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

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>
This commit is contained in:
Miaohe Lin 2020-02-21 22:04:46 +08:00 committed by Greg Kroah-Hartman
parent e6bff0cdf5
commit 647bdd69c2

View File

@ -566,9 +566,11 @@ 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) {
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;
}