Messages in this thread | | | Subject | Re: [PATCH v6 6/7] tpm: ensure that the output of PCR read contains the correct digest size | From | Roberto Sassu <> | Date | Thu, 6 Dec 2018 19:07:34 +0100 |
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On 12/5/2018 1:46 AM, Jarkko Sakkinen wrote: > On Tue, Dec 04, 2018 at 04:09:10PM -0800, Jarkko Sakkinen wrote: >> On Tue, Dec 04, 2018 at 09:21:37AM +0100, Roberto Sassu wrote: >>> out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE]; >>> digest_size = be16_to_cpu(out->digest_size); >>> - if (digest_size > sizeof(digest->digest)) { >>> + if (digest_size > sizeof(digest->digest) || >>> + (!digest_size_ptr && digest_size != expected_digest_size)) { >>> rc = -EINVAL; >>> goto out; >>> } >> >> Just noticed this but you must squash 4-6 because applying only >> previous commits will result a broken tree. It will be much bigger >> commit but won't be broken. >> >> I think you should also feed min_rsp_body_length as you should be >> able to precalculate. >> >> Last time I was asking why this isn't a bug fix. It is even for >> the existing code. The existing code should have a bug fix that >> checks that the received digest size so that it is the expected >> SHA1 size before we can apply this commit. > > My bad. This is not the same deal as the code because in the old code we > always copy a constant block. Here we use the variable as parameter for > memcpy() so it is better to check the size. You can ignore the last > paragraph completely. Sorry, had to double check this one. > > There is no need to do any type of bug fix for the current tree. > > Still 4-6 need to be squashed in order to not put purposely the tree > into broken state.
Ok. I keep the description of 5, and add few details from 4 and 6.
Roberto
> /Jarko >
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