From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752212AbbD3MSE (ORCPT ); Thu, 30 Apr 2015 08:18:04 -0400 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:53668 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751435AbbD3MMf (ORCPT ); Thu, 30 Apr 2015 08:12:35 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Christoffer Dall , Shannon Zhao , Jiri Slaby Subject: [PATCH 3.12 50/63] arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE Date: Thu, 30 Apr 2015 14:12:19 +0200 Message-Id: <91a82540f3e417f9fb908bcacffc8c8d27c59078.1430387326.git.jslaby@suse.cz> X-Mailer: git-send-email 2.3.5 In-Reply-To: <45aaf85687dd6ac119c55c5ec0dbe0bef0e62235.1430387326.git.jslaby@suse.cz> References: <45aaf85687dd6ac119c55c5ec0dbe0bef0e62235.1430387326.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christoffer Dall 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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 Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall Signed-off-by: Shannon Zhao Signed-off-by: Jiri Slaby --- 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 2e0357dd8654..f9740851a6a4 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -772,6 +772,9 @@ 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, gfn, memslot, fault_status); if (ret == 0) ret = 1; @@ -996,6 +999,14 @@ 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; } -- 2.3.5