Bug 689843
| Summary: | Python ethtool opens NETLINK_ROUTE when loaded which causes leaked descriptor | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Jan Pazdziora (Red Hat) <jpazdziora> |
| Component: | python-ethtool | Assignee: | Arnaldo Carvalho de Melo <acme> |
| Status: | CLOSED ERRATA | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 14 | CC: | acme, davids, dwalsh |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | python-ethtool-0.7-2.fc15 | Doc Type: | Bug Fix |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-04-17 21:21:26 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: | |||
We'd appreciate fixed package (even) for Fedora 14 as it causes AVC denials for Spacewalk client tools on Fedora 14. This seems to be fixed by this commit:
commit 508ffffbb3c48eeeb11eeab2bf971180fe4e1940
Author: David Sommerseth <davids>
Date: Mon Apr 11 16:36:56 2011 +0200
Only open the NETLINK interface when needed
Do not open a NETLINK connection when loading the module, but rahter
open it when needed. In a case where multiple users needs the
connection, it will be shared and only closed when the last active
user is done.
Signed-off-by: David Sommerseth <davids>
The reproducing routine results in an AVC denial with python-ethtool-0.6. When the patch above is added, the AVC is not appearing.
However, the script below will trigger it again:
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import ethtool, os
devs = ethtool.get_interfaces_info('eth0')
eth0 = devs[0] # this will cause NETLINK conn to stay open, when opened
print eth0 # this will open a NETLINK connection
os.system("service crond status")
del eth0 # this will close the NETLINK connection
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I am not sure if this is a big deal or not. It is possible to implement a separate function call which will force NETLINK to close. However, I'm uncertain if this is more a SELinux issue or if it really a python-ethtool issue. It looks like this just tickles the SELinux in a way which causes the AVC.
Pushed another commit which should make the reproducer in comment #2 run without producing any AVC situations. commit 1680cbeb40e76dd975bc8ace756e74771901d607 Author: David Sommerseth <davids> Date: Tue Apr 12 13:57:34 2011 +0200 Force O_CLOEXEC on the NETLINK socket To avoid that the NETLINK socket is available to forked children, set the FD_CLOEXEC flag on the NETLINK socket. This also avoids SELinux from complaining on Fedora 14. For more information: https://bugzilla.redhat.com/show_bug.cgi?id=689843 Signed-off-by: David Sommerseth <davids> python-ethtool-0.7-1.fc15 has been submitted as an update for Fedora 15. https://admin.fedoraproject.org/updates/python-ethtool-0.7-1.fc15 python-ethtool-0.7-1.fc14 has been submitted as an update for Fedora 14. https://admin.fedoraproject.org/updates/python-ethtool-0.7-1.fc14 python-ethtool-0.7-1.fc13 has been submitted as an update for Fedora 13. https://admin.fedoraproject.org/updates/python-ethtool-0.7-1.fc13 Package python-ethtool-0.7-1.fc13: * should fix your issue, * was pushed to the Fedora 13 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing python-ethtool-0.7-1.fc13' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/python-ethtool-0.7-1.fc13 then log in and leave karma (feedback). I confirm that package python-ethtool-0.7-1.fc14.x86_64 fixes the issue. Thank you, Jan python-ethtool-0.7-2.fc13 has been submitted as an update for Fedora 13. https://admin.fedoraproject.org/updates/python-ethtool-0.7-2.fc13 python-ethtool-0.7-2.fc14 has been submitted as an update for Fedora 14. https://admin.fedoraproject.org/updates/python-ethtool-0.7-2.fc14 python-ethtool-0.7-2.fc15 has been submitted as an update for Fedora 15. https://admin.fedoraproject.org/updates/python-ethtool-0.7-2.fc15 Package python-ethtool-0.7-2.fc13: * should fix your issue, * was pushed to the Fedora 13 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing python-ethtool-0.7-2.fc13' as soon as you are able to. Please go to the following url: https://admin.fedoraproject.org/updates/python-ethtool-0.7-2.fc13 then log in and leave karma (feedback). I confirm that package python-ethtool-0.7-2.fc14.x86_64 fixes the issue. Thank you, Jan python-ethtool-0.7-2.fc14 has been pushed to the Fedora 14 stable repository. If problems still persist, please make note of it in this bug report. python-ethtool-0.7-2.fc15 has been pushed to the Fedora 15 stable repository. If problems still persist, please make note of it in this bug report. |
Description of problem: When ethtool module is loaded in python script, it opens NETLINK_ROUTE and keeps it open throughtout the live of the script. That filehandle is then leaked to any process forked from this process. That per se is a bad thing as any subprocess can then used it. Moreover, we've hit this issue with rhnreg_ks which calls rc = os.system("/sbin/service rhnsd status > /dev/null") after importing ethtool, and that causes AVC denial avc: denied { read write } for pid=6302 comm="consoletype" path="socket:[304921]" dev=sockfs ino=304921 scontext=unconfined_u:system_r:consoletype_t:s0 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=netlink_route_socket Note that the problem is not rhnsd here, any service command reveals the issue, as demonstrated below. Version-Release number of selected component (if applicable): # rpm -q python-ethtool python-ethtool-0.6-1.fc14.x86_64 How reproducible: Deterministic. Steps to Reproduce: 1. Have cronie and python-ethtool installed on Fedora 14, make sure you have SELinux enforcing. 2. Run python -c 'import ethtool ; import os ; os.system("service crond status")' 3. Check /var/log/audit/audit.log. Actual results: avc: denied { read write } for pid=6302 comm="consoletype" path="socket:[304921]" dev=sockfs ino=304921 scontext=unconfined_u:system_r:consoletype_t:s0 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=netlink_route_socket Expected results: No AVC denial. Additional info: The code in python-ethtool/ethtool.c is /** * Connects to the NETLINK interface. This should only be * called once as part of the main ethtool module init. * * @param nlc Structure which keeps the NETLINK connection handle (struct nl_handle) * * @return Returns 1 on success, otherwise 0. */ int open_netlink(struct nl_handle **nlc) { if( *nlc ) { return 0; } *nlc = nl_handle_alloc(); nl_connect(*nlc, NETLINK_ROUTE); return (*nlc != NULL); } and that one is called from PyMODINIT_FUNC initethtool(void). My feeling is that close-on-exec should be set.