linux-kernel - Re: [PATCH] exitz syscall

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHk-=wj1qDhzGRYnfHb-jYHiT_3x+PuA8Zk9FosCzm5OL6e=GQ@mail.gmail.com>
Date:   Sun, 12 Nov 2023 10:50:10 -0800
From:   Linus Torvalds <torvalds@...ux-foundation.org>
To:     "Theodore Ts'o" <tytso@....edu>
Cc:     Jasper Niebuhr <yjnworkstation@...il.com>,
        Willy Tarreau <w@....eu>, akpm@...ux-foundation.org,
        linux-kernel@...r.kernel.org, linux-security-module@...r.kernel.org
Subject: Re: [PATCH] exitz syscall

On Sun, 12 Nov 2023 at 07:44, Theodore Ts'o <tytso@....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