From b9fa6d6ee9b88eedf2d2261f931841664aa6980e Mon Sep 17 00:00:00 2001 From: Michael Mueller Date: Thu, 31 Jan 2019 09:52:46 +0100 Subject: [PATCH] KVM: s390: fix possible null pointer dereference in pending_irqs() Assure a GISA is in use before accessing the IPM to avoid a null pointer dereference issue. Signed-off-by: Michael Mueller Reported-by: Halil Pasic Reviewed-by: Pierre Morel Reviewed-by: Cornelia Huck Message-Id: <20190131085247.13826-16-mimu@linux.ibm.com> Signed-off-by: Christian Borntraeger --- arch/s390/kvm/interrupt.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index dc446203e5a4..82162867f378 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -329,9 +329,13 @@ static inline unsigned long pending_irqs_no_gisa(struct kvm_vcpu *vcpu) static inline unsigned long pending_irqs(struct kvm_vcpu *vcpu) { - return pending_irqs_no_gisa(vcpu) | - gisa_get_ipm(vcpu->kvm->arch.gisa_int.origin) << - IRQ_PEND_IO_ISC_7; + struct kvm_s390_gisa_interrupt *gi = &vcpu->kvm->arch.gisa_int; + unsigned long pending_mask; + + pending_mask = pending_irqs_no_gisa(vcpu); + if (gi->origin) + pending_mask |= gisa_get_ipm(gi->origin) << IRQ_PEND_IO_ISC_7; + return pending_mask; } static inline int isc_to_irq_type(unsigned long isc)