From: Izik Eidus <izike@qumranet.com>
Date: Tue, 20 Nov 2007 09:30:04 +0000 (+0200)
Subject: KVM: MMU: Fix potential memory leak with smp real-mode
X-Git-Tag: v2.6.25-rc1~1138^2~112
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=2065b3727ecdb64450597d70f7e13af00b85dbd8;p=linux-2.6-omap-h63xx.git

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 87d8e70fe50..8add4d5c684 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -907,8 +907,10 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, hpa_t p)
 
 			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 |