Red Hat Bugzilla – Bug 800171
Bugs found in python-netifaces-0.5-2.fc17 using gcc-with-cpychecker static analyzer
Last modified: 2015-02-18 08:41:48 EST
Description of problem:
I've been writing an experimental static analysis tool to detect bugs commonly occurring within C Python extension modules:
I ran the latest version of the tool (in git master; post 0.9) on
python-netifaces-0.5-2.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):
I've manually reviewed the issues reported by the tool and they're mostly false positives, but there appear to be two problems if sa_family can be >= 257
Within the category "Reference count too low" the 1 issue reported may or may not be an error: it appears to be stealing a reference to dict
Within the category "Reference leaks":
netifaces.c:ifaddrs:ob_refcnt of '*dict' is 1 too high: appears to be a false positive: add_to_family steals the reference to dict.
netifaces.c:add_to_family:ob_refcnt of '*py_family' is 1 too high: is a genuine bug: it's missing a Py_DECREF (py_family) on that path. This is only an issue when the input >= 257.
Within the category "Segfaults within error-handling paths" the 1 issue reported may or may not be a genuine crasher: PyInt_FromLong can fail under low memory conditions when the input >= 257.
Within the category "Returning (PyObject*)NULL without setting an exception" the 1 issue reported appears to be a false positive.
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):
gcc-python-plugin post-0.9 git 11462291a66c8db693c8884cb84b795bb5988ffb running the checker in an *f16* chroot
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:
Thanks for this report, Dave, and sorry it's been unaddressed for so long. I'm going to go try to get your tool working over the next day or so to see if these issues affect the most up-to-date upstream, and if so how to address them. If you've got the tool working still and beat me to it, I wouldn't be upset though :)
After that, I'll see if any of this can be addressed downstream, and forward the rest upstream if appropriate.
This message is a notice that Fedora 19 is now at end of life. Fedora
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