su (PAM) gotcha

[Jonathan Corbet]

In case this is useful to anybody...after yesterday's rawhide update (my
first in a week or two), any attempt to run su would fail with a quick
"incorrect password" message.  Before it ever asked for a password.
Even I can't fat-finger something if I don't even get the opportunity to
type.

A quick look in /etc/pam.d revealed my old "su" file from a few years
back, which I had never changed.  There was an "su.rpmnew" file there as
well, dated last July.  Switching to the new one made my problem go
away.  I've not had the time to figure out just what change made the
difference - the PAM files have clearly evolved considerably over time.

I suspect I may not be the only one who runs into this; people who have
been tracking rawhide for a bit may want to take a quick look at the
state of their PAM configuration files.  I wonder if it would be
possible to make the package update somehow detect that the new system
is broken and scream accordingly?

jon