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TPM_20_E_NV_LOCKED
TPM_20_E_NV_LOCKED means that an NV operation reached a defined index but the TPM will not allow the requested read or write at this time. This is a state or attribute decision, not evidence that the index is missing or that its authorization value is necessarily wrong.
Common causes
- The index has a read or write lock state established by an NV lock command or by attributes that control access after startup or after a write.
- A workflow intentionally locks an index after provisioning so a later operation cannot alter the protected value.
- An application retries a write after a state transition without re-reading the index attributes and current lifecycle expectations.
How to diagnose it
- Inspect the public NV attributes and identify whether the failing operation is a read, write, increment, extend, or another type-specific command.
- Check whether the relevant
TPMA_NV_*attributes cause the lock to clear at the nextTPM2_Startup(TPM_SU_CLEAR), whether it is tied to a global write lock, or whether it is part of an irreversible provisioning policy. - Keep
TPM_20_E_NV_LOCKEDseparate fromTPM_20_E_NV_AUTHORIZATION: a correct authorization session cannot override an access state that the index policy has locked.
Do not treat this as cleanup
Removing and redefining the index can destroy protected state and can change the index Name and policy. First establish whether the lock is an expected security boundary and whether a documented restart or reprovisioning procedure is appropriate.
References: TCG TPM 2.0 Library Part 3: Commands, tpm2_nvreadlock, and tpm2_nvwritelock.
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