Make json{b}_populate_recordset() use the right tuple descriptor.

json{b}_populate_recordset() used the tuple descriptor created from the
query-level AS clause without worrying about whether it matched the actual
input record type.  If it didn't, that would usually result in a crash,
though disclosure of server memory contents seems possible as well, for a
skilled attacker capable of issuing crafted SQL commands.  Instead, use
the query-supplied descriptor only when there is no input tuple to look at,
and otherwise get a tuple descriptor based on the input tuple's own type
marking.  The core code will detect any type mismatch in the latter case.

Michael Paquier and Tom Lane, per a report from David Rowley.
Back-patch to 9.3 where this functionality was introduced.

Security: CVE-2017-15098

diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index 41c6139b6a8edd41f8a8caf4bc79f17cec11ee53..25f62c91b81828d97f285655f05985e312f5a7cf 100644 (file)
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -3491,26 +3491,40 @@ populate_recordset_worker(FunctionCallInfo fcinfo, const char *funcname,
 
    rsi->returnMode = SFRM_Materialize;
 
-   /*
-    * get the tupdesc from the result set info - it must be a record type
-    * because we already checked that arg1 is a record type, or we're in a
-    * to_record function which returns a setof record.
-    */
-   if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
-       ereport(ERROR,
-               (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-                errmsg("function returning record called in context "
-                       "that cannot accept type record")));
-
    /* if the json is null send back an empty set */
    if (PG_ARGISNULL(json_arg_num))
        PG_RETURN_NULL();
 
    if (!have_record_arg || PG_ARGISNULL(0))
+   {
        rec = NULL;
+
+       /*
+        * get the tupdesc from the result set info - it must be a record type
+        * because we already checked that arg1 is a record type, or we're in
+        * a to_record function which returns a setof record.
+        */
+       if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+           ereport(ERROR,
+                   (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                    errmsg("function returning record called in context "
+                           "that cannot accept type record")));
+   }
    else
+   {
+       Oid         tupType;
+       int32       tupTypmod;
+
        rec = PG_GETARG_HEAPTUPLEHEADER(0);
 
+       /*
+        * use the input record's own type marking to find a tupdesc for it.
+        */
+       tupType = HeapTupleHeaderGetTypeId(rec);
+       tupTypmod = HeapTupleHeaderGetTypMod(rec);
+       tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
+   }
+
    state = palloc0(sizeof(PopulateRecordsetState));
 
    /* make these in a sufficiently long-lived memory context */
@@ -3522,6 +3536,9 @@ populate_recordset_worker(FunctionCallInfo fcinfo, const char *funcname,
                                               false, work_mem);
    MemoryContextSwitchTo(old_cxt);
 
+   /* unnecessary, but harmless, if tupdesc came from get_call_result_type: */
+   ReleaseTupleDesc(tupdesc);
+
    state->function_name = funcname;
    state->my_extra = (RecordIOData **) &fcinfo->flinfo->fn_extra;
    state->rec = rec;

diff --git a/src/test/regress/expected/json.out b/src/test/regress/expected/json.out
index 9fc91f8d12142f5a928ec4264226834720e23c30..ce33367da8367858a0ff056edfa9213fde01017f 100644 (file)
--- a/src/test/regress/expected/json.out
+++ b/src/test/regress/expected/json.out
@@ -1806,6 +1806,19 @@ select * from json_populate_recordset(row('def',99,null)::jpop,'[{"a":[100,200,3
  {"z":true}    |  3 | Fri Jan 20 10:42:53 2012
 (2 rows)
 
+-- negative cases where the wrong record type is supplied
+select * from json_populate_recordset(row(0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned row contains 1 attribute, but query expects 2.
+select * from json_populate_recordset(row(0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned type integer at ordinal position 1, but query expects text.
+select * from json_populate_recordset(row(0::int,0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned row contains 3 attributes, but query expects 2.
+select * from json_populate_recordset(row(1000000000::int,50::int),'[{"b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned type integer at ordinal position 1, but query expects text.
 -- test type info caching in json_populate_record()
 CREATE TEMP TABLE jspoptest (js json);
 INSERT INTO jspoptest

diff --git a/src/test/regress/expected/jsonb.out b/src/test/regress/expected/jsonb.out
index eeac2a13c710a4aa32477892b2cdfd5709da3781..40594e0be327fcffac3a9d2f6fb95ffeb25221f1 100644 (file)
--- a/src/test/regress/expected/jsonb.out
+++ b/src/test/regress/expected/jsonb.out
@@ -2488,6 +2488,19 @@ SELECT * FROM jsonb_populate_recordset(row('def',99,NULL)::jbpop,'[{"a":[100,200
  {"z": true}     |  3 | Fri Jan 20 10:42:53 2012
 (2 rows)
 
+-- negative cases where the wrong record type is supplied
+select * from jsonb_populate_recordset(row(0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned row contains 1 attribute, but query expects 2.
+select * from jsonb_populate_recordset(row(0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned type integer at ordinal position 1, but query expects text.
+select * from jsonb_populate_recordset(row(0::int,0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned row contains 3 attributes, but query expects 2.
+select * from jsonb_populate_recordset(row(1000000000::int,50::int),'[{"b":"2"},{"a":"3"}]') q (a text, b text);
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned type integer at ordinal position 1, but query expects text.
 -- jsonb_to_record and jsonb_to_recordset
 select * from jsonb_to_record('{"a":1,"b":"foo","c":"bar"}')
     as x(a int, b text, d text);

diff --git a/src/test/regress/sql/json.sql b/src/test/regress/sql/json.sql
index 598498d40a294a48d4e4756df5f163b06d15ff23..d51243e5979e7757afedfc0cfa5c3acc0ac9b5a5 100644 (file)
--- a/src/test/regress/sql/json.sql
+++ b/src/test/regress/sql/json.sql
@@ -532,6 +532,12 @@ select * from json_populate_recordset(null::jpop,'[{"a":"blurfl","x":43.2},{"b":
 select * from json_populate_recordset(row('def',99,null)::jpop,'[{"a":"blurfl","x":43.2},{"b":3,"c":"2012-01-20 10:42:53"}]') q;
 select * from json_populate_recordset(row('def',99,null)::jpop,'[{"a":[100,200,300],"x":43.2},{"a":{"z":true},"b":3,"c":"2012-01-20 10:42:53"}]') q;
 
+-- negative cases where the wrong record type is supplied
+select * from json_populate_recordset(row(0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+select * from json_populate_recordset(row(0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+select * from json_populate_recordset(row(0::int,0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+select * from json_populate_recordset(row(1000000000::int,50::int),'[{"b":"2"},{"a":"3"}]') q (a text, b text);
+
 -- test type info caching in json_populate_record()
 CREATE TEMP TABLE jspoptest (js json);
 

diff --git a/src/test/regress/sql/jsonb.sql b/src/test/regress/sql/jsonb.sql
index d0e3f2a1f6d7823f3083d35e2ba6010bffb54c79..1385dc8f21bee90de0160e3b0b56096e36f06bce 100644 (file)
--- a/src/test/regress/sql/jsonb.sql
+++ b/src/test/regress/sql/jsonb.sql
@@ -648,6 +648,12 @@ SELECT * FROM jsonb_populate_recordset(NULL::jbpop,'[{"a":"blurfl","x":43.2},{"b
 SELECT * FROM jsonb_populate_recordset(row('def',99,NULL)::jbpop,'[{"a":"blurfl","x":43.2},{"b":3,"c":"2012-01-20 10:42:53"}]') q;
 SELECT * FROM jsonb_populate_recordset(row('def',99,NULL)::jbpop,'[{"a":[100,200,300],"x":43.2},{"a":{"z":true},"b":3,"c":"2012-01-20 10:42:53"}]') q;
 
+-- negative cases where the wrong record type is supplied
+select * from jsonb_populate_recordset(row(0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+select * from jsonb_populate_recordset(row(0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+select * from jsonb_populate_recordset(row(0::int,0::int,0::int),'[{"a":"1","b":"2"},{"a":"3"}]') q (a text, b text);
+select * from jsonb_populate_recordset(row(1000000000::int,50::int),'[{"b":"2"},{"a":"3"}]') q (a text, b text);
+
 -- jsonb_to_record and jsonb_to_recordset
 
 select * from jsonb_to_record('{"a":1,"b":"foo","c":"bar"}')