3.16.7-ckt12 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Christoffer Dall <[email protected]> commit c3058d5da2222629bc2223c488a4512b59bb4baf upstream. When creating or moving a memslot, make sure the IPA space is within the addressable range of the guest. Otherwise, user space can create too large a memslot and KVM would try to access potentially unallocated page table entries when inserting entries in the Stage-2 page tables. Acked-by: Catalin Marinas <[email protected]> Acked-by: Marc Zyngier <[email protected]> Signed-off-by: Christoffer Dall <[email protected]> Signed-off-by: Shannon Zhao <[email protected]> [ luis: backported to 3.16: used shannon's backport for 3.14 ] Signed-off-by: Luis Henriques <[email protected]> --- arch/arm/kvm/mmu.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 0258b22bf9d1..2555a52cccd2 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -926,6 +926,9 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) memslot = gfn_to_memslot(vcpu->kvm, gfn); + /* Userspace should not be able to register out-of-bounds IPAs */ + VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE); + ret = user_mem_abort(vcpu, fault_ipa, memslot, fault_status); if (ret == 0) ret = 1; @@ -1150,6 +1153,14 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, struct kvm_userspace_memory_region *mem, enum kvm_mr_change change) { + /* + * Prevent userspace from creating a memory region outside of the IPA + * space addressable by the KVM guest IPA space. + */ + if (memslot->base_gfn + memslot->npages >= + (KVM_PHYS_SIZE >> PAGE_SHIFT)) + return -EFAULT; + return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
