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| author | Michael Paquier <michael@paquier.xyz> | 2019-12-27 17:58:43 +0900 |
|---|---|---|
| committer | Michael Paquier <michael@paquier.xyz> | 2019-12-27 17:58:43 +0900 |
| commit | a052f6cbb84e5630d50b68586cecc127e64be639 (patch) | |
| tree | 00fff555b3903cc0a1bb9213aad830d6b9108d08 /src | |
| parent | 7854e07f25be3a3dfa9c94011a30767eca3c10ba (diff) | |
| download | postgresql-a052f6cbb84e5630d50b68586cecc127e64be639.tar.gz postgresql-a052f6cbb84e5630d50b68586cecc127e64be639.zip | |
Forbid DROP SCHEMA on temporary namespaces
This operation was possible for the owner of the schema or a superuser.
Down to 9.4, doing this operation would cause inconsistencies in a
session whose temporary schema was dropped, particularly if trying to
create new temporary objects after the drop. A more annoying
consequence is a crash of autovacuum on an assertion failure when
logging information about an orphaned temp table dropped. Note that
because of 246a6c8 (present in v11~), which has made the removal of
orphaned temporary tables more aggressive, the failure could be
triggered more easily, but it is possible to reproduce down to 9.4.
Reported-by: Mahendra Singh, Prabhat Sahu
Author: Michael Paquier
Reviewed-by: Kyotaro Horiguchi, Mahendra Singh
Discussion: https://postgr.es/m/CAKYtNAr9Zq=1-ww4etHo-VCC-k120YxZy5OS01VkaLPaDbv2tg@mail.gmail.com
Backpatch-through: 9.4
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/commands/dropcmds.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/src/backend/commands/dropcmds.c b/src/backend/commands/dropcmds.c index be7a40d5d2d..8af09b7a001 100644 --- a/src/backend/commands/dropcmds.c +++ b/src/backend/commands/dropcmds.c @@ -101,6 +101,21 @@ RemoveObjects(DropStmt *stmt) errhint("Use DROP AGGREGATE to drop aggregate functions."))); } + /* + * Prevent the drop of a temporary schema, be it owned by the current + * session or another backend as this would mess up with the callback + * registered to clean up temporary objects at the end of a session. + * Note also that the creation of any follow-up temporary object would + * result in inconsistencies within the session whose temporary schema + * has been dropped. + */ + if (stmt->removeType == OBJECT_SCHEMA && + isAnyTempNamespace(address.objectId)) + ereport(ERROR, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("cannot drop temporary schema \"%s\"", + get_namespace_name(address.objectId)))); + /* Check permissions. */ namespaceId = get_object_namespace(&address); if (!OidIsValid(namespaceId) || |