Re: [PATCH net] ipvlan: fix addr hash list corruption

[Mahesh Bandewar <maheshb@google.com>]

On Mon, Mar 23, 2015 at 2:10 PM, Jiri Benc <jbenc@redhat.com> wrote:
> When ipvlan interface with IP addresses attached is brought down and then
> deleted, the assigned addresses are deleted twice from the address hash
> list, first on the interface down and second on the link deletion.
> Similarly, when an address is added while the interface is down, it is added
> second time once the interface is brought up.
>
Presumably this is creating problems for you and I'm not sure why? Do
you have a script  / (sequence of commands) to produce this condition?

ipvlan_ht_addr_del() does use synchronize_rcu() expect when the device
in dismantle state. Could that be a reason?

> Check the interface status before adding/removing to the hash list in the
> notifiers.
>
> Reported-by: Dan Williams <dcbw@redhat.com>
> Signed-off-by: Jiri Benc <jbenc@redhat.com>
> ---
>  drivers/net/ipvlan/ipvlan_main.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c
> index 4f4099d5603d..04cfa7a13645 100644
> --- a/drivers/net/ipvlan/ipvlan_main.c
> +++ b/drivers/net/ipvlan/ipvlan_main.c
> @@ -504,7 +504,8 @@ static void ipvlan_link_delete(struct net_device *dev, struct list_head *head)
>
>         if (ipvlan->ipv6cnt > 0 || ipvlan->ipv4cnt > 0) {
>                 list_for_each_entry_safe(addr, next, &ipvlan->addrs, anode) {
> -                       ipvlan_ht_addr_del(addr, !dev->dismantle);
> +                       if (netif_running(dev))
> +                               ipvlan_ht_addr_del(addr, !dev->dismantle);
>                         list_del_rcu(&addr->anode);
>                 }
>         }
> @@ -622,7 +623,8 @@ static int ipvlan_add_addr6(struct ipvl_dev *ipvlan, struct in6_addr *ip6_addr)
>         addr->atype = IPVL_IPV6;
>         list_add_tail_rcu(&addr->anode, &ipvlan->addrs);
>         ipvlan->ipv6cnt++;
> -       ipvlan_ht_addr_add(ipvlan, addr);
> +       if (netif_running(ipvlan->dev))
> +               ipvlan_ht_addr_add(ipvlan, addr);
>
>         return 0;
>  }
> @@ -635,7 +637,8 @@ static void ipvlan_del_addr6(struct ipvl_dev *ipvlan, struct in6_addr *ip6_addr)
>         if (!addr)
>                 return;
>
> -       ipvlan_ht_addr_del(addr, true);
> +       if (netif_running(ipvlan->dev))
> +               ipvlan_ht_addr_del(addr, true);
>         list_del_rcu(&addr->anode);
>         ipvlan->ipv6cnt--;
>         WARN_ON(ipvlan->ipv6cnt < 0);
> @@ -690,7 +693,8 @@ static int ipvlan_add_addr4(struct ipvl_dev *ipvlan, struct in_addr *ip4_addr)
>         addr->atype = IPVL_IPV4;
>         list_add_tail_rcu(&addr->anode, &ipvlan->addrs);
>         ipvlan->ipv4cnt++;
> -       ipvlan_ht_addr_add(ipvlan, addr);
> +       if (netif_running(ipvlan->dev))
> +               ipvlan_ht_addr_add(ipvlan, addr);
>         ipvlan_set_broadcast_mac_filter(ipvlan, true);
>
>         return 0;
> @@ -704,7 +708,8 @@ static void ipvlan_del_addr4(struct ipvl_dev *ipvlan, struct in_addr *ip4_addr)
>         if (!addr)
>                 return;
>
> -       ipvlan_ht_addr_del(addr, true);
> +       if (netif_running(ipvlan->dev))
> +               ipvlan_ht_addr_del(addr, true);
>         list_del_rcu(&addr->anode);
>         ipvlan->ipv4cnt--;
>         WARN_ON(ipvlan->ipv4cnt < 0);
> --
> 1.8.3.1
>