PDO MySQL: Fix leak with libmysqlclient and multiple rowsets

stmt->column_count gets reset before the next_rowset handler is
invoked, so we need to fetch the value from the result set instead.

Arguably PDO should be separating the destruction of the previous
result set and the switch to the next result set more cleanly...
This commit is contained in:
Nikita Popov 2020-12-11 10:47:16 +01:00
parent 54a63d91b8
commit c927c831e6

View file

@ -30,13 +30,34 @@
#ifdef PDO_USE_MYSQLND
# define pdo_mysql_stmt_execute_prepared(stmt) pdo_mysql_stmt_execute_prepared_mysqlnd(stmt)
# define pdo_free_bound_result(res) zval_ptr_dtor(res.zv)
#else
# define pdo_mysql_stmt_execute_prepared(stmt) pdo_mysql_stmt_execute_prepared_libmysql(stmt)
# define pdo_free_bound_result(res) efree(res.buffer)
#endif
static void pdo_mysql_free_result(pdo_mysql_stmt *S)
{
if (S->result) {
#ifndef PDO_USE_MYSQLND
if (S->bound_result) {
/* We can't use stmt->column_count here, because it gets reset before the
* next_rowset handler is called. */
unsigned column_count = mysql_num_fields(S->result);
for (unsigned i = 0; i < column_count; i++) {
efree(S->bound_result[i].buffer);
}
efree(S->bound_result);
efree(S->out_null);
efree(S->out_length);
S->bound_result = NULL;
}
#endif
mysql_free_result(S->result);
S->result = NULL;
}
}
static int pdo_mysql_stmt_dtor(pdo_stmt_t *stmt) /* {{{ */
{
@ -44,11 +65,8 @@ static int pdo_mysql_stmt_dtor(pdo_stmt_t *stmt) /* {{{ */
PDO_DBG_ENTER("pdo_mysql_stmt_dtor");
PDO_DBG_INF_FMT("stmt=%p", S->stmt);
if (S->result) {
/* free the resource */
mysql_free_result(S->result);
S->result = NULL;
}
pdo_mysql_free_result(S);
if (S->einfo.errmsg) {
pefree(S->einfo.errmsg, stmt->dbh->is_persistent);
S->einfo.errmsg = NULL;
@ -68,18 +86,6 @@ static int pdo_mysql_stmt_dtor(pdo_stmt_t *stmt) /* {{{ */
if (S->in_length) {
efree(S->in_length);
}
if (S->bound_result)
{
int i;
for (i = 0; i < stmt->column_count; i++) {
pdo_free_bound_result(S->bound_result[i]);
}
efree(S->bound_result);
efree(S->out_null);
efree(S->out_length);
}
#endif
if (!S->done && !Z_ISUNDEF(stmt->database_object_handle)
@ -209,15 +215,6 @@ static int pdo_mysql_stmt_execute_prepared_libmysql(pdo_stmt_t *stmt) /* {{{ */
if (S->result) {
int calc_max_length = H->buffered && S->max_length == 1;
S->fields = mysql_fetch_fields(S->result);
if (S->bound_result) {
int i;
for (i = 0; i < stmt->column_count; i++) {
efree(S->bound_result[i].buffer);
}
efree(S->bound_result);
efree(S->out_null);
efree(S->out_length);
}
php_pdo_stmt_set_column_count(stmt, (int)mysql_num_fields(S->result));
S->bound_result = ecalloc(stmt->column_count, sizeof(MYSQL_BIND));
@ -306,12 +303,7 @@ static int pdo_mysql_stmt_execute_prepared_mysqlnd(pdo_stmt_t *stmt) /* {{{ */
PDO_DBG_RETURN(0);
}
if (S->result) {
/* TODO: add a test to check if we really have zvals here... */
mysql_free_result(S->result);
S->result = NULL;
}
pdo_mysql_free_result(S);
PDO_DBG_RETURN(pdo_mysql_stmt_after_execute_prepared(stmt));
}
/* }}} */
@ -330,10 +322,7 @@ static int pdo_mysql_stmt_execute(pdo_stmt_t *stmt) /* {{{ */
}
/* ensure that we free any previous unfetched results */
if (S->result) {
mysql_free_result(S->result);
S->result = NULL;
}
pdo_mysql_free_result(S);
if (mysql_real_query(H->server, stmt->active_query_string, stmt->active_query_stringlen) != 0) {
pdo_mysql_error_stmt(stmt);
@ -355,10 +344,7 @@ static int pdo_mysql_stmt_next_rowset(pdo_stmt_t *stmt) /* {{{ */
if (S->stmt) {
mysql_stmt_free_result(S->stmt);
}
if (S->result) {
mysql_free_result(S->result);
S->result = NULL;
}
pdo_mysql_free_result(S);
#ifdef PDO_USE_MYSQLND
if (S->stmt) {
@ -845,10 +831,7 @@ static int pdo_mysql_stmt_cursor_closer(pdo_stmt_t *stmt) /* {{{ */
PDO_DBG_INF_FMT("stmt=%p", S->stmt);
S->done = 1;
if (S->result) {
mysql_free_result(S->result);
S->result = NULL;
}
pdo_mysql_free_result(S);
if (S->stmt) {
mysql_stmt_free_result(S->stmt);
}