Re: [PATCH net] sit: fix panic with route cache in ip tunnels

[Nicolas Dichtel <nicolas.dichtel@6wind.com>]

Le 19/02/2014 17:43, Eric Dumazet a écrit :
> On Wed, 2014-02-19 at 17:15 +0100, Nicolas Dichtel wrote:
>> Bug introduced by commit 7d442fab0a67 ("ipv4: Cache dst in tunnels").
>>
>> Because sit code does not call ip_tunnel_init(), the dst_cache was not
>> initialized.
>>
>> CC: Tom Herbert <therbert@google.com>
>> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
>> ---
>>   net/ipv6/sit.c | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
>> index 3dfbcf1dcb1c..5ff33d9bd5de 100644
>> --- a/net/ipv6/sit.c
>> +++ b/net/ipv6/sit.c
>> @@ -1326,6 +1326,9 @@ static const struct net_device_ops ipip6_netdev_ops = {
>>
>>   static void ipip6_dev_free(struct net_device *dev)
>>   {
>> +	struct ip_tunnel *tunnel = netdev_priv(dev);
>> +
>> +	free_percpu(tunnel->dst_cache);
>>   	free_percpu(dev->tstats);
>>   	free_netdev(dev);
>>   }
>> @@ -1375,6 +1378,12 @@ static int ipip6_tunnel_init(struct net_device *dev)
>>   		u64_stats_init(&ipip6_tunnel_stats->syncp);
>>   	}
>>
>> +	tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst);
>> +	if (!tunnel->dst_cache) {
>> +		free_percpu(dev->tstats);
>> +		return -ENOMEM;
>> +	}
>> +
>>   	return 0;
>>   }
>>
>
> I do not think this patch is complete.
>
> It seems to lack a tunnel_dst_reset_all() or something to properly
> release the dst.

Yes, it's why I ask David to drop it ;-)