fix: Limit recursion depth for unknown field detection and unpack any (…

…#22901)

CHANGELOG.md

@@ -55,7 +55,6 @@ Every module contains its own CHANGELOG.md. Please refer to the module you are i
 * [#22826](https://github.com/cosmos/cosmos-sdk/pull/22826) Simplify testing frameworks by removing `testutil/cmdtest`.
 
 ### Bug Fixes
-
 * (sims) [#21906](https://github.com/cosmos/cosmos-sdk/pull/21906) Skip sims test when running dry on validators
 * (cli) [#21919](https://github.com/cosmos/cosmos-sdk/pull/21919) Query address-by-acc-num by account_id instead of id.
 * (cli) [#22656](https://github.com/cosmos/cosmos-sdk/pull/22656) Prune cmd should disable async pruning.

codec/types/interface_registry.go

@@ -15,6 +15,17 @@ import (
 	"cosmossdk.io/x/tx/signing"
 )
 
+var (
+
+	// MaxUnpackAnySubCalls extension point that defines the maximum number of sub-calls allowed during the unpacking
+	// process of protobuf Any messages.
+	MaxUnpackAnySubCalls = 100
+
+	// MaxUnpackAnyRecursionDepth extension point that defines the maximum allowed recursion depth during protobuf Any
+	// message unpacking.
+	MaxUnpackAnyRecursionDepth = 10
+)
+
 // UnpackInterfaces is a convenience function that calls UnpackInterfaces
 // on x if x implements UnpackInterfacesMessage
 func UnpackInterfaces(x interface{}, unpacker gogoprotoany.AnyUnpacker) error {
@@ -230,6 +241,45 @@ func (registry *interfaceRegistry) ListImplementations(ifaceName string) []strin
 }
 
 func (registry *interfaceRegistry) UnpackAny(any *Any, iface interface{}) error {
+	unpacker := &statefulUnpacker{
+		registry: registry,
+		maxDepth: MaxUnpackAnyRecursionDepth,
+		maxCalls: &sharedCounter{count: MaxUnpackAnySubCalls},
+	}
+	return unpacker.UnpackAny(any, iface)
+}
+
+// sharedCounter is a type that encapsulates a counter value
+type sharedCounter struct {
+	count int
+}
+
+// statefulUnpacker is a struct that helps in deserializing and unpacking
+// protobuf Any messages while maintaining certain stateful constraints.
+type statefulUnpacker struct {
+	registry *interfaceRegistry
+	maxDepth int
+	maxCalls *sharedCounter
+}
+
+// cloneForRecursion returns a new statefulUnpacker instance with maxDepth reduced by one, preserving the registry and maxCalls.
+func (r statefulUnpacker) cloneForRecursion() *statefulUnpacker {
+	return &statefulUnpacker{
+		registry: r.registry,
+		maxDepth: r.maxDepth - 1,
+		maxCalls: r.maxCalls,
+	}
+}
+
+// UnpackAny deserializes a protobuf Any message into the provided interface, ensuring the interface is a pointer.
+// It applies stateful constraints such as max depth and call limits, and unpacks interfaces if required.
+func (r *statefulUnpacker) UnpackAny(any *Any, iface interface{}) error {
+	if r.maxDepth == 0 {
+		return errors.New("max depth exceeded")
+	}
+	if r.maxCalls.count == 0 {
+		return errors.New("call limit exceeded")
+	}
 	// here we gracefully handle the case in which `any` itself is `nil`, which may occur in message decoding
 	if any == nil {
 		return nil
@@ -240,6 +290,8 @@ func (registry *interfaceRegistry) UnpackAny(any *Any, iface interface{}) error
 		return nil
 	}
 
+	r.maxCalls.count--
+
 	rv := reflect.ValueOf(iface)
 	if rv.Kind() != reflect.Ptr {
 		return errors.New("UnpackAny expects a pointer")
@@ -255,7 +307,7 @@ func (registry *interfaceRegistry) UnpackAny(any *Any, iface interface{}) error
 		}
 	}
 
-	imap, found := registry.interfaceImpls[rt]
+	imap, found := r.registry.interfaceImpls[rt]
 	if !found {
 		return fmt.Errorf("no registered implementations of type %+v", rt)
 	}
@@ -277,7 +329,7 @@ func (registry *interfaceRegistry) UnpackAny(any *Any, iface interface{}) error
 		return err
 	}
 
-	err = UnpackInterfaces(msg, registry)
+	err = UnpackInterfaces(msg, r.cloneForRecursion())
 	if err != nil {
 		return err
 	}

codec/unknownproto/unknown_fields.go

@@ -40,9 +40,23 @@ func RejectUnknownFieldsStrict(bz []byte, msg proto.Message, resolver jsonpb.Any
 // This function traverses inside of messages nested via google.protobuf.Any. It does not do any deserialization of the proto.Message.
 // An AnyResolver must be provided for traversing inside google.protobuf.Any's.
 func RejectUnknownFields(bz []byte, msg proto.Message, allowUnknownNonCriticals bool, resolver jsonpb.AnyResolver) (hasUnknownNonCriticals bool, err error) {
+	// recursion limit with same default as https://github.com/protocolbuffers/protobuf-go/blob/v1.35.2/encoding/protowire/wire.go#L28
+	return doRejectUnknownFields(bz, msg, allowUnknownNonCriticals, resolver, 10_000)
+}
+
+func doRejectUnknownFields(
+	bz []byte,
+	msg proto.Message,
+	allowUnknownNonCriticals bool,
+	resolver jsonpb.AnyResolver,
+	recursionLimit int,
+) (hasUnknownNonCriticals bool, err error) {
 	if len(bz) == 0 {
 		return hasUnknownNonCriticals, nil
 	}
+	if recursionLimit == 0 {
+		return false, errors.New("recursion limit reached")
+	}
 
 	fieldDescProtoFromTagNum, _, err := getDescriptorInfo(msg)
 	if err != nil {
@@ -125,7 +139,7 @@ func RejectUnknownFields(bz []byte, msg proto.Message, allowUnknownNonCriticals
 
 		if protoMessageName == ".google.protobuf.Any" {
 			// Firstly typecheck types.Any to ensure nothing snuck in.
-			hasUnknownNonCriticalsChild, err := RejectUnknownFields(fieldBytes, (*types.Any)(nil), allowUnknownNonCriticals, resolver)
+			hasUnknownNonCriticalsChild, err := doRejectUnknownFields(fieldBytes, (*types.Any)(nil), allowUnknownNonCriticals, resolver, recursionLimit-1)
 			hasUnknownNonCriticals = hasUnknownNonCriticals || hasUnknownNonCriticalsChild
 			if err != nil {
 				return hasUnknownNonCriticals, err
@@ -148,7 +162,7 @@ func RejectUnknownFields(bz []byte, msg proto.Message, allowUnknownNonCriticals
 			}
 		}
 
-		hasUnknownNonCriticalsChild, err := RejectUnknownFields(fieldBytes, msg, allowUnknownNonCriticals, resolver)
+		hasUnknownNonCriticalsChild, err := doRejectUnknownFields(fieldBytes, msg, allowUnknownNonCriticals, resolver, recursionLimit-1)
 		hasUnknownNonCriticals = hasUnknownNonCriticals || hasUnknownNonCriticalsChild
 		if err != nil {
 			return hasUnknownNonCriticals, err

x/tx/CHANGELOG.md

@@ -33,7 +33,7 @@ Since v0.13.0, x/tx follows Cosmos SDK semver: https://github.com/cosmos/cosmos-
 
 ## [Unreleased]
 
-## [v1.0.0-alpha.3](https://github.com/cosmos/cosmos-sdk/releases/tag/x/tx/v1.0.0-alpha.3) - 2024-12-12
+## [v1.0.0-alpha.3](https://github.com/cosmos/cosmos-sdk/releases/tag/x/tx/v1.0.0-alpha.3) - 2024-12-16
 
 ### Bug Fixes
 

x/tx/decode/unknown.go

@@ -33,9 +33,23 @@ func RejectUnknownFieldsStrict(bz []byte, msg protoreflect.MessageDescriptor, re
 // This function traverses inside of messages nested via google.protobuf.Any. It does not do any deserialization of the proto.Message.
 // An AnyResolver must be provided for traversing inside google.protobuf.Any's.
 func RejectUnknownFields(bz []byte, desc protoreflect.MessageDescriptor, allowUnknownNonCriticals bool, resolver protodesc.Resolver) (hasUnknownNonCriticals bool, err error) {
+	// recursion limit with same default as https://github.com/protocolbuffers/protobuf-go/blob/v1.35.2/encoding/protowire/wire.go#L28
+	return doRejectUnknownFields(bz, desc, allowUnknownNonCriticals, resolver, 10_000)
+}
+
+func doRejectUnknownFields(
+	bz []byte,
+	desc protoreflect.MessageDescriptor,
+	allowUnknownNonCriticals bool,
+	resolver protodesc.Resolver,
+	recursionLimit int,
+) (hasUnknownNonCriticals bool, err error) {
 	if len(bz) == 0 {
 		return hasUnknownNonCriticals, nil
 	}
+	if recursionLimit == 0 {
+		return false, errors.New("recursion limit reached")
+	}
 
 	fields := desc.Fields()
 
@@ -111,7 +125,7 @@ func RejectUnknownFields(bz []byte, desc protoreflect.MessageDescriptor, allowUn
 
 		if fieldMessage.FullName() == anyFullName {
 			// Firstly typecheck types.Any to ensure nothing snuck in.
-			hasUnknownNonCriticalsChild, err := RejectUnknownFields(fieldBytes, anyDesc, allowUnknownNonCriticals, resolver)
+			hasUnknownNonCriticalsChild, err := doRejectUnknownFields(fieldBytes, anyDesc, allowUnknownNonCriticals, resolver, recursionLimit-1)
 			hasUnknownNonCriticals = hasUnknownNonCriticals || hasUnknownNonCriticalsChild
 			if err != nil {
 				return hasUnknownNonCriticals, err
@@ -131,7 +145,7 @@ func RejectUnknownFields(bz []byte, desc protoreflect.MessageDescriptor, allowUn
 			fieldBytes = a.Value
 		}
 
-		hasUnknownNonCriticalsChild, err := RejectUnknownFields(fieldBytes, fieldMessage, allowUnknownNonCriticals, resolver)
+		hasUnknownNonCriticalsChild, err := doRejectUnknownFields(fieldBytes, fieldMessage, allowUnknownNonCriticals, resolver, recursionLimit-1)
 		hasUnknownNonCriticals = hasUnknownNonCriticals || hasUnknownNonCriticalsChild
 		if err != nil {
 			return hasUnknownNonCriticals, err