< Changes
(→Scope) |
|||
| Line 73: | Line 73: | ||
* Proposal owners: | * Proposal owners: | ||
<!-- What work do the feature owners have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | <!-- What work do the feature owners have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | ||
Steve Dickson needs to make sure nfs-utils works properly. | |||
Dan Walsh needs to make sure selinux-policy works properly in all use cases. | |||
* Other developers: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | * Other developers: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | ||
<!-- What work do other developers have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | <!-- What work do other developers have to accomplish to complete the feature in time for release? Is it a large change affecting many parts of the distribution or is it a very isolated change? What are those changes?--> | ||
Turn on Labeled NFS in the Fedora Kernel, Fix any policy issues that arise because of this. I believe this is mainly a testing issue, and that the functionality is comeplete. | |||
* Release engineering: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | * Release engineering: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | ||
<!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)? Is a mass rebuid required? If a rel-eng ticket exists, add a link here. --> | <!-- Does this feature require coordination with release engineering (e.g. changes to installer image generation or update package delivery)? Is a mass rebuid required? If a rel-eng ticket exists, add a link here. --> | ||
| Line 82: | Line 83: | ||
* Policies and guidelines: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | * Policies and guidelines: N/A (not a System Wide Change) <!-- REQUIRED FOR SYSTEM WIDE CHANGES --> | ||
<!-- Do the packaging guidelines or other documents need to be updated for this feature? If so, does it need to happen before or after the implementation is done? If a FPC ticket exists, add a link here. --> | <!-- Do the packaging guidelines or other documents need to be updated for this feature? If so, does it need to happen before or after the implementation is done? If a FPC ticket exists, add a link here. --> | ||
== Upgrade/compatibility impact == | == Upgrade/compatibility impact == | ||
Revision as of 14:47, 24 July 2013
Enable SELinux Labeled NFS Support
Summary
The Linux Kernel has grown support for passing SELinux labels between a client and server using NFS.
Owner
- Name: Daniel Walsh
- Name: Steve Dickson
- Email: <dwalsh@redhat.com>
- Email: <steved@redhat.com>
Current status
- Targeted release: [Fedora 20]
- Last updated: Jul 24 2013
- Tracker bug: <will be assigned by the Wrangler>
- selinux-policy fixes are in Fedora 20.
- Labeled NFS Support is in 3.11.0-0.rc0.git7.1.fc20.x86_64 kernel
- nfs-utils support
- mount support
Detailed Description
We have always needed to treat NFS mounts with a single label usually something like nfs_t. Or at best allow an administrator to override the default with a label using the mount --context option. With this change we have lots of different Labels supported on an NFS share.
Benefit to Fedora
There are two huge benefits for Fedora, in that currently we can not differentiate different labels on a single NFS mount point. Applications like Secure Virtualization as launched by libvirt, can not set the label of an image file on an NFS share, so sVirt separation is severely weakened. Similarly if you setup home directories on an NFS share, then any confined application that needs to write a file in a home directory now can write any file on an NFS Share.
With labeled NFS this vulnerability goes away.
Scope
- Proposal owners:
Steve Dickson needs to make sure nfs-utils works properly. Dan Walsh needs to make sure selinux-policy works properly in all use cases.
- Other developers: N/A (not a System Wide Change)
Turn on Labeled NFS in the Fedora Kernel, Fix any policy issues that arise because of this. I believe this is mainly a testing issue, and that the functionality is comeplete.
- Release engineering: N/A (not a System Wide Change)
- Policies and guidelines: N/A (not a System Wide Change)
Upgrade/compatibility impact
In the beginning this will be turned off by default so updating a system from an older Fedora should continue to run, with nfs mounts treated as nfs_t, by SELinux.
How To Test
Do to a bug in nfs-utils:
- Server Side
Start/Stop nfs server.
systemctl start nfs systemctl stop nfs
Set the version
echo "+4.2" > /proc/fs/nfsd/versions
Start Server Again
systemctl start nfs
- Client Side
mount -o v4.2 server:mntpoint localmountpoint
There are many different scenarios that have to be tested with this new functionality.
Basically with Labeled NFS we need to test with client and servers supporting LNFS and SELinux
SELinux Testing
- SELinux Client LNFS - SELinux Server LNFS
- SELinux Client LNFS - SELinux Server No LNFS
- SELinux CLient LNFS - Server LNFS
- SELinux CLient LNFS - Server No LNFS
- Client LNFS - SELinux Server LNFS
- Client LNFS - SELInux Server No LNFS
- Client LNFS - Server LNFS
- Client LNFS - Server no LNFS
- Client no LNFS - SELinux Server LNFS
- Client no LNFS - SELInux Server No LNFS
- Client no LNFS - Server LNFS
- Client no LNFS - Server no LNFS
Also need testing on three way. IE You need two clients that support SELinux CLient NFS and change the label on one client, and make sure the other client sees the change.
User Experience
If you turn on Labeled NFS for homedirs or other content, the content will be labeled the same was as if it was on a EXT* file system. There is potential errors on mount between Systems at different versions of NFS. IE Attempting to mount a server which does not support Labelling, could cause an error, but the user/administrator should be able to handle this.
Dependencies
This will only work on the 3.11 kernel. If you boot with an older kernel NFS will fall back to the old behaviour.
Contingency Plan
We can continue using what we always did, all clients labeled the same