From: Lennart Poettering <lennart@poettering.net>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: linux-efi@vger.kernel.org, linux-crypto@vger.kernel.org,
Ard Biesheuvel <ardb@kernel.org>
Subject: Re: [PATCH RFC v1 0/6] Use EFI variables for random seed
Date: Wed, 16 Nov 2022 18:59:38 +0100 [thread overview]
Message-ID: <Y3UlCjbhXwZG0dEH@gardel-login> (raw)
In-Reply-To: <20221116161642.1670235-1-Jason@zx2c4.com>
On Mi, 16.11.22 17:16, Jason A. Donenfeld (Jason@zx2c4.com) wrote:
> Commit messages are rather sparse at the moment. I'll fill those out for
> the next non-RFC patchset if this idea isn't immediately demolished.
>
> The biggest consideration is wear leveling on the EFI variable flash
> chips. However, EFI *already* winds up writing to non-volatile memory on
> every single boot anyway, so maybe it's not actually a big deal?
So as mentioned elsewhere: This might (probably more than) double the
wear on the flash chips, since firmware is unlikely to batch these
writes with the monotonic counter write.
I have no idea how realistic these issues are, there's a lot of
handwaving involved, but to sidestep the issue I put sd-boot's seed in
a file on disk (which should not have issues that much with wear)
instead of efi vars.
Lennart
next prev parent reply other threads:[~2022-11-16 18:08 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-16 16:16 [PATCH RFC v1 0/6] Use EFI variables for random seed Jason A. Donenfeld
2022-11-16 16:16 ` [PATCH RFC v1 1/6] random: add back async readiness notifier Jason A. Donenfeld
2022-11-19 12:37 ` [lkp] [+84 bytes kernel size regression] [i386-tinyconfig] [538cb30493] " kernel test robot
2022-11-16 16:16 ` [PATCH RFC v1 2/6] vsprintf: initialize siphash key using notifier Jason A. Donenfeld
2022-11-18 14:16 ` Petr Mladek
2022-11-18 14:20 ` Jason A. Donenfeld
2022-11-16 16:16 ` [PATCH RFC v1 3/6] efi: random: combine bootloader provided RNG seed with RNG protocol output Jason A. Donenfeld
2022-11-16 16:16 ` [PATCH RFC v1 4/6] efi: stub: use random seed from EFI variable Jason A. Donenfeld
2022-11-16 16:16 ` [PATCH RFC v1 5/6] efi: efivarfs: prohibit reading random seed variables Jason A. Donenfeld
2022-11-16 17:04 ` Ard Biesheuvel
2022-11-16 18:56 ` Jason A. Donenfeld
2022-11-16 19:42 ` James Bottomley
2022-11-16 20:08 ` Jason A. Donenfeld
2022-11-27 21:36 ` James Bottomley
2022-11-16 16:16 ` [PATCH RFC v1 6/6] efi: refresh non-volatile random seed when RNG is initialized Jason A. Donenfeld
2022-11-16 17:59 ` Lennart Poettering [this message]
2022-11-16 18:57 ` [PATCH RFC v1 0/6] Use EFI variables for random seed Jason A. Donenfeld
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