Re: [PATCH net] netfilter: check duplicate config when initializing in ipt_CLUSTERIP

[Xin Long]

On Tue, Dec 20, 2016 at 8:48 AM, Pablo Neira Ayuso <pa...@netfilter.org> wrote:
> On Thu, Dec 15, 2016 at 12:31:40PM +0800, Xin Long wrote:
>> @@ -185,6 +186,17 @@ clusterip_config_init(const struct 
>> ipt_clusterip_tgt_info *i, __be32 ip,
>>       atomic_set(&c->refcount, 1);
>>       atomic_set(&c->entries, 1);
>>
>> +     spin_lock_bh(&cn->lock);
>> +     if (__clusterip_config_find(net, ip)) {
>> +             spin_unlock_bh(&cn->lock);
>> +             kfree(c);
>> +
>> +             return NULL;
>> +     }
>
> This is going to result in ENOMEM error report to userspace on race,
> which can be confusing. Time for clusterip_config_init() to return
> PTR_ERR()?
will post v2 with PTR_ERR, thanks.

>
>> +
>> +     list_add_rcu(&c->list, &cn->configs);
>> +     spin_unlock_bh(&cn->lock);
>> +
>>  #ifdef CONFIG_PROC_FS
>>       {
>>               char buffer[16];