I had a similar problem, and came here by searching for the symptoms, but the solution didn't fit my case. So I'd like to add another possible reason even if it's not exactly fitting the OP.
In my special case I used proot
(a nice chroot
wrapper). But the permissions were correct on /dev/null
and /dev
itself.
It happened to be the mount of the chroot
directory, which I did via thunar
as a normal user. So, in this case the mount did not have the correct permissions.
You have a bad time to find this, because you don't see these permissions, when only looking at the files.
The general solution path would be to start checking conditions at the problem location (/dev/null
) and step out to the next level(s) (/dev
), then the mount, the file system etc., whatever comes next.
On each step you may have several preconditions, each having it's own outer levels. E.g. the user could be in a wrong group, which leads to the group configuration file, which could have wrong permissions etc.
Obviously, you have to follow a kind of tree in general.
So i want to know why it had those permissions. You may want to reinstall. Everything in /dev is kernel managed and its odd for it to have the wrong permissions. – cripto – 2014-09-21T18:36:53.670
no, everything in /dev is not "kernel managed". – tlund – 2014-09-21T21:11:32.550
@tlund please review your favorite kernel book. " /dev directory reflects the current state of the kernel" http://doc.opensuse.org/products/draft/SLES/SLES-admin_sd_draft/cha.udev.html
– cripto – 2014-09-22T03:13:15.037@user1048138 : I would like to know too. I started from an automatic debian 7 setup from my VPS provider. Then I updated, upgraded, used only apt-get. Plus one package by "hand" with wget http://some_domain/some_package.deb; dpkg -i some_package.deb; apt-get -f install. At one point, /dev/null was changed to a standard file, and /dev permissions changed. I cannot tell more.
– lalebarde – 2014-09-22T07:57:43.187