MDEV-23198 Crash in REPLACE

row_vers_impl_x_locked_low(): clust_offsets may point to memory
that is allocated by mem_heap_alloc() and may have been freed.
For initializing clust_offsets, try to use the stack-allocated
buffer instead of a pointer that may point to freed memory.

This fixes a regression that was introduced in
commit f0aa073f2bf3d8d85b3d028df89cdb4cdfc4002d (MDEV-20950).
This commit is contained in:
Marko Mäkelä 2020-07-31 11:38:23 +03:00
parent fd0abc890f
commit f35d172103
3 changed files with 38 additions and 4 deletions

View File

@ -28,4 +28,18 @@ SELECT * FROM t1;
a
0
DROP TABLE t1;
#
# MDEV-23198 Crash in REPLACE
#
BEGIN NOT ATOMIC
DECLARE c TEXT DEFAULT(SELECT CONCAT('CREATE TABLE t1(id INT PRIMARY KEY, c',
GROUP_CONCAT(seq SEPARATOR ' INT, c'),
' INT NOT NULL UNIQUE) ENGINE=InnoDB')
FROM seq_1_to_294);
EXECUTE IMMEDIATE c;
END;
$$
INSERT INTO t1 SET id=1,c294=1;
REPLACE t1 SET id=1,c294=1;
DROP TABLE t1;
SET GLOBAL innodb_file_per_table= @save_per_table;

View File

@ -1,4 +1,5 @@
--source include/have_innodb.inc
--source include/have_sequence.inc
SET @save_per_table= @@GLOBAL.innodb_file_per_table;
SET GLOBAL innodb_file_per_table= 1;
@ -49,4 +50,23 @@ SELECT * FROM t1;
DROP TABLE t1;
--echo #
--echo # MDEV-23198 Crash in REPLACE
--echo #
DELIMITER $$;
BEGIN NOT ATOMIC
DECLARE c TEXT DEFAULT(SELECT CONCAT('CREATE TABLE t1(id INT PRIMARY KEY, c',
GROUP_CONCAT(seq SEPARATOR ' INT, c'),
' INT NOT NULL UNIQUE) ENGINE=InnoDB')
FROM seq_1_to_294);
EXECUTE IMMEDIATE c;
END;
$$
DELIMITER ;$$
INSERT INTO t1 SET id=1,c294=1;
REPLACE t1 SET id=1,c294=1;
DROP TABLE t1;
SET GLOBAL innodb_file_per_table= @save_per_table;

View File

@ -91,7 +91,7 @@ row_vers_impl_x_locked_low(
{
rec_t* prev_version = NULL;
rec_offs clust_offsets_[REC_OFFS_NORMAL_SIZE];
rec_offs* clust_offsets = clust_offsets_;
rec_offs* clust_offsets;
mem_heap_t* heap;
dtuple_t* ientry = NULL;
mem_heap_t* v_heap = NULL;
@ -105,7 +105,7 @@ row_vers_impl_x_locked_low(
heap = mem_heap_create(1024);
clust_offsets = rec_get_offsets(clust_rec, clust_index, clust_offsets,
clust_offsets = rec_get_offsets(clust_rec, clust_index, clust_offsets_,
true, ULINT_UNDEFINED, &heap);
const trx_id_t trx_id = row_get_rec_trx_id(
@ -187,7 +187,7 @@ row_vers_impl_x_locked_low(
ut_ad(committed || prev_version
|| !rec_get_deleted_flag(version, comp));
/* Free version. */
/* Free version and clust_offsets. */
mem_heap_free(old_heap);
if (committed) {
@ -222,7 +222,7 @@ not_locked:
}
clust_offsets = rec_get_offsets(
prev_version, clust_index, clust_offsets, true,
prev_version, clust_index, clust_offsets_, true,
ULINT_UNDEFINED, &heap);
vers_del = rec_get_deleted_flag(prev_version, comp);