Re: [PATCH v5 6/7] tpm: ensure that the output of PCR read contains the correct digest size
From: Roberto Sassu <roberto.sassu@huawei.com>
Date: 2018-11-28 08:40:50
Also in:
linux-integrity, lkml, stable
On 11/19/2018 5:07 PM, Jarkko Sakkinen wrote:
On Mon, Nov 19, 2018 at 04:09:34PM +0100, Roberto Sassu wrote:quoted
On 11/19/2018 3:33 PM, Jarkko Sakkinen wrote:quoted
On Mon, Nov 19, 2018 at 09:14:00AM +0100, Roberto Sassu wrote:quoted
On 11/18/2018 8:32 AM, Jarkko Sakkinen wrote:quoted
On Fri, Nov 16, 2018 at 05:06:48PM +0100, Roberto Sassu wrote:quoted
On 11/16/2018 2:41 PM, Jarkko Sakkinen wrote:quoted
On Wed, Nov 14, 2018 at 04:31:07PM +0100, Roberto Sassu wrote:quoted
This patch protects against data corruption that could happen in the bus, by checking that that the digest size returned by the TPM during a PCR read matches the size of the algorithm passed to tpm2_pcr_read(). This check is performed after information about the PCR banks has been retrieved. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Jarkko Sakkinen <redacted> Cc: stable@vger.kernel.orgMissing fixes tag.Before this patch set, tpm2_pcr_extend() always copied 20 bytes from the output sent by the TPM. RobertoAah, right, of course. Well the patch set is ATM somewhat broken because this would require a fixes tag that points to a patch insdie the patch set. Probably good way to fix the issue is to just merge this with the earlier commit.Unfortunately, it is not possible. The exact digest size has been introduced with patch 5/7.I put this in simple terms: if I merge 5/7 the driver will be broken. Any commit in the patch set should not leave the tree in broken state.Patch 6/7 does not fix patch 5/7. The check in patch 6/7 is not done for the PCR read performed by patch 5/7, because the digest sizes are not yet available.Ah, right. Point taken :-)
Should I keep CC: stable@vger.kernel.org? Roberto
/Jarkko
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