[PATCH] KVM: Fix oops on oom

__free_page() doesn't like a NULL argument, so check before calling it.  A
NULL can only happen if memory is exhausted during allocation of a memory
slot.
Signed-off-by: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/kvm/kvm_main.c

@@ -245,7 +245,8 @@ static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
 	if (!dont || free->phys_mem != dont->phys_mem)
 		if (free->phys_mem) {
 			for (i = 0; i < free->npages; ++i)
-				__free_page(free->phys_mem[i]);
+				if (free->phys_mem[i])
+					__free_page(free->phys_mem[i]);
 			vfree(free->phys_mem);
 		}