From: "Theo de Raadt" <deraadt@openbsd.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>,
Andrew Morton <akpm@linux-foundation.org>,
jeffxu@chromium.org, keescook@chromium.org, jannh@google.com,
sroettger@google.com, gregkh@linuxfoundation.org,
torvalds@linux-foundation.org, usama.anjum@collabora.com,
Liam.Howlett@oracle.com, surenb@google.com, merimus@google.com,
rdunlap@infradead.org, jeffxu@google.com, jorgelo@chromium.org,
groeck@chromium.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, linux-mm@kvack.org,
pedro.falcato@gmail.com, dave.hansen@intel.com,
linux-hardening@vger.kernel.org
Subject: Re: [PATCH v10 0/5] Introduce mseal
Date: Tue, 14 May 2024 16:48:47 -0600 [thread overview]
Message-ID: <56001.1715726927@cvs.openbsd.org> (raw)
In-Reply-To: <ZkPXcT_JuQeZCAv0@casper.infradead.org>
Matthew Wilcox <willy@infradead.org> wrote:
> > Not taking a position on merging, but I have to ask: are we convinced at
> > this point that mseal() isn't a chrome-only system call? Did we ever
> > see the glibc patches that were promised?
>
> I think _this_ version of mseal() is OpenBSD's mimmutable() with a
> basically unused extra 'flags' argument. As such, we have an existance
> proof that it's useful beyond Chrome.
Yes, it is close enough.
> I think Liam still had concerns around the
> walk-the-vmas-twice-to-error-out-early part of the implementation?
> Although we can always fix the implementation later; changing the API
> is hard.
Yes I am a bit worried about the point Liam brings up -- we've discussed
it privately at length. Matthew, to keep it short I have a different
viewpoint:
Some of the Linux m* system calls have non-conforming, partial-work-then-return-error
behaviour. I cannot find anything like this in any system call in any other
operating system, and I believe there is a defacto rule against doing this, and
Linux has an optimization which violating this, and I think it could be fixed
with fairly minor expense, and can't imagine it affecting a single application.
I worry that the non-atomicity will one day be used by an attacker.
next prev parent reply other threads:[~2024-05-14 22:55 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-15 16:35 [PATCH v10 0/5] Introduce mseal jeffxu
2024-04-15 16:35 ` [PATCH v10 1/5] mseal: Wire up mseal syscall jeffxu
2024-04-15 18:12 ` Muhammad Usama Anjum
2024-04-15 18:21 ` Linus Torvalds
2024-04-15 19:06 ` Jeff Xu
2024-04-15 16:35 ` [PATCH v10 2/5] mseal: add " jeffxu
2024-04-16 14:59 ` Liam R. Howlett
2024-04-16 15:17 ` Jann Horn
2024-04-16 16:42 ` Theo de Raadt
2024-04-15 16:35 ` [PATCH v10 3/5] selftest mm/mseal memory sealing jeffxu
2024-04-15 18:32 ` Muhammad Usama Anjum
2024-04-15 20:27 ` Jeff Xu
2024-04-16 0:34 ` Kees Cook
2024-05-02 11:24 ` Ryan Roberts
2024-05-02 15:18 ` Jeff Xu
2024-05-02 22:39 ` Jeff Xu
2024-05-03 8:30 ` Ryan Roberts
2024-04-15 16:35 ` [PATCH v10 4/5] mseal:add documentation jeffxu
2024-04-15 16:35 ` [PATCH v10 5/5] selftest mm/mseal read-only elf memory segment jeffxu
2024-04-16 15:13 ` [PATCH v10 0/5] Introduce mseal Liam R. Howlett
2024-04-16 19:40 ` Jeff Xu
2024-04-18 20:19 ` Suren Baghdasaryan
2024-04-19 1:22 ` Jeff Xu
2024-04-19 14:57 ` Suren Baghdasaryan
2024-04-19 15:14 ` Jeff Xu
2024-04-19 16:54 ` Suren Baghdasaryan
2024-04-19 17:59 ` Pedro Falcato
2024-04-20 1:23 ` Jeff Xu
2024-05-14 17:46 ` Andrew Morton
2024-05-14 19:52 ` Kees Cook
2024-05-23 23:32 ` Kees Cook
2024-05-23 23:54 ` Andrew Morton
2024-05-24 15:19 ` Linus Torvalds
2024-05-14 20:59 ` Jonathan Corbet
2024-05-14 21:28 ` Matthew Wilcox
2024-05-14 22:48 ` Theo de Raadt [this message]
2024-05-14 23:01 ` Andrew Morton
2024-05-14 23:47 ` Theo de Raadt
2024-05-15 2:58 ` Willy Tarreau
2024-05-15 3:36 ` Linus Torvalds
2024-05-15 4:14 ` Linus Torvalds
2024-05-15 6:14 ` Willy Tarreau
2024-05-15 0:43 ` Linus Torvalds
2024-05-15 0:57 ` Theo de Raadt
2024-05-15 1:20 ` Linus Torvalds
2024-05-15 1:47 ` Theo de Raadt
2024-05-15 2:28 ` Linus Torvalds
2024-05-15 2:42 ` Theo de Raadt
2024-05-15 4:53 ` Liam R. Howlett
2024-05-14 21:28 ` Liam R. Howlett
2024-05-15 17:18 ` Jeff Xu
2024-05-15 22:19 ` Liam R. Howlett
2024-05-16 0:59 ` Jeff Xu
2024-05-21 16:00 ` Liam R. Howlett
2024-05-21 20:55 ` Jeff Xu
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