Bug 13108

Summary: authunix_create_default includes egid twice
Product: Base System Reporter: David Mazieres <dm>
Component: binAssignee: freebsd-bugs (Nobody) <bugs>
Status: Closed FIXED    
Severity: Affects Only Me CC: brooks, delphij
Priority: Normal    
Version: 3.0-RELEASE   
Hardware: Any   
OS: Any   
Attachments:
Description Flags
file.diff none

Description David Mazieres 1999-08-12 16:00:00 UTC 
authunix_create_default includes the effictive group ID in the
grouplist (as well as the gid field).  This is inconsistent with
almost all other operating systems, and also inconsistent with the
FreeBSD kernel.

For instance, in nfs_subs.c, the kernel avoids putting
cr->cr_groups[0] in the grouplist, because it has already placed
it in the gid field of the marshalled authunix structure.

   714                  for (i = 1; i <= grpsiz; i++)
   715                          *tl++ = txdr_unsigned(cr->cr_groups[i]);

Fix: The fix is to change authunix_create_default to compensate for the
fact that FreeBSD keeps the effective group ID in the first element
of a processes grouplist (unlike the operating systems for which the
code was originally written).  A simple patch is appended.

Alternatively, you could change the kernel to behave like
authunix_create_default.

The current behavior of having the kernel and libc generate
different authunix structures is quite annoying.  (In particular,
it makes it virtually impossible to "autoconf" RPC behavior in
supposedly portable software).
Comment 1 Johan Karlsson freebsd_committer freebsd_triage 2002-10-28 21:29:08 UTC 
State Changed
From-To: open->closed

The code in question was removed in rev 1.13 of  
src/lib/libc/rpc/auth_unix.c 

If there is a problem with the new code please 
open a new PR.
Comment 2 Johan Karlsson freebsd_committer freebsd_triage 2002-10-29 11:43:08 UTC 
Adding this to the audit-trail.

----- Forwarded message from David Mazieres <dm@scs.cs.nyu.edu> -----

From: David Mazieres <dm@scs.cs.nyu.edu>
To: johan@FreeBSD.org
Cc: freebsd-bugs@FreeBSD.org
Subject: Re: bin/13108: authunix_create_default includes egid twice
Date: Mon, 28 Oct 2002 17:21:44 -0500 (EST)

> Date: Mon, 28 Oct 2002 13:31:29 -0800 (PST)
> From: Johan Karlsson <johan@FreeBSD.org>
> 
> Synopsis: authunix_create_default includes egid twice
> 
> State-Changed-From-To: open->closed
> State-Changed-By: johan
> State-Changed-When: Mon Oct 28 13:29:08 PST 2002
> State-Changed-Why: 
> 	The code in question was removed in rev 1.13 of 
> 	src/lib/libc/rpc/auth_unix.c
> 
> 	If there is a problem with the new code please
> 	open a new PR.
> 
> http://www.freebsd.org/cgi/query-pr.cgi?pr=13108

The new code seems to have the same problem.  The new version of
authunix_create_default() is:

        if ((len = getgroups(NGRPS, gids)) < 0)
                abort();
        /* XXX: interface problem; those should all have been unsigned */
        return (authunix_create(machname, (int)uid, (int)gid, len,
            (int *)gids));

I think this code should be:

        if ((len = getgroups(NGRPS, gids)) < 1)
                abort();
        /* XXX: interface problem; those should all have been unsigned */
        return (authunix_create(machname, (int)uid, (int)gid, len-1,
            (int *)gids + 1));

Either that, or you should change nfsm_rpchead in
nfsclient/nfs_subs.C.

Currently, the fact that authunix_create_default and the kernel create
different AUTHUNIX credentials is a pain for SFS (a FreeBSD-compatible
network file system that I work on--see www.fs.net).  I realize that
my needs are somewhat esoteric.  I certainly don't expect you to put
in a change just because it is good for SFS.  However, just on simple
aesthetic grounds, doesn't it make sense for the kernel and libc to be
consistent with each other?  Can't FreeBSD just decide if the AUTHUNIX
parms should contain a second copy of the egid in the grouplist, and
then have both libc and the kernel do the same thing?

Of course, at this point, if you were to change the kernel, it would
make things even worse for me, because right now there is no way of
autoconfing FreeBSD's behavior.  I have hard-coded the current kernel
behavior into SFS if the OS name is FreeBSD.

Thanks,
David

----- End forwarded message -----

-- 
Johan Karlsson		mailto:johan@FreeBSD.org
Comment 3 Johan Karlsson freebsd_committer freebsd_triage 2002-10-29 11:50:44 UTC 
State Changed
From-To: closed->open

Apparently this is still a problem.
Comment 4 Eitan Adler freebsd_committer freebsd_triage 2017-12-31 07:59:23 UTC 
For bugs matching the following criteria:

Status: In Progress Changed: (is less than) 2014-06-01

Reset to default assignee and clear in-progress tags.

Mail being skipped
Comment 5 Xin LI freebsd_committer freebsd_triage 2022-12-04 21:42:27 UTC 
This appears to be fixed by r194494.