[Bug 980835] Re: tty[1-6] is now root:tty 0660 instead of root:root 0600

[Joseph Salisbury]

** Changed in: util-linux (Ubuntu)
   Importance: Undecided => Medium

** Changed in: util-linux (Ubuntu)
       Status: New => Confirmed

** Tags added: kernel-da-key precise

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to util-linux in Ubuntu.
https://bugs.launchpad.net/bugs/980835

Title:
  tty[1-6] is now root:tty 0660 instead of root:root 0600

Status in “util-linux” package in Ubuntu:
  Confirmed

Bug description:
  As of precise (2.20.1-1ubuntu3 to be exact), /dev/tty[1-6] now has the following permissions:
  $ ls -l /dev/tty[1-6]
  crw-rw---- 1 root tty 4, 1 Apr 12 13:06 /dev/tty1
  crw-rw---- 1 root tty 4, 2 Apr 12 13:06 /dev/tty2
  crw-rw---- 1 root tty 4, 3 Apr 12 13:06 /dev/tty3
  crw-rw---- 1 root tty 4, 4 Apr 12 13:06 /dev/tty4
  crw-rw---- 1 root tty 4, 5 Apr 12 13:06 /dev/tty5
  crw-rw---- 1 root tty 4, 6 Apr 12 13:06 /dev/tty6

  In 11.10 and earlier (I checked back to hardy), the permissions were:
  $ ls -l /dev/tty[1-6]
  crw------- 1 root root 4, 1 2012-03-25 09:18 /dev/tty1
  crw------- 1 root root 4, 2 2012-03-25 09:17 /dev/tty2
  crw------- 1 root root 4, 3 2012-03-25 09:17 /dev/tty3
  crw------- 1 root root 4, 4 2012-03-25 09:17 /dev/tty4
  crw------- 1 root root 4, 5 2012-03-25 09:17 /dev/tty5
  crw------- 1 root root 4, 6 2012-03-25 09:17 /dev/tty6

  This appears to be because of this util-linux commit:
  http://git.kernel.org/?p=utils/util-linux/util-linux.git;a=commit;h=3aa6b68f7e19fa3e1c2bba75bee921a98b7b46af

  I'm not sure if this is a problem, but it isn't clear why the change was made and I'm having a hard time knowing why the group was changed. This is the bit of code that I think is the cause:
  +               /*
  +                * There is always a race between this reset and the call to
  +                * vhangup() that s.o. can use to get access to your tty.
  +                * Linux login(1) will change tty permissions. Use root owner and group
  +                * with permission -rw------- for the period between getty and login.
  +                */
  +               if (chown (buf, 0, gid) || chmod (buf, (gid ? 0660 : 0600))) {
  +                       if (errno == EROFS)
  +                               log_warn("%s: %m", buf);
  +                       else
  +                               log_err("%s: %m", buf);
  +               }

  There might not be anything to do with this, but I am filing it to get
  other's opinions.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/980835/+subscriptions