Bug 191727

Summary:	Nasty ncpfs symlink handling bug
Product:	Red Hat Enterprise Linux 3	Reporter:	Marcel Holtmann <holtmann>
Component:	kernel	Assignee:	Peter Staubach <staubach>
Status:	CLOSED WONTFIX	QA Contact:	Brian Brock <bbrock>
Severity:	low	Docs Contact:
Priority:	medium
Version:	3.0	CC:	lwang, peterm, petrides, security-response-team
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:	2006-05-15 19:41:44 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:

Description Marcel Holtmann 2006-05-15 14:59:33 UTC

This bug could cause oopses and page state corruption, because ncpfs used the
generic page-cache symlink handlign functions. But those functions only work if
the page cache is guaranteed to be "stable", ie a page that was installed when
the symlink walk was started has to still be installed in the page cache at the
end of the walk.

The upstream fix for 2.6 can be found here:

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cc314eef0128a807e50fa03baf2d0abc0647952c

It is not fully clear if this has a security implication at all and it got fixed
only in the 2.6 kernel series. However RHEL3 supports ncpfs and thus this needs
some investigation.

Comment 1 Ernie Petrides 2006-05-15 19:41:44 UTC

I've just discovered that "ncpfs" is in the RHEL3 kernel's "unsupported" list.