Commit 8e2207cd authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger

KVM: s390: floating irqs: fix user triggerable endless loop

If a vm with no VCPUs is created, the injection of a floating irq
leads to an endless loop in the kernel.

Let's skip the search for a destination VCPU for a floating irq if no
VCPUs were created.
Reviewed-by: default avatarDominik Dingel <dingel@linux.vnet.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v3.15+
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent f7819512
...@@ -1244,6 +1244,8 @@ static int __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info *inti) ...@@ -1244,6 +1244,8 @@ static int __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info *inti)
list_add_tail(&inti->list, &iter->list); list_add_tail(&inti->list, &iter->list);
} }
atomic_set(&fi->active, 1); atomic_set(&fi->active, 1);
if (atomic_read(&kvm->online_vcpus) == 0)
goto unlock_fi;
sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS); sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);
if (sigcpu == KVM_MAX_VCPUS) { if (sigcpu == KVM_MAX_VCPUS) {
do { do {
......
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