From: Andrea Arcangeli <aarcange@redhat.com>
To: Lokesh Gidra <lokeshgidra@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>,
Kees Cook <keescook@chromium.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Daniel Colascione <dancol@google.com>,
Jonathan Corbet <corbet@lwn.net>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Luis Chamberlain <mcgrof@kernel.org>,
Iurii Zaikin <yzaikin@google.com>,
Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andy.shevchenko@gmail.com>,
Vlastimil Babka <vbabka@suse.cz>,
Mel Gorman <mgorman@techsingularity.net>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Peter Xu <peterx@redhat.com>, Mike Rapoport <rppt@linux.ibm.com>,
Jerome Glisse <jglisse@redhat.com>, Shaohua Li <shli@fb.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org, Tim Murray <timmurray@google.com>,
Minchan Kim <minchan@google.com>,
Sandeep Patil <sspatil@google.com>,
kernel@android.com
Subject: Re: [PATCH 2/2] Add a new sysctl knob: unprivileged_userfaultfd_user_mode_only
Date: Wed, 20 May 2020 17:16:34 -0400 [thread overview]
Message-ID: <20200520211634.GL26186@redhat.com> (raw)
In-Reply-To: <CA+EESO4wEQz3CMxNLh8mQmTpUHdO+zZbV10zUfYGKEwfRPK2nQ@mail.gmail.com>
On Wed, May 20, 2020 at 01:17:20PM -0700, Lokesh Gidra wrote:
> Adding the Android kernel team in the discussion.
Unless I'm mistaken that you can already enforce bit 1 of the second
parameter of the userfaultfd syscall to be set with seccomp-bpf, this
would be more a question to the Android userland team.
The question would be: does it ever happen that a seccomp filter isn't
already applied to unprivileged software running without
SYS_CAP_PTRACE capability?
If answer is "no" the behavior of the new sysctl in patch 2/2 (in
subject) should be enforceable with minor changes to the BPF
assembly. Otherwise it'd require more changes.
Thanks!
Andrea
next prev parent reply other threads:[~2020-05-20 21:16 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 0:26 [PATCH 0/2] Control over userfaultfd kernel-fault handling Daniel Colascione
2020-04-23 0:26 ` [PATCH 1/2] Add UFFD_USER_MODE_ONLY Daniel Colascione
2020-07-24 14:28 ` Michael S. Tsirkin
2020-07-24 14:46 ` Lokesh Gidra
2020-07-26 10:09 ` Michael S. Tsirkin
2020-04-23 0:26 ` [PATCH 2/2] Add a new sysctl knob: unprivileged_userfaultfd_user_mode_only Daniel Colascione
2020-05-06 19:38 ` Peter Xu
2020-05-07 19:15 ` Jonathan Corbet
2020-05-20 4:06 ` Andrea Arcangeli
2020-05-08 16:52 ` Michael S. Tsirkin
2020-05-08 16:54 ` Michael S. Tsirkin
2020-05-20 4:59 ` Andrea Arcangeli
2020-05-20 18:03 ` Kees Cook
2020-05-20 19:48 ` Andrea Arcangeli
2020-05-20 19:51 ` Andrea Arcangeli
2020-05-20 20:17 ` Lokesh Gidra
2020-05-20 21:16 ` Andrea Arcangeli [this message]
2020-07-17 12:57 ` Jeffrey Vander Stoep
2020-07-23 17:30 ` Lokesh Gidra
2020-07-24 0:13 ` Nick Kralevich
2020-07-24 13:40 ` Michael S. Tsirkin
2020-08-06 0:43 ` Nick Kralevich
2020-08-06 5:44 ` Michael S. Tsirkin
2020-08-17 22:11 ` Lokesh Gidra
2020-09-04 3:34 ` Andrea Arcangeli
2020-09-05 0:36 ` Lokesh Gidra
2020-09-19 18:14 ` Nick Kralevich
2020-07-24 14:01 ` [PATCH 0/2] Control over userfaultfd kernel-fault handling Michael S. Tsirkin
2020-07-24 14:41 ` Lokesh Gidra
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