Should not be a problem right now, but it could theoretically happen
in the future.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
 hw/mem/memory-device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
index 996ad1490f..8be63c8032 100644
--- a/hw/mem/memory-device.c
+++ b/hw/mem/memory-device.c
@@ -85,7 +85,8 @@ static void memory_device_check_addable(MachineState *ms, uint64_t size,
 
     /* will we exceed the total amount of memory specified */
     memory_device_used_region_size(OBJECT(ms), &used_region_size);
-    if (used_region_size + size > ms->maxram_size - ms->ram_size) {
+    if (used_region_size + size < used_region_size ||
+        used_region_size + size > ms->maxram_size - ms->ram_size) {
         error_setg(errp, "not enough space, currently 0x%" PRIx64
                    " in use of total space for memory devices 0x" RAM_ADDR_FMT,
                    used_region_size, ms->maxram_size - ms->ram_size);
-- 
2.17.1