Kernel panic when accessing ZFS-Filesystem via NFS

Bjoern A. Zeeb bz at
Wed Jun 3 20:01:09 UTC 2009

On Wed, 3 Jun 2009, Wesley Shields wrote:



> [ The panic message and backtrace from ddb is at
> ]
> cred->cr_prison is null? It is my understanding that when not jailed
> cred->cr_prison should be &prison0 with the new hierarchical jails. The
> fact that it is null is causing prison_priv_check to enter the switch
> statement, leading to the crash.
> I'm not sure why cred->cr_prison is null in this case.

The question here is not if  cred->cr_prison can be null but where is
the cred coming from?

If you look at init_main.c around lines 440 - 457 you'll find prison0
being further initialized (cpuset) and p_ucred->cr_prison being set to
&prsion0. And a bit further down in l470 td_ucred is initialized from
that. cr_prison should thus always be setup.

What you are looking at above looks like a crget() with only
cr_ngroups updated.

[removing a lot more text as I was going on debugging in a very small

I would start looking at svc_getcred() and blame at least the
AUTH_UNIX case;  end of rpc/svc_auth.c.  This looks like a big NO-NO.
I am pretty sure I'd also want to audit svc_rpc_gss(), just in case.


Bjoern A. Zeeb                      The greatest risk is not taking one.

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