3.16.39-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: James Hogan <james.hogan@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: "Radim Krčmář" <rkrcmar@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/mips/kvm/kvm_tlb.c | 23 +++++++++++++++--------
1 file changed, 15 insertions(+), 8 deletions(-)
--- a/arch/mips/kvm/kvm_tlb.c
+++ b/arch/mips/kvm/kvm_tlb.c
@@ -361,6 +361,7 @@ kvm_mips_handle_mapped_seg_tlb_fault(str
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];
@@ -375,18 +376,24 @@ kvm_mips_handle_mapped_seg_tlb_fault(str
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, mips3_tlbpfn_to_paddr(tlb_lo[1])
- >> PAGE_SHIFT) < 0)
+ if (kvm_mips_map_page(kvm, gfn0) < 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];
+ if (kvm_mips_map_page(kvm, gfn1) < 0)
+ return -1;
+
+ pfn0 = kvm->arch.guest_pmap[gfn0];
+ pfn1 = kvm->arch.guest_pmap[gfn1];
if (hpa0)
*hpa0 = pfn0 << PAGE_SHIFT;
--
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