On Fri, Sep 8, 2017 at 1:26 AM, Sabrina Dubroca <s...@queasysnail.net> wrote:
> fib6_net_exit only frees the main and local tables. If another table was
> created with fib6_alloc_table, we leak it when the netns is destroyed.
>
> Fix this in the same way ip_fib_net_exit cleans up tables, by walking
> through the whole hashtable of fib6_table's. We can get rid of the
> special cases for local and main, since they're also part of the
> hashtable.
>
> Reproducer:
> ip netns add x
> ip -net x -6 rule add from 6003:1::/64 table 100
> ip netns del x
>
> Reported-by: Jianlin Shi <ji...@redhat.com>
> Fixes: 58f09b78b730 ("[NETNS][IPV6] ip6_fib - make it per network namespace")
> Signed-off-by: Sabrina Dubroca <s...@queasysnail.net>
> ---
> net/ipv6/ip6_fib.c | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
> index a3b5c163325f..8280172c806c 100644
> --- a/net/ipv6/ip6_fib.c
> +++ b/net/ipv6/ip6_fib.c
> @@ -191,6 +191,12 @@ void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
> }
> EXPORT_SYMBOL_GPL(rt6_free_pcpu);
>
> +static void fib6_free_table(struct fib6_table *table)
> +{
> + inetpeer_invalidate_tree(&table->tb6_peers);
> + kfree(table);
> +}
> +
> static void fib6_link_table(struct net *net, struct fib6_table *tb)
> {
> unsigned int h;
> @@ -2022,15 +2028,22 @@ static int __net_init fib6_net_init(struct net *net)
>
> static void fib6_net_exit(struct net *net)
> {
> + unsigned int i;
> +
> rt6_ifdown(net, NULL);
> del_timer_sync(&net->ipv6.ip6_fib_timer);
>
> -#ifdef CONFIG_IPV6_MULTIPLE_TABLES
> - inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
> - kfree(net->ipv6.fib6_local_tbl);
> -#endif
> - inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
> - kfree(net->ipv6.fib6_main_tbl);
> + for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
> + struct hlist_head *head = &net->ipv6.fib_table_hash[i];
> + struct hlist_node *tmp;
> + struct fib6_table *tb;
> +
> + hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
> + hlist_del(&tb->tb6_hlist);
hlist_del_rcu() ?
> + fib6_free_table(tb);
kfree_rcu() in fib6_free_table()?
> + }
> + }
> +
> kfree(net->ipv6.fib_table_hash);
> kfree(net->ipv6.rt6_stats);
> fib6_notifier_exit(net);
> --
> 2.14.1
>
