compiz crashed with SIGSEGV in intel_miptree_release()

[Daniel Hahler]

Compiz crashed/froze after me pressing Alt-Tab.

I then switched to VT1 and back to VT7 to get the crash report and a new unity instance.

ProblemType: Crash
DistroRelease: Ubuntu 12.04
Package: unity 5.6.0-0ubuntu4
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic-pae 3.2.9
Uname: Linux 3.2.0-18-generic-pae i686
ApportVersion: 1.94.1-0ubuntu2
Architecture: i386
CrashCounter: 1
Date: Fri Mar 16 15:44:00 2012
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/compiz
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
ProcCmdline: compiz
SegvAnalysis:
 Segfault happened at: 0xb5f5b9a5 <intel_miptree_release+21>: mov (%esi),%eax
 PC (0xb5f5b9a5) ok
 source "(%esi)" (0x000001a0) not located in a known VMA region (needed readable region)!
 destination "%eax" ok
SegvReason: reading NULL VMA
Signal: 11
SourcePackage: unity
StacktraceTop:
 intel_miptree_release () from /usr/lib/i386-linux-gnu/dri/i965_dri.so
 intel_update_renderbuffers () from /usr/lib/i386-linux-gnu/dri/i965_dri.so
 intelSetTexBuffer2 () from /usr/lib/i386-linux-gnu/dri/i965_dri.so
 ?? () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1
 ?? () from /usr/lib/i386-linux-gnu/mesa/libGL.so.1
Title: compiz crashed with SIGSEGV in intel_miptree_release()
UpgradeStatus: Upgraded to precise on 2011-12-16 (91 days ago)
UserGroups: adm admin cdrom dialout libvirtd lpadmin plugdev sambashare vboxusers

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #927720, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.