eject and pam support in Fedora

[Karel Zak]

On Tue, Mar 04, 2008 at 01:57:02PM +0100, Miloslav Trmac wrote:
> Hello,
> Zdenek Prikryl napsal(a):
>> I don't know, why eject has to use pam in Fedora. So, could anyone explain why?
> The goal was probably to allow console users (=> pam_console.so) eject the 
> CD/DVD medium without knowing the root password.  Some platforms have 

 Unfortunately, it also works for non-CD/DVD devices.

 Unfortunately, eject(8) is ***broken by design***, because
 automatically calls umount(8) before an eject ioctl.


         $ umount /dev/sda8
         umount: only root can unmount LABEL=/mnt/misc from /mnt/misc

 Well, try other way:

         $ grep sda8 /proc/mounts
         /dev/sda8 /mnt/misc ext3 rw,relatime,data=ordered 0 0

         $ eject sda8
         umount: /: device is busy
         umount: /: device is busy
         eject: unmount of `/' failed

        $ grep sda8 /proc/mounts; echo $?
        1


 From my point of view this is ***security bug*** (#432187), because
 eject(8) bypasses /etc/fstab setting.

 The normal UNIX design is use small separated commands rather than
 one super-command. eject(8) should print "error: device is mounted"
 rather than directly umount the device.

    Karel

-- 
 Karel Zak  <kzak at redhat.com>