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Bug 125590 - x11 security extension corrupts xclock display
x11 security extension corrupts xclock display
Product: Fedora
Classification: Fedora
Component: xorg-x11 (Show other bugs)
All Linux
medium Severity medium
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Assigned To: X/OpenGL Maintenance List
David Lawrence
Depends On:
  Show dependency treegraph
Reported: 2004-06-09 01:43 EDT by Barry K. Nathan
Modified: 2007-11-30 17:10 EST (History)
2 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
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Clone Of:
Last Closed: 2004-09-29 07:47:58 EDT
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Verified Versions:
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oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description Barry K. Nathan 2004-06-09 01:43:21 EDT
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.6)
Gecko/20040523 Firefox/0.8

Description of problem:
Now that fc-devel has OpenSSH 3.8.1p1, we can finally use the X11
security extension. However, many X11 libraries have problems with the
security extension, or so I hear. Whatever the cause, it does cause

Since FC-devel has OpenSSH 3.8.1p1 now, I can use an fc-devel system
to ssh into itself, and reproduce problems that way. :) This is a
report of one such bug.

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

How reproducible:

Steps to Reproduce:
1. ssh -X localhost
2. Run "xclock" in the SSH session
3. Look at the resulting window

Actual Results:  the clock looks like it has a few extra scribbles

Expected Results:  a proper-looking clock

Additional info:

I'll attach a screenshot if anyone wants.

The workaround is to use -Y instead of -X.

I'm not completely sure which component is at fault; xorg-x11 is just
my best guess.
Comment 1 Bill Nottingham 2004-08-05 16:52:14 EDT
IIRC, something about X security changes shaped windows, to avoid
people figuring out what you're running via the shape. But I could be
Comment 2 Chris Kuivenhoven 2004-09-04 17:24:54 EDT

I attempted to reproduce this but was unable to ascertain any
difference between the local xclock and xclock over ssh. Could you
check to see if this is still a problem, and if so, attach a
screenshot identifying the differences?

My environment is Fedora Core 3 Test 1 "rawhide" with:

-Chris Kuivenhoven
Comment 3 Barry K. Nathan 2004-09-05 08:35:53 EDT
I'll retest at some point in the next few days. (I'm *real* busy with
other stuff so I don't know for sure that I'll be able to fit it in
Comment 4 Barry K. Nathan 2004-09-29 07:47:58 EDT
Ugh... things have sure been busy. :( I *finally* got a chance to
retest this, albeit on RHEL 4 beta 1, not FC3-test or rawhide. I can't
reproduce this anymore, so I'll close the bug.

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