From 1edd4ec831458e10b524d1473a7de5791aa8753e Mon Sep 17 00:00:00 2001
From: Andrew Dunstan <andrew@dunslane.net>
Date: Sun, 4 Oct 2015 13:28:16 -0400
Subject: [PATCH] Disallow invalid path elements in jsonb_set

Null path elements and, where the object is an array, invalid integer
elements now cause an error.

Incorrect behaviour noted by Thom Brown, patch from Dmitry Dolgov.

Backpatch to 9.5 where jsonb_set was introduced
---
 src/backend/utils/adt/jsonfuncs.c     |  5 ++++-
 src/test/regress/expected/jsonb.out   | 24 +++++++++---------------
 src/test/regress/expected/jsonb_1.out | 24 +++++++++---------------
 src/test/regress/sql/jsonb.sql        |  3 +++
 4 files changed, 25 insertions(+), 31 deletions(-)

diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 154a8837e17..01b6bb0a483 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -3724,6 +3724,9 @@ setPath(JsonbIterator **it, Datum *path_elems,
 	JsonbValue *res = NULL;
 	int			r;
 
+	if (path_nulls[level])
+		elog(ERROR, "path element at the position %d is NULL", level + 1);
+
 	r = JsonbIteratorNext(it, &v, false);
 
 	switch (r)
@@ -3875,7 +3878,7 @@ setPathArray(JsonbIterator **it, Datum *path_elems, bool *path_nulls,
 		lindex = strtol(c, &badp, 10);
 		if (errno != 0 || badp == c || *badp != '\0' || lindex > INT_MAX ||
 			lindex < INT_MIN)
-			idx = nelems;
+			elog(ERROR, "path element at the position %d is not an integer", level + 1);
 		else
 			idx = lindex;
 	}
diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index 82d1b69bfaa..6da5a151d72 100644
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -3127,11 +3127,7 @@ select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::j
 (1 row)
 
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,NULL,0}', '[1,2,3]');
-                              jsonb_set                              
----------------------------------------------------------------------
- {"a": 1, "b": [1, 2], "c": {"1": 2}, "d": {"1": [2, 3]}, "n": null}
-(1 row)
-
+ERROR:  path element at the position 2 is NULL
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{n}', '{"1": 2}');
                                 jsonb_set                                
 -------------------------------------------------------------------------
@@ -3151,11 +3147,7 @@ select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::j
 (1 row)
 
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,NULL,0}', '{"1": 2}');
-                              jsonb_set                              
----------------------------------------------------------------------
- {"a": 1, "b": [1, 2], "c": {"1": 2}, "d": {"1": [2, 3]}, "n": null}
-(1 row)
-
+ERROR:  path element at the position 2 is NULL
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{b,-1}', '"test"');
                                 jsonb_set                                 
 --------------------------------------------------------------------------
@@ -3199,11 +3191,7 @@ select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb #- '{
 (1 row)
 
 select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb #- '{b,-1e}'; -- invalid array subscript
-                              ?column?                               
----------------------------------------------------------------------
- {"a": 1, "b": [1, 2], "c": {"1": 2}, "d": {"1": [2, 3]}, "n": null}
-(1 row)
-
+ERROR:  path element at the position 2 is not an integer
 select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb #- '{d,1,0}';
                              ?column?                             
 ------------------------------------------------------------------
@@ -3331,3 +3319,9 @@ select jsonb_set('[]','{-99}','{"foo":123}');
  [{"foo": 123}]
 (1 row)
 
+select jsonb_set('{"a": [1, 2, 3]}', '{a, non_integer}', '"new_value"');
+ERROR:  path element at the position 2 is not an integer
+select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, non_integer}', '"new_value"');
+ERROR:  path element at the position 3 is not an integer
+select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, NULL}', '"new_value"');
+ERROR:  path element at the position 3 is NULL
diff --git a/src/test/regress/expected/jsonb_1.out b/src/test/regress/expected/jsonb_1.out
index 2cbc0c79bba..39e7b1ff570 100644
--- a/src/test/regress/expected/jsonb_1.out
+++ b/src/test/regress/expected/jsonb_1.out
@@ -3127,11 +3127,7 @@ select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::j
 (1 row)
 
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,NULL,0}', '[1,2,3]');
-                              jsonb_set                              
----------------------------------------------------------------------
- {"a": 1, "b": [1, 2], "c": {"1": 2}, "d": {"1": [2, 3]}, "n": null}
-(1 row)
-
+ERROR:  path element at the position 2 is NULL
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{n}', '{"1": 2}');
                                 jsonb_set                                
 -------------------------------------------------------------------------
@@ -3151,11 +3147,7 @@ select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::j
 (1 row)
 
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{d,NULL,0}', '{"1": 2}');
-                              jsonb_set                              
----------------------------------------------------------------------
- {"a": 1, "b": [1, 2], "c": {"1": 2}, "d": {"1": [2, 3]}, "n": null}
-(1 row)
-
+ERROR:  path element at the position 2 is NULL
 select jsonb_set('{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb, '{b,-1}', '"test"');
                                 jsonb_set                                 
 --------------------------------------------------------------------------
@@ -3199,11 +3191,7 @@ select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb #- '{
 (1 row)
 
 select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb #- '{b,-1e}'; -- invalid array subscript
-                              ?column?                               
----------------------------------------------------------------------
- {"a": 1, "b": [1, 2], "c": {"1": 2}, "d": {"1": [2, 3]}, "n": null}
-(1 row)
-
+ERROR:  path element at the position 2 is not an integer
 select '{"n":null, "a":1, "b":[1,2], "c":{"1":2}, "d":{"1":[2,3]}}'::jsonb #- '{d,1,0}';
                              ?column?                             
 ------------------------------------------------------------------
@@ -3331,3 +3319,9 @@ select jsonb_set('[]','{-99}','{"foo":123}');
  [{"foo": 123}]
 (1 row)
 
+select jsonb_set('{"a": [1, 2, 3]}', '{a, non_integer}', '"new_value"');
+ERROR:  path element at the position 2 is not an integer
+select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, non_integer}', '"new_value"');
+ERROR:  path element at the position 3 is not an integer
+select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, NULL}', '"new_value"');
+ERROR:  path element at the position 3 is NULL
diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index cb03ada1731..b1a0764cfaa 100644
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -816,3 +816,6 @@ select jsonb_set('{}','{x}','{"foo":123}');
 select jsonb_set('[]','{0}','{"foo":123}');
 select jsonb_set('[]','{99}','{"foo":123}');
 select jsonb_set('[]','{-99}','{"foo":123}');
+select jsonb_set('{"a": [1, 2, 3]}', '{a, non_integer}', '"new_value"');
+select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, non_integer}', '"new_value"');
+select jsonb_set('{"a": {"b": [1, 2, 3]}}', '{a, b, NULL}', '"new_value"');
-- 
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