KVM: arm64: nv: Use kvm_phys_size() for VNCR invalidation range Protected mode uses `pkvm_mappings` of the union inside `struct kvm_pgtable`. This aliases `ia_bits`, which is used in non-protected mode. Attempting to use `pgt->ia_bits` in kvm_nested_s2_unmap() and kvm_nested_s2_wp() results in reading mapping pointers or state as a shift amount. This triggers a UBSAN shift-out-of-bounds error: UBSAN: shift-out-of-bounds in arch/arm64/kvm/nested.c:1127:34 shift exponent 174565952 is too large for 64-bit type 'unsigned long' Call trace: __ubsan_handle_shift_out_of_bounds+0x28c/0x2c0 kvm_nested_s2_unmap+0x228/0x248 kvm_arch_flush_shadow_memslot+0x98/0xc0 kvm_set_memslot+0x248/0xce0 Fix this by using kvm_phys_size() to determine the IPA size. This helper is independent of the software page table representation and works correctly for both protected and non-protected modes, as it derives the size directly from VTCR_EL2. Fixes: 7270cc9157f47 ("KVM: arm64: nv: Handle VNCR_EL2 invalidation from MMU notifiers") Signed-off-by: Fuad Tabba --- Based on Linux 6.19-rc8 --- arch/arm64/kvm/nested.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index cdeeb8f09e72..eb9666ba15b4 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -1108,7 +1108,7 @@ void kvm_nested_s2_wp(struct kvm *kvm) kvm_stage2_wp_range(mmu, 0, kvm_phys_size(mmu)); } - kvm_invalidate_vncr_ipa(kvm, 0, BIT(kvm->arch.mmu.pgt->ia_bits)); + kvm_invalidate_vncr_ipa(kvm, 0, kvm_phys_size(&kvm->arch.mmu)); } void kvm_nested_s2_unmap(struct kvm *kvm, bool may_block) @@ -1124,7 +1124,7 @@ void kvm_nested_s2_unmap(struct kvm *kvm, bool may_block) kvm_stage2_unmap_range(mmu, 0, kvm_phys_size(mmu), may_block); } - kvm_invalidate_vncr_ipa(kvm, 0, BIT(kvm->arch.mmu.pgt->ia_bits)); + kvm_invalidate_vncr_ipa(kvm, 0, kvm_phys_size(&kvm->arch.mmu)); } void kvm_nested_s2_flush(struct kvm *kvm) base-commit: 18f7fcd5e69a04df57b563360b88be72471d6b62 -- 2.53.0.rc1.225.gd81095ad13-goog