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Add limits to wasm structures #404

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Merged
ksh8281 merged 1 commit into from
Apr 16, 2026
Merged

Add limits to wasm structures #404

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53 changes: 52 additions & 1 deletion src/parser/WASMParser.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,8 @@

namespace wabt {

#define PARSER_RESOURCE_LIMIT (uint16_t)16384
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kulcsaradam marked this conversation as resolved.

enum class WASMOpcode : size_t {
#define WABT_OPCODE(rtype, type1, type2, type3, memSize, prefix, code, name, \
text, decomp) \
Expand Down Expand Up @@ -911,7 +913,11 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnTypeCount(Index count) override
{
// TODO reserve vector if possible
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many type declarations.");
}

m_result.m_compositeTypes.reserve(count);
}

virtual void OnRecursiveType(Index firstTypeIndex, Index typeCount) override
Expand All @@ -927,6 +933,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {
Type* resultTypes,
GCTypeExtension* gcExt) override
{
if (paramCount > PARSER_RESOURCE_LIMIT || resultCount > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many function params or results.");
}

Walrus::FunctionType* functionType = new Walrus::FunctionType(paramCount, getRefCountOfTypes(paramTypes, paramCount),
resultCount, getRefCountOfTypes(resultTypes, resultCount),
gcExt->is_final_sub_type, toSubType(gcExt));
Expand Down Expand Up @@ -1008,6 +1018,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnImportCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many imports.");
}

m_result.m_imports.reserve(count);
}

Expand Down Expand Up @@ -1072,6 +1086,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnExportCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many exports.");
}

m_result.m_exports.reserve(count);
}

Expand All @@ -1084,6 +1102,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {
/* Table section */
virtual void OnTableCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many tables declarations.");
}

m_result.m_tableTypes.reserve(count);
}

Expand All @@ -1109,6 +1131,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnElemSegmentCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many elem segment declarations.");
}

m_result.m_elements.reserve(count);
}

Expand Down Expand Up @@ -1168,6 +1194,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {
/* Memory section */
virtual void OnMemoryCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many memory declarations.");
}

m_result.m_memoryTypes.reserve(count);
}

Expand All @@ -1179,6 +1209,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnDataSegmentCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many elem segment declarations.");
}

m_result.m_datas.reserve(count);
}

Expand Down Expand Up @@ -1215,6 +1249,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {
/* Function section */
virtual void OnFunctionCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many function declarations.");
}

m_result.m_functions.reserve(count);
}

Expand All @@ -1228,6 +1266,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnGlobalCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many global declarations.");
}

m_result.m_globalTypes.reserve(count);
}

Expand Down Expand Up @@ -1261,6 +1303,10 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnTagCount(Index count) override
{
if (count > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many tags.");
}

m_result.m_tagTypes.reserve(count);
}

Expand Down Expand Up @@ -1291,6 +1337,11 @@ class WASMBinaryReader : public wabt::WASMBinaryReaderDelegate {

virtual void OnLocalDecl(Index decl_index, Index count, Type type) override
{
uint64_t totalLocalCount = static_cast<uint64_t>(m_localInfo.size()) + count;
if (totalLocalCount > PARSER_RESOURCE_LIMIT) {
m_walrusParseError = std::string("Engine limit reached: too many local declarations.");
}

while (count) {
auto wType = toValueKind(type, &m_result);
m_currentFunction->m_local.push_back(wType);
Expand Down
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