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[interp] Add bounds checks in func/table/memory/global/tag handlers #2794

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[interp] Add bounds checks in func/table/memory/global/tag handlers #2794

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7aa88f0
Add bounds checks in func/table/memory/global/tag handlers
lexi-nadia Jul 9, 2026
2c0a60c
Merge branch 'main' into fuzz1
lexi-nadia Jul 9, 2026
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58 changes: 52 additions & 6 deletions src/interp/binary-reader-interp.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -549,6 +549,9 @@ Result BinaryReaderInterp::OnImportFunc(Index import_index,
Index sig_index) {
CHECK_RESULT(
validator_.OnFunction(GetLocation(), Var(sig_index, GetLocation())));
if (sig_index >= module_.func_types.size()) {
return Result::Error;
}

@sbc100 sbc100 Jul 9, 2026

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I'm curious.. does hitting this (and the other errors here) require disabling the validator? If so I think we should instead remove the ability for the fuzzers to skip validation. I think its reasonable to more of the code in wabt to assume valid inputs only (and use the validator and single point of protection against such).

In I'm right then these could maybe be assertions instead?

If I'm wrong then this change lgtm :)

FuncType& func_type = module_.func_types[sig_index];
module_.imports.push_back(ImportDesc{ImportType(
std::string(module_name), std::string(field_name), func_type.Clone())});
Expand Down Expand Up @@ -607,6 +610,9 @@ Result BinaryReaderInterp::OnImportTag(Index import_index,
Index tag_index,
Index sig_index) {
CHECK_RESULT(validator_.OnTag(GetLocation(), Var(sig_index, GetLocation())));
if (sig_index >= module_.func_types.size()) {
return Result::Error;
}
FuncType& func_type = module_.func_types[sig_index];
TagType tag_type{TagAttr::Exception, func_type.params};
module_.imports.push_back(ImportDesc{ImportType(
Expand All @@ -623,6 +629,9 @@ Result BinaryReaderInterp::OnFunctionCount(Index count) {
Result BinaryReaderInterp::OnFunction(Index index, Index sig_index) {
CHECK_RESULT(
validator_.OnFunction(GetLocation(), Var(sig_index, GetLocation())));
if (sig_index >= module_.func_types.size()) {
return Result::Error;
}
FuncType& func_type = module_.func_types[sig_index];
module_.funcs.push_back(FuncDesc{func_type, {}, Istream::kInvalidOffset, {}});
func_types_.push_back(func_type);
Expand Down Expand Up @@ -726,6 +735,9 @@ Result BinaryReaderInterp::OnTagCount(Index count) {

Result BinaryReaderInterp::OnTagType(Index index, Index sig_index) {
CHECK_RESULT(validator_.OnTag(GetLocation(), Var(sig_index, GetLocation())));
if (sig_index >= module_.func_types.size()) {
return Result::Error;
}
FuncType& func_type = module_.func_types[sig_index];
TagType tag_type{TagAttr::Exception, func_type.params};
module_.tags.push_back(TagDesc{tag_type});
Expand All @@ -742,11 +754,36 @@ Result BinaryReaderInterp::OnExport(Index index,

std::unique_ptr<ExternType> type;
switch (kind) {
case ExternalKind::Func: type = func_types_[item_index].Clone(); break;
case ExternalKind::Table: type = table_types_[item_index].Clone(); break;
case ExternalKind::Memory: type = memory_types_[item_index].Clone(); break;
case ExternalKind::Global: type = global_types_[item_index].Clone(); break;
case ExternalKind::Tag: type = tag_types_[item_index].Clone(); break;
case ExternalKind::Func:
if (item_index >= func_types_.size()) {
return Result::Error;
}
type = func_types_[item_index].Clone();
break;
case ExternalKind::Table:
if (item_index >= table_types_.size()) {
return Result::Error;
}
type = table_types_[item_index].Clone();
break;
case ExternalKind::Memory:
if (item_index >= memory_types_.size()) {
return Result::Error;
}
type = memory_types_[item_index].Clone();
break;
case ExternalKind::Global:
if (item_index >= global_types_.size()) {
return Result::Error;
}
type = global_types_[item_index].Clone();
break;
case ExternalKind::Tag:
if (item_index >= tag_types_.size()) {
return Result::Error;
}
type = tag_types_[item_index].Clone();
break;
}
module_.exports.push_back(
ExportDesc{ExportType(std::string(name), std::move(type)), item_index});
Expand Down Expand Up @@ -1239,6 +1276,9 @@ Result BinaryReaderInterp::OnReturnCallExpr(Index func_index) {
CHECK_RESULT(
validator_.OnReturnCall(GetLocation(), Var(func_index, GetLocation())));

if (func_index >= func_types_.size()) {
return Result::Error;
}
FuncType& func_type = func_types_[func_index];

Index drop_count, keep_count, catch_drop_count;
Expand Down Expand Up @@ -1273,6 +1313,9 @@ Result BinaryReaderInterp::OnReturnCallIndirectExpr(Index sig_index,
GetLocation(), Var(sig_index, GetLocation()),
Var(table_index, GetLocation())));

if (sig_index >= module_.func_types.size()) {
return Result::Error;
}
FuncType& func_type = module_.func_types[sig_index];

Index drop_count, keep_count, catch_drop_count;
Expand Down Expand Up @@ -1352,7 +1395,10 @@ Result BinaryReaderInterp::OnGlobalGetExpr(Index global_index) {
CHECK_RESULT(
validator_.OnGlobalGet(GetLocation(), Var(global_index, GetLocation())));

Type type = global_types_.at(global_index).type;
if (global_index >= global_types_.size()) {
return Result::Error;
}
Type type = global_types_[global_index].type;
if (type.IsRef()) {
istream_.Emit(Opcode::InterpGlobalGetRef, global_index);
} else {
Expand Down
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