Bug 21464

possibly related : #16458

Created attachment 25861 [details]
Xorg log

i've had this also, very annoying. happens to me when loading oowriter.i've been unable to get a backtrace so far.

I can confirm this as well — happens sometimes when loading oowriter. The backtrace I get in Xorg.0.log corresponds to what's said in the first comment. In my case, the difference between the two numbers is 16 as well.

I will try to apply the following quickfix, which I think may prevent the server from crashing (but the error is somewhere else, of course):

--- a/xkb/xkb.c
+++ b/xkb/xkb.c
@@ -1366,7 +1366,7 @@ unsigned  i,len;
 char           *desc,*start;
 
     len= (rep->length*4)-(SIZEOF(xkbGetMapReply)-SIZEOF(xGenericReply));
-    start= desc= (char *)xalloc(len);
+    start= desc= (char *)xalloc(len + 128);
     if (!start)
        return BadAlloc;
     if ( rep->nTypes>0 )

I will report later.

Okay, I can confirm that the patch prevents the X server from crashing. I will further investigate what causes the length to be bigger.

I can confirm regularly seeing this problem in Ubuntu Intrepid and Jaunty.

See https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/334626

Created attachment 26038 [details] [review]
fix

Okay, I believe the attached patch fixes this issue properly.

*** Bug 16458 has been marked as a duplicate of this bug. ***

*** Bug 6428 has been marked as a duplicate of this bug. ***

Pushed as 525aa17f804d37d1cfcbbf6b8e6cddb45e999b20. Thanks for your time and the patch, it is much appreciated.

Hello!

Thanks for solving this problem. I am also severely hit by this bug. The only question:

How do we, end users, apply the patch? I am using openSuSE 11.1 with X.Org X Server version 1.5.2 (released on 2008.10.10) installed. Should I just wait till openSuSE releases a patched X Server via their update repositories? Or should I manually get the sources, apply the patch and compile the X server myself?

You could file a bugreport into their bugzilla and have them include this patch in an update, but if you're experiencing the problem every other day, it may be better to apply it yourself.

I think the easiest way is grabbing the source package for xserver for your distribution (http://en.opensuse.org/Zypper/Usage#Source_Packages_and_Build_Dependencies), applying the patch (RPM specfiles aren't difficult, but it's more than just doing patch -p1) and building that with rpmbuild.

(In reply to comment #12)
> You could file a bugreport into their bugzilla and have them include this patch
> in an update, but if you're experiencing the problem every other day, it may be
> better to apply it yourself.
> 
> I think the easiest way is grabbing the source package for xserver for your
> distribution
> (http://en.opensuse.org/Zypper/Usage#Source_Packages_and_Build_Dependencies),
> applying the patch (RPM specfiles aren't difficult, but it's more than just
> doing patch -p1) and building that with rpmbuild.
> 

Thanks for your reply, Tomas! Do you know, in what version of X server will this patch be already included?
Say, will it be enough to just recompile the core X server, or should I rebuild all the modules/drivers as well?
Cheers!

Hello,

(In reply to comment #13)
> Thanks for your reply, Tomas! Do you know, in what version of X server will
> this patch be already included?

Nope, but I think this patch should be nominated for inclusion in server-1.6-branch — that would mean distributions shipping xserver 1.6 would pick it up soon.

> Say, will it be enough to just recompile the core X server, or should I rebuild
> all the modules/drivers as well?

Core xserver is the only thing you need to patch and build.

> Nope, but I think this patch should be nominated for inclusion in
> server-1.6-branch — that would mean distributions shipping xserver 1.6 would
> pick it up soon.

I agree, please add the nomination to the wiki page.

*** Bug 20081 has been marked as a duplicate of this bug. ***

FTR, patch is now in 1.6.1.902.

Cheers