Check column list length in XMLTABLE/JSON_TABLE alias

We weren't checking the length of the column list in the alias clause of
an XMLTABLE or JSON_TABLE function (a "tablefunc" RTE), and it was
possible to make the server crash by passing an overly long one.  Fix it
by throwing an error in that case, like the other places that deal with
alias lists.

In passing, modify the equivalent test used for join RTEs to look like
the other ones, which was different for no apparent reason.

This bug came in when XMLTABLE was born in version 10; backpatch to all
stable versions.

Reported-by: Wang Ke <krking@zju.edu.cn>
Discussion: https://postgr.es/m/17480-1c9d73565bb28e90@postgresql.org

12 files changed, 49 insertions, 17 deletions

diff --git a/src/backend/parser/parse_clause.c b/src/backend/parser/parse_clause.c
index e2baa9d852e..249255b65f5 100644
--- a/src/backend/parser/parse_clause.c
+++ b/src/backend/parser/parse_clause.c
@@ -1445,21 +1445,6 @@ transformFromClauseItem(ParseState *pstate, Node *n,
 									res_nscolumns + res_colindex);
 
 		/*
-		 * Check alias (AS clause), if any.
-		 */
-		if (j->alias)
-		{
-			if (j->alias->colnames != NIL)
-			{
-				if (list_length(j->alias->colnames) > list_length(res_colnames))
-					ereport(ERROR,
-							(errcode(ERRCODE_SYNTAX_ERROR),
-							 errmsg("column alias list for \"%s\" has too many entries",
-									j->alias->aliasname)));
-			}
-		}
-
-		/*
 		 * Now build an RTE and nsitem for the result of the join.
 		 * res_nscolumns isn't totally done yet, but that's OK because
 		 * addRangeTableEntryForJoin doesn't examine it, only store a pointer.
diff --git a/src/backend/parser/parse_relation.c b/src/backend/parser/parse_relation.c
index 00469763e88..926dcbf30e2 100644
--- a/src/backend/parser/parse_relation.c
+++ b/src/backend/parser/parse_relation.c
@@ -1989,11 +1989,13 @@ addRangeTableEntryForTableFunc(ParseState *pstate,
 							   bool inFromCl)
 {
 	RangeTblEntry *rte = makeNode(RangeTblEntry);
-	char	   *refname = alias ? alias->aliasname :
-	pstrdup(tf->functype == TFT_XMLTABLE ? "xmltable" : "json_table");
+	char	   *refname;
 	Alias	   *eref;
 	int			numaliases;
 
+	refname = alias ? alias->aliasname :
+		pstrdup(tf->functype == TFT_XMLTABLE ? "xmltable" : "json_table");
+
 	Assert(pstate != NULL);
 
 	rte->rtekind = RTE_TABLEFUNC;
@@ -2013,6 +2015,13 @@ addRangeTableEntryForTableFunc(ParseState *pstate,
 		eref->colnames = list_concat(eref->colnames,
 									 list_copy_tail(tf->colnames, numaliases));
 
+	if (numaliases > list_length(tf->colnames))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+				 errmsg("%s function has %d columns available but %d columns specified",
+						tf->functype == TFT_XMLTABLE ? "XMLTABLE" : "JSON_TABLE",
+						list_length(tf->colnames), numaliases)));
+
 	rte->eref = eref;
 
 	/*
@@ -2192,6 +2201,12 @@ addRangeTableEntryForJoin(ParseState *pstate,
 		eref->colnames = list_concat(eref->colnames,
 									 list_copy_tail(colnames, numaliases));
 
+	if (numaliases > list_length(colnames))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+				 errmsg("join expression \"%s\" has %d columns available but %d columns specified",
+						eref->aliasname, list_length(colnames), numaliases)));
+
 	rte->eref = eref;
 
 	/*
diff --git a/src/test/regress/expected/int2.out b/src/test/regress/expected/int2.out
index 0306648fa28..109cf9baaac 100644
--- a/src/test/regress/expected/int2.out
+++ b/src/test/regress/expected/int2.out
@@ -45,6 +45,10 @@ SELECT * FROM INT2_TBL;
  -32767
 (5 rows)
 
+SELECT * FROM INT2_TBL AS f(a, b);
+ERROR:  table "f" has 1 columns available but 2 columns specified
+SELECT * FROM (TABLE int2_tbl) AS s (a, b);
+ERROR:  table "s" has 1 columns available but 2 columns specified
 SELECT i.* FROM INT2_TBL i WHERE i.f1 <> int2 '0';
    f1   
 --------
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index bd3375f2bae..2538bd6a79b 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -5872,6 +5872,9 @@ select * from
  3 | 3
 (6 rows)
 
+-- check the number of columns specified
+SELECT * FROM (int8_tbl i cross join int4_tbl j) ss(a,b,c,d);
+ERROR:  join expression "ss" has 3 columns available but 4 columns specified
 -- check we don't try to do a unique-ified semijoin with LATERAL
 explain (verbose, costs off)
 select * from
diff --git a/src/test/regress/expected/jsonb_sqljson.out b/src/test/regress/expected/jsonb_sqljson.out
index 28338b4d193..ec7dc505933 100644
--- a/src/test/regress/expected/jsonb_sqljson.out
+++ b/src/test/regress/expected/jsonb_sqljson.out
@@ -1031,6 +1031,8 @@ SELECT * FROM JSON_TABLE(NULL, '$' COLUMNS ());
 ERROR:  syntax error at or near ")"
 LINE 1: SELECT * FROM JSON_TABLE(NULL, '$' COLUMNS ());
                                                     ^
+SELECT * FROM JSON_TABLE (NULL::jsonb, '$' COLUMNS (v1 timestamp)) AS f (v1, v2);
+ERROR:  JSON_TABLE function has 1 columns available but 2 columns specified
 -- NULL => empty table
 SELECT * FROM JSON_TABLE(NULL::jsonb, '$' COLUMNS (foo int)) bar;
  foo 
diff --git a/src/test/regress/expected/with.out b/src/test/regress/expected/with.out
index d7316043748..30dd900e114 100644
--- a/src/test/regress/expected/with.out
+++ b/src/test/regress/expected/with.out
@@ -1794,6 +1794,11 @@ DROP TABLE y;
 --
 -- error cases
 --
+WITH x(n, b) AS (SELECT 1)
+SELECT * FROM x;
+ERROR:  WITH query "x" has 1 columns available but 2 columns specified
+LINE 1: WITH x(n, b) AS (SELECT 1)
+             ^
 -- INTERSECT
 WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT SELECT n+1 FROM x)
 	SELECT * FROM x;
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 55b65ef324d..55ac49be261 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1145,6 +1145,9 @@ EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1;
          Table Function Call: XMLTABLE(('/ROWS/ROW'::text) PASSING (xmldata.data) COLUMNS id integer PATH ('@id'::text), _id FOR ORDINALITY, country_name text PATH ('COUNTRY_NAME/text()'::text) NOT NULL, country_id text PATH ('COUNTRY_ID'::text), region_id integer PATH ('REGION_ID'::text), size double precision PATH ('SIZE'::text), unit text PATH ('SIZE/@unit'::text), premier_name text DEFAULT ('not specified'::text) PATH ('PREMIER_NAME'::text))
 (7 rows)
 
+-- errors
+SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2);
+ERROR:  XMLTABLE function has 1 columns available but 2 columns specified
 -- XMLNAMESPACES tests
 SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz),
                       '/zz:rows/zz:row'
diff --git a/src/test/regress/sql/int2.sql b/src/test/regress/sql/int2.sql
index 8e8d33892db..ea29066b78e 100644
--- a/src/test/regress/sql/int2.sql
+++ b/src/test/regress/sql/int2.sql
@@ -17,6 +17,10 @@ INSERT INTO INT2_TBL(f1) VALUES ('');
 
 SELECT * FROM INT2_TBL;
 
+SELECT * FROM INT2_TBL AS f(a, b);
+
+SELECT * FROM (TABLE int2_tbl) AS s (a, b);
+
 SELECT i.* FROM INT2_TBL i WHERE i.f1 <> int2 '0';
 
 SELECT i.* FROM INT2_TBL i WHERE i.f1 <> int4 '0';
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 6dd01b022e9..a27a72086ef 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -1985,6 +1985,9 @@ select * from
    (select q1.v)
   ) as q2;
 
+-- check the number of columns specified
+SELECT * FROM (int8_tbl i cross join int4_tbl j) ss(a,b,c,d);
+
 -- check we don't try to do a unique-ified semijoin with LATERAL
 explain (verbose, costs off)
 select * from
diff --git a/src/test/regress/sql/jsonb_sqljson.sql b/src/test/regress/sql/jsonb_sqljson.sql
index ba1895d42db..fff25374808 100644
--- a/src/test/regress/sql/jsonb_sqljson.sql
+++ b/src/test/regress/sql/jsonb_sqljson.sql
@@ -328,6 +328,8 @@ SELECT JSON_TABLE('[]', '$');
 -- Should fail (no columns)
 SELECT * FROM JSON_TABLE(NULL, '$' COLUMNS ());
 
+SELECT * FROM JSON_TABLE (NULL::jsonb, '$' COLUMNS (v1 timestamp)) AS f (v1, v2);
+
 -- NULL => empty table
 SELECT * FROM JSON_TABLE(NULL::jsonb, '$' COLUMNS (foo int)) bar;
 
diff --git a/src/test/regress/sql/with.sql b/src/test/regress/sql/with.sql
index 3251c29584b..5c52561a8aa 100644
--- a/src/test/regress/sql/with.sql
+++ b/src/test/regress/sql/with.sql
@@ -803,6 +803,9 @@ DROP TABLE y;
 -- error cases
 --
 
+WITH x(n, b) AS (SELECT 1)
+SELECT * FROM x;
+
 -- INTERSECT
 WITH RECURSIVE x(n) AS (SELECT 1 INTERSECT SELECT n+1 FROM x)
 	SELECT * FROM x;
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index f3f83c7827d..e3f90db4d56 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -384,6 +384,9 @@ SELECT * FROM xmltableview1;
 EXPLAIN (COSTS OFF) SELECT * FROM xmltableview1;
 EXPLAIN (COSTS OFF, VERBOSE) SELECT * FROM xmltableview1;
 
+-- errors
+SELECT * FROM XMLTABLE (ROW () PASSING null COLUMNS v1 timestamp) AS f (v1, v2);
+
 -- XMLNAMESPACES tests
 SELECT * FROM XMLTABLE(XMLNAMESPACES('http://x.y' AS zz),
                       '/zz:rows/zz:row'