KVM: MMU: Fix potential memory leak with smp real-mode
When we map a page, we check whether some other vcpu mapped it for us and if
so, bail out. But we should decrease the refcount on the page as we do so.
Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 87d8e70..8add4d5 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -907,8 +907,10 @@
pte = table[index];
was_rmapped = is_rmap_pte(pte);
- if (is_shadow_present_pte(pte) && is_writeble_pte(pte))
+ if (is_shadow_present_pte(pte) && is_writeble_pte(pte)) {
+ kvm_release_page(pfn_to_page(p >> PAGE_SHIFT));
return 0;
+ }
mark_page_dirty(vcpu->kvm, v >> PAGE_SHIFT);
page_header_update_slot(vcpu->kvm, table, v);
table[index] = p | PT_PRESENT_MASK | PT_WRITABLE_MASK |