linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: "Theodore Ts'o" <tytso@mit.edu>
Cc: Jasper Niebuhr <yjnworkstation@gmail.com>,
	Willy Tarreau <w@1wt.eu>,
	akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
	linux-security-module@vger.kernel.org
Subject: Re: [PATCH] exitz syscall
Date: Sun, 12 Nov 2023 10:50:10 -0800	[thread overview]
Message-ID: <CAHk-=wj1qDhzGRYnfHb-jYHiT_3x+PuA8Zk9FosCzm5OL6e=GQ@mail.gmail.com> (raw)
In-Reply-To: <20231112154424.GE35991@mit.edu>

On Sun, 12 Nov 2023 at 07:44, Theodore Ts'o <tytso@mit.edu> wrote:
>
> How about adding a flag MLOCK_ZERO_ON_FREE used by the mlock2() system
> call?  The number of pages which an unprivileged process can lock is
> already capped via RLIMIT_MEMLOCK (or else mlock would be it own
> denial of service attack).  That way if process dies from crash, the
> keys would be zero'ed.

Yes, that is a lot better as an interface.

However, it still needs to also make sure that the memory in question
is not file-backed etc. Which the patch I saw didn't seem to do
either.

End result: as it was, that exitz patch was not helping security. It
was anything but.

              Linus

  reply	other threads:[~2023-11-12 18:50 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-11 12:51 [PATCH] exitz syscall York Jasper Niebuhr
2023-11-11 13:24 ` Willy Tarreau
2023-11-12  1:24   ` Linus Torvalds
2023-11-12 10:03     ` Jasper Niebuhr
2023-11-12 15:44       ` Theodore Ts'o
2023-11-12 18:50         ` Linus Torvalds [this message]
2023-11-12 19:03           ` Theodore Ts'o
2023-11-13  0:08     ` Andy Lutomirski
2023-11-12  4:52   ` Theodore Ts'o
2023-11-13  7:37     ` Vlastimil Babka
2023-11-19 14:54       ` Jasper Niebuhr

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAHk-=wj1qDhzGRYnfHb-jYHiT_3x+PuA8Zk9FosCzm5OL6e=GQ@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=tytso@mit.edu \
    --cc=w@1wt.eu \
    --cc=yjnworkstation@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).