Here is the backtrace from gdb: Program received signal SIGSEGV, Segmentation fault. list_add (head=0xb36748, entry=0xb9f098) at ../../../../../xf86-video-intel/src/intel_list.h:161 161 __list_add(entry, head, head->next); (gdb) p entry $1 = (struct list *) 0xb9f098 (gdb) p head $2 = (struct list *) 0xb36748 (gdb) p head->next $3 = (struct list *) 0x21 (gdb) bt #0 list_add (head=0xb36748, entry=0xb9f098) at ../../../../../xf86-video-intel/src/intel_list.h:161 #1 list_move (head=0xb36748, list=0xb9f098) at ../../../../../xf86-video-intel/src/intel_list.h:248 #2 __kgem_bo_mark_dirty (bo=0xb9f080) at ../../../../../xf86-video-intel/src/sna/kgem.h:596 #3 kgem_add_reloc (kgem=kgem@entry=0x7ffff7f29220, pos=, bo=0xb9f080, bo@entry=0x8b7990, read_write_domain=read_write_domain@entry=163842, delta=64, delta@entry=0) at ../../../../../xf86-video-intel/src/sna/kgem.c:4144 #4 0x00007ffff508a12e in sna_blt_copy_boxes (sna=sna@entry=0x7ffff7f29010, alu=alu@entry=3 '\003', src_bo=src_bo@entry=0x8b7dc0, src_dx=src_dx@entry=0, src_dy=src_dy@entry=0, dst_bo=dst_bo@entry=0x8b7990, dst_dx=dst_dx@entry=0, dst_dy=0, bpp=32, box=box@entry=0x8b7be0, nbox=0, nbox@entry=2) at ../../../../../xf86-video-intel/src/sna/sna_blt.c:2559 #5 0x00007ffff5101d0f in gen7_render_copy_boxes (sna=0x7ffff7f29010, alu=3 '\003', src=, src_bo=0x8b7dc0, src_dx=0, src_dy=0, dst=0x8b78a0, dst_bo=0x8b7990, dst_dx=0, dst_dy=0, box=0x8b7be0, n=2, flags=1) at ../../../../../xf86-video-intel/src/sna/gen7_render.c:2817 #6 0x00007ffff5094e55 in sna_mode_redisplay (sna=sna@entry=0x7ffff7f29010) at ../../../../../xf86-video-intel/src/sna/sna_display.c:3292 #7 0x00007ffff508454c in sna_accel_flush (sna=) at ../../../../../xf86-video-intel/src/sna/sna_accel.c:14052 #8 sna_accel_block_handler (sna=0x7ffff7f29010, tv=0x7fffffffdbc0) at ../../../../../xf86-video-intel/src/sna/sna_accel.c:14407 #9 0x0000000000443264 in BlockHandler (pTimeout=pTimeout@entry=0x7fffffffdbc0, pReadmask=pReadmask@entry=0x8555e0) at ../../../xserver/dix/dixutils.c:387 #10 0x00000000005c51a7 in WaitForSomething (pClientsReady=pClientsReady@entry=0xa927d0) at ../../../xserver/os/WaitFor.c:210 #11 0x000000000043e6f1 in Dispatch () at ../../../xserver/dix/dispatch.c:361 #12 0x000000000042ba7b in main (argc=4, argv=0x7fffffffdf08, envp=) at ../../../xserver/dix/main.c:295 Another gdb backtrace: Program received signal SIGSEGV, Segmentation fault. kgem_check_many_bo_fenced (kgem=kgem@entry=0x7ffff7f29220) at ../../../../../xf86-video-intel/src/sna/kgem.c:4027 4027 while (bo->proxy) (gdb) p bo $1 = (struct kgem_bo *) 0x30 (gdb) p bo->proxy Cannot access memory at address 0x30 (gdb) bt #0 kgem_check_many_bo_fenced (kgem=kgem@entry=0x7ffff7f29220) at ../../../../../xf86-video-intel/src/sna/kgem.c:4027 #1 0x00007ffff508a011 in sna_blt_copy_boxes (sna=sna@entry=0x7ffff7f29010, alu=alu@entry=3 '\003', src_bo=src_bo@entry=0xb2b340, src_dx=src_dx@entry=0, src_dy=src_dy@entry=0, dst_bo=dst_bo@entry=0x8b7ca0, dst_dx=dst_dx@entry=0, dst_dy=0, bpp=32, box=box@entry=0x7fffffffda60, nbox=nbox@entry=1) at ../../../../../xf86-video-intel/src/sna/sna_blt.c:2518 #2 0x00007ffff5101d0f in gen7_render_copy_boxes (sna=0x7ffff7f29010, alu=3 '\003', src=, src_bo=0xb2b340, src_dx=0, src_dy=0, dst=0x8b78a0, dst_bo=0x8b7ca0, dst_dx=0, dst_dy=0, box=0x7fffffffda60, n=1, flags=1) at ../../../../../xf86-video-intel/src/sna/gen7_render.c:2817 #3 0x00007ffff51077d2 in sna_dri_copy_to_front (sna=sna@entry=0x7ffff7f29010, draw=draw@entry=0xb2b3d0, region=, region@entry=0x0, dst_bo=0x8b7ca0, src_bo=0xb2b340, sync=, sync@entry=true) at ../../../../../xf86-video-intel/src/sna/sna_dri.c:684 #4 0x00007ffff5108994 in sna_dri_immediate_blit (info=, draw=0xb2b3d0, sna=0x7ffff7f29010) at ../../../../../xf86-video-intel/src/sna/sna_dri.c:1972 #5 sna_dri_schedule_swap (client=0xb2af90, draw=0xb2b3d0, front=0xb2b1c0, back=0xb2b120, target_msc=, divisor=0, remainder=0, func=0x594590 , data=0xb2b3d0) at ../../../../../xf86-video-intel/src/sna/sna_dri.c:2103 ---Type to continue, or q to quit--- #6 0x000000000059338b in DRI2SwapBuffers (client=client@entry=0xb2af90, pDraw=0xb2b3d0, target_msc=, divisor=, remainder=, swap_target=swap_target@entry=0x7fffffffdce0, func=func@entry=0x594590 , data=0xb2b3d0) at ../../../../../xserver/hw/xfree86/dri2/dri2.c:1178 #7 0x0000000000594d61 in ProcDRI2SwapBuffers (client=0xb2af90) at ../../../../../xserver/hw/xfree86/dri2/dri2ext.c:413 #8 ProcDRI2Dispatch (client=0xb2af90) at ../../../../../xserver/hw/xfree86/dri2/dri2ext.c:610 #9 0x000000000043e99e in Dispatch () at ../../../xserver/dix/dispatch.c:432 #10 0x000000000042ba7b in main (argc=3, argv=0x7fffffffdf18, envp=) at ../../../xserver/dix/main.c:295 Another backtrace (not from gdb): (EE) (EE) Backtrace: (EE) 0: /opt/gfx-x64/bin/Xorg (xorg_backtrace+0x3f) [0x5c875f] (EE) 1: /opt/gfx-x64/bin/Xorg (0x400000+0x1cc719) [0x5cc719] (EE) 2: /lib/x86_64-linux-gnu/libpthread.so.0 (0x7fe22962f000+0xf030) [0x7fe22963e030] (EE) 3: /opt/gfx-x64/lib/xorg/modules/drivers/intel_drv.so (0x7fe22748c000+0x3a2e3) [0x7fe2274c62e3] (EE) 4: /opt/gfx-x64/lib/xorg/modules/drivers/intel_drv.so (0x7fe22748c000+0x6c011) [0x7fe2274f8011] (EE) 5: /opt/gfx-x64/lib/xorg/modules/drivers/intel_drv.so (0x7fe22748c000+0xe3d0f) [0x7fe22756fd0f] (EE) 6: /opt/gfx-x64/lib/xorg/modules/drivers/intel_drv.so (0x7fe22748c000+0x76e55) [0x7fe227502e55] (EE) 7: /opt/gfx-x64/lib/xorg/modules/drivers/intel_drv.so (0x7fe22748c000+0x6654c) [0x7fe2274f254c] (EE) 8: /opt/gfx-x64/bin/Xorg (BlockHandler+0x44) [0x443264] (EE) 9: /opt/gfx-x64/bin/Xorg (WaitForSomething+0x287) [0x5c51a7] (EE) 10: /opt/gfx-x64/bin/Xorg (0x400000+0x3e6f1) [0x43e6f1] (EE) 11: /opt/gfx-x64/bin/Xorg (0x400000+0x2ba7b) [0x42ba7b] (EE) 12: /lib/x86_64-linux-gnu/libc.so.6 (__libc_start_main+0xfd) [0x7fe228327ead] (EE) 13: /opt/gfx-x64/bin/Xorg (0x400000+0x2be4d) [0x42be4d] (EE) (EE) Segmentation fault at address 0x1000 Fatal server error: Caught signal 11 (Segmentation fault). Server aborting