| Bug #51208 | Extra string allocation from thd->mem_root in sql_show.cc, find_files() | ||
|---|---|---|---|
| Submitted: | 16 Feb 2010 14:29 | Modified: | 20 Nov 2010 22:44 |
| Reporter: | Kevin Lewis | Email Updates: | |
| Status: | Closed | Impact on me: | |
| Category: | MySQL Server: Information schema | Severity: | S3 (Non-critical) |
| Version: | 5.1 | OS: | Any |
| Assigned to: | Georgi Kodinov | CPU Architecture: | Any |
| Tags: | Leak, memory leak | ||
[16 Feb 2010 14:46]
Valeriy Kravchuk
Thank you for the problem report. Verified with recent 5.1.45 from bzr by code review.
[25 Feb 2010 9:59]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/101416 3354 Georgi Kodinov 2010-02-25 Bug #51208: Extra string allocation from thd->mem_root in sql_show.cc, find_files() Removed the extra allocation.
[25 Feb 2010 15:37]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/101466 3356 Georgi Kodinov 2010-02-25 Bug #51208: Extra string allocation from thd->mem_root in sql_show.cc, find_files() Removed the extra allocation.
[2 Mar 2010 14:34]
Bugs System
Pushed into 6.0.14-alpha (revid:alik@sun.com-20100302142746-u1gxdf5yk2bjrq3e) (version source revid:alik@sun.com-20100301095421-4cz64ibem1h2quve) (merge vers: 6.0.14-alpha) (pib:16)
[3 Mar 2010 1:10]
Paul DuBois
Noted in 6.0.14 changelog. The find_files() function used by SHOW statements performed redundant and unnecessary memory allocation. Setting report to Need Merge pending push to 5.1.x, Celosia.
[2 Nov 2010 13:21]
Bugs System
A patch for this bug has been committed. After review, it may be pushed to the relevant source trees for release in the next version. You can access the patch from: http://lists.mysql.com/commits/122535 3550 Georgi Kodinov 2010-11-02 Bug #51208: Extra string allocation from thd->mem_root in sql_show.cc, find_files() Removed the extra allocation.
[13 Nov 2010 16:12]
Bugs System
Pushed into mysql-trunk 5.6.99-m5 (revid:alexander.nozdrin@oracle.com-20101113155825-czmva9kg4n31anmu) (version source revid:alexander.nozdrin@oracle.com-20101113152450-2zzcm50e7i4j35v7) (merge vers: 5.6.1-m4) (pib:21)
[13 Nov 2010 16:32]
Bugs System
Pushed into mysql-next-mr (revid:alexander.nozdrin@oracle.com-20101113160336-atmtmfb3mzm4pz4i) (version source revid:alexander.nozdrin@oracle.com-20101113152540-gxro4g0v29l27f5x) (pib:21)
[20 Nov 2010 22:44]
Paul DuBois
Noted in 5.1.54, 5.5.8 changelogs.
[15 Dec 2010 5:53]
Bugs System
Pushed into mysql-5.1 5.1.55 (revid:sunanda.menon@oracle.com-20101215054055-vgwki317xg1wphhh) (version source revid:sunanda.menon@oracle.com-20101215054055-vgwki317xg1wphhh) (merge vers: 5.1.55) (pib:23)
[16 Dec 2010 22:34]
Bugs System
Pushed into mysql-5.5 5.5.9 (revid:jonathan.perkin@oracle.com-20101216101358-fyzr1epq95a3yett) (version source revid:jonathan.perkin@oracle.com-20101216101358-fyzr1epq95a3yett) (merge vers: 5.5.9) (pib:24)
Description: In sql_show.cc, function find_files() there is a *for* loop which looks at each file name in the current directory. If the function is called by make_db_list(), with dir=true, the last thing it does in that section is; if (!(file_name= thd->make_lex_string(file_name, uname, file_name_len, TRUE))) { my_dirend(dirp); DBUG_RETURN(FIND_FILES_OOM); } If that succeeds, it will fall through to below the 'else' section where it checks privileges and then does this; if (!(file_name= thd->make_lex_string(file_name, uname, file_name_len, TRUE)) || files->push_back(file_name)) { my_dirend(dirp); DBUG_RETURN(FIND_FILES_OOM); } The first allocated memory buffer pointed to by file_name for is replaced by the second buffer. The first pointer was thus lost. The actual memory comes out of thd->mem_root which is released at the end of the transaction. So it does not actually leak memory. But the first allocation is redundant and should be removed. How to repeat: Debug the code. Suggested fix: Remove the following code from find_files() in sql_show.cc - if (!(file_name= - thd->make_lex_string(file_name, uname, file_name_len, TRUE))) - { - my_dirend(dirp); - DBUG_RETURN(FIND_FILES_OOM); - }