From: Jarkko Sakkinen <jarkko@kernel.org>
To: Eric Biggers <ebiggers@kernel.org>
Cc: Hannes Reinecke <hare@suse.de>,
David Howells <dhowells@redhat.com>,
bpf@vger.kernel.org, dm-devel@lists.linux.dev,
fsverity@lists.linux.dev, keyrings@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org,
linux-security-module@vger.kernel.org,
Alasdair Kergon <agk@redhat.com>,
Alexei Starovoitov <ast@kernel.org>, Alex Shi <alexs@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Andrii Nakryiko <andrii@kernel.org>,
Benjamin Marzinski <bmarzins@redhat.com>,
Daniel Borkmann <daniel@iogearbox.net>,
Dongliang Mu <dzm91@hust.edu.cn>,
Eduard Zingerman <eddyz87@gmail.com>,
Emil Tsalapatis <emil@etsalapatis.com>,
Ihor Solodrai <ihor.solodrai@linux.dev>,
James Morris <jmorris@namei.org>, Jiri Olsa <jolsa@kernel.org>,
Jonathan Corbet <corbet@lwn.net>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Martin KaFai Lau <martin.lau@linux.dev>,
Mike Snitzer <snitzer@kernel.org>,
Mikulas Patocka <mpatocka@redhat.com>,
Paul Moore <paul@paul-moore.com>,
Randy Dunlap <rdunlap@infradead.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Shuah Khan <skhan@linuxfoundation.org>,
Song Liu <song@kernel.org>, "Theodore Y. Ts'o" <tytso@mit.edu>,
Yanteng Si <si.yanteng@linux.dev>,
Yonghong Song <yonghong.song@linux.dev>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH v5 2/3] KEYS: Replace assoc_array with rhashtable
Date: Fri, 6 Nov 2026 21:41:21 +0200 [thread overview]
Message-ID: <au4tYR8ZgTLVDWHv@kernel.org> (raw)
In-Reply-To: <au4q4Wh7PK1-Ge9P@kernel.org>
On Fri, Nov 06, 2026 at 09:30:45PM +0200, Jarkko Sakkinen wrote:
> > SipHash is also useful for resistance against denial-of-service attacks,
> > where a user puts all their keys in one hash bucket.
> >
> > As I mentioned, it's already used for secure hash tables elsewhere in
> > the kernel. That is what it's for; see
> > Documentation/security/siphash.rst. It's very fast as well, so if you
> > are thinking of cryptography as being something very slow and hard to
> > use, that is not what this is (or ever needed to be).
> >
> > Let's just use it and not over-complicate things.
>
> I'm pretty much non-opionated when it comes to this detail. I just
> merely represent all the possible if anything comes up to mind. DoS
> protection that you explained was not something I did even consider so
> that seals it for me.
I'm cutting hairs now but indices + siphash adds to defence in depth as
it only takes DoS protection from SipHash while not protecting a secret.
Not sure if this has that much pratical meaning tho :-)
Br, Jarkko
next prev parent reply other threads:[~2026-11-06 19:41 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-05 3:13 [PATCH v5 0/3] " Jarkko Sakkinen
2026-11-05 3:13 ` [PATCH v5 1/3] KEYS: Introduce keyring_is_empty() Jarkko Sakkinen
2026-11-05 3:14 ` [PATCH v5 2/3] KEYS: Replace assoc_array with rhashtable Jarkko Sakkinen
2026-11-06 8:21 ` Hannes Reinecke
2026-11-06 9:05 ` Eric Biggers
2026-11-06 13:02 ` Hannes Reinecke
2026-11-06 19:05 ` Jarkko Sakkinen
2026-11-06 19:19 ` Eric Biggers
2026-11-06 19:30 ` Jarkko Sakkinen
2026-11-06 19:41 ` Jarkko Sakkinen [this message]
2026-11-06 15:08 ` Jarkko Sakkinen
2026-11-05 3:14 ` [PATCH v5 3/3] lib: Remove assoc_array Jarkko Sakkinen
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