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MIPS: KVM: Add missing gfn range check

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commit 8985d50382359e5bf118fdbefc859d0dbf6cebc7 upstream.

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: 858dd5d45733 ("KVM/MIPS32: MMU/TLB operations for the Guest.")
Signed-off-by: James 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
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[james.hogan@imgtec.com: Backport to v3.17.y - v4.4.y]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
James Hogan 2016-08-18 10:05:30 +01:00 committed by Greg Kroah-Hartman
parent ed7e1dd5ab
commit f26fac101c
1 changed files with 15 additions and 8 deletions
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23
arch/mips/kvm/tlb.c
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@ -361,6 +361,7 @@ 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;
pfn_t pfn0, pfn1;
gfn_t gfn0, gfn1;
long tlb_lo[2];
tlb_lo[0] = tlb->tlb_lo0;
@ -374,18 +375,24 @@ 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];
if (hpa0)
*hpa0 = pfn0 << PAGE_SHIFT;