Bug 230823 - CVE-2007-1716 Ownership of devices not returned to root after logout from console
CVE-2007-1716 Ownership of devices not returned to root after logout from con...
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: pam (Show other bugs)
i386 Linux
medium Severity medium
: ---
: ---
Assigned To: Tomas Mraz
Brian Brock
Depends On:
  Show dependency treegraph
Reported: 2007-03-03 00:33 EST by Andrew D.
Modified: 2007-11-16 20:14 EST (History)
0 users

See Also:
Fixed In Version: RHSA-2007-0737
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2007-11-15 10:03:24 EST
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)

  None (edit)
Description Andrew D. 2007-03-03 00:33:02 EST
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv: Gecko/20070221 Red Hat/ Firefox/

Description of problem:
I dont really know if this is a kernel bug but it didn't start happening until after I upgraded to the 2.6.9-42.0.10.ELsmp kernel. When a user logs in from the console, may devices such as /dev/mixer and /dev/floppy change ownership to the console user, which is normal. However, sometimes after the user logs out, the ownership permissions are not changed back to root.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Log in as a user from the console.
2. Log out.
3. Log in as another user from the console.
4. Do dir /dev .

Actual Results:
Many devices are still owned by the previous user.

Expected Results:
Devices should be owned by the current user.

Additional info:
Comment 1 Andrew D. 2007-03-03 01:20:35 EST
I experimented a bit more and the problem seems to be triggered by when a second
user logs into the console. For example, a user is logged in at the text login
(cntl-F5) and another user is logged in at the graphical login (cntl-F7). When
one of these users logs out, ownership is not always released and does not get
fixed when all users log out. Granted, it is rare that two users will ever e
logged in at the console but sometimes it is useful to log in two users for
testing purposes (say root and a regular user). I cant always reproduce it. It
seems to be related to which user logs in and which user logs out first (the
graphical or the text one) but it has happened several times. Once the problem
occurs, logging in as root does not reset ownership to root.
Comment 2 Jason Baron 2007-03-12 13:57:56 EDT
hmm, so if you go back to an older kernel this goes away? what version would
that be so we can identify what broke. thanks.
Comment 3 Andrew D. 2007-03-12 21:13:56 EDT
Hi. I cant reboot at the moment due to user jobs running but I experimented a
bit more with this. It seems more probable now that it's a pam bug and not
kernel. I may not have noticed it in previous kernels just by not looking. Here
are the exact steps to produce the issue as well as how to fix it without rebooting:

1) log in a user from the text login (cntl-alt-f5).
2) log in another user from the graphical login (cntl-alt-f7).
3) log out the text-login user.
4) log out the graphical login user.
5) log back in the graphical login user (user of step 2).
6) "ls -laF /dev" and notice that a bunch of devices are still owned by the
original text login user (user of step 1).
7) As root do a "pam_console_apply -r", this resets the device ownerships to root.
8) remove the files in /var/run/console/
9) log out and now everything is happy when you log back in again.

If  you skip step 8 the devices still remain property of root when a user logs
in again.

Comment 4 Tomas Mraz 2007-03-23 06:43:46 EDT
Found the cause - it is a bug in pam_console which was always there. I don't
know why nobody found it before.
Comment 5 RHEL Product and Program Management 2007-05-09 02:59:33 EDT
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
Comment 10 errata-xmlrpc 2007-11-15 10:03:24 EST
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


Note You need to log in before you can comment on or make changes to this bug.