3.16.39-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: James Hogan <[email protected]> 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 <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: "Radim Krčmář" <[email protected]> Cc: Ralf Baechle <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Radim Krčmář <[email protected]> [bwh: Backported to 3.16: adjust filename, context] Signed-off-by: Ben Hutchings <[email protected]> --- 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;
