Bug 443044

Summary: fix setuid/setgid clearing by knfsd
Product: Red Hat Enterprise Linux 4 Reporter: Jeff Layton <jlayton>
Component: kernelAssignee: Jeff Layton <jlayton>
Status: CLOSED ERRATA QA Contact: Martin Jenner <mjenner>
Severity: medium Docs Contact:
Priority: medium    
Version: 4.7CC: staubach, steved
Target Milestone: rc   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2009-05-18 19:31:28 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: 443043    
Bug Blocks: 461304    
Attachments:
Description Flags
patch -- revoke both setuid and setgid on uid/gid changes none

Description Jeff Layton 2008-04-18 12:09:20 UTC 
+++ This bug was initially created as a clone of Bug #443043 +++

I just pushed a couple of patches upstream that we should backport for the next
RHEL updates. I suspect that Bruce will push them for 2.6.26. Here is the
description of the problem:

Currently, knfsd only clears the setuid bit if the owner of a file is
changed on a SETATTR call, and only clears the setgid bit if the group
is changed. POSIX says this in the spec for chown():

    "If the specified file is a regular file, one or more of the
     S_IXUSR, S_IXGRP, or S_IXOTH bits of the file mode are set, and the
     process does not have appropriate privileges, the set-user-ID
     (S_ISUID) and set-group-ID (S_ISGID) bits of the file mode shall
     be cleared upon successful return from chown()."

If I'm reading this correctly, then knfsd is doing this wrong. It should
be clearing both the setuid and setgid bit on any SETATTR that changes
the uid or gid. This wasn't really as noticable before, but now that the
ATTR_KILL_S*ID bits are a no-op for the NFS client, it's more evident.
Comment 1 Jeff Layton 2008-04-23 15:24:03 UTC 
Created attachment 303511 [details]
patch -- revoke both setuid and setgid on uid/gid changes
Comment 3 RHEL Program Management 2008-05-02 16:20:48 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 4 RHEL Program Management 2008-09-03 13:13:34 UTC 
Updating PM score.
Comment 5 Vivek Goyal 2008-09-25 13:18:17 UTC 
Committed in 78.11.EL . RPMS are available at http://people.redhat.com/vgoyal/rhel4/
Comment 8 errata-xmlrpc 2009-05-18 19:31:28 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 therefore 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-2009-1024.html