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[4.9,152/165] KVM: apic: avoid calculating pending eoi from an uninitialized val

Message ID 20200227132252.910073462@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman Feb. 27, 2020, 1:37 p.m. UTC 
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(-)
diff mbox series

Patch

--- 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;
 }