From: James Hogan Date: Thu, 18 Aug 2016 09:05:30 +0000 (+0100) Subject: MIPS: KVM: Add missing gfn range check X-Git-Tag: firefly_0821_release~176^2~4^2~31^2~386 X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=f26fac101c44492ca80d7ec65d484589299d8c99;p=firefly-linux-kernel-4.4.55.git MIPS: KVM: Add missing gfn range check 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 Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Radim Krčmář [james.hogan@imgtec.com: Backport to v3.17.y - v4.4.y] Signed-off-by: James Hogan Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c index d3c5715426c4..59e885fa4c65 100644 --- a/arch/mips/kvm/tlb.c +++ b/arch/mips/kvm/tlb.c @@ -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;