[wasm] Fix and tighten memory validation

src/wasm/function-body-decoder.cc

Index: src/wasm/function-body-decoder.cc
diff --git a/src/wasm/function-body-decoder.cc b/src/wasm/function-body-decoder.cc
index 152fba1ffe92a42b9cd27c05f1180134cde89ef9..c48ad31136e517bddda3b37b652fa707a4be7db6 100644
--- a/src/wasm/function-body-decoder.cc
+++ b/src/wasm/function-body-decoder.cc
@@ -1112,6 +1112,10 @@ class WasmFullDecoder : public WasmDecoder {
             len = DecodeStoreMem(kWasmF64, MachineType::Float64());
             break;
           case kExprGrowMemory: {
+            if (!module_->has_memory) {

[titzer, 2017/01/18 10:17:30]

Can you factor out a little helper to turn this into a one-liner?

if (!CheckHasMemory(error_msg)) break;

[rossberg, 2017/01/18 11:28:09]

Done.

+              error(pc_ - 1, "memory instruction with no memory");
+              break;
+            }
             MemoryIndexOperand operand(this, pc_);
             DCHECK_NOT_NULL(module_);
             if (module_->origin != kAsmJsOrigin) {
@@ -1124,6 +1128,10 @@ class WasmFullDecoder : public WasmDecoder {
             break;
           }
           case kExprMemorySize: {
+            if (!module_->has_memory) {
+              error(pc_ - 1, "memory instruction with no memory");
+              break;
+            }
             MemoryIndexOperand operand(this, pc_);
             Push(kWasmI32, BUILD(CurrentMemoryPages));
             len = 1 + operand.length;
@@ -1304,6 +1312,10 @@ class WasmFullDecoder : public WasmDecoder {
   void PopControl() { control_.pop_back(); }
 
   int DecodeLoadMem(ValueType type, MachineType mem_type) {
+    if (!module_->has_memory) {
+      error(pc_ - 1, "load instruction with no memory");
+      return 0;
+    }
     MemoryAccessOperand operand(this, pc_,
                                 ElementSizeLog2Of(mem_type.representation()));
 
@@ -1315,6 +1327,10 @@ class WasmFullDecoder : public WasmDecoder {
   }
 
   int DecodeStoreMem(ValueType type, MachineType mem_type) {
+    if (!module_->has_memory) {
+      error(pc_ - 1, "store instruction with no memory");
+      return 0;
+    }
     MemoryAccessOperand operand(this, pc_,
                                 ElementSizeLog2Of(mem_type.representation()));
     Value val = Pop(1, type);