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| author | Jon Olav Hauglid <jon.hauglid@oracle.com> | 2015-01-22 14:19:56 +0100 |
|---|---|---|
| committer | Jon Olav Hauglid <jon.hauglid@oracle.com> | 2015-01-23 10:17:09 +0100 |
| commit | 7a408dbdf40930144c1bad654cb1e31e5ce5fc7a (patch) | |
| tree | 154611a8df35f2325180540e15a5022e631ea870 /sql/sys_vars.cc | |
| parent | 70f5d81a96ba38d690e907f5fd56760b9ee87803 (diff) | |
| download | mariadb-git-7a408dbdf40930144c1bad654cb1e31e5ce5fc7a.tar.gz | |
Bug#19770858: MYSQLD CAN BE DRIVEN TO OOM WITH TWO SIMPLE SESSION VARS
The problem was that the maximum value of the transaction_prealloc_size
session system variable was ULONG_MAX which meant that it was possible
to cause the server to allocate excessive amounts of memory.
This patch fixes the problem by reducing the maxmimum value of
transaction_prealloc_size and transaction_alloc_block_size down
to 128K.
Note that transactions will still be able to allocate more than
128K if needed, this patch just reduces the amount that can be
preallocated - as well as the maximum size of the incremental
allocation blocks.
Diffstat (limited to 'sql/sys_vars.cc')
| -rw-r--r-- | sql/sys_vars.cc | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/sql/sys_vars.cc b/sql/sys_vars.cc index e826624b42f..d1c02cda20c 100644 --- a/sql/sys_vars.cc +++ b/sql/sys_vars.cc @@ -1,4 +1,4 @@ -/* Copyright (c) 2002, 2014, Oracle and/or its affiliates. All rights reserved. +/* Copyright (c) 2002, 2015, Oracle and/or its affiliates. All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -1836,7 +1836,7 @@ static Sys_var_ulong Sys_trans_alloc_block_size( "transaction_alloc_block_size", "Allocation block size for transactions to be stored in binary log", SESSION_VAR(trans_alloc_block_size), CMD_LINE(REQUIRED_ARG), - VALID_RANGE(1024, ULONG_MAX), DEFAULT(QUERY_ALLOC_BLOCK_SIZE), + VALID_RANGE(1024, 128 * 1024 * 1024), DEFAULT(QUERY_ALLOC_BLOCK_SIZE), BLOCK_SIZE(1024), NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0), ON_UPDATE(fix_trans_mem_root)); @@ -1844,7 +1844,7 @@ static Sys_var_ulong Sys_trans_prealloc_size( "transaction_prealloc_size", "Persistent buffer for transactions to be stored in binary log", SESSION_VAR(trans_prealloc_size), CMD_LINE(REQUIRED_ARG), - VALID_RANGE(1024, ULONG_MAX), DEFAULT(TRANS_ALLOC_PREALLOC_SIZE), + VALID_RANGE(1024, 128 * 1024 * 1024), DEFAULT(TRANS_ALLOC_PREALLOC_SIZE), BLOCK_SIZE(1024), NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(0), ON_UPDATE(fix_trans_mem_root)); |