# DF-1990 - Source Verification

## Verdict: REPRODUCED (source-only confirmation)

**Finding**: sys/dev/crypto/tpm/tpm_crb.c:328-401

**Mechanism**: tpmcrb_transmit acquires locality 0 at L328 but four error-return paths return EIO without calling tpmcrb_relinquish_locality. CRB left in partially-active state → subsequent commands fail.

**Hardware dependency**: Requires TPM CRB device.

**Fix**: Add err_locality label; all error paths goto err_locality which relinquishes locality.

## Verification method
Source-only confirmation. The cited code path was traced line-by-line in the
audited sys/ tree. The bug exists exactly as described. This is a HW-gated
driver finding — the vulnerable code path requires specific hardware (GPU,
controller, PHY, TPM, etc.) not present in the QEMU audit guest. Runtime
reproduction on this guest is not possible without the hardware.

## Fix validation
fix.diff authored and applied to guest source. All 40 fixes in this batch
compile cleanly in a single combined kernel build: `make -j6 nativekernel
KERNCONF=X86_64_GENERIC` → rc=0, zero -Werror violations.

**Kernel**: DragonFly 6.5-DEVELOPMENT #0: Thu Jul  2 06:02:54 UTC 2026