Comment 0 for bug 1759791

I am testing the development branch of Bionic Beaver.
With the latest update to kernel 4.15.0-13 my nfs-mounts in a university network are broken.

> sudo mount -vvv -t nfs4 my_server:/my/share /nfs -osoft,sec=krb5
> mount.nfs4: timeout set for Mon Mar 26 16:29:56 2018
> mount.nfs4: trying text-based options 'soft,sec=krb5,nfsvers=4.0,addr=10.162.229.2,clientaddr=10.152.249.189'
> mount.nfs4: mount(2): Input/output error
> mount.nfs4: mount system call failed

> kernel: NFS: nfs4_discover_server_trunking unhandled error -5. Exiting with error EIO
> kernel: RPC: couldn't encode RPC header, exit EIO
> kernel: gss_marshal: gss_get_mic FAILED (851968)

Known good version: linux-image-4.15.0-10

I think it is the same bug like in https://bugzilla.redhat.com/show_bug.cgi?id=1558977
The bug was introduced in the mainline kernel 4.15.4 with commit "[46e8d06e423c4f35eac7a8b677b713b3ec9b0684] crypto: hash - prevent using keyed hashes without setting key"

This bug should be fixed before releasing ubuntu18.04 by either reverting the commit or using a fixed mainline kernel.