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author | Monty <monty@mariadb.org> | 2021-02-20 14:46:19 +0200 |
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committer | Sergei Golubchik <serg@mariadb.org> | 2021-02-22 22:42:38 +0100 |
commit | 640f42311a72fa82bf7117c2791fc47ceb420361 (patch) | |
tree | 6135b491b2a6d6325f1f3d55c3f13779c80b90fb /sql/sql_show.cc | |
parent | 0ab1e3914c78e4a82a8e4502b58b20e5598727ab (diff) | |
download | mariadb-git-640f42311a72fa82bf7117c2791fc47ceb420361.tar.gz |
MDEV-24929 Server crash in thr_multi_unlock or in get_schema_tables_result
This was caused by two different bugs:
1) Information_schema tables where not locked by lock_tables, but
get_lock_data() was not filtering these out. This caused a crash when
mysql_unlock_some_tables() tried to unlock tables early, including
not locked information schema tables.
Fixed by not locking SYSTEM_TMP_TABLES
2) In some cases the optimizer will notice that we do not need to read
the information_schema tables at all. In this case
join_tab->read_record is not set, which caused a crash in
get_schema_tables_result()
Fixed by ignoring const tables in get_schema_tables_result()
Diffstat (limited to 'sql/sql_show.cc')
-rw-r--r-- | sql/sql_show.cc | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/sql/sql_show.cc b/sql/sql_show.cc index 2e0a44e4b8a..e6b5461e5af 100644 --- a/sql/sql_show.cc +++ b/sql/sql_show.cc @@ -8837,6 +8837,16 @@ bool get_schema_tables_result(JOIN *join, if (table_list->schema_table->fill_table == 0) continue; + /* + Do not fill in tables thare are marked as JT_CONST as these will never + be read and they also don't have a tab->read_record.table set! + This can happen with queries like + SELECT * FROM t1 LEFT JOIN (t1 AS t1b JOIN INFORMATION_SCHEMA.ROUTINES) + ON (t1b.a IS NULL); + */ + if (tab->type == JT_CONST) + continue; + /* skip I_S optimizations specific to get_all_tables */ if (lex->describe && (table_list->schema_table->fill_table != get_all_tables)) |