The *_get_synthetic_symtab functions in the Binary File Descriptor (BFD) library (aka libbfd) as distributed in GNU Binutils 2.29 mishandle the failure of a certain canonicalization step which allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted ELF file related to elf32-i386.c and elf64-x86-64.c.