Commit 0fd46044 authored by Peter Xu's avatar Peter Xu Committed by Paolo Bonzini
Browse files

KVM: X86: Sanity check on gfn before removal 



The index returned by kvm_async_pf_gfn_slot() will be removed when an
async pf gfn is going to be removed.  However kvm_async_pf_gfn_slot()
is not reliable in that it can return the last key it loops over even
if the gfn is not found in the async gfn array.  It should never
happen, but it's still better to sanity check against that to make
sure no unexpected gfn will be removed.

Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <20200416155910.267514-1-peterx@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5b494aea

arch/x86/kvm/x86.c

+4 −0
Original line number Diff line number Diff line
@@ -10353,6 +10353,10 @@ static void kvm_del_async_pf_gfn(struct kvm_vcpu *vcpu, gfn_t gfn) 
	u32 i, j, k;



	i = j = kvm_async_pf_gfn_slot(vcpu, gfn);



	if (WARN_ON_ONCE(vcpu->arch.apf.gfns[i] != gfn))

		return;



	while (true) {

		vcpu->arch.apf.gfns[i] = ~0;

		do {