Re: Updates of SE-PostgreSQL 8.4devel patches (r1710)

Alvaro Herrera wrote:
> Gregory Stark escribió:
>> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>>
>>> KaiGai Kohei wrote:
>>>> * ACL_SELECT_FOR_UPDATE has same value with ACL_UPDATE, so SE-PostgreSQL
>>>> checks db_table:{update} permission on SELECT ... FOR SHARE OF,
>>>> instead of db_table:{lock} permission.
>>> This again falls into the category of trying to have more fine-grained
>>> permissions than vanilla PostgreSQL has. Just give up on the lock permission,
>>> and let it check update permission instead. Yes, it can be annoying that you
>>> need update-permission to do SELECT FOR SHARE, but that's an existing problem
>>> and not in scope for this patch.
>> Would it make sense to instead of removing and deferring pieces bit by bit to
>> instead work the other way around? Extract just the part of the patch that
>> maps SELinux capabilities to Postgres privileges as a first patch? Then
>> discuss any other parts individually at a later date?
>
> I think that makes sense. Implement just a very basic core in a first
> patch, and start adding checks slowly, one patch each. We have talked
> about "incremental patches" in the past.
>
> We wouldn't get "unbreakable PostgreSQL" in a single commit, but we
> would at least start moving.
>
> The good thing about having started in the opposite direction is that by
> now we know that the foundation APIs are good enough to build the
> complete feature.

What should I do for this matter?
At least, it is necessary to decide when we should fix it. v8.4? v8.5?

If we fix it soon, what strategy is desirable?
1) Add a new GRANT privilege something like "LOCK".
It is straight forward approach, but contains user visible change.
In MySQL, it has an individual privilege for explicit table locks.

2) Shrink ACL_SELECT_FOR_UPDATE to ACL_UPDATE in runtime.
It is invisible from users, but GRANT UPDATE still contains
a meaning of explicit table locks.

3) "GRANT UPDATE ..." also allows users ACL_SELECT_FOR_UPDATE, not only
ACL_UPDATE.
It is similar to 2) option, but it also modifies ACL side, not the
requiredPerms side.

4) Other strategy?

Thanks,
--
OSS Platform Development Division, NEC
KaiGai Kohei <kaigai(at)ak(dot)jp(dot)nec(dot)com>