pam_fprintd.so leaks memory when used for authentication on RHEL 6

Issue

When setting the pam_fprintd.so, the amount of used memory for a process increased by repeating authentication.

 /etc/pam.d/system-auth:
  ---
  #%PAM-1.0
  # This file is auto-generated.
  # User changes will be destroyed the next time authconfig is run.
  auth        required      pam_env.so
  auth        sufficient    pam_fprintd.so <--- Setting
  auth        sufficient    pam_unix.so nullok try_first_pass
  auth        requisite     pam_succeed_if.so uid >= 500 quiet
  auth        required      pam_deny.so
  <snip>
  ---