From: KarimAllah Ahmed <karahmed@amazon.de>
Date: Wed, 10 Jul 2019 09:13:13 +0000 (+0200)
Subject: KVM: Properly check if "page" is valid in kvm_vcpu_unmap
X-Git-Tag: v5.2.3~83
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3ac6994561a29bff4bdf65833d6a88c0abab1691;p=users%2Fdwmw2%2Flinux.git

KVM: Properly check if "page" is valid in kvm_vcpu_unmap

commit b614c6027896ff9ad6757122e84760d938cab15e upstream.

The field "page" is initialized to KVM_UNMAPPED_PAGE when it is not used
(i.e. when the memory lives outside kernel control). So this check will
always end up using kunmap even for memremap regions.

Fixes: e45adf665a53 ("KVM: Introduce a new guest mapping API")
Cc: stable@vger.kernel.org
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2f2d24a4dd5c2..e629766f0ec87 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1790,7 +1790,7 @@ void kvm_vcpu_unmap(struct kvm_vcpu *vcpu, struct kvm_host_map *map,
 	if (!map->hva)
 		return;
 
-	if (map->page)
+	if (map->page != KVM_UNMAPPED_PAGE)
 		kunmap(map->page);
 #ifdef CONFIG_HAS_IOMEM
 	else