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| author | Christoffer Dall <christoffer.dall@linaro.org> | 2014-10-10 12:14:29 +0200 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2014-10-14 05:48:25 -0700 |
| commit | c3058d5da2222629bc2223c488a4512b59bb4baf (patch) | |
| tree | c34f1e9fcf3909ddd493f644902b29ca18168236 | |
| parent | 38f791a4e499792eeb2a3c0572dd5133511c5bbb (diff) | |
| download | linux-c3058d5da2222629bc2223c488a4512b59bb4baf.tar.gz linux-c3058d5da2222629bc2223c488a4512b59bb4baf.tar.bz2 linux-c3058d5da2222629bc2223c488a4512b59bb4baf.zip | |
arm/arm64: KVM: Ensure memslots are within KVM_PHYS_SIZE
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>
| -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 ee142edcca84..8c40829d4a52 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1003,6 +1003,9 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run) goto out_unlock; } + /* 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, hva, fault_status); if (ret == 0) ret = 1; @@ -1229,6 +1232,14 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, return 0; /* + * 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; + + /* * A memory region could potentially cover multiple VMAs, and any holes * between them, so iterate over all of them to find out if we can map * any of them right now. |