Re: Patch proposal for id.c and groups.c to fix afs bug

[Didi]

Hey

Just so we don't talk past each other. The problem is that there could
be a case where the 'id' or 'group' commands are called but there is
no user name, neither on the command line nore in the system
(getlogin() == NULL).

The case when an invalid user is given on the commandline is cought by
 202       if (pwd == NULL)
 203         error (EXIT_FAILURE, 0, _("%s: No such user"), argv[optind]);

So I am assuming that getlogin in combination with getpwnam is the problem. ?!?
Knowing that there must always be a uid we can chage the line :

pwdg = getpwnam (getlogin());
to :
pwdg = getpwuid (geteuid());

I should have know this :) Sorry for the hassle.

Cheers

Didi

On Mon, Mar 3, 2008 at 9:35 PM, Jim Meyering <address@hidden> wrote:
> Didi <address@hidden> wrote:
>  > Sorry for any violation of any mailing list rules, this is my first
>  > patch to coreutils.
>
>  Hello!
>
>  No violation ;-)
>  Thanks for the report and patch.
>
>
>  > On some systems, with AFS, if you call 'id' or 'groups' without a user
>  > name parameter it will return a huge group number:
>  > $ id -G
>  > 500 1103556127
>  >
>  > The same behavior applies to groups:
>  > $ groups
>  > ribalba id: cannot find name for group ID 1103556127
>  > 1103556127
>  >
>  > Because of this I propose following patch :
>
>  Unfortunately, we can't use that approach, since
>  both id and groups have to work even when there isn't
>  a user or group name (i.e., when getlogin returns NULL).
>
>  Maybe you can find a way to distinguish (at run time)
>  between the regular no-user-or-group-name case and your
>  AFS nameless-huge-ID case.
>
>  ...
>
>
> > The behavior is due to AFS creating a pseudo group in the kernel that
>  > does not have a name.
>  >
>  >
>  > Some information to the system I am using:
>  > Linux mypc 2.6.9-67.0.4.EL.cernsmp #1 SMP Mon Feb 4 10:15:50 CET 2008
>  > x86_64 x86_64 x86_64 GNU/Linux
>

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