[ +John ]
On 10/22/2018 05:41 PM, Taehee Yoo wrote:
> The dev_map_notification() removes interface in devmap if
> unregistering interface's ifindex is same.
> But only checking ifindex is not enough because other netns can have
> same ifindex. so that wrong interface selection could occurred.
> Hence the net_eq() is needed.
>
> Fixes: 2ddf71e23cc2 ("net: add notifier hooks for devmap bpf map")
> Signed-off-by: Taehee Yoo <ap420...@gmail.com>
> ---
> kernel/bpf/devmap.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
> index 141710b82a6c..0d9211e49a4a 100644
> --- a/kernel/bpf/devmap.c
> +++ b/kernel/bpf/devmap.c
> @@ -496,6 +496,7 @@ static int dev_map_notification(struct notifier_block
> *notifier,
> ulong event, void *ptr)
> {
> struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
> + struct net *net = dev_net(netdev);
> struct bpf_dtab *dtab;
> int i;
>
> @@ -512,7 +513,7 @@ static int dev_map_notification(struct notifier_block
> *notifier,
> struct bpf_dtab_netdev *dev, *odev;
>
> dev = READ_ONCE(dtab->netdev_map[i]);
> - if (!dev ||
> + if (!dev || !net_eq(net, dev_net(dev->dev)) ||
> dev->dev->ifindex != netdev->ifindex)
Can't we just compare netdev pointers directly here?
> continue;
> odev = cmpxchg(&dtab->netdev_map[i], dev, NULL);
>
