From: Linus Torvalds <torvalds@linux-foundation.org>
To: Willy Tarreau <w@1wt.eu>
Cc: Theo de Raadt <deraadt@openbsd.org>,
Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Jonathan Corbet <corbet@lwn.net>,
jeffxu@chromium.org, keescook@chromium.org, jannh@google.com,
sroettger@google.com, gregkh@linuxfoundation.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 21:14:37 -0700 [thread overview]
Message-ID: <CAHk-=wh_GHCwCiC-ZR=idjNEb0xZq20=fQnQxnjGkiq-ba5DLg@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wiW4V5HRQ5Jm_MnSMVTeivS_4kdm1dnc08d03UKzmyp+A@mail.gmail.com>
On Tue, 14 May 2024 at 20:36, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> Guys, if you let untrusted code execute random system calls, the whole
> "look, now unmap() acts oddly" IS THE LEAST OF YOUR ISSUES.
Side note: it doesn't even help to make things "atomic". munmap() acts
oddly whether it fals completely or whether it fails partially, and if
the user doesn't check the result, neither case is great.
If you want to have some "hardened mseal()", you make any attempt to
change a mseal'ed memory area be a fatal error. The whole "atomic or
not" is a complete red herring.
I'd certainly be ok with that. If the point of mseal is "you can't
change this mapping", then anybody who tries to change it is obviously
untrustworthy, and killing the whole thing sounds perfectly sane to
me.
Maybe that's a first valid use-case for the flags argument.
Linus
next prev parent reply other threads:[~2024-05-15 4:15 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-15 16:35 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
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 [this message]
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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