From: Paul Moore <paul@paul-moore.com>
To: David Hildenbrand <david@redhat.com>
Cc: Sam James <sam@gentoo.org>,
Michael McCracken <michael.mccracken@gmail.com>,
linux-kernel@vger.kernel.org, serge@hallyn.com,
tycho@tycho.pizza, Luis Chamberlain <mcgrof@kernel.org>,
Kees Cook <keescook@chromium.org>,
Iurii Zaikin <yzaikin@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
kernel-hardening@lists.openwall.com
Subject: Re: [PATCH] sysctl: add config to make randomize_va_space RO
Date: Fri, 5 May 2023 11:23:24 -0400 [thread overview]
Message-ID: <CAHC9VhTX3ohxL0i3vT8sObQ+v+-TOK95+EH1DtJZdyMmrm3A2A@mail.gmail.com> (raw)
In-Reply-To: <c50ac5e4-3f84-c52a-561d-de6530e617d7@redhat.com>
On Fri, May 5, 2023 at 11:15 AM David Hildenbrand <david@redhat.com> wrote:
> On 05.05.23 09:46, Sam James wrote:
> > David Hildenbrand <david@redhat.com> writes:
> >> On 04.05.23 23:30, Michael McCracken wrote:
> >>> Add config RO_RANDMAP_SYSCTL to set the mode of the randomize_va_space
> >>> sysctl to 0444 to disallow all runtime changes. This will prevent
> >>> accidental changing of this value by a root service.
> >>> The config is disabled by default to avoid surprises.
...
> If we really care, not sure what's better: maybe we want to disallow
> disabling it only in a security lockdown kernel?
If we're bringing up the idea of Lockdown, controlling access to
randomize_va_space is possible with the use of LSMs. One could easily
remove write access to randomize_va_space, even for tasks running as
root.
(On my Rawhide system with SELinux enabled)
% ls -Z /proc/sys/kernel/randomize_va_space
system_u:object_r:proc_security_t:s0 /proc/sys/kernel/randomize_va_space
--
paul-moore.com
next prev parent reply other threads:[~2023-05-05 15:23 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-04 21:30 [PATCH] sysctl: add config to make randomize_va_space RO Michael McCracken
2023-05-05 7:35 ` David Hildenbrand
2023-05-05 7:46 ` Sam James
2023-05-05 15:15 ` David Hildenbrand
2023-05-05 15:16 ` David Hildenbrand
2023-05-05 15:23 ` Paul Moore [this message]
2023-05-06 7:04 ` Kaiwan N Billimoria
2023-05-07 19:53 ` Paul Moore
2023-05-15 21:43 ` Serge Hallyn
2023-05-16 20:17 ` Kees Cook
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