Bug 188068

Summary:

FC4 kernel doesn't understand MLS

Product:

[Fedora] Fedora

Reporter:

Ron Yorston <rmy>

Component:

kernel

Assignee:

Kernel Maintainer List <kernel-maint>

Status:

CLOSED ERRATA

QA Contact:

Brian Brock <bbrock>

Severity:

medium

Docs Contact:

Priority:

medium

Version:

CC:

jmorris, sdsmall, wtogami

Target Milestone:

---

Target Release:

---

Hardware:

i686

OS:

Linux

Whiteboard:

Fixed In Version:

2.6.16-1.2107_FC4

Doc Type:

Bug Fix

Doc Text:

Story Points:

---

Clone Of:

Environment:

Last Closed:

2006-05-03 19:26:48 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:

Attachments:

Description	Flags
Fix MLS compatibility patch in 2.6.16	none

Description Ron Yorston 2006-04-05 18:21:47 UTC

Description of problem:
The FC4 kernel doesn't understand the MLS suffix in the context of on-disk
inodes which have been created in FC5.  This results in errors like:

Apr  1 10:30:24 random kernel: inode_doinit_with_dentry: 
context_to_sid(user_u:object_r:user_home_t:s0) returned 22 for dev=dm-1 ino=352500

for files in the /home directory that I want to share between FC4 and FC5.  To
get FC4 to work I have to boot with enforcing=0.

I think the RHEL4 kernel has the same problem.

Version-Release number of selected component (if applicable):
2.6.16-1.2069_FC4

How reproducible:


Steps to Reproduce:
1.
2.
3.
  
Actual results:


Expected results:


Additional info:

Comment 1 Stephen Smalley 2006-04-05 18:49:41 UTC

I thought that this was resolved in bug 174618 and upstream in 2.6.15.
But the reporter indicates that it is still causing problems.
Bug 177349 tracks the RHEL4 fix.

Comment 2 Stephen Smalley 2006-04-05 18:57:17 UTC

(In reply to comment #1)
> I thought that this was resolved in bug 174618 and upstream in 2.6.15.
> But the reporter indicates that it is still causing problems.
> Bug 177349 tracks the RHEL4 fix.

Oops, the latter should be bug 177439.

Comment 3 Ron Yorston 2006-04-06 21:12:41 UTC

Created attachment 127429 [details]
Fix MLS compatibility patch in 2.6.16

It looks as though it's an off-by-one issue.  In mls_context_to_sid in mls.c
the parsing code is returning *scontext pointing to one beyond the terminating
null in the string.  The compatibility code needs to add one more to *scontext
to allow for this.

With this patch added to the 2.6.16-1.2069_FC4 kernel I'm able to boot my FC4
installation in enforcing mode and access files in my shared /home.  The
context_to_sid warnings have all gone.

Comment 4 Stephen Smalley 2006-04-11 14:58:44 UTC

Attachment 127429 [details] is correct (to the extent that the mls parsing code and length
check is correct, which can be debated, but that is another matter).
Acked-by:  Stephen Smalley <sds.gov>