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| author | Christoffer Dall <christoffer.dall@linaro.org> | 2014-10-10 12:14:29 +0200 |
|---|---|---|
| committer | Jiri Slaby <jslaby@suse.cz> | 2015-04-30 11:15:11 +0200 |
| commit | 91a82540f3e417f9fb908bcacffc8c8d27c59078 (patch) | |
| tree | 2e6c3798837ebe5d6d3845f6ffff0244f7e7bb57 /arch | |
| parent | 296cffc0f8705d35c2bcb754154ee4e829de238b (diff) | |
| download | lwn-91a82540f3e417f9fb908bcacffc8c8d27c59078.tar.gz lwn-91a82540f3e417f9fb908bcacffc8c8d27c59078.zip | |
arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE
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 <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kvm/mmu.c | 11 |
1 files changed, 11 insertions, 0 deletions
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; } |