Bug 419132

Summary:	potential memory leakage: forget using libxml2 API 'xmlXPathFreeContext‘ after 'xmlXPathNewContext'
Product:	[Applications] amarok	Reporter:	summerlinasity
Component:	Services/MP3tunes	Assignee:	Amarok Bugs <amarok-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	unnamedrambler
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	kf5
Platform:	Other
OS:	Linux
Latest Commit:	https://invent.kde.org/multimedia/amarok/-/commit/312c36046bf49dadb2edbb0398989ffb6230c3e0	Version Fixed/Implemented In:
Sentry Crash Report:

Description summerlinasity 2020-03-23 08:19:35 UTC

SUMMARY
I found this issue when reading source code in the file 'src/services/mp3tunes/libmp3tunes/locker.c'.

STEPS TO REPRODUCE
1. first, there are 2 functions using libxml2 API: the defined xml_xpath_init() in 84 line uses API 'xmlXPathNewContext', the defined xml_xpath_deinit() in 119 line uses API 'xmlXPathFreeContext'.
2. the second usage of xml_xpath_init() in this c file lies in 422 line, inside the defined function mp3tunes_locker_api_post_fetch()
3. then mp3tunes_locker_api_post_fetch() is used in line 1391. After it, xml_xpath_deinit() is not called to free 'result->xpath_ctx' while free() is used directly to free 'result'.
So the unfree 'result->xpath_ctx' memory is leaked.

OBSERVED RESULT


EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION

Comment 1 Myriam Schweingruber 2020-03-23 21:29:48 UTC

I am not even sure this service still exists...

Comment 2 Bug Janitor Service 2024-06-21 10:35:11 UTC

A possibly relevant merge request was started @ https://invent.kde.org/multimedia/amarok/-/merge_requests/106

Comment 3 Tuomas Nurmi 2024-06-21 10:52:28 UTC

Git commit 312c36046bf49dadb2edbb0398989ffb6230c3e0 by Tuomas Nurmi.
Committed on 21/06/2024 at 10:31.
Pushed by nurmi into branch 'master'.

Some theoretical mp3tunes fixes

Fix the regexes so it compiles again. Add fixes to reported bugs, including a patch
posted by Zhouyang on bugs.kde.org. Fix some issues reported by code quality scans.

The compilation works now, but no effort was made even to try to test the functionality,
which probably doesn't. The service as is would need work and everything is turned off
in CMakeLists. Hard to predict if someone will ever update the mp3tunes to usable state,
but I guess there's no point in NOT applying the potential fixes (as the service still
exists, so maybe not everything's not broken enough to justify removing) so the existing
issues can be happily cleaned up at least.
Related: bug 391146

M  +3    -2    src/services/mp3tunes/Mp3tunesService.cpp
M  +3    -3    src/services/mp3tunes/Mp3tunesServiceCollection.cpp
M  +27   -5    src/services/mp3tunes/libmp3tunes/locker.c

https://invent.kde.org/multimedia/amarok/-/commit/312c36046bf49dadb2edbb0398989ffb6230c3e0