ruby: Integer overflows in rb_str_buf_append()

Multiple integer overflows in the rbstrbufappend function in Ruby 1.8.4 and earlier, 1.8.5 before 1.8.5-p231, 1.8.6 before 1.8.6-p230, 1.8.7 before 1.8.7-p22, and 1.9.0 before 1.9.0-2 allow context-dependent attackers to execute arbitrary code or cause a denial of service via unknown vectors that...