On 11.12.2020 19:27, Pavel Stehule wrote:
On 11.12.2020 18:40, Pavel Stehule wrote:
is not correct. It makes it not possible to superuser to disable triggers for all users.
pg_database_ownercheck returns true for superuser always.
Sorry, but I consider different case: when normal user is connected to the database.
In this case pg_database_ownercheck returns false and trigger is not disabled, isn't it?
My idea was to reduce necessary rights to database owners. But you have a true, so only superuser can create event trigger, so this feature cannot be used in DBaaS environments, and then my original idea was wrong.
Also GUCs are not associated with any database. So I do not understand why this check of database ownership is relevant at all?
What kind of protection violation we want to prevent?
It seems to be obvious that normal user should not be able to prevent trigger execution because this triggers may be used to enforce some security policies.
If trigger was created by user itself, then it can drop or disable it using ALTER statement. GUC is not needed for it.
when you cannot connect to the database, then you cannot do ALTER. In DBaaS environments lot of users has not superuser rights.
But only superusers can set login triggers, right?
So only superuser can make a mistake in this trigger. But he have enough rights to recover this error. Normal users are not able to define on connection triggers and
should not have rights to disable them.
yes, it is true
Pavel
So what's next?
I see three options:
1. Do not introduce GUC for disabling all event triggers (especially taken in account that them are disabled by default).
Return back to the patch on_connect_event_trigger_WITH_SUGGESTED_UPDATES.patch with "disable_client_connection_trigger"
and make it true by default (to eliminate any overhead for users which are not using on logintriggers).
2. Have two GUCS: "disable_client_connection_trigger" and "disable_event_triggers".
3. Implement some mechanism for caching presence of event triggers in shared memory.
--
Konstantin Knizhnik
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
