| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 152/165] KVM: apic: avoid calculating pending eoi from an uninitialized val | Date | Thu, 27 Feb 2020 14:37:06 +0100 |
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From: Miaohe Lin <linmiaohe@huawei.com>
commit 23520b2def95205f132e167cf5b25c609975e959 upstream.
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 <vkuznets@redhat.com> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/kvm/lapic.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -532,9 +532,11 @@ static inline bool pv_eoi_enabled(struct 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) { apic_debug("Can't read EOI MSR value: 0x%llx\n", (unsigned long long)vcpu->arch.pv_eoi.msr_val); + return false; + } return val & 0x1; }
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