From: Matthew Garrett <mjg59@srcf.ucam.org>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: linux-efi@vger.kernel.org, linux-crypto@vger.kernel.org,
patches@lists.linux.dev, linux-kernel@vger.kernel.org,
ardb@kernel.org
Subject: Re: [PATCH v3 1/5] efi: vars: prohibit reading random seed variables
Date: Sun, 27 Nov 2022 21:00:40 +0000 [thread overview]
Message-ID: <20221127210040.GA32253@srcf.ucam.org> (raw)
In-Reply-To: <20221122020404.3476063-2-Jason@zx2c4.com>
On Tue, Nov 22, 2022 at 03:04:00AM +0100, Jason A. Donenfeld wrote:
> In anticipation of putting random seeds in EFI variables, it's important
> that the random GUID namespace of variables remains hidden from
> userspace. We accomplish this by not populating efivarfs with entries
> from that GUID, as well as denying the creation of new ones in that
> GUID.
What's the concern here? Booting an older kernel would allow a malicious
actor to either read the seed variable or set it to a value under their
control, so we can't guarantee that the information is secret.
next prev parent reply other threads:[~2022-11-27 21:08 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-22 2:03 [PATCH v3 0/5] Use EFI variables for random seed Jason A. Donenfeld
2022-11-22 2:04 ` [PATCH v3 1/5] efi: vars: prohibit reading random seed variables Jason A. Donenfeld
2022-11-27 21:00 ` Matthew Garrett [this message]
2022-11-28 1:10 ` Jason A. Donenfeld
2022-11-22 2:04 ` [PATCH v3 2/5] efi: stub: use random seed from EFI variable Jason A. Donenfeld
2022-11-27 21:12 ` Matthew Garrett
2022-11-28 1:12 ` Jason A. Donenfeld
2022-11-28 1:35 ` Matthew Garrett
2022-11-22 2:04 ` [PATCH v3 3/5] random: add back async readiness notifier Jason A. Donenfeld
2022-11-22 2:04 ` [PATCH v3 4/5] vsprintf: initialize siphash key using notifier Jason A. Donenfeld
2022-11-22 2:04 ` [PATCH v3 5/5] efi: random: refresh non-volatile random seed when RNG is initialized Jason A. Donenfeld
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