From 7f7bf1606fa8fa0e3aecdeac0ba8005f2a0fbdef Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 1 Dec 2016 05:02:06 -0800 Subject: [PATCH] mlx4: fix use-after-free in mlx4_en_fold_software_stats() My recent commit to get more precise rx/tx counters in ndo_get_stats64() can lead to crashes at device dismantle, as Jesper found out. We must prevent mlx4_en_fold_software_stats() trying to access tx/rx rings if they are deleted. Fix this by adding a test against priv->port_up in mlx4_en_fold_software_stats() Calling mlx4_en_fold_software_stats() from mlx4_en_stop_port() allows us to eventually broadcast the latest/current counters to rtnetlink monitors. Fixes: 40931b85113d ("mlx4: give precise rx/tx bytes/packets counters") Signed-off-by: Eric Dumazet Reported-and-bisected-by: Jesper Dangaard Brouer Tested-by: Jesper Dangaard Brouer Cc: Tariq Toukan Cc: Saeed Mahameed Acked-by: Saeed Mahameed Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 4 ++++ drivers/net/ethernet/mellanox/mlx4/en_port.c | 2 +- 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c index 12ea3405f442..091b904262bc 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c @@ -1809,8 +1809,12 @@ void mlx4_en_stop_port(struct net_device *dev, int detach) netif_tx_disable(dev); + spin_lock_bh(&priv->stats_lock); + mlx4_en_fold_software_stats(dev); /* Set port as not active */ priv->port_up = false; + spin_unlock_bh(&priv->stats_lock); + priv->counter_index = MLX4_SINK_COUNTER_INDEX(mdev->dev); /* Promsicuous mode */ diff --git a/drivers/net/ethernet/mellanox/mlx4/en_port.c b/drivers/net/ethernet/mellanox/mlx4/en_port.c index c6c4f1238923..9166d90e7328 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_port.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_port.c @@ -154,7 +154,7 @@ void mlx4_en_fold_software_stats(struct net_device *dev) unsigned long packets, bytes; int i; - if (mlx4_is_master(mdev->dev)) + if (!priv->port_up || mlx4_is_master(mdev->dev)) return; packets = 0; -- 2.20.1