diff --git a/encoding/protowire/wire.go b/encoding/protowire/wire.go index a427f8b70..9c61112f5 100644 --- a/encoding/protowire/wire.go +++ b/encoding/protowire/wire.go @@ -21,10 +21,11 @@ import ( type Number int32 const ( - MinValidNumber Number = 1 - FirstReservedNumber Number = 19000 - LastReservedNumber Number = 19999 - MaxValidNumber Number = 1<<29 - 1 + MinValidNumber Number = 1 + FirstReservedNumber Number = 19000 + LastReservedNumber Number = 19999 + MaxValidNumber Number = 1<<29 - 1 + DefaultRecursionLimit = 10000 ) // IsValid reports whether the field number is semantically valid. @@ -55,6 +56,7 @@ const ( errCodeOverflow errCodeReserved errCodeEndGroup + errCodeRecursionDepth ) var ( @@ -112,6 +114,10 @@ func ConsumeField(b []byte) (Number, Type, int) { // When parsing a group, the length includes the end group marker and // the end group is verified to match the starting field number. func ConsumeFieldValue(num Number, typ Type, b []byte) (n int) { + return consumeFieldValueD(num, typ, b, DefaultRecursionLimit) +} + +func consumeFieldValueD(num Number, typ Type, b []byte, depth int) (n int) { switch typ { case VarintType: _, n = ConsumeVarint(b) @@ -126,6 +132,9 @@ func ConsumeFieldValue(num Number, typ Type, b []byte) (n int) { _, n = ConsumeBytes(b) return n case StartGroupType: + if depth < 0 { + return errCodeRecursionDepth + } n0 := len(b) for { num2, typ2, n := ConsumeTag(b) @@ -140,7 +149,7 @@ func ConsumeFieldValue(num Number, typ Type, b []byte) (n int) { return n0 - len(b) } - n = ConsumeFieldValue(num2, typ2, b) + n = consumeFieldValueD(num2, typ2, b, depth-1) if n < 0 { return n // forward error code } diff --git a/internal/fuzz/wirefuzz/fuzz.go b/internal/fuzz/wirefuzz/fuzz.go index f7a9b74a4..fd27cca69 100644 --- a/internal/fuzz/wirefuzz/fuzz.go +++ b/internal/fuzz/wirefuzz/fuzz.go @@ -41,7 +41,7 @@ func Fuzz(data []byte) (score int) { // Unmarshal, Validate, and CheckInitialized should agree about initialization. checkInit := proto.CheckInitialized(m1) == nil methods := m1.ProtoReflect().ProtoMethods() - in := piface.UnmarshalInput{Message: mt.New(), Resolver: protoregistry.GlobalTypes} + in := piface.UnmarshalInput{Message: mt.New(), Resolver: protoregistry.GlobalTypes, Depth: 10000} if checkInit { // If the message initialized, the both Unmarshal and Validate should // report it as such. False negatives are tolerated, but have a diff --git a/internal/impl/decode.go b/internal/impl/decode.go index 949dc49a6..c65b0325c 100644 --- a/internal/impl/decode.go +++ b/internal/impl/decode.go @@ -18,6 +18,7 @@ import ( ) var errDecode = errors.New("cannot parse invalid wire-format data") +var errRecursionDepth = errors.New("exceeded maximum recursion depth") type unmarshalOptions struct { flags protoiface.UnmarshalInputFlags @@ -25,6 +26,7 @@ type unmarshalOptions struct { FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error) } + depth int } func (o unmarshalOptions) Options() proto.UnmarshalOptions { @@ -44,6 +46,7 @@ func (o unmarshalOptions) IsDefault() bool { var lazyUnmarshalOptions = unmarshalOptions{ resolver: preg.GlobalTypes, + depth: protowire.DefaultRecursionLimit, } type unmarshalOutput struct { @@ -62,6 +65,7 @@ func (mi *MessageInfo) unmarshal(in piface.UnmarshalInput) (piface.UnmarshalOutp out, err := mi.unmarshalPointer(in.Buf, p, 0, unmarshalOptions{ flags: in.Flags, resolver: in.Resolver, + depth: in.Depth, }) var flags piface.UnmarshalOutputFlags if out.initialized { @@ -82,6 +86,10 @@ var errUnknown = errors.New("unknown") func (mi *MessageInfo) unmarshalPointer(b []byte, p pointer, groupTag protowire.Number, opts unmarshalOptions) (out unmarshalOutput, err error) { mi.init() + opts.depth-- + if opts.depth < 0 { + return out, errRecursionDepth + } if flags.ProtoLegacy && mi.isMessageSet { return unmarshalMessageSet(mi, b, p, opts) } diff --git a/proto/decode.go b/proto/decode.go index 49f9b8c88..11bf7173b 100644 --- a/proto/decode.go +++ b/proto/decode.go @@ -42,18 +42,25 @@ type UnmarshalOptions struct { FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error) } + + // RecursionLimit limits how deeply messages may be nested. + // If zero, a default limit is applied. + RecursionLimit int } // Unmarshal parses the wire-format message in b and places the result in m. // The provided message must be mutable (e.g., a non-nil pointer to a message). func Unmarshal(b []byte, m Message) error { - _, err := UnmarshalOptions{}.unmarshal(b, m.ProtoReflect()) + _, err := UnmarshalOptions{RecursionLimit: protowire.DefaultRecursionLimit}.unmarshal(b, m.ProtoReflect()) return err } // Unmarshal parses the wire-format message in b and places the result in m. // The provided message must be mutable (e.g., a non-nil pointer to a message). func (o UnmarshalOptions) Unmarshal(b []byte, m Message) error { + if o.RecursionLimit == 0 { + o.RecursionLimit = protowire.DefaultRecursionLimit + } _, err := o.unmarshal(b, m.ProtoReflect()) return err } @@ -63,6 +70,9 @@ func (o UnmarshalOptions) Unmarshal(b []byte, m Message) error { // This method permits fine-grained control over the unmarshaler. // Most users should use Unmarshal instead. func (o UnmarshalOptions) UnmarshalState(in protoiface.UnmarshalInput) (protoiface.UnmarshalOutput, error) { + if o.RecursionLimit == 0 { + o.RecursionLimit = protowire.DefaultRecursionLimit + } return o.unmarshal(in.Buf, in.Message) } @@ -86,12 +96,17 @@ func (o UnmarshalOptions) unmarshal(b []byte, m protoreflect.Message) (out proto Message: m, Buf: b, Resolver: o.Resolver, + Depth: o.RecursionLimit, } if o.DiscardUnknown { in.Flags |= protoiface.UnmarshalDiscardUnknown } out, err = methods.Unmarshal(in) } else { + o.RecursionLimit-- + if o.RecursionLimit < 0 { + return out, errors.New("exceeded max recursion depth") + } err = o.unmarshalMessageSlow(b, m) } if err != nil { diff --git a/reflect/protoreflect/methods.go b/reflect/protoreflect/methods.go index 6be5d16e9..d5d5af6eb 100644 --- a/reflect/protoreflect/methods.go +++ b/reflect/protoreflect/methods.go @@ -53,6 +53,7 @@ type ( FindExtensionByName(field FullName) (ExtensionType, error) FindExtensionByNumber(message FullName, field FieldNumber) (ExtensionType, error) } + Depth int } unmarshalOutput = struct { pragma.NoUnkeyedLiterals diff --git a/runtime/protoiface/methods.go b/runtime/protoiface/methods.go index 32c04f67e..44cf467d8 100644 --- a/runtime/protoiface/methods.go +++ b/runtime/protoiface/methods.go @@ -103,6 +103,7 @@ type UnmarshalInput = struct { FindExtensionByName(field protoreflect.FullName) (protoreflect.ExtensionType, error) FindExtensionByNumber(message protoreflect.FullName, field protoreflect.FieldNumber) (protoreflect.ExtensionType, error) } + Depth int } // UnmarshalOutput is output from the Unmarshal method.