On Tue 07 Aug 2018 at 23:26, Cong Wang <xiyou.wangc...@gmail.com> wrote:
> On Thu, Jul 5, 2018 at 7:24 AM Vlad Buslov <vla...@mellanox.com> wrote:
>> attr_size = tcf_action_full_attrs_size(attr_size);
>>
>> if (event == RTM_GETACTION)
>> - ret = tcf_get_notify(net, portid, n, &actions, event,
>> extack);
>> + ret = tcf_get_notify(net, portid, n, actions, event, extack);
>> else { /* delete */
>> - ret = tcf_del_notify(net, n, &actions, portid, attr_size,
>> extack);
>> + ret = tcf_del_notify(net, n, actions, &acts_deleted, portid,
>> + attr_size, extack);
>> if (ret)
>> goto err;
>> return ret;
>> }
>> err:
>> - tcf_action_put_lst(&actions);
>> + tcf_action_put_many(&actions[acts_deleted]);
>> return ret;
>
> How does this even work?
>
> You save an index in 'acts_deleted', but you pass &actions[acts_deleted]
> to tcf_action_put_many(), which seems you want to start from
> where it fails, but inside tcf_action_put_many() it starts from 0
> to TCA_ACT_MAX_PRIO, out-of-bound access at least?
Actions array is declared to be TCA_ACT_MAX_PRIO+1 in size, and
initialized to NULL pointers. In loop inside tcf_action_put_many() there
are two checks: One is that index is less than TCA_ACT_MAX_PRIO and
another one that pointer is not NULL. In this case I rely on extra NULL
pointer at the end of actions array to prevent out-of-bound access.
