From 58164eaff530a1e804f5710936dd37518ab5a90e Mon Sep 17 00:00:00 2001 From: Igor Mammedov Date: Mon, 10 Jun 2019 15:50:35 +0200 Subject: [PATCH] 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: Igor Mammedov Message-Id: <1560174635-22602-1-git-send-email-imammedo@redhat.com> Signed-off-by: Paolo Bonzini --- hw/i386/pc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index e96360b47a..552f3401e2 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -2458,7 +2458,11 @@ 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); }