Bug 454388 (CVE-2008-2931)

Summary: CVE-2008-2931 kernel: missing check before setting mount propagation
Product: [Other] Security Response Reporter: Eugene Teo (Security Response) <eteo>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: anton, dhoward, jpirko, lwang, vgoyal
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2010-12-21 17:20:50 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: 454389, 454390, 454391, 454392, 454393    
Bug Blocks:    
Attachments:
Description Flags
Proposed backported patch for RHEL-5.3 none

Description Eugene Teo (Security Response) 2008-07-08 06:32:00 UTC 
The do_change_type routine has a missing check for capable(CAP_SYS_ADMIN). Even
though the mount command restricts the changing of mountpoint type to only root
users, it is possible for local unprivileged users to bypass and abuse this.
Comment 1 Eugene Teo (Security Response) 2008-07-08 06:37:14 UTC 
Created attachment 311232 [details]
Upstream patch for this issue
Comment 2 Eugene Teo (Security Response) 2008-07-08 06:48:27 UTC 
Proposed upstream patch:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ee6f958291e2a768fd727e7a67badfff0b67711a
Comment 6 Eugene Teo (Security Response) 2008-07-08 09:59:48 UTC 
It is possible for a normal user to mark a mount unbindable which cannot be
rebounded, and deny the administrator from bind mounting it to somewhere else.
It is also possible for a normal user to mark a private mount shared silently,
such that if the administrator decides to bind mount it, it will become a
sharable mount, even though the administrator may not intend it to be sharable.
Comment 7 Eugene Teo (Security Response) 2008-07-10 07:20:04 UTC 
Created attachment 311453 [details]
Proposed backported patch for RHEL-5.3
Comment 10 Vincent Danen 2010-12-21 17:20:50 UTC 
This was addressed via:

Red Hat Enterprise Linux version 5 (RHSA-2008:0885)