[PATCH v1 1/6] kvm: s390: Reject setting flic pfault attributes on ucontrol VMs

Christoph Schlameuss
2024-12-09T11:07:32Z

Prevent null pointer dereference when processing the
KVM_DEV_FLIC_APF_ENABLE and KVM_DEV_FLIC_APF_DISABLE_WAIT ioctls in the
interrupt controller.

Reported-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
---
arch/s390/kvm/interrupt.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index ea8dce299954..22d73c13e555 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2678,9 +2678,13 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
kvm_s390_clear_float_irqs(dev->kvm);
break;
case KVM_DEV_FLIC_APF_ENABLE:
+ if (kvm_is_ucontrol(dev->kvm))
+ return -EINVAL;
dev->kvm->arch.gmap->pfault_enabled = 1;
break;
case KVM_DEV_FLIC_APF_DISABLE_WAIT:
+ if (kvm_is_ucontrol(dev->kvm))
+ return -EINVAL;
dev->kvm->arch.gmap->pfault_enabled = 0;
/*
* Make sure no async faults are in transition when
--
2.47.1