From 59081de6280e7d49e206ce9d4d5728869e17e8d2 Mon Sep 17 00:00:00 2001
From: thoshiai <45982834+thoshiai@users.noreply.github.com>
Date: Thu, 15 Dec 2022 19:03:49 +0900
Subject: [PATCH] Fix segmentation fault in incorrect view def (#39)

A segfault was occurred when non-SELECT query was specified in create_immv since the statement type was not checked.

issue #37
---
 expected/create_immv.out | 11 +++++++++++
 pg_ivm.c                 |  6 ++++++
 sql/create_immv.sql      |  7 +++++++
 3 files changed, 24 insertions(+)

diff --git a/expected/create_immv.out b/expected/create_immv.out
index 22e0e18..da9f95d 100644
--- a/expected/create_immv.out
+++ b/expected/create_immv.out
@@ -31,6 +31,17 @@ SELECT create_immv('mv_in_immv01', 'SELECT i FROM mv');
 ERROR:  including IMMV in definition is not supported on incrementally maintainable materialized view
 SELECT create_immv('mv_in_immv02', 'SELECT t.i FROM t INNER JOIN mv2 ON t.i = mv2.x');
 ERROR:  including IMMV in definition is not supported on incrementally maintainable materialized view
+-- SQL other than SELECT
+SELECT create_immv('mv_in_create', 'CREATE TABLE in_create(i int)');
+ERROR:  view definition must specify SELECT statement
+SELECT create_immv('mv_in_insert', 'INSERT INTO t VALUES(10)');
+ERROR:  view definition must specify SELECT statement
+SELECT create_immv('mv_in_update', 'UPDATE t SET i = 10');
+ERROR:  view definition must specify SELECT statement
+SELECT create_immv('mv_in_delete', 'DELETE FROM t');
+ERROR:  view definition must specify SELECT statement
+SELECT create_immv('mv_in_drop', 'DROP TABLE t');
+ERROR:  view definition must specify SELECT statement
 DROP TABLE t;
 ERROR:  cannot drop table t because other objects depend on it
 DETAIL:  table mv depends on table t
diff --git a/pg_ivm.c b/pg_ivm.c
index b61967d..02c96a6 100644
--- a/pg_ivm.c
+++ b/pg_ivm.c
@@ -197,6 +197,12 @@ create_immv(PG_FUNCTION_ARGS)
 
 	parsetree = linitial_node(RawStmt, parsetree_list);
 
+	/* view definition should spcify SELECT query */
+	if (!IsA(parsetree->stmt, SelectStmt))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("view definition must specify SELECT statement")));
+
 	ctas = makeNode(CreateTableAsStmt);
 	ctas->query = parsetree->stmt;
 #if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 140000)
diff --git a/sql/create_immv.sql b/sql/create_immv.sql
index 8d1602e..c8d3415 100644
--- a/sql/create_immv.sql
+++ b/sql/create_immv.sql
@@ -12,6 +12,13 @@ SELECT immvrelid, get_immv_def(immvrelid) FROM pg_ivm_immv ORDER BY 1;
 SELECT create_immv('mv_in_immv01', 'SELECT i FROM mv');
 SELECT create_immv('mv_in_immv02', 'SELECT t.i FROM t INNER JOIN mv2 ON t.i = mv2.x');
 
+-- SQL other than SELECT
+SELECT create_immv('mv_in_create', 'CREATE TABLE in_create(i int)');
+SELECT create_immv('mv_in_insert', 'INSERT INTO t VALUES(10)');
+SELECT create_immv('mv_in_update', 'UPDATE t SET i = 10');
+SELECT create_immv('mv_in_delete', 'DELETE FROM t');
+SELECT create_immv('mv_in_drop', 'DROP TABLE t');
+
 DROP TABLE t;
 
 DROP TABLE mv;