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Date:   Mon, 28 Nov 2022 01:35:23 +0000
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 2/5] efi: stub: use random seed from EFI variable
Message-ID: <20221128013523.GA6780@srcf.ucam.org>
References: <20221122020404.3476063-1-Jason@zx2c4.com>
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 <20221127211244.GB32253@srcf.ucam.org>
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On Mon, Nov 28, 2022 at 02:12:38AM +0100, Jason A. Donenfeld wrote:

> Yea this is a bummer. During my first attempt at this, I actually
> overwrote the whole thing with zeros and then deleted it. But Ard
> pointed out that this doesn't make a difference anyway. But, as it turns
> out, that's more or less the same thing that happens with seed files on
> SSDs (nobody calls fstrim after overwriting a seed file). So at the very
> least, it's no worse?

Anyone with the ability to directly read the flash variable store is 
almost certainly in a position to do worse things, so I wouldn't worry 
about it.