Bug 809280

Summary:	Memory leaks and crashers found in error-handling within libssh2-python-0.7.1-4.fc17 using gcc-with-cpychecker static analyzer
Product:	[Fedora] Fedora	Reporter:	Dave Malcolm <dmalcolm>
Component:	libssh2-python	Assignee:	Chris Lalancette <clalancette>
Status:	CLOSED EOL	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	19	CC:	clalancette
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
URL:	http://fedorapeople.org/~dmalcolm/gcc-python-plugin/2012-04-02/libssh2-python-0.7.1-4.fc17/
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-02-17 14:11:28 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	789472

Description Dave Malcolm 2012-04-02 23:50:22 UTC

Description of problem:
I've been writing an experimental static analysis tool to detect bugs commonly occurring within C Python extension modules:
  https://fedorahosted.org/gcc-python-plugin/
  http://gcc-python-plugin.readthedocs.org/en/latest/cpychecker.html
  http://fedoraproject.org/wiki/Features/StaticAnalysisOfPythonRefcounts

I ran the latest version of the tool (in git master; post 0.9) on
libssh2-python-0.7.1-4.fc17.src.rpm, and it reports various errors.

You can see a list of errors here, triaged into categories (from most significant to least significant):
http://fedorapeople.org/~dmalcolm/gcc-python-plugin/2012-04-02/libssh2-python-0.7.1-4.fc17/

I've manually reviewed the issues reported by the tool.

Within the category "Reference count too low" the 1 issue reported may or may not be a true error: I can't tell from the context

Within the category "Reference leaks" the 30 issues reported seem to stem from the CHECK_RETURN_CODE() macro: in particular, the RAISE_SSH2_ERROR() macro that it uses: in each case, each error-handling path has two reference leaks: that of _exc, and that of the Py_BuildValue result: both of these are built as new references, and nothing DECREFs them.  (Also, in each case the calls could fail)

Within the category "Reference count too low within an initialization routine" the 2 issues reported are likely to be inconsequential.

Within the category "Segfaults within error-handling paths" the 14 issues reported appear to be genuine crashers under low-memory conditions, where an earlier function call could return NULL, and nothing checks for it.  Many of these relate to the macros mentioned above.

There may of course be other bugs in my checker tool.

Hope this is helpful; let me know if you need help reading the logs that the tool generates - I know that it could use some improvement.

Version-Release number of selected component (if applicable):
libssh2-python-0.7.1-4.fc17
gcc-python-plugin post-0.9 git d578ee0e46d93647d0f94502784f890c38139d60 running the checker in an *f16* chroot

Comment 1 Fedora End Of Life 2013-04-03 14:10:33 UTC

This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle.
Changing version to '19'.

(As we did not run this process for some time, it could affect also pre-Fedora 19 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 19 End Of Life. Thank you.)

More information and reason for this action is here:
https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora19

Comment 2 Fedora End Of Life 2015-01-09 17:05:30 UTC

This message is a notice that Fedora 19 is now at end of life. Fedora 
has stopped maintaining and issuing updates for Fedora 19. It is 
Fedora's policy to close all bug reports from releases that are no 
longer maintained. Approximately 4 (four) weeks from now this bug will
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Comment 3 Fedora End Of Life 2015-02-17 14:11:28 UTC

Fedora 19 changed to end-of-life (EOL) status on 2015-01-06. Fedora 19 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

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