database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00
Code Activity

Bug#30882 Dropping a temporary table inside a stored function may cause a server crash

Browse Source 
If a stored function that contains a drop temporary table statement
is invoked by a create temporary table of the same name may cause
a server crash. The problem is that when dropping a table no check
is done to ensure that table is not being used by some outer query
(or outer statement), potentially leaving the outer query with a
reference to a stale (freed) table.

The solution is when dropping a temporary table, always check if
the table is being used by some outer statement as a temporary
table can be dropped inside stored procedures.

The check is performed by looking at the TABLE::query_id value for
temporary tables. To simplify this check and to solve a bug related
to handling of temporary tables in prelocked mode, this patch changes
the way in which this member is used to track the fact that table is
used/unused. Now we ensure that TABLE::query_id is zero for unused
temporary tables (which means that all temporary tables which were
used by a statement should be marked as free for reuse after it's
execution has been completed).
This commit is contained in:
davi@endora.local
2007-11-01 18:52:56 -02:00
parent 6bd9f5c1cb
commit cc007acb78
15 changed files with 431 additions and 83 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
sql/slave.cc
View File

@ -2353,7 +2353,7 @@ err:
change_rpl_status(RPL_ACTIVE_SLAVE,RPL_IDLE_SLAVE);
DBUG_ASSERT(thd->net.buff != 0);
net_end(&thd->net); // destructor will not free it, because net.vio is 0
close_thread_tables(thd, 0);
close_thread_tables(thd);
pthread_mutex_lock(&LOCK_thread_count);
THD_CHECK_SENTRY(thd);
delete thd;