As per discussion in  crbug.com/888031 :

The logs are getting spammed with these error messages:

2018-09-21T18:19:07.582809-07:00 ERR cryptohomed[1393]: The TPM failed to unwrap the intermediate key with the supplied credentials
2018-09-21T18:19:07.582924-07:00 ERR cryptohomed[1393]: Failed to decrypt any keysets for abd5a2707ffef6938a0ed7caab52a3b12fd50335: mount error 2, crypto error 8
2018-09-21T18:19:07.582960-07:00 WARNING cryptohomed[1393]: AddKeyset: invalid authentication provided

This is because Smart Lock has no label on its keyset, so it's trying to authorize against all other keysets.

apronin@ recommends that we use labels, but unfortunately, Smart Lock has in the past not used labels -- simply adding them will not allow migration (the old key set without a label will be lost). Investigation is needed to determine the best way to implement this and still allow migration.