From 4fc30ed9b7412cf02d0c19a0e491000f060da2d7 Mon Sep 17 00:00:00 2001 From: Greg Felice Date: Fri, 3 Jul 2026 07:07:28 -0400 Subject: [PATCH] Fix segfault on CREATE/MERGE/SET with generated or extra label columns (#2450) AGE builds the insert/update tuple slot from the full label-table descriptor (table_slot_create), but only populates the columns it manages: id/properties for vertices and id/start_id/end_id/properties for edges. A user-added column on the label table -- most notably a GENERATED ALWAYS ... STORED column, but also any plain ADD COLUMN -- therefore left an uninitialized slot entry. ExecStoreVirtualTuple marks all attributes valid, so heap_form_tuple() -> heap_compute_data_size() read the uninitialized tts_isnull[]/tts_values[] for that column and segfaulted dereferencing garbage as a varlena. This crashed the backend on CREATE, MERGE and SET. Fix in two parts: - clear_entity_slot() clears the slot and marks every attribute NULL before AGE fills in its own columns, so columns AGE does not manage default to NULL instead of stale slot memory. It is used at every slot build site: create_vertex, create_edge, merge_vertex, merge_edge, and the populate_vertex_tts/populate_edge_tts helpers used by SET. - insert_entity_tuple_cid (CREATE/MERGE) and update_entity_tuple (SET) call ExecComputeStoredGenerated() before materializing the heap tuple when the relation has stored generated columns, so those columns are computed on insert and recomputed on update per PostgreSQL semantics. Adds a generated_columns regression test covering stored generated columns on vertex and edge labels across CREATE, MERGE and SET, plus a plain user column that must not crash. --- Makefile | 1 + regress/expected/generated_columns.out | 222 +++++++++++++++++++++++++ regress/sql/generated_columns.sql | 129 ++++++++++++++ src/backend/executor/cypher_create.c | 4 +- src/backend/executor/cypher_merge.c | 22 ++- src/backend/executor/cypher_set.c | 23 +++ src/backend/executor/cypher_utils.c | 47 ++++++ src/include/executor/cypher_utils.h | 1 + 8 files changed, 445 insertions(+), 4 deletions(-) create mode 100644 regress/expected/generated_columns.out create mode 100644 regress/sql/generated_columns.sql diff --git a/Makefile b/Makefile index 32f34d6e6..2ea8f64ed 100644 --- a/Makefile +++ b/Makefile @@ -223,6 +223,7 @@ REGRESS = scan \ age_reduce \ map_projection \ direct_field_access \ + generated_columns \ security \ reserved_keyword_alias \ agtype_jsonb_cast \ diff --git a/regress/expected/generated_columns.out b/regress/expected/generated_columns.out new file mode 100644 index 000000000..4e929110c --- /dev/null +++ b/regress/expected/generated_columns.out @@ -0,0 +1,222 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +/* + * Regression test for issue #2450. + * + * A GENERATED ALWAYS ... STORED column (or any user-added column) on a label + * table adds an attribute AGE's CREATE/MERGE/SET paths do not populate. The + * slot's tuple descriptor is the full relation descriptor, so heap_form_tuple() + * used to read the uninitialized slot entry and segfault. AGE now null-inits the + * entity slot and computes stored generated columns before materializing the + * tuple. Generated columns must be computed on insert and recomputed on update; + * plain user columns must default to NULL rather than crash. + */ +LOAD 'age'; +SET search_path TO ag_catalog; +SELECT create_graph('generated_columns'); +NOTICE: graph "generated_columns" has been created + create_graph +-------------- + +(1 row) + +-- +-- GENERATED ALWAYS ... STORED column on a vertex label +-- +SELECT create_vlabel('generated_columns', 'Product'); +NOTICE: VLabel "Product" has been created + create_vlabel +--------------- + +(1 row) + +ALTER TABLE generated_columns."Product" + ADD COLUMN category varchar(25) + GENERATED ALWAYS AS (agtype_access_operator(properties, '"category"')) STORED; +-- CREATE: the generated column is computed from the new properties +SELECT * FROM cypher('generated_columns', $$ + CREATE (p:Product {category: 'disk', type: 'M1234'}) RETURN p +$$) AS (p agtype); + p +---------------------------------------------------------------------------------------------------------- + {"id": 844424930131969, "label": "Product", "properties": {"type": "M1234", "category": "disk"}}::vertex +(1 row) + +-- CREATE where the generation expression yields NULL (no such key) +SELECT * FROM cypher('generated_columns', $$ + CREATE (p:Product {type: 'no-cat'}) RETURN p +$$) AS (p agtype); + p +--------------------------------------------------------------------------------------- + {"id": 844424930131970, "label": "Product", "properties": {"type": "no-cat"}}::vertex +(1 row) + +-- MERGE also computes the generated column +SELECT * FROM cypher('generated_columns', $$ + MERGE (p:Product {category: 'merged'}) RETURN p +$$) AS (p agtype); + p +------------------------------------------------------------------------------------------- + {"id": 844424930131971, "label": "Product", "properties": {"category": "merged"}}::vertex +(1 row) + +-- MERGE again on the same pattern must MATCH (not re-insert); this exercises the +-- matched path where the slot is intentionally left uncleared (issue #2450) +SELECT * FROM cypher('generated_columns', $$ + MERGE (p:Product {category: 'merged'}) RETURN p +$$) AS (p agtype); + p +------------------------------------------------------------------------------------------- + {"id": 844424930131971, "label": "Product", "properties": {"category": "merged"}}::vertex +(1 row) + +-- SET recomputes the generated column from the updated properties +SELECT * FROM cypher('generated_columns', $$ + MATCH (p:Product {category: 'disk'}) SET p.category = 'ssd', p.note = 'x' RETURN p +$$) AS (p agtype); + p +---------------------------------------------------------------------------------------------------------------------- + {"id": 844424930131969, "label": "Product", "properties": {"note": "x", "type": "M1234", "category": "ssd"}}::vertex +(1 row) + +-- The stored generated column always mirrors properties.category +SELECT category, properties FROM generated_columns."Product" ORDER BY category NULLS LAST; + category | properties +----------+--------------------------------------------------- + "merged" | {"category": "merged"} + "ssd" | {"note": "x", "type": "M1234", "category": "ssd"} + | {"type": "no-cat"} +(3 rows) + +-- +-- GENERATED ALWAYS ... STORED column on an edge label +-- +SELECT create_elabel('generated_columns', 'REL'); +NOTICE: ELabel "REL" has been created + create_elabel +--------------- + +(1 row) + +ALTER TABLE generated_columns."REL" + ADD COLUMN kind varchar(25) + GENERATED ALWAYS AS (agtype_access_operator(properties, '"kind"')) STORED; +SELECT * FROM cypher('generated_columns', $$ + CREATE (:Product {category: 'a'})-[r:REL {kind: 'link'}]->(:Product {category: 'b'}) + RETURN r +$$) AS (r agtype); + r +---------------------------------------------------------------------------------------------------------------------------------------- + {"id": 1125899906842625, "label": "REL", "end_id": 844424930131973, "start_id": 844424930131972, "properties": {"kind": "link"}}::edge +(1 row) + +SELECT kind FROM generated_columns."REL"; + kind +-------- + "link" +(1 row) + +-- +-- Plain (non-generated) user column: must not crash; defaults to NULL +-- +SELECT create_vlabel('generated_columns', 'Plain'); +NOTICE: VLabel "Plain" has been created + create_vlabel +--------------- + +(1 row) + +ALTER TABLE generated_columns."Plain" ADD COLUMN tag text; +SELECT * FROM cypher('generated_columns', $$ + CREATE (p:Plain {n: 1}) RETURN p +$$) AS (p agtype); + p +---------------------------------------------------------------------------- + {"id": 1407374883553281, "label": "Plain", "properties": {"n": 1}}::vertex +(1 row) + +SELECT * FROM cypher('generated_columns', $$ + MATCH (p:Plain) SET p.n = 2 RETURN p +$$) AS (p agtype); + p +---------------------------------------------------------------------------- + {"id": 1407374883553281, "label": "Plain", "properties": {"n": 2}}::vertex +(1 row) + +SELECT properties, tag FROM generated_columns."Plain"; + properties | tag +------------+----- + {"n": 2} | +(1 row) + +-- +-- Generated column referencing the tableoid system column: the entity slot must +-- carry tts_tableOid before the generated columns are computed, otherwise the +-- expression sees InvalidOid instead of the label table's OID (issue #2450). +-- +SELECT create_vlabel('generated_columns', 'T'); +NOTICE: VLabel "T" has been created + create_vlabel +--------------- + +(1 row) + +ALTER TABLE generated_columns."T" + ADD COLUMN tbl oid GENERATED ALWAYS AS (tableoid) STORED; +SELECT * FROM cypher('generated_columns', $$ + CREATE (n:T {k: 1}) RETURN n +$$) AS (n agtype); + n +------------------------------------------------------------------------ + {"id": 1688849860263937, "label": "T", "properties": {"k": 1}}::vertex +(1 row) + +SELECT * FROM cypher('generated_columns', $$ + MATCH (n:T) SET n.k = 2 RETURN n +$$) AS (n agtype); + n +------------------------------------------------------------------------ + {"id": 1688849860263937, "label": "T", "properties": {"k": 2}}::vertex +(1 row) + +-- tbl must equal the real label-table OID on both the CREATE and SET paths +SELECT tbl = 'generated_columns."T"'::regclass::oid AS tableoid_ok +FROM generated_columns."T"; + tableoid_ok +------------- + t +(1 row) + +-- +-- Cleanup +-- +SELECT drop_graph('generated_columns', true); +NOTICE: drop cascades to 6 other objects +DETAIL: drop cascades to table generated_columns._ag_label_vertex +drop cascades to table generated_columns._ag_label_edge +drop cascades to table generated_columns."Product" +drop cascades to table generated_columns."REL" +drop cascades to table generated_columns."Plain" +drop cascades to table generated_columns."T" +NOTICE: graph "generated_columns" has been dropped + drop_graph +------------ + +(1 row) + diff --git a/regress/sql/generated_columns.sql b/regress/sql/generated_columns.sql new file mode 100644 index 000000000..5229c28f1 --- /dev/null +++ b/regress/sql/generated_columns.sql @@ -0,0 +1,129 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +/* + * Regression test for issue #2450. + * + * A GENERATED ALWAYS ... STORED column (or any user-added column) on a label + * table adds an attribute AGE's CREATE/MERGE/SET paths do not populate. The + * slot's tuple descriptor is the full relation descriptor, so heap_form_tuple() + * used to read the uninitialized slot entry and segfault. AGE now null-inits the + * entity slot and computes stored generated columns before materializing the + * tuple. Generated columns must be computed on insert and recomputed on update; + * plain user columns must default to NULL rather than crash. + */ + +LOAD 'age'; +SET search_path TO ag_catalog; + +SELECT create_graph('generated_columns'); + +-- +-- GENERATED ALWAYS ... STORED column on a vertex label +-- +SELECT create_vlabel('generated_columns', 'Product'); +ALTER TABLE generated_columns."Product" + ADD COLUMN category varchar(25) + GENERATED ALWAYS AS (agtype_access_operator(properties, '"category"')) STORED; + +-- CREATE: the generated column is computed from the new properties +SELECT * FROM cypher('generated_columns', $$ + CREATE (p:Product {category: 'disk', type: 'M1234'}) RETURN p +$$) AS (p agtype); + +-- CREATE where the generation expression yields NULL (no such key) +SELECT * FROM cypher('generated_columns', $$ + CREATE (p:Product {type: 'no-cat'}) RETURN p +$$) AS (p agtype); + +-- MERGE also computes the generated column +SELECT * FROM cypher('generated_columns', $$ + MERGE (p:Product {category: 'merged'}) RETURN p +$$) AS (p agtype); + +-- MERGE again on the same pattern must MATCH (not re-insert); this exercises the +-- matched path where the slot is intentionally left uncleared (issue #2450) +SELECT * FROM cypher('generated_columns', $$ + MERGE (p:Product {category: 'merged'}) RETURN p +$$) AS (p agtype); + +-- SET recomputes the generated column from the updated properties +SELECT * FROM cypher('generated_columns', $$ + MATCH (p:Product {category: 'disk'}) SET p.category = 'ssd', p.note = 'x' RETURN p +$$) AS (p agtype); + +-- The stored generated column always mirrors properties.category +SELECT category, properties FROM generated_columns."Product" ORDER BY category NULLS LAST; + +-- +-- GENERATED ALWAYS ... STORED column on an edge label +-- +SELECT create_elabel('generated_columns', 'REL'); +ALTER TABLE generated_columns."REL" + ADD COLUMN kind varchar(25) + GENERATED ALWAYS AS (agtype_access_operator(properties, '"kind"')) STORED; + +SELECT * FROM cypher('generated_columns', $$ + CREATE (:Product {category: 'a'})-[r:REL {kind: 'link'}]->(:Product {category: 'b'}) + RETURN r +$$) AS (r agtype); + +SELECT kind FROM generated_columns."REL"; + +-- +-- Plain (non-generated) user column: must not crash; defaults to NULL +-- +SELECT create_vlabel('generated_columns', 'Plain'); +ALTER TABLE generated_columns."Plain" ADD COLUMN tag text; + +SELECT * FROM cypher('generated_columns', $$ + CREATE (p:Plain {n: 1}) RETURN p +$$) AS (p agtype); + +SELECT * FROM cypher('generated_columns', $$ + MATCH (p:Plain) SET p.n = 2 RETURN p +$$) AS (p agtype); + +SELECT properties, tag FROM generated_columns."Plain"; + +-- +-- Generated column referencing the tableoid system column: the entity slot must +-- carry tts_tableOid before the generated columns are computed, otherwise the +-- expression sees InvalidOid instead of the label table's OID (issue #2450). +-- +SELECT create_vlabel('generated_columns', 'T'); +ALTER TABLE generated_columns."T" + ADD COLUMN tbl oid GENERATED ALWAYS AS (tableoid) STORED; + +SELECT * FROM cypher('generated_columns', $$ + CREATE (n:T {k: 1}) RETURN n +$$) AS (n agtype); + +SELECT * FROM cypher('generated_columns', $$ + MATCH (n:T) SET n.k = 2 RETURN n +$$) AS (n agtype); + +-- tbl must equal the real label-table OID on both the CREATE and SET paths +SELECT tbl = 'generated_columns."T"'::regclass::oid AS tableoid_ok +FROM generated_columns."T"; + +-- +-- Cleanup +-- +SELECT drop_graph('generated_columns', true); diff --git a/src/backend/executor/cypher_create.c b/src/backend/executor/cypher_create.c index 40f446bf6..36ef61b32 100644 --- a/src/backend/executor/cypher_create.c +++ b/src/backend/executor/cypher_create.c @@ -396,7 +396,7 @@ static void create_edge(cypher_create_custom_scan_state *css, estate->es_result_relations = &resultRelInfo; - ExecClearTuple(elemTupleSlot); + clear_entity_slot(elemTupleSlot); /* Graph Id for the edge */ id = ExecEvalExpr(node->id_expr_state, econtext, &isNull); @@ -491,7 +491,7 @@ static Datum create_vertex(cypher_create_custom_scan_state *css, estate->es_result_relations = &resultRelInfo; - ExecClearTuple(elemTupleSlot); + clear_entity_slot(elemTupleSlot); /* get the next graphid for this vertex. */ id = ExecEvalExpr(node->id_expr_state, econtext, &isNull); diff --git a/src/backend/executor/cypher_merge.c b/src/backend/executor/cypher_merge.c index 6f2e9376e..9c52073c2 100644 --- a/src/backend/executor/cypher_merge.c +++ b/src/backend/executor/cypher_merge.c @@ -1199,7 +1199,16 @@ static Datum merge_vertex(cypher_merge_custom_scan_state *css, estate->es_result_relations = &resultRelInfo; - ExecClearTuple(elemTupleSlot); + /* + * Only clear and null-init the slot when we will actually insert. On a + * matched MERGE the slot is never materialized (the output is built from + * id/prop directly), so the null-init memset would be wasted work that + * scales with any user-added columns (issue #2450 review follow-up). + */ + if (should_insert) + { + clear_entity_slot(elemTupleSlot); + } /* if we not are going to insert, we need our structure pointers */ if (should_insert == false && @@ -1526,7 +1535,16 @@ static void merge_edge(cypher_merge_custom_scan_state *css, estate->es_result_relations = &resultRelInfo; - ExecClearTuple(elemTupleSlot); + /* + * Only clear and null-init the slot when we will actually insert. On a + * matched MERGE the slot is never materialized (the output is built from + * id/prop directly), so the null-init memset would be wasted work that + * scales with any user-added columns (issue #2450 review follow-up). + */ + if (should_insert) + { + clear_entity_slot(elemTupleSlot); + } /* if we not are going to insert, we need our structure pointers */ if (should_insert == false && diff --git a/src/backend/executor/cypher_set.c b/src/backend/executor/cypher_set.c index fe3633f8d..7a0d48f0c 100644 --- a/src/backend/executor/cypher_set.c +++ b/src/backend/executor/cypher_set.c @@ -21,6 +21,7 @@ #include "common/hashfn.h" #include "executor/executor.h" +#include "executor/nodeModifyTable.h" #include "storage/bufmgr.h" #include "utils/rls.h" @@ -131,6 +132,28 @@ static HeapTuple update_entity_tuple(ResultRelInfo *resultRelInfo, close_indices = true; } ExecStoreVirtualTuple(elemTupleSlot); + + /* + * Recompute any stored generated columns before materializing the heap + * tuple. The slot's tuple descriptor is the full relation descriptor, + * which may include a GENERATED ALWAYS ... STORED column that the SET + * path does not populate; leaving those slot entries uninitialized makes + * heap_form_tuple() segfault on the garbage values (issue #2450). + */ + if (resultRelInfo->ri_RelationDesc->rd_att->constr != NULL && + resultRelInfo->ri_RelationDesc->rd_att->constr->has_generated_stored) + { + /* + * A generation expression may reference the tableoid system column, + * so the slot must carry the relation's OID before we recompute the + * stored generated columns (mirrors PostgreSQL's own ExecUpdate path). + */ + elemTupleSlot->tts_tableOid = + RelationGetRelid(resultRelInfo->ri_RelationDesc); + ExecComputeStoredGenerated(resultRelInfo, estate, elemTupleSlot, + CMD_UPDATE); + } + tuple = ExecFetchSlotHeapTuple(elemTupleSlot, true, NULL); tuple->t_self = old_tuple->t_self; diff --git a/src/backend/executor/cypher_utils.c b/src/backend/executor/cypher_utils.c index 8237cdcce..c697a560c 100644 --- a/src/backend/executor/cypher_utils.c +++ b/src/backend/executor/cypher_utils.c @@ -25,6 +25,7 @@ #include "postgres.h" #include "executor/executor.h" +#include "executor/nodeModifyTable.h" #include "miscadmin.h" #include "nodes/makefuncs.h" #include "parser/parse_relation.h" @@ -128,6 +129,24 @@ void destroy_entity_result_rel_info(ResultRelInfo *result_rel_info) table_close(result_rel_info->ri_RelationDesc, RowExclusiveLock); } +/* + * Clear an entity slot and mark every attribute NULL before AGE fills in the + * columns it manages (id/start_id/end_id/properties). + * + * The slot's tuple descriptor is the full label-table descriptor, which may + * contain columns AGE does not populate -- e.g. a user-added plain column, or a + * GENERATED ALWAYS ... STORED column. Without this, those attributes keep stale + * slot memory and heap_form_tuple() segfaults dereferencing the garbage + * (issue #2450). Plain columns then default to NULL; generated columns are + * recomputed via ExecComputeStoredGenerated() before the tuple is materialized. + */ +void clear_entity_slot(TupleTableSlot *elemTupleSlot) +{ + ExecClearTuple(elemTupleSlot); + memset(elemTupleSlot->tts_isnull, true, + elemTupleSlot->tts_tupleDescriptor->natts * sizeof(bool)); +} + TupleTableSlot *populate_vertex_tts( TupleTableSlot *elemTupleSlot, agtype_value *id, agtype_value *properties) { @@ -139,6 +158,8 @@ TupleTableSlot *populate_vertex_tts( errmsg("vertex id field cannot be NULL"))); } + clear_entity_slot(elemTupleSlot); + properties_isnull = properties == NULL; elemTupleSlot->tts_values[vertex_tuple_id] = GRAPHID_GET_DATUM(id->val.int_value); @@ -174,6 +195,8 @@ TupleTableSlot *populate_edge_tts( errmsg("edge end_id field cannot be NULL"))); } + clear_entity_slot(elemTupleSlot); + properties_isnull = properties == NULL; elemTupleSlot->tts_values[edge_tuple_id] = @@ -318,6 +341,30 @@ HeapTuple insert_entity_tuple_cid(ResultRelInfo *resultRelInfo, HeapTuple tuple = NULL; ExecStoreVirtualTuple(elemTupleSlot); + + /* + * The slot's tuple descriptor is the full relation descriptor, which may + * contain columns AGE does not populate itself -- most notably a + * GENERATED ALWAYS ... STORED column added to the label table. Those slot + * entries are left uninitialized by the create/merge/set paths, so we must + * compute the stored generated columns here before materializing the heap + * tuple. Otherwise heap_form_tuple() reads the uninitialized slot values + * and segfaults dereferencing garbage (issue #2450). + */ + if (resultRelInfo->ri_RelationDesc->rd_att->constr != NULL && + resultRelInfo->ri_RelationDesc->rd_att->constr->has_generated_stored) + { + /* + * A generation expression may reference the tableoid system column, so + * the slot must carry the relation's OID before we compute the stored + * generated columns (mirrors PostgreSQL's own ExecInsert path). + */ + elemTupleSlot->tts_tableOid = + RelationGetRelid(resultRelInfo->ri_RelationDesc); + ExecComputeStoredGenerated(resultRelInfo, estate, elemTupleSlot, + CMD_INSERT); + } + tuple = ExecFetchSlotHeapTuple(elemTupleSlot, true, NULL); /* Check the constraints of the tuple */ diff --git a/src/include/executor/cypher_utils.h b/src/include/executor/cypher_utils.h index ac4b5ea5a..8b65bc964 100644 --- a/src/include/executor/cypher_utils.h +++ b/src/include/executor/cypher_utils.h @@ -119,6 +119,7 @@ typedef struct cypher_merge_custom_scan_state void apply_update_list(CustomScanState *node, cypher_update_information *set_info); +void clear_entity_slot(TupleTableSlot *elemTupleSlot); TupleTableSlot *populate_vertex_tts(TupleTableSlot *elemTupleSlot, agtype_value *id, agtype_value *properties); TupleTableSlot *populate_edge_tts(