systemd / systemd / 29461261567

73%

Build Type

push

github

Committed by yuwata

Commit Message

tpm2-util: keep the measurement log's torn-write marker intact

The userspace measurement log carries a sticky-bit marker while a writer
is between updating a measurement register and appending the matching
record, so that a writer dying in between leaves the log detectably
incomplete.

However, the next successful writer used to clear the marker again after
appending its own record, erasing the evidence that an earlier writer
had died and the log is still missing a record. Keep the marker set in
that case instead; the new record is appended and synced regardless. The
marker likewise stays set if the measurement itself fails, so that any
non-clean completion remains flagged: a spurious flag on a failed but
harmless measurement is preferable to erasing evidence of a real gap,
and PCR replay stays authoritative either way.

Finally, warn when systemd-pcrlock loads a marked log, so the resulting
PCR validation failures come with a hint at their cause.

Signed-off-by: Paul Meyer <katexochen0@gmail.com>

Coverage Stats

11 of 12 new or added lines in 2 files covered. (91.67%)

2475 existing lines in 54 files now uncovered.

346100 of 474222 relevant lines covered (72.98%)

1321758.71 hits per line