[PATCH] KVM: x86: fix uninitialized variable use on KVM_REQ_TRIPLE_FAULT

From: Paolo Bonzini
Date: Wed Nov 30 2022 - 11:16:38 EST


If a triple fault was fixed by kvm_x86_ops.nested_ops->triple_fault (by
turning it into a vmexit), there is no need to leave vcpu_enter_guest().
Any vcpu->requests will be caught later before the actual vmentry,
and in fact vcpu_enter_guest() was not initializing the "r" variable.
Depending on the compiler's whims, this could cause the
x86_64/triple_fault_event_test test to fail.

Cc: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Fixes: 92e7d5c83aff ("KVM: x86: allow L1 to not intercept triple fault")
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
arch/x86/kvm/x86.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 246bdc9a9154..7f850dfb4086 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10280,8 +10280,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
vcpu->mmio_needed = 0;
r = 0;
+ goto out;
}
- goto out;
}
if (kvm_check_request(KVM_REQ_APF_HALT, vcpu)) {
/* Page is swapped out. Do synthetic halt */
--
2.31.1