tpm2_checkquote: Fix off-by-one in PCR digest list handling#3543
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JuergenReppSIT merged 1 commit intotpm2-software:masterfrom Feb 3, 2026
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parse_selection_data_from_selection_string() now updates TPML_DIGEST.count correctly and rolls over to a new list only after 8 digests, resolving failures with 8+ PCRs in the -f/-l path. Fixes: tpm2-software#3542 Signed-off-by: Takuma IMAMURA <209989118+hyperfinitism@users.noreply.github.com>
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@hyperfinitism Thank you for the PR!
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Summary
This PR fixes the bug reported in #3542 where
tpm2_checkquotefails when the PCR selection contains 8 or more PCRs.The root cause is an off-by-one error in
parse_selection_data_from_selection_string()when splitting PCR digests intoTPML_DIGESTlists: the code populated 8 digests in a list but leftTPML_DIGEST.countat 7. This causes subsequent processing to detect an inconsistent count, leading to failure.This change ensures that:
TPML_DIGEST.countis kept in sync with the actual number of digests stored.TPML_DIGESTis only started after 8 digests have been fully added to the current list.Testing
I verified the fix using the reproduction script from Issue #3542.
Before this change:
7pcrcase succeeded.8pcrcase failed withSomething wrong, trying to print but nothing more.After this change:
7pcrand8pcrcases complete successfully.