| Bug #79122 | memory leaks when doing INSERT... UPDATE ... prepared statements | ||
|---|---|---|---|
| Submitted: | 4 Nov 2015 15:41 | Modified: | 10 Nov 2015 17:09 |
| Reporter: | Tor Didriksen | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Prepared statements | Severity: | S3 (Non-critical) |
| Version: | 5.7.10 | OS: | Any |
| Assigned to: | CPU Architecture: | Any | |
[10 Nov 2015 17:09]
Paul DuBois
Noted in 5.7.10, 5.8.0 changelogs. INSERT ... ON DUPLICATE KEY UPDATE statements could result in a memory leak when executed as prepared statements.
Description: Problem: memory leaks when doing INSERT... UPDATE ... prepared statements. Regression source is patch for Bug#21908206 MEMORY LEAK ON WINDOWS WHEN SELECT FROM VIEW IN SUBQUERY Which fixed a regression caused by Bug#13901905 - CRASH: INSERT ON DUPLICATE KEY UPDATE READS FREED MEMORY The patch for Bug#21908206 fixed a leak for LEX objects that were not properly destroyed. Solution: clear the std::map for LEX objects thar *are* destroyed. How to repeat: ./mtr --mem --ps-protocol --valgrind i_main.type_blob-bug13901905 Suggested fix: --- a/sql/sql_prepare.cc +++ b/sql/sql_prepare.cc @@ -3106,6 +3106,7 @@ Prepared_statement::~Prepared_statement() if (lex) { delete lex->result; + lex->clear_values_map(); delete (st_lex_local *) lex; } free_root(&main_mem_root, MYF(0));