before going to nfs-utils-2.4.1-r4 I ran into the follwing problem:
rpc.mountd always crashed after a few seconds with the following error message ( I have about 20 clients) :
rpc.mountd: nfsd_fh: inbuf '10.5.16.0/22 6 \x8f424d6d527342799abc1d30bed385cd'
*** stack smashing detected ***: <unknown> terminated
If I turned off all access in /etc/exports and rexported, I could start rpc.mountd without any issues, but of course without any access to the exported directories.
Today I checked by chance for a newer version, found 2.4.1-r4, gave it a try and - voila -no more stack smashing aborts any more.
I just filed the bug to possible help others that ran into the same error using the buggy version 2.4.1-r3.
Affected version is gone. This was fixed by https://bugs.gentoo.org/688644#c25. Closing as duplicate.
*** This bug has been marked as a duplicate of bug 688644 ***
Sorry for reporting as duplicate, now at the error is at least reported with *both* client and server error message ;-) - as all my clients dropped off I did'nt even think to check there as the problem was located @ server