Bug 1366968
| Summary: | SELinux does not allow systemd to create a TCP/UDP socket on port 53 (DNS) | ||
|---|---|---|---|
| Product: | [Fedora] Fedora | Reporter: | Victor Costan <costan> |
| Component: | selinux-policy | Assignee: | Lukas Vrabec <lvrabec> |
| Status: | CLOSED ERRATA | QA Contact: | Fedora Extras Quality Assurance <extras-qa> |
| Severity: | high | Docs Contact: | |
| Priority: | high | ||
| Version: | 27 | CC: | antoine, antonin.vecera, brian, dominick.grift, dwalsh, j, lvrabec, mcepl, mcepl, mgrepl, plautrba, ppywlkiqletw, pspacek, tkrizek, ToddAndMargo |
| Target Milestone: | --- | Keywords: | Reopened |
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | selinux-policy-3.13.1-283.23.fc27 | Doc Type: | If docs needed, set a value |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2018-01-10 02:06:55 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Can I do anything to help move this bug along? Thank you very much! We need new policy for skydns package. I confirm this is still a problem. It also applies to knot-resolver package which has exactly the same problem. Lukas, is there anything I can do to help you move this forward? For the record, here is output from audit2allow:
allow init_t unconfined_service_t:tcp_socket { bind create listen setopt };
allow init_t unconfined_service_t:udp_socket { bind create setopt };
I used following commands to produce it:
setenforce 0
systemctl start kresd.socket
dig @127.0.0.1 . NS
Looks very similar to: https://bugzilla.redhat.com/show_bug.cgi?id=1372754 https://bugzilla.redhat.com/show_bug.cgi?id=1399758 Could be related to: https://bugzilla.redhat.com/show_bug.cgi?id=1343685 I don't understand the comment saying that a policy is needed. This AVC happens in systemd, before any domain transition can be made. Also, the administrator can change the port in ListenStream as they wish, so a policy can't possibly whitelist a specific port. How do other packages do it? This message is a reminder that Fedora 24 is nearing its end of life. Approximately 2 (two) weeks from now Fedora will stop maintaining and issuing updates for Fedora 24. It is Fedora's policy to close all bug reports from releases that are no longer maintained. At that time this bug will be closed as EOL if it remains open with a Fedora 'version' of '24'. Package Maintainer: If you wish for this bug to remain open because you plan to fix it in a currently maintained version, simply change the 'version' to a later Fedora version. Thank you for reporting this issue and we are sorry that we were not able to fix it before Fedora 24 is end of life. If you would still like to see this bug fixed and are able to reproduce it against a later version of Fedora, you are encouraged change the 'version' to a later Fedora version prior this bug is closed as described in the policy above. Although we aim to fix as many bugs as possible during every release's lifetime, sometimes those efforts are overtaken by events. Often a more recent Fedora release includes newer upstream software that fixes bugs or makes them obsolete. Fedora 24 changed to end-of-life (EOL) status on 2017-08-08. Fedora 24 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. If you can reproduce this bug against a currently maintained version of Fedora please feel free to reopen this bug against that version. If you are unable to reopen this bug, please file a new report against the current release. If you experience problems, please add a comment to this bug. Thank you for reporting this bug and we are sorry it could not be fixed. This issue still affects knot-resolver in Fedora 27. *** Bug 1399758 has been marked as a duplicate of this bug. *** *** Bug 1528526 has been marked as a duplicate of this bug. *** *** Bug 1528189 has been marked as a duplicate of this bug. *** *** Bug 1483635 has been marked as a duplicate of this bug. *** *** Bug 1372754 has been marked as a duplicate of this bug. *** Please note that DNS servers need to listed on UDP and TCP ports at once. selinux-policy-3.13.1-283.21.fc27 has been submitted as an update to Fedora 27. https://bodhi.fedoraproject.org/updates/FEDORA-2018-0d8506aba4 selinux-policy-3.13.1-283.21.fc27 has been submitted as an update to Fedora 27. https://bodhi.fedoraproject.org/updates/FEDORA-2018-0d8506aba4 selinux-policy-3.13.1-283.21.fc27 has been pushed to the Fedora 27 testing repository. If problems still persist, please make note of it in this bug report. See https://fedoraproject.org/wiki/QA:Updates_Testing for instructions on how to install test updates. You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2018-0d8506aba4 selinux-policy-3.13.1-283.21.fc27 only allows TCP. UDP still doesn't work.
type=AVC msg=audit(1515403081.502:412): avc: denied { create } for pid=1 comm="systemd" scontext=system_u:system_r:init_t:s0 tcontext=system_u:system_r:unconfined_service_t:s0 tclass=udp_socket permissive=0
Tomas, Thanks, I overlooked it. It will be fixed in -23.fc27 release. Lukas. selinux-policy-3.13.1-283.21.fc27 has been pushed to the Fedora 27 stable repository. If problems still persist, please make note of it in this bug report. |
Description of problem: selinux is blocking systemd from creating a socket on port 53. I am using this to run skydns without giving it root privileges. Version-Release number of selected component (if applicable): selinux-policy.noarch 3.13.1-191.10.fc24 systemd.x86_64 229-12.fc24 How reproducible: always on F24; this used to work on F23 Steps to Reproduce: 1. sudo dnf install skydns 2. sudo systemctl start skydns.socket 3. sudo systemctl status skydns.socket Actual results: ● skydns.socket Loaded: loaded (/usr/lib/systemd/system/skydns.socket; enabled; vendor preset: disabled) Active: failed (Result: resources) Listen: 0.0.0.0:53 (Stream) 0.0.0.0:53 (Datagram) Aug 15 06:53:44 localhost.localdomain systemd[1]: skydns.socket: Failed to listen on sockets: Permission denied Aug 15 06:53:44 localhost.localdomain systemd[1]: Failed to listen on skydns.socket. Aug 15 06:53:44 localhost.localdomain systemd[1]: skydns.socket: Unit entered failed state. Expected results: systemd should be able to create the socket Additional info: > audit2allow -a -w type=AVC msg=audit(1471244024.006:1043): avc: denied { create } for pid=1 comm="systemd" scontext=system_u:system_r:init_t:s0 tcontext=system_u:system_r:unconfined_service_t:s0 tclass=tcp_socket permissive=0 Was caused by: Missing type enforcement (TE) allow rule. You can use audit2allow to generate a loadable module to allow this access. > audit2allow -a #============= init_t ============== allow init_t unconfined_service_t:tcp_socket create; > cat /usr/lib/systemd/system/skydns.socket [Socket] ListenStream=0.0.0.0:53 ListenDatagram=0.0.0.0:53 [Install] WantedBy=sockets.target