KVM: apic: avoid calculating pending eoi from an uninitialized val

When pv_eoi_get_user() fails, 'val' may remain uninitialized and the return value of pv_eoi_get_pending() becomes random. Fix the issue by initializing the variable. Reviewed-by: Vitaly Kuznetsov <[email protected]> Signed-off-by: Miaohe Lin <[email protected]> Cc: [email protected] Signed-off-by: Paolo Bonzini <[email protected]>
josf · Feb 21, 2020 · 23520b2 · 23520b2
1 parent a444326
commit 23520b2
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
@@ -627,9 +627,11 @@ static inline bool pv_eoi_enabled(struct kvm_vcpu *vcpu)
 static bool pv_eoi_get_pending(struct kvm_vcpu *vcpu)
 {
 	u8 val;
-	if (pv_eoi_get_user(vcpu, &val) < 0)
+	if (pv_eoi_get_user(vcpu, &val) < 0) {
 		printk(KERN_WARNING "Can't read EOI MSR value: 0x%llx\n",
 			   (unsigned long long)vcpu->arch.pv_eoi.msr_val);
+		return false;
+	}
 	return val & 0x1;
 }