Commit 534287403 invented SHARED_DEPENDENCY_INITACL entries in
pg_shdepend, but installed them only for non-owner roles mentioned
in a pg_init_privs entry. This turns out to be the wrong thing,
because there is nothing to cue REASSIGN OWNED to go and update
pg_init_privs entries when the object's ownership is reassigned.
That leads to leaving dangling entries in pg_init_privs, as
reported by Hannu Krosing. Instead, install INITACL entries for
all roles mentioned in pg_init_privs entries (except pinned roles),
and change ALTER OWNER to not touch them, just as it doesn't
touch pg_init_privs entries.
REASSIGN OWNED will now substitute the new owner OID for the old
in pg_init_privs entries. This feels like perhaps not quite the
right thing, since pg_init_privs ought to be a historical record
of the state of affairs just after CREATE EXTENSION. However,
it's hard to see what else to do, if we don't want to disallow
dropping the object's original owner. In any case this is
better than the previous do-nothing behavior, and we're unlikely
to come up with a superior solution in time for v17.
While here, tighten up some coding rules about how ACLs in
pg_init_privs should never be null or empty. There's not any
obvious reason to allow that, and perhaps asserting that it's
not so will catch some bugs. (We were previously inconsistent
on the point, with some code paths taking care not to store
empty ACLs and others not.)
This leaves recordExtensionInitPrivWorker not doing anything
with its ownerId argument, but we'll deal with that separately.
catversion bump forced because of change of expected contents
of pg_shdepend when pg_init_privs entries exist.
Discussion: https://postgr.es/m/CAMT0RQSVgv48G5GArUvOVhottWqZLrvC5wBzBa4HrUdXe9VRXw@mail.gmail.com
When the list of roles gathered by roles_is_member_of() grows very
large, a Bloom filter is created to help avoid some linear searches
through the list. The threshold for creating the Bloom filter is
set arbitrarily high and may require future adjustment.
Suggested-by: Tom Lane
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/CAGvXd3OSMbJQwOSc-Tq-Ro1CAz%3DvggErdSG7pv2s6vmmTOLJSg%40mail.gmail.com
Roles with MAINTAIN on a relation may run VACUUM, ANALYZE, REINDEX,
REFRESH MATERIALIZE VIEW, CLUSTER, and LOCK TABLE on the relation.
Roles with privileges of pg_maintain may run those same commands on
all relations.
This was previously committed for v16, but it was reverted in
commit 151c22deee due to concerns about search_path tricks that
could be used to escalate privileges to the table owner. Commits
2af07e2f74, 59825d1639, and c7ea3f4229 resolved these concerns by
restricting search_path when running maintenance commands.
Bumps catversion.
Reviewed-by: Jeff Davis
Discussion: https://postgr.es/m/20240305161235.GA3478007%40nathanxps13
as determined by include-what-you-use (IWYU)
While IWYU also suggests to *add* a bunch of #include's (which is its
main purpose), this patch does not do that. In some cases, a more
specific #include replaces another less specific one.
Some manual adjustments of the automatic result:
- IWYU currently doesn't know about includes that provide global
variable declarations (like -Wmissing-variable-declarations), so
those includes are being kept manually.
- All includes for port(ability) headers are being kept for now, to
play it safe.
- No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the
patch from exploding in size.
Note that this patch touches just *.c files, so nothing declared in
header files changes in hidden ways.
As a small example, in src/backend/access/transam/rmgr.c, some IWYU
pragma annotations are added to handle a special case there.
Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
The versions of these functions that accept object OIDs are supposed
to return NULL, rather than failing, if the target object has been
dropped. This makes it safe(r) to use them in queries that scan
catalogs, since the functions will be applied to objects that are
visible in the query's snapshot but might now be gone according to
the catalog snapshot. In most cases we implemented this by doing
a SearchSysCacheExists test and assuming that if that succeeds, we
can safely invoke the appropriate aclchk.c function, which will
immediately re-fetch the same syscache entry. It was argued that
if the existence test succeeds then the followup fetch must succeed
as well, for lack of any intervening AcceptInvalidationMessages call.
Alexander Lakhin demonstrated that this is not so when
CATCACHE_FORCE_RELEASE is enabled: the syscache entry will be forcibly
dropped at the end of SearchSysCacheExists, and then it is possible
for the catalog snapshot to get advanced while re-fetching the entry.
Alexander's test case requires the operation to happen inside a
parallel worker, but that seems incidental to the fundamental problem.
What remains obscure is whether there is a way for this to happen in a
non-debug build. Nonetheless, CATCACHE_FORCE_RELEASE is a very useful
test methodology, so we'd better make the code safe for it.
After some discussion we concluded that the most future-proof fix
is to give up the assumption that checking SearchSysCacheExists can
guarantee success of a later fetch. At best that assumption leads
to fragile code --- for example, has_type_privilege appears broken
for array types even if you believe the assumption holds. And it's
not even particularly efficient.
There had already been some work towards extending the aclchk.c
APIs to include "is_missing" output flags, so this patch extends
that work to cover all the aclchk.c functions that are used by the
has_xxx_privilege() functions. (This allows getting rid of some
ad-hoc decisions about not throwing errors in certain places in
aclchk.c.)
In passing, this fixes the has_sequence_privilege() functions to
provide the same guarantees as their cousins: for some reason the
SearchSysCacheExists tests never got added to those.
There is more work to do to remove the unsafe coding pattern with
SearchSysCacheExists in other places, but this is a pretty
self-contained patch so I'll commit it separately.
Per bug #18014 from Alexander Lakhin. Given the lack of hard evidence
that there's a bug in non-debug builds, I'm content to fix this only
in HEAD. (Perhaps we should clean up the has_sequence_privilege()
oversight in the back branches, but in the absence of field complaints
I'm not too excited about that either.)
Discussion: https://postgr.es/m/18014-28c81cb79d44295d@postgresql.org
Based on how postgres.h foes the Oid <-> Datum conversion, there is no
existing bugs but let's be consistent. 17 spots have been noticed as
incorrectly passing down Oids rather than Datums. Aleksander got one,
Zhang two and I the rest.
Author: Michael Paquier, Aleksander Alekseev, Zhang Mingli
Discussion: https://postgr.es/m/ZLUhqsqQN1MOaxdw@paquier.xyz
This fixes many spelling mistakes in comments, but a few references to
invalid parameter names, function names and option names too in comments
and also some in string constants
Also, fix an #undef that was undefining the incorrect definition
Author: Alexander Lakhin
Reviewed-by: Justin Pryzby
Discussion: https://postgr.es/m/d5f68d19-c0fc-91a9-118d-7c6a5a3f5fad@gmail.com
Convert assorted internal-ish datatypes, namely aclitemin,
int2vectorin, oidin, oidvectorin, pg_lsn_in, pg_snapshot_in,
and tidin to the new style.
(Some others you might expect to find in this group, such as
cidin and xidin, need no changes because they never throw
errors at all. That seems a little cheesy ... but it is not in
the charter of this patch series to add new error conditions.)
Amul Sul, minor mods by me
Discussion: https://postgr.es/m/CAAJ_b97KeDWUdpTKGOaFYPv0OicjOu6EW+QYWj-Ywrgj_aEy1g@mail.gmail.com
Currently a table can only be vacuumed or analyzed by its owner or
a superuser. This can now be extended to any user by means of an
appropriate GRANT.
Nathan Bossart
Reviewed by: Bharath Rupireddy, Kyotaro Horiguchi, Stephen Frost, Robert
Haas, Mark Dilger, Tom Lane, Corey Huinker, David G. Johnston, Michael
Paquier.
Discussion: https://postgr.es/m/20220722203735.GB3996698@nathanxps13
Similar to how the INHERIT option controls whether or not the
permissions of the granted role are automatically available to the
grantee, the new SET permission controls whether or not the grantee
may use the SET ROLE command to assume the privileges of the granted
role.
In addition, the new SET permission controls whether or not it
is possible to transfer ownership of objects to the target role
or to create new objects owned by the target role using commands
such as CREATE DATABASE .. OWNER. We could alternatively have made
this controlled by the INHERIT option, or allow it when either
option is given. An advantage of this approach is that if you
are granted a predefined role with INHERIT TRUE, SET FALSE, you
can't go and create objects owned by that role.
The underlying theory here is that the ability to create objects
as a target role is not a privilege per se, and thus does not
depend on whether you inherit the target role's privileges. However,
it's surely something you could do anyway if you could SET ROLE
to the target role, and thus making it contingent on whether you
have that ability is reasonable.
Design review by Nathan Bossat, Wolfgang Walther, Jeff Davis,
Peter Eisentraut, and Stephen Frost.
Discussion: http://postgr.es/m/CA+Tgmob+zDSRS6JXYrgq0NWdzCXuTNzT5eK54Dn2hhgt17nm8A@mail.gmail.com
Instead of dozens of mostly-duplicate pg_foo_aclcheck() functions,
write one common function object_aclcheck() that can handle almost all
of them. We already have all the information we need, such as which
system catalog corresponds to which catalog table and which column is
the ACL column.
There are a few pg_foo_aclcheck() that don't work via the generic
function and have special APIs, so those stay as is.
I also changed most pg_foo_aclmask() functions to static functions,
since they are not used outside of aclchk.c.
Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Reviewed-by: Antonin Houska <ah@cybertec.at>
Discussion: https://www.postgresql.org/message-id/flat/95c30f96-4060-2f48-98b5-a4392d3b6066@enterprisedb.com
This prevents marking the argument string for translation for gettext,
and it also prevents the given string (which is already translated) from
being translated at runtime.
Also, mark the strings used as arguments to check_rolespec_name for
translation.
Backpatch all the way back as appropriate. None of this is caught by
any tests (necessarily so), so I verified it manually.
Commit e3ce2de09d rearranged this
function to be able to identify which inherited role had admin option
on the target role, but it got the order of operations wrong, causing
the function to return wrong answers in the presence of non-inherited
grants.
Fix that, and add a test case that verifies the correct behavior.
Patch by me, reviewed by Nathan Bossart
Discussion: http://postgr.es/m/CA+TgmoYamnu-xt-u7CqjYWnRiJ6BQaSpYOHXP=r4QGTfd1N_EA@mail.gmail.com
The GRANT statement can now specify WITH INHERIT TRUE or WITH
INHERIT FALSE to control whether the member inherits the granted
role's permissions. For symmetry, you can now likewise write
WITH ADMIN TRUE or WITH ADMIN FALSE to turn ADMIN OPTION on or off.
If a GRANT does not specify WITH INHERIT, the behavior based on
whether the member role is marked INHERIT or NOINHERIT. This means
that if all roles are marked INHERIT or NOINHERIT before any role
grants are performed, the behavior is identical to what we had before;
otherwise, it's different, because ALTER ROLE [NO]INHERIT now only
changes the default behavior of future grants, and has no effect on
existing ones.
Patch by me. Reviewed and testing by Nathan Bossart and Tushar Ahuja,
with design-level comments from various others.
Discussion: http://postgr.es/m/CA+Tgmoa5Sf4PiWrfxA=sGzDKg0Ojo3dADw=wAHOhR9dggV=RmQ@mail.gmail.com
Previously, membership of role A in role B could be recorded in the
catalog tables only once. This meant that a new grant of role A to
role B would overwrite the previous grant. For other object types, a
new grant of permission on an object - in this case role A - exists
along side the existing grant provided that the grantor is different.
Either grant can be revoked independently of the other, and
permissions remain so long as at least one grant remains. Make role
grants work similarly.
Previously, when granting membership in a role, the superuser could
specify any role whatsoever as the grantor, but for other object types,
the grantor of record must be either the owner of the object, or a
role that currently has privileges to perform a similar GRANT.
Implement the same scheme for role grants, treating the bootstrap
superuser as the role owner since roles do not have owners. This means
that attempting to revoke a grant, or admin option on a grant, can now
fail if there are dependent privileges, and that CASCADE can be used
to revoke these. It also means that you can't grant ADMIN OPTION on
a role back to a user who granted it directly or indirectly to you,
similar to how you can't give WITH GRANT OPTION on a privilege back
to a role which granted it directly or indirectly to you.
Previously, only the superuser could specify GRANTED BY with a user
other than the current user. Relax that rule to allow the grantor
to be any role whose privileges the current user posseses. This
doesn't improve compatibility with what we do for other object types,
where support for GRANTED BY is entirely vestigial, but it makes this
feature more usable and seems to make sense to change at the same time
we're changing related behaviors.
Along the way, fix "ALTER GROUP group_name ADD USER user_name" to
require the same privileges as "GRANT group_name TO user_name".
Previously, CREATEROLE privileges were sufficient for either, but
only the former form was permissible with ADMIN OPTION on the role.
Now, either CREATEROLE or ADMIN OPTION on the role suffices for
either spelling.
Patch by me, reviewed by Stephen Frost.
Discussion: http://postgr.es/m/CA+TgmoaFr-RZeQ+WoQ5nKPv97oT9+aDgK_a5+qWHSgbDsMp1Vg@mail.gmail.com
This replaces all MemSet() calls with struct initialization where that
is easily and obviously possible. (For example, some cases have to
worry about padding bits, so I left those.)
(The same could be done with appropriate memset() calls, but this
patch is part of an effort to phase out MemSet(), so it doesn't touch
memset() calls.)
Reviewed-by: Ranier Vilela <ranier.vf@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/9847b13c-b785-f4e2-75c3-12ec77a3b05c@enterprisedb.com
Interpret its privileges argument as a comma-separated list of
privilege names, as in has_table_privilege and other functions.
This is actually net less code, since the support routine to
parse that already exists, and we can drop convert_priv_string()
which had no other use-case.
Robins Tharakan
Discussion: https://postgr.es/m/e5a05dc54ba64408b3dd260171c1abaf@EX13D05UWC001.ant.amazon.com
This patch allows "PGC_SUSET" parameters to be set by non-superusers
if they have been explicitly granted the privilege to do so.
The privilege to perform ALTER SYSTEM SET/RESET on a specific parameter
can also be granted.
Such privileges are cluster-wide, not per database. They are tracked
in a new shared catalog, pg_parameter_acl.
Granting and revoking these new privileges works as one would expect.
One caveat is that PGC_USERSET GUCs are unaffected by the SET privilege
--- one could wish that those were handled by a revocable grant to
PUBLIC, but they are not, because we couldn't make it robust enough
for GUCs defined by extensions.
Mark Dilger, reviewed at various times by Andrew Dunstan, Robert Haas,
Joshua Brindle, and myself
Discussion: https://postgr.es/m/3D691E20-C1D5-4B80-8BA5-6BEB63AF3029@enterprisedb.com
Generally if a role is granted membership to another role with NOINHERIT
they must use SET ROLE to access the privileges of that role, however
with predefined roles the membership and privilege is conflated. Fix that
by replacing is_member_of_role with has_privs_for_role for predefined
roles. Patch does not remove is_member_of_role from acl.h, but it does
add a warning not to use that function for privilege checking. Not
backpatched based on hackers list discussion.
Author: Joshua Brindle
Reviewed-by: Stephen Frost, Nathan Bossart, Joe Conway
Discussion: https://postgr.es/m/flat/CAGB+Vh4Zv_TvKt2tv3QNS6tUM_F_9icmuj0zjywwcgVi4PAhFA@mail.gmail.com
Commit f9fd176461 effectively gave
every role ADMIN OPTION on itself. However, this appears to be
something that happened accidentally as a result of refactoring
work rather than an intentional decision. Almost a decade later,
it was discovered that this was a security vulnerability. As a
result, commit fea164a72a restricted
this implicit ADMIN OPTION privilege to be exercisable only when
the role being administered is the same as the session user and
when no security-restricted operation is in progress. That
commit also documented the existence of this implicit privilege
for what seems to be the first time.
The effect of the privilege is to allow a login role to grant
the privileges of that role, and optionally ADMIN OPTION on it,
to some other role. That's an unusual thing to do, because generally
membership is granted in roles used as groups, rather than roles
used as users. Therefore, it does not seem likely that removing
the privilege will break things for many PostgreSQL users.
However, it will make it easier to reason about the permissions
system. This is the only case where a user who has not been given any
special permission (superuser, or ADMIN OPTION on some role) can
modify role membership, so removing it makes things more consistent.
For example, if a superuser sets up role A and B and grants A to B
but no other privileges to anyone, she can now be sure that no one
else will be able to revoke that grant. Without this change, that
would have been true only if A was a non-login role.
Patch by me. Reviewed by Tom Lane and Stephen Frost.
Discussion: http://postgr.es/m/CA+Tgmoawdt03kbA+dNyBcNWJpRxu0f4X=69Y3+DkXXZqmwMDLg@mail.gmail.com
Also "make reformat-dat-files".
The only change worthy of note is that pgindent messed up the formatting
of launcher.c's struct LogicalRepWorkerId, which led me to notice that
that struct wasn't used at all anymore, so I just took it out.
Commit c9c41c7a33 used two different
naming patterns. Standardize on the majority pattern, which was the
only pattern in the last reviewed version of that commit.
According to the comments, when an invalid or dropped column oid is passed
to has_column_privilege(), the intention has always been to return NULL.
However, when the caller had table level privilege the invalid/missing
column was never discovered, because table permissions were checked first.
Fix that by introducing extended versions of pg_attribute_acl(check|mask)
and pg_class_acl(check|mask) which take a new argument, is_missing. When
is_missing is NULL, the old behavior is preserved. But when is_missing is
passed by the caller, no ERROR is thrown for dropped or missing
columns/relations, and is_missing is flipped to true. This in turn allows
has_column_privilege to check for column privileges first, providing the
desired semantics.
Not backpatched since it is a user visible behavioral change with no previous
complaints, and the fix is a bit on the invasive side.
Author: Joe Conway
Reviewed-By: Tom Lane
Reported by: Ian Barwick
Discussion: https://postgr.es/m/flat/9b5f4311-157b-4164-7fe7-077b4fe8ed84%40joeconway.com
Membership consists, implicitly, of the current database owner. Expect
use in template databases. Once pg_database_owner has rights within a
template, each owner of a database instantiated from that template will
exercise those rights.
Reviewed by John Naylor.
Discussion: https://postgr.es/m/20201228043148.GA1053024@rfd.leadboat.com
This makes existing sessions reflect "ALTER ROLE ... [NO]INHERIT" as
quickly as they have been reflecting "GRANT role_name". Back-patch to
9.5 (all supported versions).
Reviewed by Nathan Bossart.
Discussion: https://postgr.es/m/20201221095028.GB3777719@rfd.leadboat.com
In the particular case of GRANTED BY, this is specified in the SQL
standard. Since in PostgreSQL, CURRENT_ROLE is equivalent to
CURRENT_USER, and CURRENT_USER is already supported here, adding
CURRENT_ROLE is trivial. The other cases are PostgreSQL extensions,
but for the same reason it also makes sense there.
Reviewed-by: Vik Fearing <vik@postgresfriends.org>
Reviewed-by: Asif Rehman <asifr.rehman@gmail.com>
Reviewed-by: Alvaro Herrera <alvherre@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/f2feac44-b4c5-f38f-3699-2851d6a76dc9%402ndquadrant.com
In the footsteps of aaf069aa3, remove ACLDEBUG, which was the only
other remaining undocumented symbol in pg_config_manual.h. The fact
that nobody had bothered to document it in seventeen years is a good
clue to its usefulness. In practice, none of the tracing logic it
enabled would be of any value without additional effort.
Discussion: https://postgr.es/m/6631.1587565046@sss.pgh.pa.us
This also involves renaming src/include/utils/hashutils.h, which
becomes src/include/common/hashfn.h. Perhaps an argument can be
made for keeping the hashutils.h name, but it seemed more
consistent to make it match the name of the file, and also more
descriptive of what is actually going on here.
Patch by me, reviewed by Suraj Kharage and Mark Dilger. Off-list
advice on how not to break the Windows build from Davinder Singh
and Amit Kapila.
Discussion: http://postgr.es/m/CA+TgmoaRiG4TXND8QuM6JXFRkM_1wL2ZNhzaUKsuec9-4yrkgw@mail.gmail.com
For most uses of acl.h the details of how "Acl" internally looks like
are irrelevant. It might make sense to move a lot of the
implementation details into a separate header at a later point.
The main motivation of this change is to avoid including fmgr.h (via
array.h, which needs it for exposed structs) in a lot of files that
otherwise don't need it. A subsequent commit will remove the fmgr.h
include from a lot of files.
Directly include utils/array.h and utils/expandeddatum.h from the
files that need them, but previously included them indirectly, via
acl.h.
Author: Andres Freund
Discussion: https://postgr.es/m/20190803193733.g3l3x3o42uv4qj7l@alap3.anarazel.de
... as well as its implementation from backend/access/hash/hashfunc.c to
backend/utils/hash/hashfn.c.
access/hash is the place for the hash index AM, not really appropriate
for generic facilities, which is what hash_any is; having things the old
way meant that anything using hash_any had to include the AM's include
file, pointlessly polluting its namespace with unrelated, unnecessary
cruft.
Also move the HTEqual strategy number to access/stratnum.h from
access/hash.h.
To avoid breaking third-party extension code, add an #include
"utils/hashutils.h" to access/hash.h. (An easily removed line by
committers who enjoy their asbestos suits to protect them from angry
extension authors.)
Discussion: https://postgr.es/m/201901251935.ser5e4h6djt2@alvherre.pgsql
Previously tables declared WITH OIDS, including a significant fraction
of the catalog tables, stored the oid column not as a normal column,
but as part of the tuple header.
This special column was not shown by default, which was somewhat odd,
as it's often (consider e.g. pg_class.oid) one of the more important
parts of a row. Neither pg_dump nor COPY included the contents of the
oid column by default.
The fact that the oid column was not an ordinary column necessitated a
significant amount of special case code to support oid columns. That
already was painful for the existing, but upcoming work aiming to make
table storage pluggable, would have required expanding and duplicating
that "specialness" significantly.
WITH OIDS has been deprecated since 2005 (commit ff02d0a05280e0).
Remove it.
Removing includes:
- CREATE TABLE and ALTER TABLE syntax for declaring the table to be
WITH OIDS has been removed (WITH (oids[ = true]) will error out)
- pg_dump does not support dumping tables declared WITH OIDS and will
issue a warning when dumping one (and ignore the oid column).
- restoring an pg_dump archive with pg_restore will warn when
restoring a table with oid contents (and ignore the oid column)
- COPY will refuse to load binary dump that includes oids.
- pg_upgrade will error out when encountering tables declared WITH
OIDS, they have to be altered to remove the oid column first.
- Functionality to access the oid of the last inserted row (like
plpgsql's RESULT_OID, spi's SPI_lastoid, ...) has been removed.
The syntax for declaring a table WITHOUT OIDS (or WITH (oids = false)
for CREATE TABLE) is still supported. While that requires a bit of
support code, it seems unnecessary to break applications / dumps that
do not use oids, and are explicit about not using them.
The biggest user of WITH OID columns was postgres' catalog. This
commit changes all 'magic' oid columns to be columns that are normally
declared and stored. To reduce unnecessary query breakage all the
newly added columns are still named 'oid', even if a table's column
naming scheme would indicate 'reloid' or such. This obviously
requires adapting a lot code, mostly replacing oid access via
HeapTupleGetOid() with access to the underlying Form_pg_*->oid column.
The bootstrap process now assigns oids for all oid columns in
genbki.pl that do not have an explicit value (starting at the largest
oid previously used), only oids assigned later by oids will be above
FirstBootstrapObjectId. As the oid column now is a normal column the
special bootstrap syntax for oids has been removed.
Oids are not automatically assigned during insertion anymore, all
backend code explicitly assigns oids with GetNewOidWithIndex(). For
the rare case that insertions into the catalog via SQL are called for
the new pg_nextoid() function can be used (which only works on catalog
tables).
The fact that oid columns on system tables are now normal columns
means that they will be included in the set of columns expanded
by * (i.e. SELECT * FROM pg_class will now include the table's oid,
previously it did not). It'd not technically be hard to hide oid
column by default, but that'd mean confusing behavior would either
have to be carried forward forever, or it'd cause breakage down the
line.
While it's not unlikely that further adjustments are needed, the
scope/invasiveness of the patch makes it worthwhile to get merge this
now. It's painful to maintain externally, too complicated to commit
after the code code freeze, and a dependency of a number of other
patches.
Catversion bump, for obvious reasons.
Author: Andres Freund, with contributions by John Naylor
Discussion: https://postgr.es/m/20180930034810.ywp2c7awz7opzcfr@alap3.anarazel.de
The variants of these functions that take numeric inputs (OIDs or
column numbers) are supposed to return NULL rather than failing
on bad input; this rule reduces problems with snapshot skew when
queries apply the functions to all rows of a catalog.
has_column_privilege() had careless handling of the case where the
table OID didn't exist. You might get something like this:
select has_column_privilege(9999,'nosuchcol','select');
ERROR: column "nosuchcol" of relation "(null)" does not exist
or you might get a crash, depending on the platform's printf's response
to a null string pointer.
In addition, while applying the column-number variant to a dropped
column returned NULL as desired, applying the column-name variant
did not:
select has_column_privilege('mytable','........pg.dropped.2........','select');
ERROR: column "........pg.dropped.2........" of relation "mytable" does not exist
It seems better to make this case return NULL as well.
Also, the OID-accepting variants of has_foreign_data_wrapper_privilege,
has_server_privilege, and has_tablespace_privilege didn't follow the
principle of returning NULL for nonexistent OIDs. Superusers got TRUE,
everybody else got an error.
Per investigation of Jaime Casanova's report of a new crash in HEAD.
These behaviors have been like this for a long time, so back-patch to
all supported branches.
Patch by me; thanks to Stephen Frost for discussion and review
Discussion: https://postgr.es/m/CAJGNTeP=-6Gyqq5TN9OvYEydi7Fv1oGyYj650LGTnW44oAzYCg@mail.gmail.com
Tom Lane