UBUNTU-CVE-2026-99221: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: keys/trustedkeys: return immediately after TPM unseal failure trustedtpmunseal() proceeds to pcrlock() when the TPM unseal operation fails. If pcrlock() succeeds, its return value overwrites the unseal error, causing key instantiation to succeed. Return immediately when unseal fails to preserve the original error.
Affected Software
Event History
Frequently Asked Questions
What condition is required for the incorrect key instantiation outcome?
A TPM unseal operation must fail, and the subsequent pcrlock() operation must succeed. In that sequence, pcrlock() can overwrite the unseal error and allow key instantiation to succeed.
Which Ubuntu kernel package families are listed as affected?
The listed software includes ubuntu/linux, ubuntu/linux-fips, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-oracle, ubuntu/linux-aws-fips, and ubuntu/linux-azure-fips.
How can an administrator determine whether the vulnerable behavior may have occurred?
The provided data identifies the relevant condition as a failed TPM unseal followed by successful pcrlock() and successful key instantiation. Reviewing logs or instrumentation for that sequence can indicate whether the incorrect success path was reached.