On Fri, 15 Mar 2019 12:01:05 -0700, Jakub Kicinski wrote: > On Fri, 15 Mar 2019 11:05:55 -0700, Jakub Kicinski wrote: > > Hi, > > > > I just upgraded from: > > > > commit a3b1933d34d5bb26d7503752e3528315a9e28339 (net) > > Merge: c6873d18cb4a 24319258660a > > Author: David S. Miller <davem@xxxxxxxxxxxxx> > > Date: Mon Mar 11 16:22:49 2019 -0700 > > > > to > > > > commit 3b319ee220a8795406852a897299dbdfc1b09911 > > Merge: 9352ca585b2a b6e88119f1ed > > Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> > > Date: Thu Mar 14 10:48:14 2019 -0700 > > > > and I'm seeing: > > > > # mount /home/ > > mount.nfs: Protocol error > > > > No errors in dmesg, please let me know if it's a known problem or what > > other info could be of use. > > Hm.. I tried to bisect but reverting to that commit doesn't help. > > Looks like the server responds with: > > ICMP parameter problem - octet 22, length 80 > > pointing at some IP options (type 134)... Okay, figured it out, it's the commit 13e735c0e953 ("LSM: Introduce CONFIG_LSM") and all the related changes in security/ I did olddefconfig and it changed my security module from apparmor to smack silently. smack must be slapping those IP options on by default. Pretty awful user experience, and a non-zero chance that users who upgrade their kernels will miss this and end up with the wrong security module...