diff options
| author | Jan H. Schönherr | 2017-09-07 19:02:30 +0100 |
|---|---|---|
| committer | Paolo Bonzini | 2017-09-15 16:56:43 +0200 |
| commit | 3a8b0677fc6180a467e26cc32ce6b0c09a32f9bb (patch) | |
| tree | 9b852407d70fb9b566c6cc1e99f2f635633c0321 | |
| parent | 36ae3c0a36b7456432fedce38ae2f7bd3e01a563 (diff) | |
KVM: VMX: Do not BUG() on out-of-bounds guest IRQ
The value of the guest_irq argument to vmx_update_pi_irte() is
ultimately coming from a KVM_IRQFD API call. Do not BUG() in
vmx_update_pi_irte() if the value is out-of bounds. (Especially,
since KVM as a whole seems to hang after that.)
Instead, print a message only once if we find that we don't have a
route for a certain IRQ (which can be out-of-bounds or within the
array).
This fixes CVE-2017-1000252.
Fixes: efc644048ecde54 ("KVM: x86: Update IRTE for posted-interrupts")
Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/vmx.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 8e1ae716f938..0b15b43ef45d 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -11834,7 +11834,7 @@ static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq, struct kvm_lapic_irq irq; struct kvm_vcpu *vcpu; struct vcpu_data vcpu_info; - int idx, ret = -EINVAL; + int idx, ret = 0; if (!kvm_arch_has_assigned_device(kvm) || !irq_remapping_cap(IRQ_POSTING_CAP) || @@ -11843,7 +11843,12 @@ static int vmx_update_pi_irte(struct kvm *kvm, unsigned int host_irq, idx = srcu_read_lock(&kvm->irq_srcu); irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu); - BUG_ON(guest_irq >= irq_rt->nr_rt_entries); + if (guest_irq >= irq_rt->nr_rt_entries || + hlist_empty(&irq_rt->map[guest_irq])) { + pr_warn_once("no route for guest_irq %u/%u (broken user space?)\n", + guest_irq, irq_rt->nr_rt_entries); + goto out; + } hlist_for_each_entry(e, &irq_rt->map[guest_irq], link) { if (e->type != KVM_IRQ_ROUTING_MSI) |