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From:   Paul Moore <paul@paul-moore.com>
Date:   Fri, 20 Jan 2023 15:16:28 -0500
Message-ID: <CAHC9VhSfr2Re6ZV6_USdvw__c1ou87uM6K_MF1wm-ENdEY7X5Q@mail.gmail.com>
Subject: Re: [PATCH] public_key: Add a comment to public_key_signature struct definition
To:     Eric Biggers <ebiggers@kernel.org>
Cc:     Roberto Sassu <roberto.sassu@huaweicloud.com>, dhowells@redhat.com,
        herbert@gondor.apana.org.au, davem@davemloft.net,
        zohar@linux.ibm.com, dmitry.kasatkin@gmail.com, jmorris@namei.org,
        serge@hallyn.com, keyrings@vger.kernel.org,
        linux-crypto@vger.kernel.org, linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Roberto Sassu <roberto.sassu@huawei.com>
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On Fri, Jan 20, 2023 at 2:43 PM Eric Biggers <ebiggers@kernel.org> wrote:
> On Fri, Jan 20, 2023 at 02:21:04PM -0500, Paul Moore wrote:
> > On Wed, Dec 7, 2022 at 5:55 AM Roberto Sassu
> > <roberto.sassu@huaweicloud.com> wrote:
> > >
> > > From: Roberto Sassu <roberto.sassu@huawei.com>
> > >
> > > public_key_verify_signature() calls sg_set_buf() to set the signature and
> > > digest for the signature verification.
> > >
> > > As sg_set_buf() requires the buffer to be in physically contiguous memory,
> > > see commit ac4e97abce9b8 ("scatterlist: sg_set_buf() argument must be in
> > > linear mapping"), mention that in a comment for the signature and digest
> > > fields of the public_key_signature structure.
> > >
> > > Link: https://lore.kernel.org/linux-integrity/Y4pIpxbjBdajymBJ@sol.localdomain/
> > > Suggested-by: Eric Biggers <ebiggers@kernel.org>
> > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> > > ---
> > >  include/crypto/public_key.h | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > This seems especially important considering the BUG_ON that could be triggered.
> >
> > David, are you going to pick this up?
> >
> > Reviewed-by: Paul Moore <paul@paul-moore.com>
> >
> > > diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
> > > index 68f7aa2a7e55..6d623e063034 100644
> > > --- a/include/crypto/public_key.h
> > > +++ b/include/crypto/public_key.h
> > > @@ -37,8 +37,8 @@ extern void public_key_free(struct public_key *key);
> > >   */
> > >  struct public_key_signature {
> > >         struct asymmetric_key_id *auth_ids[3];
> > > -       u8 *s;                  /* Signature */
> > > -       u8 *digest;
> > > +       u8 *s;                  /* Signature (in physically contiguous mem) */
> > > +       u8 *digest;             /* Digest (in physically contiguous mem) */
> > >         u32 s_size;             /* Number of bytes in signature */
> > >         u32 digest_size;        /* Number of bytes in digest */
> > >         const char *pkey_algo;
> > > --
> > > 2.25.1
>
> This patch has been superseded by
> "KEYS: asymmetric: Copy sig and digest in public_key_verify_signature()"
> (https://lore.kernel.org/r/20221227142740.2807136-1-roberto.sassu@huaweicloud.com).

Well nevermind then :)

-- 
paul-moore.com