From: Jiri Kosina <jikos@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: y0un9n132@gmail.com, Geert Uytterhoeven <geert@linux-m68k.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
Qi Zheng <zhengqi.arch@bytedance.com>,
Alexandre Ghiti <alexghiti@rivosinc.com>,
x86@kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
Eric Biederman <ebiederm@xmission.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Josh Poimboeuf <jpoimboe@kernel.org>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Brian Gerst <brgerst@gmail.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Tony Battersby <tonyb@cybernetics.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH 1/2] x86: Increase brk randomness entropy on x86_64
Date: Mon, 26 Feb 2024 11:39:35 +0100 (CET) [thread overview]
Message-ID: <nycvar.YFH.7.76.2402261138370.21798@cbobk.fhfr.pm> (raw)
In-Reply-To: <20240217062545.1631668-1-keescook@chromium.org>
On Fri, 16 Feb 2024, Kees Cook wrote:
> In commit c1d171a00294 ("x86: randomize brk"), arch_randomize_brk() was
> defined to use a 32MB range (13 bits of entropy), but was never increased
> when moving to 64-bit. The default arch_randomize_brk() uses 32MB for
> 32-bit tasks, and 1GB (18 bits of entropy) for 64-bit tasks. Update
> x86_64 to match the entropy used by arm64 and other 64-bit architectures.
>
> Reported-by: y0un9n132@gmail.com
> Closes: https://lore.kernel.org/linux-hardening/CA+2EKTVLvc8hDZc+2Yhwmus=dzOUG5E4gV7ayCbu0MPJTZzWkw@mail.gmail.com/
> Signed-off-by: Kees Cook <keescook@chromium.org>
Wow, this is a pretty aged code indeed.
Acked-by: Jiri Kosina <jkosina@suse.com>
Thanks,
--
Jiri Kosina
SUSE Labs
next prev parent reply other threads:[~2024-02-26 10:39 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-17 6:25 [PATCH 0/2] Adjust brk randomness Kees Cook
2024-02-17 6:25 ` [PATCH 1/2] x86: Increase brk randomness entropy on x86_64 Kees Cook
2024-02-26 10:39 ` Jiri Kosina [this message]
2024-02-17 6:25 ` [PATCH 2/2] binfmt_elf: Leave a gap between .bss and brk Kees Cook
2024-04-24 19:20 ` (subset) " Kees Cook
2024-02-18 0:25 ` [PATCH 0/2] Adjust brk randomness H. Peter Anvin
2024-02-18 1:25 ` Kees Cook
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=nycvar.YFH.7.76.2402261138370.21798@cbobk.fhfr.pm \
--to=jikos@kernel.org \
--cc=alexghiti@rivosinc.com \
--cc=bhelgaas@google.com \
--cc=bp@alien8.de \
--cc=brauner@kernel.org \
--cc=brgerst@gmail.com \
--cc=christophe.leroy@csgroup.eu \
--cc=dave.hansen@linux.intel.com \
--cc=ebiederm@xmission.com \
--cc=geert@linux-m68k.org \
--cc=hpa@zytor.com \
--cc=jack@suse.cz \
--cc=jpoimboe@kernel.org \
--cc=keescook@chromium.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-hardening@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rick.p.edgecombe@intel.com \
--cc=tglx@linutronix.de \
--cc=tonyb@cybernetics.com \
--cc=viro@zeniv.linux.org.uk \
--cc=x86@kernel.org \
--cc=y0un9n132@gmail.com \
--cc=zhengqi.arch@bytedance.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