Xorg crashed with SIGABRT [SEGV in recreate_growing_buffer() from intel_batchbuffer_reset()]

[David Kastrup]

Happened while video editing with Shotcut and changing zoom setting. First time this happened, so no idea how to reproduce.

ProblemType: Crash
DistroRelease: Ubuntu 18.04
Package: xserver-xorg-core 2:1.19.6-1ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-10.11-lowlatency 4.15.3
Uname: Linux 4.15.0-10-lowlatency x86_64
ApportVersion: 2.20.8-0ubuntu10
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: None
Date: Wed Mar 7 10:11:24 2018
DistUpgraded: 2018-01-23 01:04:27,253 DEBUG Running PostInstallScript: './xorg_fix_proprietary.py'
DistroCodename: bionic
DistroVariant: ubuntu
DkmsStatus:
 tp_smapi, 0.42, 4.13.0-32-lowlatency, x86_64: installed
 tp_smapi, 0.42, 4.15.0-10-lowlatency, x86_64: installed
 v4l2loopback, 0.10.0, 4.13.0-32-lowlatency, x86_64: installed
 v4l2loopback, 0.10.0, 4.15.0-10-lowlatency, x86_64: installed
ExecutablePath: /usr/lib/xorg/Xorg
ExtraDebuggingInterest: Yes
GraphicsCard:
 Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) [8086:2a02] (rev 0c) (prog-if 00 [VGA controller])
   Subsystem: Lenovo ThinkPad T61/R61 [17aa:20b5]
   Subsystem: Lenovo ThinkPad T61/R61 [17aa:20b5]
InstallationDate: Installed on 2011-10-14 (2335 days ago)
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release i386 (20111011)
MachineType: LENOVO 7661LN8
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcCmdline: /usr/lib/xorg/Xorg -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
ProcEnviron: PATH=(custom, no user)
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.15.0-10-lowlatency root=UUID=a5b30f2d-d555-4bea-9b89-e322f13656be ro quiet splash threadirqs resume=UUID=29869a91-5410-4e9b-9bd9-2aea1ecb1637 vt.handoff=1
Signal: 6
SourcePackage: xorg-server
StacktraceTop:
 ()
 ()
 ()
 ()
 ()
Title: Xorg crashed with SIGABRT
UpgradeStatus: Upgraded to bionic on 2018-01-23 (43 days ago)
UserGroups:

dmi.bios.date: 03/18/2011
dmi.bios.vendor: LENOVO
dmi.bios.version: 7LETC9WW (2.29 )
dmi.board.name: 7661LN8
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: 000L004051
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr7LETC9WW(2.29):bd03/18/2011:svnLENOVO:pn7661LN8:pvrThinkPadT61:rvnLENOVO:rn7661LN8:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.family: ThinkPad T61
dmi.product.name: 7661LN8
dmi.product.version: ThinkPad T61
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.90-1
version.libgl1-mesa-dri: libgl1-mesa-dri 18.0.0~rc4-1ubuntu3
version.libgl1-mesa-glx: libgl1-mesa-glx 18.0.0~rc4-1ubuntu3
version.xserver-xorg-core: xserver-xorg-core 2:1.19.6-1ubuntu2
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.10.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20171229-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.15-2

[Apport retracing service (apport)]

StacktraceTop:
 recreate_growing_buffer (brw=brw@entry=0x7f436e56b040, grow=grow@entry=0x7f436e5903f8, name=name@entry=0x7f43673b5d38 "batchbuffer", size=size@entry=20480) at ../../../../../../src/mesa/drivers/dri/i965/intel_batchbuffer.c:173
 intel_batchbuffer_reset (brw=brw@entry=0x7f436e56b040) at ../../../../../../src/mesa/drivers/dri/i965/intel_batchbuffer.c:193
 intel_batchbuffer_reset_and_clear_render_cache (brw=0x7f436e56b040) at ../../../../../../src/mesa/drivers/dri/i965/intel_batchbuffer.c:221
 brw_new_batch (brw=<optimized out>) at ../../../../../../src/mesa/drivers/dri/i965/intel_batchbuffer.c:694
 _intel_batchbuffer_flush_fence (brw=brw@entry=0x7f436e56b040, in_fence_fd=in_fence_fd@entry=-1, out_fence_fd=out_fence_fd@entry=0x0, file=file@entry=0x7f43673ba440 "../../../../../../src/mesa/drivers/dri/i965/brw_context.c", line=line@entry=244) at ../../../../../../src/mesa/drivers/dri/i965/intel_batchbuffer.c:1032