Check criticalSharedRelcachesBuilt in GetSharedSecurityLabel().

An extension may want to call GetSecurityLabel() on a shared object
before the shared relcaches are fully initialized. For instance, a
ClientAuthentication_hook might want to retrieve the security label on
a role.

Discussion: https://postgr.es/m/ecb7af0b26e3be1d96d291c8453a86f1f82d9061.camel@j-davis.com
Backpatch-through: 9.6

diff --git a/src/backend/commands/seclabel.c b/src/backend/commands/seclabel.c
index 5ee46905d840cc794e7bf74634c0758022352698..1ce62b1e2caf4dadc79e0ecf4ee13bda420d7e0c 100644 (file)
--- a/src/backend/commands/seclabel.c
+++ b/src/backend/commands/seclabel.c
@@ -169,8 +169,8 @@ GetSharedSecurityLabel(const ObjectAddress *object, const char *provider)
 
        pg_shseclabel = heap_open(SharedSecLabelRelationId, AccessShareLock);
 
-       scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId, true,
-                                                         NULL, 3, keys);
+       scan = systable_beginscan(pg_shseclabel, SharedSecLabelObjectIndexId,
+                                                         criticalSharedRelcachesBuilt, NULL, 3, keys);
 
        tuple = systable_getnext(scan);
        if (HeapTupleIsValid(tuple))