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From:   Luca Boccassi <bluca@debian.org>
Date:   Thu, 8 Dec 2022 20:42:56 +0000
Message-ID: <CAMw=ZnQUmeOWQkMM9Kn5iYaT4dyDQ3j1K=dUgk9jFNcHPxxHrg@mail.gmail.com>
Subject: Re: [PATCH] fsverity: don't check builtin signatures when require_signatures=0
To:     Eric Biggers <ebiggers@kernel.org>
Cc:     linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net,
        linux-btrfs@vger.kernel.org, linux-integrity@vger.kernel.org,
        stable@vger.kernel.org
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On Thu, 8 Dec 2022 at 03:35, Eric Biggers <ebiggers@kernel.org> wrote:
>
> From: Eric Biggers <ebiggers@google.com>
>
> An issue that arises when migrating from builtin signatures to userspace
> signatures is that existing files that have builtin signatures cannot be
> opened unless either CONFIG_FS_VERITY_BUILTIN_SIGNATURES is disabled or
> the signing certificate is left in the .fs-verity keyring.
>
> Since builtin signatures provide no security benefit when
> fs.verity.require_signatures=0 anyway, let's just skip the signature
> verification in this case.
>
> Fixes: 432434c9f8e1 ("fs-verity: support builtin file signatures")
> Cc: <stable@vger.kernel.org> # v5.4+
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  fs/verity/signature.c | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)

Acked-by: Luca Boccassi <bluca@debian.org>