From: "Jarkko Sakkinen" <jarkko@kernel.org>
To: "Serge E. Hallyn" <serge@hallyn.com>
Cc: <linux-integrity@vger.kernel.org>,
"James Bottomley" <jejb@linux.ibm.com>,
"Mimi Zohar" <zohar@linux.ibm.com>,
"David Howells" <dhowells@redhat.com>,
"Paul Moore" <paul@paul-moore.com>,
"James Morris" <jmorris@namei.org>
Subject: Re: [PATCH v5 8/8] KEYS: trusted: tpm2: Use struct tpm_buf for sized buffers
Date: Mon, 04 Dec 2023 06:03:11 +0200 [thread overview]
Message-ID: <CXF91MI4A4C3.PIVZWW1SENCZ@suppilovahvero> (raw)
In-Reply-To: <20231128034802.GA33794@mail.hallyn.com>
On Tue Nov 28, 2023 at 5:48 AM EET, Serge E. Hallyn wrote:
> On Wed, Nov 22, 2023 at 12:31:20AM +0200, Jarkko Sakkinen wrote:
> > Take advantage of the new sized buffer (TPM2B) mode of struct tpm_buf in
> > tpm2_seal_trusted(). This allows to add robustness to the command
> > construction without requiring to calculate buffer sizes manually.
> >
> > Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
> > ---
> > v3 [2023-11-21]: A boundary error check as response for the feeedback
> > from Mario Limenciello:
> > https://lore.kernel.org/linux-integrity/3f9086f6-935f-48a7-889b-c71398422fa1@amd.com/
> > v2: Use tpm_buf_read_*
> > ---
> > security/keys/trusted-keys/trusted_tpm2.c | 54 +++++++++++++----------
> > 1 file changed, 31 insertions(+), 23 deletions(-)
> >
> > diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
> > index bc700f85f80b..97b1dfca2dba 100644
> > --- a/security/keys/trusted-keys/trusted_tpm2.c
> > +++ b/security/keys/trusted-keys/trusted_tpm2.c
> > @@ -228,8 +228,9 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> > struct trusted_key_payload *payload,
> > struct trusted_key_options *options)
> > {
> > + off_t offset = TPM_HEADER_SIZE;
> > + struct tpm_buf buf, sized;
> > int blob_len = 0;
> > - struct tpm_buf buf;
> > u32 hash;
> > u32 flags;
> > int i;
> > @@ -258,6 +259,14 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
> > return rc;
> > }
> >
> > + rc = tpm_buf_init_sized(&sized);
> > + if (rc) {
> > + tpm_buf_destroy(&buf);
>
> It won't really hurt, but at the moment if tpm_buf_init_sized() returns
> non-zero, then it must be returning -ENOMEM, and tpm_buf_destroy(&buf)
> is not needed, right?
It should cause corrateral damage since the rollback emits only
free_page(buf->data) and it will become NULL in the case when
tpm_buf_init_sized(). Despite that this behaviour is illegit and
the call should be removed. Thanks for the remark!
BR, Jarkko
next prev parent reply other threads:[~2023-12-04 4:03 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-21 22:31 [PATCH v5 0/8] Extend struct tpm_buf to support sized buffers (TPM2B) Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 1/8] tpm: Remove unused tpm_buf_tag() Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 2/8] tpm: Remove tpm_send() Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 3/8] tpm: Move buffer handling from static inlines to real functions Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 4/8] tpm: Update &tpm_buf documentation Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 5/8] tpm: Store the length of the tpm_buf data separately Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 6/8] tpm: TPM2B formatted buffers Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 7/8] tpm: Add tpm_buf_read_{u8,u16,u32} Jarkko Sakkinen
2023-11-21 22:31 ` [PATCH v5 8/8] KEYS: trusted: tpm2: Use struct tpm_buf for sized buffers Jarkko Sakkinen
2023-11-28 3:48 ` Serge E. Hallyn
2023-11-28 12:24 ` James Bottomley
2023-11-28 14:34 ` Serge E. Hallyn
2023-11-28 14:37 ` James Bottomley
2023-12-04 4:03 ` Jarkko Sakkinen [this message]
2023-11-28 14:42 ` [PATCH v5 0/8] Extend struct tpm_buf to support sized buffers (TPM2B) Serge E. Hallyn
2023-12-04 4:06 ` Jarkko Sakkinen
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