From 23520b2def95205f132e167cf5b25c609975e959 Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Fri, 21 Feb 2020 22:04:46 +0800 Subject: [PATCH] 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 Signed-off-by: Miaohe Lin Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/x86/kvm/lapic.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index cc8ee8125712..e3099c642fec 100644 --- 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; } -- 2.11.0