Commit fc3b77e2 authored by Igor Mammedov's avatar Igor Mammedov Committed by Eduardo Habkost
Browse files

pc: fix possible NULL pointer dereference in pc_machine_get_device_memory_region_size() 



QEMU will crash when device-memory-region-size property is read if ms->device_memory
wasn't initialized yet.

Crash can be reproduced with:
 $QEMU -preconfig -qmp unix:qmp_socket,server,nowait &
 ./scripts/qmp/qom-get -s qmp_socket /machine.device-memory-region-size

Instead of crashing return 0 if ms->device_memory hasn't been initialized.

Signed-off-by: default avatarIgor Mammedov <imammedo@redhat.com>
Message-Id: <20190624090200.5383-1-imammedo@redhat.com>
Signed-off-by: default avatarEduardo Habkost <ehabkost@redhat.com>
parent d65af288

hw/i386/pc.c

+5 −1
Original line number Diff line number Diff line
@@ -2553,7 +2553,11 @@ pc_machine_get_device_memory_region_size(Object *obj, Visitor *v, 
                                         Error **errp)

{

    MachineState *ms = MACHINE(obj);

    int64_t value = memory_region_size(&ms->device_memory->mr);

    int64_t value = 0;



    if (ms->device_memory) {

        value = memory_region_size(&ms->device_memory->mr);

    }



    visit_type_int(v, name, &value, errp);

}