From: Andy Lutomirski <luto@kernel.org>
To: Florian Weimer <fweimer@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Linux API <linux-api@vger.kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
linux-x86_64@vger.kernel.org,
linux-arch <linux-arch@vger.kernel.org>,
Kees Cook <keescook@chromium.org>,
Carlos O'Donell <carlos@redhat.com>, X86 ML <x86@kernel.org>
Subject: Re: Detecting the availability of VSYSCALL
Date: Wed, 26 Jun 2019 09:52:15 -0700 [thread overview]
Message-ID: <CALCETrUG9yHf4D_fDEj054Bgo4zXpmK5UzME9mKNqD70U7vy5Q@mail.gmail.com> (raw)
In-Reply-To: <87sgrw1ejv.fsf@oldenburg2.str.redhat.com>
On Wed, Jun 26, 2019 at 9:45 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> * Andy Lutomirski:
>
> > Can’t an ELF note be done with some more or less ordinary asm such
> > that any link editor will insert it correctly?
>
> We've just been over this for the CET enablement. ELF PT_NOTE parsing
> was rejected there.
No one told me this. Unless I missed something, the latest kernel
patches still had PT_NOTE parsing. Can you point me at an
enlightening thread or explain what happened?
> > The problem with a personality flag is that it needs to have some kind
> > of sensible behavior for setuid programs, and getting that right in a
> > way that doesn’t scream “exploit me” while preserving useful
> > compatibility may be tricky.
>
> Are restrictive personality flags still a problem with user namespaces?
> I think it would be fine to restrict this one to CAP_SYS_ADMIN.
We could possibly get away with this, but now we're introducing a
whole new mechanism. I'd rather just add proper per-namespace
sysctls, but this is a pretty big hammer.
next prev parent reply other threads:[~2019-06-26 16:52 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-25 15:15 Detecting the availability of VSYSCALL Florian Weimer
2019-06-25 16:30 ` Thomas Gleixner
2019-06-25 16:38 ` Florian Weimer
2019-06-25 20:11 ` Andy Lutomirski
2019-06-25 20:47 ` Florian Weimer
2019-06-25 21:49 ` Andy Lutomirski
2019-06-26 12:12 ` Florian Weimer
2019-06-26 14:15 ` Andy Lutomirski
2019-06-26 15:00 ` Florian Weimer
2019-06-26 15:21 ` Andy Lutomirski
2019-06-26 15:36 ` Florian Weimer
2019-06-26 16:24 ` Andy Lutomirski
2019-06-26 16:45 ` Florian Weimer
2019-06-26 16:52 ` Andy Lutomirski [this message]
2019-06-26 17:04 ` Florian Weimer
2019-06-26 17:14 ` Andy Lutomirski
2019-06-25 20:08 ` Kees Cook
2019-06-25 20:13 ` Andy Lutomirski
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