From: David Rientjes <rientjes@google.com>
To: Kees Cook <kees@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>,
Sergio Perez Gonzalez <sperezglz@gmail.com>,
Jonathan Corbet <corbet@lwn.net>, Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Roman Gushchin <roman.gushchin@linux.dev>,
Harry Yoo <harry.yoo@oracle.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Randy Dunlap <rdunlap@infradead.org>,
Tamir Duberstein <tamird@gmail.com>,
Miguel Ojeda <ojeda@kernel.org>,
Alice Ryhl <aliceryhl@google.com>,
linux-doc@vger.kernel.org, linux-mm@kvack.org,
Thomas Huth <thuth@redhat.com>,
"Borislav Petkov (AMD)" <bp@alien8.de>,
Ard Biesheuvel <ardb@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andreas Hindborg <a.hindborg@kernel.org>,
Stephen Boyd <swboyd@chromium.org>,
linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH] slab: Decouple slab_debug and no_hash_pointers
Date: Sun, 13 Apr 2025 16:00:41 -0700 (PDT) [thread overview]
Message-ID: <f381d2f4-f86c-e714-c67a-1d060b8669d5@google.com> (raw)
In-Reply-To: <20250410174428.work.488-kees@kernel.org>
On Thu, 10 Apr 2025, Kees Cook wrote:
> Some system owners use slab_debug=FPZ (or similar) as a hardening option,
> but do not want to be forced into having kernel addresses exposed due
> to the implicit "no_hash_pointers" boot param setting.[1]
>
> Introduce the "hash_pointers" boot param, which defaults to "auto"
> (the current behavior), but also includes "always" (forcing on hashing
> even when "slab_debug=..." is defined), and "never". The existing
> "no_hash_pointers" boot param becomes an alias for "hash_pointers=never".
>
> This makes it possible to boot with "slab_debug=FPZ hash_pointers=always".
>
> Link: https://github.com/KSPP/linux/issues/368 [1]
> Fixes: 792702911f58 ("slub: force on no_hash_pointers when slub_debug is enabled")
> Co-developed-by: Sergio Perez Gonzalez <sperezglz@gmail.com>
> Signed-off-by: Sergio Perez Gonzalez <sperezglz@gmail.com>
> Signed-off-by: Kees Cook <kees@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
next prev parent reply other threads:[~2025-04-13 23:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-10 17:44 [PATCH] slab: Decouple slab_debug and no_hash_pointers Kees Cook
2025-04-11 7:47 ` Vlastimil Babka
2025-04-13 23:00 ` David Rientjes [this message]
2025-04-13 23:57 ` Bagas Sanjaya
2025-04-14 12:31 ` Petr Mladek
2025-04-15 17:00 ` Kees Cook
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