I usually perform a binary update of my jails using
#freebsd-update fetch install #freebsd-update -d /usr/jails/basejail fetch install
This has worked for years. After doing it yesterday I was unable to login to any of my jails and pretty much everything broke. For example logging in using
ssh gave logged the error:
/bin/sh permission denied
After spending the day on it I have discovered that the upgrade process changed permissions on
700. Changing it to
755 fixed everything.