From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Borntraeger Subject: [PATCH 1/7] KVM: s390: floating irqs: fix user triggerable endless loop Date: Wed, 4 Feb 2015 10:44:46 +0100 Message-ID: <1423043092-34044-2-git-send-email-borntraeger@de.ibm.com> References: <1423043092-34044-1-git-send-email-borntraeger@de.ibm.com> Return-path: In-Reply-To: <1423043092-34044-1-git-send-email-borntraeger@de.ibm.com> Sender: kvm-owner@vger.kernel.org List-Archive: List-Post: To: Paolo Bonzini Cc: KVM , Cornelia Huck , Jens Freimann , linux-s390 , Alexander Graf , David Hildenbrand , stable@vger.kernel.org, #@tuxmaker.boeblingen.de.ibm.com, v3.15+@tuxmaker.boeblingen.de.ibm.com, Christian Borntraeger List-ID: From: David Hildenbrand 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: Dominik Dingel Reviewed-by: Cornelia Huck Signed-off-by: David Hildenbrand Cc: stable@vger.kernel.org # v3.15+ Signed-off-by: Christian Borntraeger --- arch/s390/kvm/interrupt.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index c34e1d9..073b5f3 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -1244,6 +1244,8 @@ static int __inject_vm(struct kvm *kvm, struct kvm_s390_interrupt_info *inti) list_add_tail(&inti->list, &iter->list); } 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); if (sigcpu == KVM_MAX_VCPUS) { do { -- 1.9.3