Mailinglist Archive: opensuse-security (471 mails)

[MaD dUCK <madduck@xxxxxxxxxxx>]

> This action looks like it's caused by a PAM module that isn't shipped with
> SuSE linux (pam_console). We have found that it is useful but it also
> brings along some problems (also security related) that aren't easy to
> come by.

so i obviously have /lib/security/pam_console.so and it is mentioned in a
couple of files in /etc/pam.d.

[nathaniel: check this out - it makes sense...]
<snip from man pam_console>
	When a user logs in at the console and no  other  user  is
	currently  logged  in  at the console, pam_console.so will
	change permissions and ownership of files as described  in
	the  file /etc/security/console.perms.  That user may then
	log in on other terminals that are considered part of  the
	console, and as long as the user is still logged in at any
	one of those terminals, that user will own those  devices.
	When  the  user logs out of the last terminal, the console
	may be taken by the next user to log in.  Other users  who
	have  logged  in  at  the console during the time that the
	first user was logged in will not be  given  ownership  of
	the  devices  unless  they log in on one of the terminals;
	having done so on any one terminal, the next user will own
	those devices until he or she has logged out of every ter­
	minal that is part of the physical console.  Then the race
	can  start  for the next user.  In practice, this is not a
	problem; the physical console is not generally in  use  by
	many  people  at  the  same  time, and pam_console.so just
	tries to do the right thing in weird cases.
</snip>

so this is a good idea and it makes sense, but what it means that i cannot
use the cdrom for instance from an ssh console if i wasn't the user last
logged in physically? of course, we don't really want this, because then
i could freely do whatever i wish with the floppy of someone else.

my question then (considering that i will probably go ahead and amend
/etc/security/console.perms appropriately) is how suse handles this. so on
a suse system, what determines what to do if a ssh user and a console user
both request /dev/ttyS0 write access, and how will this situation be handled?

martin

	madduck@xxxxxxxxxxx

(greetings from the heart of the sun)