This is a note to let you know that I've just added the patch titled
arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-arm64-kvm-ensure-memslots-are-within-kvm_phys_size.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c3058d5da2222629bc2223c488a4512b59bb4baf Mon Sep 17 00:00:00 2001
From: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Date: Fri, 10 Oct 2014 12:14:29 +0200
Subject: arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE
From: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
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 <catalin.marinas@xxxxxxx>
Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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;
}
Patches currently in stable-queue which might be from christoffer.dall@xxxxxxxxxx are
queue-3.14/arm-arm64-kvm-ensure-memslots-are-within-kvm_phys_size.patch
queue-3.14/arm-arm64-kvm-fix-potential-null-dereference-in.patch
queue-3.14/arm64-kvm-fix-unmapping-with-48-bit-vas.patch
queue-3.14/arm-arm64-kvm-fix-set_clear_sgi_pend_reg-offset.patch
queue-3.14/arm-kvm-strict_mm_typechecks-fix-for-user_mem_abort.patch
queue-3.14/arm-arm64-kvm-fix-use-of-wnr-bit-in-kvm_is_write_fault.patch
queue-3.14/arm-kvm-fix-cpu-hotplug.patch
queue-3.14/arm-arm64-kvm-fix-vttbr_baddr_mask-and-pgd-alloc.patch
queue-3.14/arm-arm64-kvm-vgic-fix-error-code-in-kvm_vgic_create.patch
queue-3.14/kvm-arm-vgic-plug-irq-injection-race.patch
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