From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v7 15/15] KVM: s390: fix possible null pointer dereference in pending_irqs() Date: Fri, 1 Feb 2019 10:36:10 +0100 Message-ID: References: <20190131085247.13826-1-mimu@linux.ibm.com> <20190131085247.13826-16-mimu@linux.ibm.com> Reply-To: pmorel@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190131085247.13826-16-mimu@linux.ibm.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Michael Mueller , KVM Mailing List Cc: Linux-S390 Mailing List , linux-kernel@vger.kernel.org, Martin Schwidefsky , Heiko Carstens , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Halil Pasic List-ID: On 31/01/2019 09:52, Michael Mueller wrote: > 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 > --- > 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 d322400ca587..660ec87b6e60 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) > Reviewed-by: Pierre Morel -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany