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| author | Sergey Vojtovich <svoj@mariadb.org> | 2014-09-18 19:45:06 +0400 |
|---|---|---|
| committer | Sergey Vojtovich <svoj@mariadb.org> | 2014-09-18 19:45:06 +0400 |
| commit | d1e46a50bc59dd42e5aae55e4e20f2548c5cf3ba (patch) | |
| tree | c2567d37edf5e6297f8019e9d7d6a1e1698ccab7 /sql | |
| parent | 53a44915c53a16f4c52c98227b71f44ae421025c (diff) | |
| download | mariadb-git-d1e46a50bc59dd42e5aae55e4e20f2548c5cf3ba.tar.gz | |
MDEV-6749 - Deadlock between GRANT/REVOKE, SELECT FROM I_S.COLUMNS,
SET slow_query_log and failed connection attempt
A very subtle though valid deadlock. Deadlock chain:
wrlock(LOCK_grant) -> lock(acl_cache->lock) GRANT/REVOKE CREATE/DROP USER
lock(LOCK_open) -> rdlock(LOCK_grant) SELECT * FROM I_S.COLUMNS
wrlock(LOCK_logger) -> lock(LOCK_open) SET @@global.slow_query_log='ON'
lock(acl_cache->lock) -> rdlock(LOCK_logger) Failed connection
Fixed by removing relationship between acl_cache->lock and LOCK_logger
during failed connection attempt.
Diffstat (limited to 'sql')
| -rw-r--r-- | sql/sql_acl.cc | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc index 083f23d0820..c4ef699c049 100644 --- a/sql/sql_acl.cc +++ b/sql/sql_acl.cc @@ -9224,9 +9224,9 @@ bool acl_authenticate(THD *thd, uint connect_errors, mpvio.auth_info.authenticated_as, TRUE); if (!acl_proxy_user) { + mysql_mutex_unlock(&acl_cache->lock); if (!thd->is_error()) login_failed_error(thd); - mysql_mutex_unlock(&acl_cache->lock); DBUG_RETURN(1); } acl_user= acl_proxy_user->copy(thd->mem_root); |