Commit 95989e82 authored by Rucha Deodhar's avatar Rucha Deodhar

MDEV-28762: recursive call of some json functions without stack control

    This commit is a fixup for MDEV-28762

    Analysis: Some recursive json functions dont check for stack control
    Fix: Add check_stack_overrun(). The last argument is NULL because it is not
    used
parent 4bc34ef3
......@@ -4,8 +4,8 @@
#
SET @saved_dbug = @@debug_dbug;
SET debug_dbug='+d,json_check_min_stack_requirement';
SET @json1= '{"key1":"val1"}';
SET @json2= '{"key1":"val1"}';
SET @json1= '{"key1":{"key1":"val1"}}';
SET @json2= '{"key1":{"key1":"val1"}}';
SELECT JSON_CONTAINS(@json1, @json2);
ERROR HY000: Thread stack overrun: 'used bytes' used of a 'available' byte stack, and 'X' bytes needed. Use 'mysqld --thread_stack=#' to specify a bigger stack
SET debug_dbug='+d,temp';
......
......@@ -9,8 +9,8 @@
SET @saved_dbug = @@debug_dbug;
SET debug_dbug='+d,json_check_min_stack_requirement';
SET @json1= '{"key1":"val1"}';
SET @json2= '{"key1":"val1"}';
SET @json1= '{"key1":{"key1":"val1"}}';
SET @json2= '{"key1":{"key1":"val1"}}';
--replace_regex /overrun: [0-9]* bytes used of a [0-9]* byte stack, and [0-9]* bytes needed/overrun: 'used bytes' used of a 'available' byte stack, and 'X' bytes needed/
--error ER_STACK_OVERRUN_NEED_MORE
......
......@@ -20,7 +20,6 @@
#include "item.h"
#include "sql_parse.h" // For check_stack_overrun
/*
Compare ASCII string against the string with the specified
character set.
......@@ -136,9 +135,11 @@ int json_path_parts_compare(
{
int res, res2;
long arbitrary_var;
long stack_used_up= (available_stack_size(current_thd->thread_stack, &arbitrary_var));
DBUG_EXECUTE_IF("json_check_min_stack_requirement",
{alloca(my_thread_stack_size-(STACK_MIN_SIZE));});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE, NULL))
{alloca(my_thread_stack_size-stack_used_up-STACK_MIN_SIZE);});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE , NULL))
return 1;
while (a <= a_end)
{
......@@ -1135,6 +1136,12 @@ static int check_contains(json_engine_t *js, json_engine_t *value)
{
json_engine_t loc_js;
bool set_js;
long arbitrary_var;
long stack_used_up= (available_stack_size(current_thd->thread_stack, &arbitrary_var));
DBUG_EXECUTE_IF("json_check_min_stack_requirement",
{alloca(my_thread_stack_size-stack_used_up-STACK_MIN_SIZE);});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE , NULL))
return 1;
DBUG_EXECUTE_IF("json_check_min_stack_requirement",
{alloca(my_thread_stack_size-(STACK_MIN_SIZE));});
......@@ -2030,10 +2037,12 @@ String *Item_func_json_object::val_str(String *str)
static int do_merge(String *str, json_engine_t *je1, json_engine_t *je2)
{
long arbitrary_var;
long stack_used_up= (available_stack_size(current_thd->thread_stack, &arbitrary_var));
DBUG_EXECUTE_IF("json_check_min_stack_requirement",
{alloca(my_thread_stack_size-(STACK_MIN_SIZE));});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE, NULL))
return 1;
{alloca(my_thread_stack_size-stack_used_up-STACK_MIN_SIZE);});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE , NULL))
return 1;
if (json_read_value(je1) || json_read_value(je2))
return 1;
......@@ -2367,9 +2376,11 @@ static int copy_value_patch(String *str, json_engine_t *je)
static int do_merge_patch(String *str, json_engine_t *je1, json_engine_t *je2,
bool *empty_result)
{
long arbitrary_var;
long stack_used_up= (available_stack_size(current_thd->thread_stack, &arbitrary_var));
DBUG_EXECUTE_IF("json_check_min_stack_requirement",
{alloca(my_thread_stack_size-(STACK_MIN_SIZE));});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE, NULL))
{alloca(my_thread_stack_size-stack_used_up-STACK_MIN_SIZE);});
if (check_stack_overrun(current_thd, STACK_MIN_SIZE , NULL))
return 1;
if (json_read_value(je1) || json_read_value(je2))
......
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