RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Bug 585286 - IMA breaks users of the dentry_open kernel interface
Summary: IMA breaks users of the dentry_open kernel interface
Keywords:
Status: CLOSED DUPLICATE of bug 584901
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: kernel
Version: 6.1
Hardware: All
OS: Linux
low
medium
Target Milestone: rc
: ---
Assignee: Red Hat Kernel Manager
QA Contact: Red Hat Kernel QE team
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2010-04-23 15:40 UTC by Simon Wilkinson
Modified: 2010-04-24 22:54 UTC (History)
5 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2010-04-23 18:14:20 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)

Description Simon Wilkinson 2010-04-23 15:40:57 UTC
Description of problem:

The IMA subsystem adds an asymmetric interface to monitoring files. That is, in-kernel users of the dentry_open interface must register their open files with IMA, but the registrations are automatically deregistered by filp_close. IMA provides verbose debugging output if it sees a file being deregistered that wasn't registered earlier.

ima_path_check(), which must be used to perform the registration, is a GPL-only symbol, so enabling IMA in effect breaks the dentry_open interface for non-GPL kernel modules. Whilst such modules can continue to function, the volume of debugging produced by IMA (a dump_stack every time a file is closed) seriously hampers the performance of the machine.

Whilst this is a general problem, in particular it breaks the Linux version of OpenAFS, which uses the dentry_open interface to access its cache files.

I raised this problem on the linux-security-module list in December 2009, and as a result the IMA interface was redesigned to remove the asymmetry of the register/unregister process. Those changes are in 2.6.33 - see the thread beginning at http://osdir.com/ml/linux-security-module/2009-12/msg00015.html for more details.

Many institutional users of OpenAFS use it with RHEL, so it would be great to have this fixed before the final release.

Comment 3 RHEL Program Management 2010-04-23 17:51:12 UTC
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux major release.  Product Management has requested further
review of this request by Red Hat Engineering, for potential inclusion in a Red
Hat Enterprise Linux Major release.  This request is not yet committed for
inclusion.

Comment 4 Eric Paris 2010-04-23 18:14:20 UTC
I am going to mark this a duplicate of BZ 584901.  Even though this BZ has a much better description of the real problem, that one was opened first.  You should be able to find a patch which applies against RHEL6 in that BZ which should take care of this problem.  I will be proposing that patch for inclusion in RHEL6 although it's final determination is not yet known.

*** This bug has been marked as a duplicate of bug 584901 ***

Comment 5 Stephan Wiesand 2010-04-24 19:20:51 UTC
#584901 is private - would it be possible to make it accessible? I'd really like to keep track of this issue. Thanks.


Note You need to log in before you can comment on or make changes to this bug.