Free invalid pointer crash in vnc Attempt to send qemu monitor command crashed the VM. I have sent the following qemu monitor command to a running instance: virsh qemu-monitor-command --hmp instance-xxxxxxx 'change vnc none' At the time I was connected via VNC. Closing my xvncviewer resulted in a crash of the VM. Backtrace: *** Error in `/usr/bin/qemu-system-x86_64': free(): invalid pointer: 0x0000564f887a87e0 *** ======= Backtrace: ========= /lib/x86_64-linux-gnu/libc.so.6(+0x777e5)[0x7fa18b38b7e5] /lib/x86_64-linux-gnu/libc.so.6(+0x8037a)[0x7fa18b39437a] /lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7fa18b39853c] /usr/bin/qemu-system-x86_64(+0x4b25dd)[0x564f871a75dd] /usr/bin/qemu-system-x86_64(visit_type_VncServerInfo+0xa2)[0x564f871b9612] /usr/bin/qemu-system-x86_64(qapi_free_VncServerInfo+0x30)[0x564f871a6be0] /usr/bin/qemu-system-x86_64(+0x441bca)[0x564f87136bca] /usr/bin/qemu-system-x86_64(vnc_disconnect_finish+0x37)[0x564f87137bf7] /usr/bin/qemu-system-x86_64(aio_dispatch+0x68)[0x564f8715dcb8] /usr/bin/qemu-system-x86_64(+0x45bf9e)[0x564f87150f9e] /lib/x86_64-linux-gnu/libglib-2.0.so.0(g_main_context_dispatch+0x2a7)[0x7fa18c06c197] /usr/bin/qemu-system-x86_64(main_loop_wait+0x18b)[0x564f8715c5bb] /usr/bin/qemu-system-x86_64(main+0x17b4)[0x564f86ed64e4] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7fa18b334830] /usr/bin/qemu-system-x86_64(_start+0x29)[0x564f86edbb79] Version info: ii qemu-system 1:2.5+dfsg-5ubuntu10.16 amd64 QEMU full system emulation binaries ii qemu-system-x86 1:2.5+dfsg-5ubuntu10.16 amd64 QEMU full system emulation binaries (x86) ii qemu-utils 1:2.5+dfsg-5ubuntu10.16 amd64 QEMU utilities ii libvirt-bin 1.3.1-1ubuntu10.14 amd64 programs for the libvirt library ii libvirt0:amd64 1.3.1-1ubuntu10.14 amd64 library for interfacing with different virtualization systems ii nova-compute-libvirt 2:13.1.4-0ubuntu3 all OpenStack Compute - compute node libvirt support ii python-libvirt 1.3.1-1ubuntu1 amd64 libvirt Python bindings uname -a Linux 4.10.0-32-generic #36~16.04.1-Ubuntu SMP Wed Aug 9 09:19:02 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux Qemu startup: starting up libvirt version: 1.3.1, package: 1ubuntu10.14 (Jorge Niedbalski