From 3cdf2421a299f2ebca0f79166b4d959d3e6a5184 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 16 Apr 2020 14:45:54 -0400 Subject: [PATCH] Fix cache reference leak in contrib/sepgsql. fixup_whole_row_references() did the wrong thing with a dropped column, resulting in a commit-time warning about a cache reference leak. I (tgl) added a test case exercising this, but back-patched the test only as far as v10; the patch didn't apply cleanly to 9.6 and it didn't seem worth the trouble to adapt it. The bug is pretty old though, so apply the code change all the way back. Michael Luo, with cosmetic improvements by me Discussion: https://postgr.es/m/BYAPR08MB5606D1453D7F50E2AF4D2FD29AD80@BYAPR08MB5606.namprd08.prod.outlook.com --- contrib/sepgsql/dml.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/contrib/sepgsql/dml.c b/contrib/sepgsql/dml.c index d1e9f53cda9..745d2616dce 100644 --- a/contrib/sepgsql/dml.c +++ b/contrib/sepgsql/dml.c @@ -31,9 +31,9 @@ /* * fixup_whole_row_references * - * When user reference a whole of row, it is equivalent to reference to + * When user references a whole-row Var, it is equivalent to referencing * all the user columns (not system columns). So, we need to fix up the - * given bitmapset, if it contains a whole of the row reference. + * given bitmapset, if it contains a whole-row reference. */ static Bitmapset * fixup_whole_row_references(Oid relOid, Bitmapset *columns) @@ -44,7 +44,7 @@ fixup_whole_row_references(Oid relOid, Bitmapset *columns) AttrNumber attno; int index; - /* if no whole of row references, do not anything */ + /* if no whole-row references, nothing to do */ index = InvalidAttrNumber - FirstLowInvalidHeapAttributeNumber; if (!bms_is_member(index, columns)) return columns; @@ -56,7 +56,7 @@ fixup_whole_row_references(Oid relOid, Bitmapset *columns) natts = ((Form_pg_class) GETSTRUCT(tuple))->relnatts; ReleaseSysCache(tuple); - /* fix up the given columns */ + /* remove bit 0 from column set, add in all the non-dropped columns */ result = bms_copy(columns); result = bms_del_member(result, index); @@ -66,14 +66,13 @@ fixup_whole_row_references(Oid relOid, Bitmapset *columns) ObjectIdGetDatum(relOid), Int16GetDatum(attno)); if (!HeapTupleIsValid(tuple)) - continue; - - if (((Form_pg_attribute) GETSTRUCT(tuple))->attisdropped) - continue; - - index = attno - FirstLowInvalidHeapAttributeNumber; + continue; /* unexpected case, should we error? */ - result = bms_add_member(result, index); + if (!((Form_pg_attribute) GETSTRUCT(tuple))->attisdropped) + { + index = attno - FirstLowInvalidHeapAttributeNumber; + result = bms_add_member(result, index); + } ReleaseSysCache(tuple); } -- 2.39.5