Bug 562072

Summary:	kernel: vfs: add MNT_NOFOLLOW flag to umount(2) [rhel-5.7]
Product:	Red Hat Enterprise Linux 5	Reporter:	Eugene Teo (Security Response) <eteo>
Component:	kernel	Assignee:	Josef Bacik <jbacik>
Status:	CLOSED WONTFIX	QA Contact:	Filesystem QE <fs-qe>
Severity:	high	Docs Contact:
Priority:	high
Version:	5.6	CC:	aviro, dhoward, eguan, jarod, jpirko, kzhang, lwang, martinez, plyons, rwheeler, snagar
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	562074 562075 562078 673177 (view as bug list)		Environment:
Last Closed:	2011-06-08 15:35:45 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:	562074, 562075, 562078

Description Eugene Teo (Security Response) 2010-02-05 07:09:04 UTC

Description of problem:
[RFC PATCH] vfs: add MNT_NOFOLLOW flag to umount(2)

From: Miklos Szeredi <mszeredi>

Add a new MNT_NOFOLLOW flag to umount(2).  This is needed to prevent
symlink attacks in unprivileged unmounts (fuse, samba, ncpfs).

Additionally, return -EINVAL if an unknown flag is encountered.  This
makes it possible for the caller to determine if a flag is supported
or not (at least on kernels with this patch).

Discussion is at:
http://patchwork.kernel.org/patch/77169/

Comment 3 Eugene Teo (Security Response) 2010-06-21 23:54:08 UTC

Upstream commit:
http://git.kernel.org/linus/db1f05bb85d7966b9176e293f3ceead1cb8b5d79

Comment 10 RHEL Program Management 2011-02-01 17:07:06 UTC

This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.

Comment 11 Josef Bacik 2011-06-08 15:35:45 UTC

This requires an invasive change to the fuse package in order for it to be useful, and since we don't officially support fuse anyway and only provide it as a courtesy to customers and you need to be in the fuse group to even use the affected binary I'm closing this as wontfix

Comment 12 Ric Wheeler 2011-06-08 15:44:29 UTC

We actually do support FUSE, we just don't currently support any user space file systems that use FUSE in RHEL5.x.

That said, I am fine with punting this fix out to RHEL6.x.