From ccb7c819942daaeda58978d26fb45a3a48c2f8f6 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 15 Mar 2021 11:08:33 +0000 Subject: KVM: arm64: Fix exclusive limit for IPA size Commit 262b003d059c6671601a19057e9fe1a5e7f23722 upstream. When registering a memslot, we check the size and location of that memslot against the IPA size to ensure that we can provide guest access to the whole of the memory. Unfortunately, this check rejects memslot that end-up at the exact limit of the addressing capability for a given IPA size. For example, it refuses the creation of a 2GB memslot at 0x8000000 with a 32bit IPA space. Fix it by relaxing the check to accept a memslot reaching the limit of the IPA space. Fixes: c3058d5da222 ("arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE") Reviewed-by: Eric Auger Signed-off-by: Marc Zyngier Cc: stable@vger.kernel.org # 4.4, 4.9, 4.14, 4.19 Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20210311100016.3830038-3-maz@kernel.org Signed-off-by: Greg Kroah-Hartman --- virt/kvm/arm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'virt') diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c index 7fe673248e98..03bca28182b6 100644 --- a/virt/kvm/arm/mmu.c +++ b/virt/kvm/arm/mmu.c @@ -1870,7 +1870,7 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, * 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 >= + if (memslot->base_gfn + memslot->npages > (KVM_PHYS_SIZE >> PAGE_SHIFT)) return -EFAULT; -- cgit v1.2.3