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linux-kernel: Re: [PATCH] CRED: Fix check_unsafe_exec()

Re: [PATCH] CRED: Fix check_unsafe_exec()

From: Joe Malicki <jmalicki_at_nospam>
Date: Tue Mar 17 2009 - 23:07:42 GMT
To: Hugh Dickins <hugh@veritas.com>

  • "Joe Malicki" <jmalicki@metacarta.com> wrote:

> ----- "Hugh Dickins" <hugh@veritas.com> wrote:
>
> > On Thu, 12 Mar 2009, David Howells wrote:
> > > Hugh Dickins <hugh@veritas.com> wrote:
> > >
> > > > We do. See the original thread. It's here at
> > > > http://lkml.org/lkml/2009/2/26/233
> > > > and appended below for convenience. We do know that patch did
> > not
> > > > fix Joe's problem, and we don't yet know whether addressing the
> > > > files->count issue will actually fix it, but I'm hopeful.
> > >
> > > Looks reasonable.
> >
> > Thanks for taking a look.
> >
> > Yes, I'm inclined to go with that, and removing the files->count
> > check from exec.c. Joe, did you manage to try your testing with
> > my original patch plus that files->count check removed from 2.6.28's
> > unsafe_exec()?
>
> Sorry for not responding earlier.
>
> I still got one failure with this new patch. I added some printks
> to illuminate exactly why it's failing when it fails to setuid, but
> of course, since adding the printks I haven't reproduced yet.
>

My tests were accidentally run without removing the files->count check.

The printks confirmed the failure case was the files->count check, and removing the files->check has worked thus far (though I can't be sure until after a day or two has gone by given how infrequent it is).

Thanks!
Joe -- To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html