Re(2): Strange behavior of su

[George Williams]

>From various responces I have managed to piece together what happens.

>Every now and then after I have been logged in for a while I will try to
>su, have su ask the password, and then it sits for a bit and exits.  It
>does not generate any error messages, the exit status is 0.  After this
>has happened it will keep happening until I log out, I have always been
>able to su immediately after logging in.

Actually this isn't su it's the csh (sh does not have this problem).
When csh starts up it looks at the directory tree above it (somehow)
if . is protected everything works fine, if .. or ../.. (and I assume
......./..) are protected against the new user then it dies.

I poked around in csh but could not find an obvious reason for this,
I assume it does a pwd type thing and checking . is a special case.

I have tweaked su to attempt to open ../../.. before execing the shell,
and have it give a warning message if it fails.