kern/69420: chown(8) not possible on NFS Filesystems from a FreeBSD Server

Thu Jul 22 01:50:28 PDT 2004

>Number:         69420
>Category:       kern
>Synopsis:       chown(8) not possible on NFS Filesystems from a FreeBSD Server
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Thu Jul 22 08:50:27 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator:     Matthias Schuendehuette
>Release:        FreeBSD 5.2.1-RELEASE-p9
>Organization:
SIEMENS AG
>Environment:
FreeBSD blnn719x.ww004.siemens.net 5.2.1-RELEASE-p9 FreeBSD 5.2.1-RELEASE-p9 #2: Fri Jul  2 09:50:02 CEST 2004     root at blnn719x.ww004.siemens.net:/usr/obj/usr/src/sys/BLNN719X  i386

>Description:
If I try as an ordinary user to chown(8) a file which is owned by that user, the (FreeBSD-) NFS-Server responds with 'not owner' and refuses the change of ownership.

It works as 'root' if root-access is enabled on that filesystem.
chmod(1) and chgrp(1) are working as expected.

I tested on NFS-Servers with FreeBSD 4.10-STABLE, 5.2.1-RELEASE-p9 and 5.2-CURRENT (of Jul 20, 2004) and HP-UX 11.11 - the HP-UX Server behaves as expected and lets a user change the ownership of his files.

I have libpcap-format networktraces of the SETATTR call&reply available for NFSv2 and NFSv3. Especially with NFSv3 one can see the RPC-credentials (UID) and the unchanged UID of the fileowner in question - they are explicitly the same. The returncode of the SETATTR-call is ERR_PERM(1).

Priority is 'high' because this occurs on two production servers :-(
>How-To-Repeat:
Mount a filesystem from a FreeBSD-Server and try (as a non-root user) to change the ownership of your files,  
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: