From: Christoph Schlameuss Date: Mon, 16 Dec 2024 09:21:35 +0000 (+0100) Subject: KVM: s390: Reject setting flic pfault attributes on ucontrol VMs X-Git-Tag: v6.13-rc7~6^2^2~4 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df989238fa46039393f0af5cfb93a863a233c061;p=thirdparty%2Flinux.git KVM: s390: Reject setting flic pfault attributes on ucontrol VMs Prevent null pointer dereference when processing the KVM_DEV_FLIC_APF_ENABLE and KVM_DEV_FLIC_APF_DISABLE_WAIT ioctls in the interrupt controller. Fixes: 3c038e6be0e2 ("KVM: async_pf: Async page fault support on s390") Reported-by: Claudio Imbrenda Signed-off-by: Christoph Schlameuss Reviewed-by: Hariharan Mari Reviewed-by: Claudio Imbrenda Link: https://lore.kernel.org/r/20241216092140.329196-2-schlameuss@linux.ibm.com Message-ID: <20241216092140.329196-2-schlameuss@linux.ibm.com> Signed-off-by: Claudio Imbrenda --- diff --git a/Documentation/virt/kvm/devices/s390_flic.rst b/Documentation/virt/kvm/devices/s390_flic.rst index ea96559ba5016..b784f80167483 100644 --- a/Documentation/virt/kvm/devices/s390_flic.rst +++ b/Documentation/virt/kvm/devices/s390_flic.rst @@ -58,11 +58,15 @@ Groups: Enables async page faults for the guest. So in case of a major page fault the host is allowed to handle this async and continues the guest. + -EINVAL is returned when called on the FLIC of a ucontrol VM. + KVM_DEV_FLIC_APF_DISABLE_WAIT Disables async page faults for the guest and waits until already pending async page faults are done. This is necessary to trigger a completion interrupt for every init interrupt before migrating the interrupt list. + -EINVAL is returned when called on the FLIC of a ucontrol VM. + KVM_DEV_FLIC_ADAPTER_REGISTER Register an I/O adapter interrupt source. Takes a kvm_s390_io_adapter describing the adapter to register:: diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index ea8dce299954a..22d73c13e5557 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