Update

vendor/golang.org/x/net/dns/dnsmessage/message.go

@@ -751,10 +751,7 @@ func (p *Parser) AllAnswers() ([]Resource, error) {
 	//
 	// Pre-allocate up to a certain limit, since p.header is
 	// untrusted data.
-	n := int(p.header.answers)
-	if n > 20 {
-		n = 20
-	}
+	n := min(int(p.header.answers), 20)
 	as := make([]Resource, 0, n)
 	for {
 		a, err := p.Answer()
@@ -804,10 +801,7 @@ func (p *Parser) AllAuthorities() ([]Resource, error) {
 	//
 	// Pre-allocate up to a certain limit, since p.header is
 	// untrusted data.
-	n := int(p.header.authorities)
-	if n > 10 {
-		n = 10
-	}
+	n := min(int(p.header.authorities), 10)
 	as := make([]Resource, 0, n)
 	for {
 		a, err := p.Authority()
@@ -857,10 +851,7 @@ func (p *Parser) AllAdditionals() ([]Resource, error) {
 	//
 	// Pre-allocate up to a certain limit, since p.header is
 	// untrusted data.
-	n := int(p.header.additionals)
-	if n > 10 {
-		n = 10
-	}
+	n := min(int(p.header.additionals), 10)
 	as := make([]Resource, 0, n)
 	for {
 		a, err := p.Additional()
@@ -2085,7 +2076,11 @@ Loop:
 					return off, errInvalidName
 				}
 			}
-
+			// Reject names that are too long while unpacking
+			// See issue golang/go#77540
+			if len(name)+(endOff-currOff) >= nonEncodedNameMax {
+				return off, errNameTooLong
+			}
 			name = append(name, msg[currOff:endOff]...)
 			name = append(name, '.')
 			currOff = endOff
@@ -2111,9 +2106,6 @@ Loop:
 	if len(name) == 0 {
 		name = append(name, '.')
 	}
-	if len(name) > nonEncodedNameMax {
-		return off, errNameTooLong
-	}
 	n.Length = uint8(len(name))
 	if ptr == 0 {
 		newOff = currOff

vendor/golang.org/x/net/dns/dnsmessage/svcb.go

@@ -168,9 +168,8 @@ func (r *SVCBResource) pack(msg []byte, _ map[string]uint16, _ int) ([]byte, err
 	if err != nil {
 		return oldMsg, &nestedError{"SVCBResource.Target", err}
 	}
-	var previousKey SVCParamKey
 	for i, param := range r.Params {
-		if i > 0 && param.Key <= previousKey {
+		if i > 0 && param.Key <= r.Params[i-1].Key {
 			return oldMsg, &nestedError{"SVCBResource.Params", errParamOutOfOrder}
 		}
 		if len(param.Value) > (1<<16)-1 {
@@ -189,6 +188,10 @@ func unpackSVCBResource(msg []byte, off int, length uint16) (SVCBResource, error
 	paramsOff := off
 	bodyEnd := off + int(length)
 
+	if bodyEnd > len(msg) {
+		return SVCBResource{}, errResourceLen
+	}
+
 	var err error
 	if r.Priority, paramsOff, err = unpackUint16(msg, paramsOff); err != nil {
 		return SVCBResource{}, &nestedError{"Priority", err}
@@ -205,7 +208,7 @@ func unpackSVCBResource(msg []byte, off int, length uint16) (SVCBResource, error
 	off = paramsOff
 	var previousKey uint16
 	for off < bodyEnd {
-		var key, len uint16
+		var key, size uint16
 		if key, off, err = unpackUint16(msg, off); err != nil {
 			return SVCBResource{}, &nestedError{"Params key", err}
 		}
@@ -214,14 +217,15 @@ func unpackSVCBResource(msg []byte, off int, length uint16) (SVCBResource, error
 			// consider the RR malformed if the SvcParamKeys are not in strictly increasing numeric order
 			return SVCBResource{}, &nestedError{"Params", errParamOutOfOrder}
 		}
-		if len, off, err = unpackUint16(msg, off); err != nil {
+		if size, off, err = unpackUint16(msg, off); err != nil {
 			return SVCBResource{}, &nestedError{"Params value length", err}
 		}
-		if off+int(len) > bodyEnd {
+		if off+int(size) > bodyEnd {
 			return SVCBResource{}, errResourceLen
 		}
-		totalValueLen += len
-		off += int(len)
+		previousKey = key
+		totalValueLen += size
+		off += int(size)
 		n++
 	}
 	if off != bodyEnd {
@@ -236,20 +240,23 @@ func unpackSVCBResource(msg []byte, off int, length uint16) (SVCBResource, error
 	off = paramsOff
 	for i := 0; i < n; i++ {
 		p := &r.Params[i]
-		var key, len uint16
+		var key, size uint16
 		if key, off, err = unpackUint16(msg, off); err != nil {
 			return SVCBResource{}, &nestedError{"param key", err}
 		}
 		p.Key = SVCParamKey(key)
-		if len, off, err = unpackUint16(msg, off); err != nil {
+		if size, off, err = unpackUint16(msg, off); err != nil {
 			return SVCBResource{}, &nestedError{"param length", err}
 		}
-		if copy(valuesBuf, msg[off:off+int(len)]) != int(len) {
+		if len(msg[off:]) < int(size) {
 			return SVCBResource{}, &nestedError{"param value", errCalcLen}
 		}
-		p.Value = valuesBuf[:len:len]
-		valuesBuf = valuesBuf[len:]
-		off += int(len)
+		if copy(valuesBuf, msg[off:][:int(size)]) != int(size) {
+			return SVCBResource{}, &nestedError{"param value", errCalcLen}
+		}
+		p.Value = valuesBuf[:size:size]
+		valuesBuf = valuesBuf[size:]
+		off += int(size)
 	}
 
 	return r, nil