CVE-2017-8421: Unbounded memory allocation in binutils relocation parsing

Processing specially crafted ELF files with objdump causes unbounded memory allocation. The vulnerability exists in how relocation section metadata is parsed without proper validation of relocation counts. When bfd_get_reloc_upper_bound() is called on a malicious ELF section, it returns an allocation size computed from the unchecked reloc_count field: (asect->reloc_count + 1) * sizeof(arelent *). This value is then used directly in xmalloc() without any bounds checking, allowing attackers to craft ELF files with extremely large reloc_count values to cause unbounded memory allocation (DoS).