Bug 120914

Summary: xdm should use /dev/urandom [xdm error: Cannot read randomFile "/dev/mem"; X cookies may be easily guessable]
Product: [Fedora] Fedora Reporter: Aleksey Nogin <aleksey>
Component: xorg-x11Assignee: Mike A. Harris <mharris>
Status: CLOSED RAWHIDE QA Contact: David Lawrence <dkl>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: jdennis, russell, wtogami
Target Milestone: ---Keywords: Security, SELinux
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
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Clone Of: Environment:
Last Closed: 2004-09-01 11:37:13 UTC Type: ---
Regression: --- Mount Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Aleksey Nogin 2004-04-15 07:08:11 UTC
Currently xdm attempts to use /dev/mem as a source of randomness for
cookie generation. This is a bad idea in any case, but when SELinux is
in enforcing mode, this is especially bad since SELinux prohibits this
and, as xdm-errors log file states, "X cookies may be easily guessable".

The similar bug exists for kdm as well (bug 118051) and it looks that
kdm just borrowed code from xdm. I have investigated the kdm case a
bit more, see details in bug 118051.

Comment 1 Aleksey Nogin 2004-05-06 07:00:31 UTC
RYI: the kdm version of this bug - bug 118051 - was fixed a few days ago.

Comment 2 Warren Togami 2004-05-06 07:08:23 UTC
I suspect this is more about avoiding another X rebuild, because it is
very large.  This does not seem to be a very serious problem because
nobody would prefer to use xdm over gdm/kdm, but I could be assuming
too much of course...


Comment 3 Søren Sandmann Pedersen 2004-07-20 17:49:18 UTC
Fixed upstream.

Comment 4 Mike A. Harris 2004-09-01 11:37:13 UTC
Upstream X.Org is in our fedora devel builds, changing status to
"RAWHIDE".