How to recover from a stupid chown command "chown -hR userA /." ??

Question

greetings
i am a terrible newbie of linux.
and when i am trying to chown one directory /home/someone/dX to be owned by account , say userA, i stupidly cd to /home/someone/dX and using the below command as a root:
chown -hR userA /.
I cant exlain why i did this, but the result is that nearly all the directory/files of the computer become owned by userA.
My question is , is there any way to restore all my changes caused by this command...
Last edited by samp (2008-02-28 17:42:43)

Answer 1

It should be possible to recover to get a working system. My son did an identical thing trying to set the mount point for his external caddy to be owned by his user. This was on SimplyMEPIS 64.
He had everything owned by jon:users, so here are excerpts from my emails (using guest user on my Mepis 32 system):
DON'T DO THIS:
I mucked up my 32 bit Mepis "su" (roughly in the same way as you?) I su'd and cd'd to / then
chown -R guest *
chown -R root *
chown -R guest /home/guest
Logging into guest I had the same problems i.e. got invalid password when su
from in a terminal or when running mepis system stuff from kmenu (uses kdesu)
DO THIS:
This should solve it:
Login in as root
run konqueror and navigate to /bin
right click on su
click the permissions tab
check the box "user: Set UID"
click on OK to close etc
You should know be able to log in as jon and use su and kdesu
his response was:
Since reseting the profile using the User Manager when I start up I get an error saying I;m not permitted to connect to the powersave daemon via DBUS, however I haven't noticed any ill-effects.
Well mostly fixed anyway.  I can still enter the password on synaptic etc. but for some reason if I am changing between sessions it wouldn't accept the password for 'jon'.  Not that this is a huge problem.
My response was
Me too. Tick the "Set UID" box for /usr/bin/kcheckpass
On my Arch linux, the following programs are UID or GID:
$ ls -l /opt/kde/bin/ | grep "sr-"
-rwsr-xr-x 1 root root      2852 2007-11-10 20:54 fileshareset
-rwsr-xr-x 1 root root     15194 2008-01-26 17:45 kcheckpass
-rwxr-sr-x 1 root nobody   56265 2008-01-26 17:46 kdesud
-rwsr-xr-x 1 root root      5876 2007-11-10 20:54 kgrantpty
-rwsr-xr-x 1 root root    567112 2007-10-14 22:28 kppp
-rwsr-xr-x 1 root root      5500 2007-11-10 20:54 start_kdeinit
Mepis has those programs in /usr/bin. "s" in the first block means "Set
UID", "s" in the second block (kdesud) means "Set GID".
The powersave problem may be due to start_kdeinit not being able to run as
root so let me know if that is fixed by the above mod.
Of course some ownerships are still wrong (nobody etc) so I guess security isn't quite up to scratch.
That was on 4th Feb and it is his main system - no problems reported back so far.
Basically, chown everything (/, recursively) to root, chown each users home recursively to that user, then deal with a few set UID & GID problems.