Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6724,6 +6724,9 @@
     "cannot use variable-length arrays in "
     "%select{__device__|__global__|__host__|__host__ __device__}0 functions">;
 def err_cuda_extern_shared : Error<"__shared__ variable %0 cannot be 'extern'">;
+def err_cuda_host_shared : Error<
+    "__shared__ local variables not allowed in "
+    "%select{__device__|__global__|__host__|__host__ __device__}0 functions">;
 def err_cuda_nonglobal_constant : Error<"__constant__ variables must be global">;
 
 def warn_non_pod_vararg_with_format_string : Warning<
Index: clang/lib/Sema/SemaDeclAttr.cpp
===================================================================
--- clang/lib/Sema/SemaDeclAttr.cpp
+++ clang/lib/Sema/SemaDeclAttr.cpp
@@ -3718,6 +3718,11 @@
     S.Diag(Attr.getLoc(), diag::err_cuda_extern_shared) << VD;
     return;
   }
+  if (VD->hasLocalStorage() &&
+      !(S.CUDADiagIfHostCode(Attr.getLoc(), diag::err_cuda_host_shared)
+        << S.CurrentCUDATarget())
+           .IsDeferredOrNop())
+    return;
   D->addAttr(::new (S.Context) CUDASharedAttr(
       Attr.getRange(), S.Context, Attr.getAttributeSpellingListIndex()));
 }
Index: clang/test/SemaCUDA/bad-attributes.cu
===================================================================
--- clang/test/SemaCUDA/bad-attributes.cu
+++ clang/test/SemaCUDA/bad-attributes.cu
@@ -65,6 +65,7 @@
 __constant__ int global_constant;
 void host_fn() {
   __constant__ int c; // expected-error {{__constant__ variables must be global}}
+  __shared__ int s; // expected-error {{__shared__ local variables not allowed in __host__ functions}}
 }
 __device__ void device_fn() {
   __constant__ int c; // expected-error {{__constant__ variables must be global}}