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 @@ -637,9 +637,11 @@ 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) { 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; }