boehme@leah.albany.edu (Eric M. Boehm) (11/27/90)
I have run into a problem out of the blue. Suddenly, our DECstation 500 won't let me use su to switch to another user. I get the following error message: getwd: can't open .. -- can't start new shell This happened suddenly. Also, after rebooting the machine, su may work once or twice and then give the error message. This also screws up commands I have in crontab -- they do not get run. Lately, even commands running as root in crontab weren't being run. I even went so far as to redo the Ultrix installation. That did not help. Any suggestions would be greatly appreciated. Please respond (if by e-mail) to boehme@unvax.union.edu. Thanks in advance. -- Eric M. Boehm boehme@unvax.union.edu boehme@union.bitnet
weimer@ssd.kodak.com (Gary Weimer) (11/27/90)
In article <1990Nov27.005226.18032@sarah.albany.edu> boehme@unvax.union.edu (Eric M. Boehm) writes: > >I have run into a problem out of the blue. Suddenly, our DECstation 500 >won't let me use su to switch to another user. I get the following error >message: > >getwd: can't open .. -- can't start new shell > >This happened suddenly. Also, after rebooting the machine, su may work >once or twice and then give the error message. This also screws up >commands I have in crontab -- they do not get run. Lately, even commands >running as root in crontab weren't being run. I even went so far as to >redo the Ultrix installation. That did not help. Try changing to a different directory. The error message is telling you that you do not have permission (read? execute?--I forget what you need) for the previous directory (..). For some reason, su needs to access every directory in your current path to be able to access the /etc/passwd file (added security?). Changing directories, or adding permission to directories in your path should fix the problem. Gary Weimer
boehme@leah.albany.edu (Eric M. Boehm) (11/28/90)
Thanks to all who responded. The problem seemed to be the directory permissions/ownership. I didn't think they would affect su on the way *up* the directory tree, but it appears they do. Additionally, I found some other permissions were not what I thought they were. -- Eric M. Boehme boehme@unvax.union.edu boehme@union.bitnet
barrett@jhunix.HCF.JHU.EDU (Dan Barrett) (11/29/90)
In article <1990Nov27.141002.5396@ssd.kodak.com> weimer@ssd.kodak.com (Gary Weimer) writes: >For some reason, su needs to access every directory >in your current path to be able to access the /etc/passwd file (added >security?). I think there's a simpler explanation. Imagine what would happen if you were in a private directory: $ cd $ mkdir private $ chmod 700 private $ cd private and then you tried to "su" to another user and succeeded: $ su anotheruser Password: % Now "anotheruser" is inside your protected directory. This contradicts the mode (-rwx------) of the directory "private", and therefore it cannot happen. Dan //////////////////////////////////////\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ | Dan Barrett, Department of Computer Science Johns Hopkins University | | INTERNET: barrett@cs.jhu.edu | | | COMPUSERVE: >internet:barrett@cs.jhu.edu | UUCP: barrett@jhunix.UUCP | \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\/////////////////////////////////////