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Commit 8985d503 authored by James Hogan's avatar James Hogan Committed by Radim Krčmář
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MIPS: KVM: Add missing gfn range check 



kvm_mips_handle_mapped_seg_tlb_fault() calculates the guest frame number
based on the guest TLB EntryLo values, however it is not range checked
to ensure it lies within the guest_pmap. If the physical memory the
guest refers to is out of range then dump the guest TLB and emit an
internal error.

Fixes: 858dd5d4 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Cc: <stable@vger.kernel.org> # 3.10.x-
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent c604cffa

arch/mips/kvm/mmu.c

+15 −8
Original line number Diff line number Diff line
@@ -138,6 +138,7 @@ int kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu, 
	unsigned long entryhi = 0, entrylo0 = 0, entrylo1 = 0;

	struct kvm *kvm = vcpu->kvm;

	kvm_pfn_t pfn0, pfn1;

	gfn_t gfn0, gfn1;

	long tlb_lo[2];

	int ret;
@@ -152,18 +153,24 @@ int kvm_mips_handle_mapped_seg_tlb_fault(struct kvm_vcpu *vcpu, 
			VPN2_MASK & (PAGE_MASK << 1)))

		tlb_lo[(KVM_GUEST_COMMPAGE_ADDR >> PAGE_SHIFT) & 1] = 0;



	if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb_lo[0])

				   >> PAGE_SHIFT) < 0)

	gfn0 = mips3_tlbpfn_to_paddr(tlb_lo[0]) >> PAGE_SHIFT;

	gfn1 = mips3_tlbpfn_to_paddr(tlb_lo[1]) >> PAGE_SHIFT;

	if (gfn0 >= kvm->arch.guest_pmap_npages ||

	    gfn1 >= kvm->arch.guest_pmap_npages) {

		kvm_err("%s: Invalid gfn: [%#llx, %#llx], EHi: %#lx\n",

			__func__, gfn0, gfn1, tlb->tlb_hi);

		kvm_mips_dump_guest_tlbs(vcpu);

		return -1;

	}



	if (kvm_mips_map_page(kvm, gfn0) < 0)

		return -1;



	if (kvm_mips_map_page(kvm, mips3_tlbpfn_to_paddr(tlb_lo[1])

				   >> PAGE_SHIFT) < 0)

	if (kvm_mips_map_page(kvm, gfn1) < 0)

		return -1;



	pfn0 = kvm->arch.guest_pmap[

		mips3_tlbpfn_to_paddr(tlb_lo[0]) >> PAGE_SHIFT];

	pfn1 = kvm->arch.guest_pmap[

		mips3_tlbpfn_to_paddr(tlb_lo[1]) >> PAGE_SHIFT];

	pfn0 = kvm->arch.guest_pmap[gfn0];

	pfn1 = kvm->arch.guest_pmap[gfn1];



	/* Get attributes from the Guest TLB */

	entrylo0 = mips3_paddr_to_tlbpfn(pfn0 << PAGE_SHIFT) |