Bug 562074

Summary:	kernel: vfs: add MNT_NOFOLLOW flag to umount(2) [rhel-4.9]
Product:	Red Hat Enterprise Linux 4	Reporter:	Eugene Teo (Security Response) <eteo>
Component:	kernel	Assignee:	Josef Bacik <jbacik>
Status:	CLOSED WONTFIX	QA Contact:	Red Hat Kernel QE team <kernel-qe>
Severity:	high	Docs Contact:
Priority:	high
Version:	4.9	CC:	dhoward, jolsa, lwang, mkhusid, plyons, vgoyal
Target Milestone:	rc
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	562072	Environment:
Last Closed:	2010-12-14 14:38:59 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:	562072, 562078, 673177
Bug Blocks:

Description Eugene Teo (Security Response) 2010-02-05 07:22:35 UTC

+++ This bug was initially created as a clone of Bug #562072 +++

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/