Why would enabling FIPS mode in the kernel break CIFS mounts?

Issue

• CIFS mounts work well as long as FIPS mode is disabled.
• Enabling FIPS mode and rebooting the server results in CIFS mounts failing. The kernel logs show this as:

CIFS VFS: could not allocate crypto hmacmd5

CIFS VFS: could not setup hash structures rc -2
CIFS VFS: cifs_mount failed w/return code = -2

• The only difference between the success or failure of the CIFS mount is fips mode as enabled via fips=1 on the kernel command line in grub.conf.
• Is FIPS mode supported with CIFS mounts?