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References: <20220411180006.4187548-1-jackyli@google.com>
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From:   Peter Gonda <pgonda@google.com>
Date:   Wed, 13 Apr 2022 09:40:12 -0600
Message-ID: <CAMkAt6rzVmi6iFM_phsCEtb1c-r2PYL9SYwSGX6JqWARnDWgWw@mail.gmail.com>
Subject: Re: [PATCH] crypto: ccp - Fix the INIT_EX data file open failure
To:     Jacky Li <jackyli@google.com>
Cc:     Brijesh Singh <brijesh.singh@amd.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        John Allen <john.allen@amd.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Marc Orr <marcorr@google.com>, Alper Gun <alpergun@google.com>,
        Linux Crypto Mailing List <linux-crypto@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Mon, Apr 11, 2022 at 12:00 PM Jacky Li <jackyli@google.com> wrote:
>
> There are 2 common cases when INIT_EX data file might not be
> opened successfully and fail the sev initialization:
>
> 1. In user namespaces, normal user tasks (e.g. VMM) can change their
>    current->fs->root to point to arbitrary directories. While
>    init_ex_path is provided as a module param related to root file
>    system. Solution: use the root directory of init_task to avoid
>    accessing the wrong file.
>
> 2. Normal user tasks (e.g. VMM) don't have the privilege to access
>    the INIT_EX data file. Solution: open the file as root and
>    restore permissions immediately.
>
> Signed-off-by: Jacky Li <jackyli@google.com>

Reviewed-by: Peter Gonda <pgonda@google.com>

Agreed about the fixes tag.