Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754190AbbGASmL (ORCPT ); Wed, 1 Jul 2015 14:42:11 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44738 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754061AbbGASlq (ORCPT ); Wed, 1 Jul 2015 14:41:46 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Catalin Marinas , Marc Zyngier , Christoffer Dall , Shannon Zhao Subject: [PATCH 3.14 24/34] arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE Date: Wed, 1 Jul 2015 11:40:31 -0700 Message-Id: <20150701183956.224616896@linuxfoundation.org> X-Mailer: git-send-email 2.4.4 In-Reply-To: <20150701183955.306219425@linuxfoundation.org> References: <20150701183955.306219425@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2047 Lines: 60 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christoffer Dall commit c3058d5da2222629bc2223c488a4512b59bb4baf upstream. [Since we don't backport commit 8eef912 (arm/arm64: KVM: map MMIO regions at creation time) for linux-3.14.y, the context of this patch is different, while the change itself is same.] 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 Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Shannon Zhao Signed-off-by: Greg Kroah-Hartman --- arch/arm/kvm/mmu.c | 11 +++++++++++ 1 file changed, 11 insertions(+) --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -926,6 +926,9 @@ int kvm_handle_guest_abort(struct kvm_vc 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(struc 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/