fix: out-of-bounds-read in parseItemOrInnerList

Author: marten-seemann

dictionary_test.go

@@ -99,6 +99,7 @@ func TestUnmarshalDictionary(t *testing.T) {
 		valid    bool
 	}{
 		{[]string{"a=?0, b, c; foo=bar"}, d1, false},
+		{[]string{"a="}, nil, false},
 		{[]string{"a=?0, b", "c; foo=bar"}, d1, false},
 		{[]string{""}, NewDictionary(), false},
 		{[]string{"é"}, nil, true},

list.go

@@ -87,6 +87,9 @@ func parseList(s *scanner) (List, error) {
 // parseItemOrInnerList parses as defined in
 // https://httpwg.org/http-extensions/draft-ietf-httpbis-header-structure.html#parse-item-or-list.
 func parseItemOrInnerList(s *scanner) (Member, error) {
+	if s.eof() {
+		return nil, &UnmarshalError{s.off, ErrInvalidInnerListFormat}
+	}
 	if s.data[s.off] == '(' {
 		return parseInnerList(s)
 	}