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| author | Vicențiu Ciorbaru <vicentiu@mariadb.org> | 2016-08-16 11:25:11 +0300 |
|---|---|---|
| committer | Vicențiu Ciorbaru <vicentiu@mariadb.org> | 2016-08-23 21:24:36 +0300 |
| commit | 4eb898bb1663ab470a07e8419de4aa14b5afc667 (patch) | |
| tree | 81bb1fe2e773e70bfcd4c3500d54333cf7f3ef2d /sql/item_func.cc | |
| parent | 4da2b83af712492e4c3cb85e0005cde8511fa810 (diff) | |
| download | mariadb-git-4eb898bb1663ab470a07e8419de4aa14b5afc667.tar.gz | |
MDEV-10563 Crash during shutdown in Master_info_index::any_slave_sql_running
In well defined C code, the "this" pointer is never NULL. Currently, we
were potentially dereferencing a NULL pointer (master_info_index). GCC v6
removes any "if (!this)" conditions as it assumes this is always a
non-null pointer. In order to prevent undefined behaviour, check the
pointer before dereferencing and remove the check within member
functions.
Diffstat (limited to 'sql/item_func.cc')
| -rw-r--r-- | sql/item_func.cc | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/sql/item_func.cc b/sql/item_func.cc index b637213bc2d..9ee1ba4c7a7 100644 --- a/sql/item_func.cc +++ b/sql/item_func.cc @@ -3942,7 +3942,7 @@ longlong Item_master_pos_wait::val_int() longlong timeout = (arg_count>=3) ? args[2]->val_int() : 0 ; String connection_name_buff; LEX_STRING connection_name; - Master_info *mi; + Master_info *mi= NULL; if (arg_count >= 4) { String *con; @@ -3962,8 +3962,9 @@ longlong Item_master_pos_wait::val_int() connection_name= thd->variables.default_master_connection; mysql_mutex_lock(&LOCK_active_mi); - mi= master_info_index->get_master_info(&connection_name, - Sql_condition::WARN_LEVEL_WARN); + if (master_info_index) // master_info_index is set to NULL on shutdown. + mi= master_info_index->get_master_info(&connection_name, + Sql_condition::WARN_LEVEL_WARN); mysql_mutex_unlock(&LOCK_active_mi); if (!mi) goto err; |