From 9bf782d34c0227f0bc403e95b014a9f2cc84eed3 Mon Sep 17 00:00:00 2001 From: Peter Geoghegan Date: Fri, 27 May 2016 14:24:22 -0700 Subject: [PATCH] Initialize SortSupport state correctly Commit 35fcb1b3 failed to initialize SortSupport states it introduced to allow the executor to re-check ORDER BY expressions containing distance operators. This simple omission could result in a NULL pointer dereference. Per bug #14134, from Jihyun Yu. --- src/backend/executor/nodeIndexscan.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c index bf16cb1..32ba75b 100644 --- a/src/backend/executor/nodeIndexscan.c +++ b/src/backend/executor/nodeIndexscan.c @@ -967,9 +967,18 @@ ExecInitIndexScan(IndexScan *node, EState *estate, int eflags) Oid orderbyop = lfirst_oid(lco); Node *orderbyexpr = (Node *) lfirst(lcx); Oid orderbyType = exprType(orderbyexpr); + Oid orderbyColl = exprCollation(orderbyexpr); + SortSupport orderbysort = &indexstate->iss_SortSupport[i]; - PrepareSortSupportFromOrderingOp(orderbyop, - &indexstate->iss_SortSupport[i]); + /* Initialize sort support */ + orderbysort->ssup_cxt = CurrentMemoryContext; + orderbysort->ssup_collation = orderbyColl; + /* See cmp_orderbyvals() comments on NULLS LAST */ + orderbysort->ssup_nulls_first = false; + /* ssup_attno is unused here and elsewhere */ + orderbysort->ssup_attno = 0; + + PrepareSortSupportFromOrderingOp(orderbyop, orderbysort); get_typlenbyval(orderbyType, &indexstate->iss_OrderByTypLens[i], &indexstate->iss_OrderByTypByVals[i]); -- 2.7.4