Difference in the behavior of unlock_time in pam_faillock and pam_tally modules

Issue

• Discrepancy in the behavior of unlock_time in pam_faillock when compared with pam_tally. (unlock_time is not drifted according to the last failed attempt)
• Configure pam_faillock in system-auth and password-auth with deny=3 and unlock_time=300, Now try to login with any non-root user and enter invalid password 3 times after which the account gets locked as expected, say the current time is 1300 hrs. The account locks out and you will not be allow to login with correct password until 13:05 hrs, If the user again tries to login again at 13:02, system denies as account is locked-out.
• For the same scenario, In case of pam_tally, as user attempts to login at 13:02, the user will be unlocked only after 13:07 instead of 13:05. unlock_time is drifted after failed attempt and adjusted here.