fixes: cc5387f7346a ("net/mlx4_en: Add unicast MAC filtering") Signed-off-by: Dan Carpenter Reviewed-by: Tariq Toukan Link: https://patch.msgid.link/aNvMHX4g8RksFFvV@stanley.mountain Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index d2071aff7b8f..308b4458e0d4 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -1180,9 +1180,9 @@ static void mlx4_en_do_uc_filter(struct mlx4_en_priv *priv, mlx4_unregister_mac(mdev->dev, priv->port, mac); hlist_del_rcu(&entry->hlist); - kfree_rcu(entry, rcu); en_dbg(DRV, priv, "Removed MAC %pM on port:%d\n", entry->mac, priv->port); + kfree_rcu(entry, rcu); ++removed; } } -- 2.51.0