Bug 164991

Summary: CAN-2005-2099 Destruction of failed keyring oopses
Product: Red Hat Enterprise Linux 4 Reporter: David Howells <dhowells>
Component: kernelAssignee: David Howells <dhowells>
Status: CLOSED ERRATA QA Contact: Brian Brock <bbrock>
Severity: high Docs Contact:
Priority: medium    
Version: 4.0CC: security-response-team, wtogami
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: source=redhat,reported=20050803,public=20050804,impact=important
Fixed In Version: RHSA-2005-514 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2005-10-05 13:48:18 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:
Bug Depends On:    
Bug Blocks: 156322    

Description David Howells 2005-08-03 11:38:56 UTC 
+++ This bug was initially created as a clone of Bug #164989 +++ 
 
From Bugzilla Helper: 
User-Agent: Mozilla/5.0 (compatible; Konqueror/3.4; Linux) KHTML/3.4.0 (like 
Gecko) 
 
Description of problem: 
This was found on RHEL-4-pre-U2 and patched there before U2 was frozen.  
   
If a keyring is not fully instantiated when it is destroyed, the kernel will    
oops when it tries to unlink the keyring name from the name list.    
    
The problem occurs in three stages:    
    
 (1) The key allocator initialises the type-specific data to all zeroes. In    
     the case of a keyring, this will become a link in the keyring name list    
     when the keyring is instantiated.    
    
 (2) If a user (any user) attempts to add a keyring with anything other than    
     an empty payload, the keyring instantiation function will fail with an    
     error and won't add the keyring to the name list.    
    
 (3) The keyring's destructor then sees that the keyring has a description    
     (name) and tries to remove the keyring from the name list, which oopses    
     because the link pointers are both zero.    
    
 
Version-Release number of selected component (if applicable): 
 
 
How reproducible: 
Always 
 
Steps to Reproduce: 
1.keyctl add keyring a a @p    
 
Actual Results:  It oopses on a NULL pointer dereference.  
 
Expected Results:  It should get EINVAL.  
 
Additional info: 
This bug is already fixed in RHEL-4 U2.
Comment 1 Mark J. Cox 2005-08-10 11:56:49 UTC 
We sent this to security on 20050803 and it was fixed upstream 20050804
http://linux.bkbits.net:8080/linux-2.6/cset@42f276630QbcBD4i-OfNI6BXaPLWPg
Comment 3 Red Hat Bugzilla 2005-10-05 13:48:18 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2005-514.html