Commit 0fd46044 authored Apr 16, 2020 by Peter Xu Committed by Paolo Bonzini May 15, 2020

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: Peter Xu <peterx@redhat.com>
Message-Id: <20200416155910.267514-1-peterx@redhat.com>
Signed-off-by: Paolo 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 {

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