On Wed, 2018-09-26 at 10:40 -0400, Mimi Zohar wrote: > On Mon, 2018-09-17 at 11:38 +0200, Roberto Sassu wrote: > > Resending to maintainer with correct mailing lists in CC. > > > > The TPM driver currently relies on the crypto subsystem to determine the > > digest size of supported TPM algorithms. In the future, TPM vendors might > > implement new algorithms in their chips, and those algorithms might not > > be supported by the crypto subsystem. > > > > Usually, vendors provide patches for the new hardware, and likely > > the crypto subsystem will be updated before the new algorithm is > > introduced. However, old kernels might be updated later, after patches > > are included in the mainline kernel. This would leave the opportunity > > for attackers to misuse PCRs, as PCR banks with an unknown algorithm > > are not extended. > > > > This patch set provides a long term solution for this issue. If a TPM > > algorithm is not known by the crypto subsystem, the TPM driver retrieves > > the digest size from the TPM with a PCR read. All the PCR banks are > > extended, even if the algorithm is not yet supported by the crypto > > subsystem. > > Other than checking the digest size before copying the pcrread buffer, > the patches look good. Please add my Ack on all 3 patches. > > (New address) Acked-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> I've reviewed, and am currently running with these patches. Even if the IMA changes were in a separate patch, we wouldn't be able to break up the patch set anyway. Jarkko, I'd appreciate your carrying the entire patch set. Roberto, a similar change needs to be made for tpm_pcr_extend. Are you planning on posting those changes as well? Mimi
