Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock

From	Paolo Bonzini <pbonzini@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock
Date	2017-01-03 18:30 +0100
Message-ID	<sVB4l-1a8-9@gated-at.bofh.it> (permalink)
References	(2 earlier) <sV7SG-5kc-19@gated-at.bofh.it> <sVfdv-2gm-15@gated-at.bofh.it> <sVtzQ-4gf-9@gated-at.bofh.it> <sVuPf-4XV-17@gated-at.bofh.it> <sVw4G-5Va-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 03/01/2017 13:06, David Hildenbrand wrote:
>>
>>      switch (cap->cap) {
>>      case KVM_CAP_HYPERV_SYNIC:
>> -        return kvm_hv_activate_synic(vcpu);
>> +        if (!irqchip_in_kernel(vcpu->kvm))
>> +            return -EINVAL;
>> +        else
> 
> You can simply drop the else and return directly.
> 
> Can't really say if this is the right fix, my first thought was that
> a request has been set although it should never have been set for
> that VCPU. Maybe that is an effect of synic being activated
> (because synic code unconditionally later on sets the request).
> 
> Fixing the cause of the request seems better than fixing up the result.

Yes, I agree.  Wanpeng's second patch is fine.

Paolo

Thread

[PATCH] KVM: ioapic: fix NULL deref ioapic->lock Wanpeng Li <kernellwp@gmail.com> - 2017-01-01 04:50 +0100
  Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Paolo Bonzini <pbonzini@redhat.com> - 2017-01-02 11:10 +0100
    Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Dmitry Vyukov <dvyukov@google.com> - 2017-01-02 11:20 +0100
      Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Paolo Bonzini <pbonzini@redhat.com> - 2017-01-02 19:10 +0100
        Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Wanpeng Li <kernellwp@gmail.com> - 2017-01-02 23:40 +0100
        Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Dmitry Vyukov <dvyukov@google.com> - 2017-01-03 10:30 +0100
          Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Wanpeng Li <kernellwp@gmail.com> - 2017-01-03 11:50 +0100
            Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock David Hildenbrand <david@redhat.com> - 2017-01-03 13:10 +0100
              Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Paolo Bonzini <pbonzini@redhat.com> - 2017-01-03 18:30 +0100
                Re: [PATCH] KVM: ioapic: fix NULL deref ioapic->lock Wanpeng Li <kernellwp@gmail.com> - 2017-01-03 23:10 +0100

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