Re: 2.6.13-rc6-mm1

Reuben Farrelly
2005-08-21T06:25:25Z

Hi,

On 21/08/2005 1:40 a.m., David Woodhouse wrote:
> On Fri, 2005-08-19 at 18:36 -0700, Andrew Morton wrote:
>> Reuben Farrelly <reuben-lkml@reub.net> wrote:
>>> ...
>>>>> 4. PAM is complaining about "PAM audit_open() failed: Protocol not suppor
>>>>> ted" and I can't log in as any user including root. I would have picked this
>>>>> was a userspace problem, but it doesn't break with -rc5-mm1, yet reproduceably
>>>>> breaks with -rc6-mm1. Weird.
>>>> hm. How come you're able to use the machine then?
>>> Machine was booting up ok, and things were being written to syslog. Rebooted
>>> into -rc5-mm1 to investigate, and of course could boot into rc6-mm1 in single
>>> user mode, test and bring services up one by one from there. Having two boxes
>>> helped too.
>>>
>>>> Is it possible to get an strace of this failure somehow?
>>> Not sure if this is needed anymore, as I found that the problem goes away when
>>> I compile in kernel auditing. This not required for -rc5-mm1. Is that change
>>> intended?
>>>
>> Sounds wrong to me, especially if 2.6.13-rc6 doesn't do that.
>
> Hm. It sounds like you'd configured PAM to require the pam_loginuid
> module even though you didn't have auditing enabled in your kernel. That
> seems strange and wrong to me, and _is_ a userspace problem.

I haven't touched my pam config since it was installed a long time ago - it's
one of those things that is too annoying to fix once broked, so I leave it
alone at the system defaults ;)

I had logged this as a Fedora bug as I figured the pam_loginuid
detection of the presence of auditing in the kernel is not very robust. There
was a patch modified in pam-0.80-6 at the start of August which was to fix
this on non audit enabled kernels, which works for anything up to and older
than 2.6.12-rc5-mm1.

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=166422

It was closed 8 mins later, and the suggestion made that I take it to a pam
development list instead. Redhat don't seem so interested in fixing things as
a result of breakage when running an -mm kernel.

> I'd also agree that it shouldn't have changed with the new kernel though
> -- and I can't think of anything I changed recently which would have
> that effect. An strace would still be useful.

Done. Posted up at http://www.reub.net/kernel/strace-login

> Can you double-check that you didn't have auditing enabled in your
> older, working kernel?

Definitely wasn't enabled. I still have the .config that I used to build
-rc5-mm1 with and my original -rc6-mm1 and it reads:

CONFIG_SYSCTL=y
# CONFIG_AUDIT is not set
CONFIG_HOTPLUG=y

Thanks for taking a look.

Reuben