file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
    size_t nbytes)
{
	union {
		int32_t l;
		char c[sizeof (int32_t)];
	} u;
	int clazz;
	int swap;
	struct stat st;
	off_t fsize;
	int flags = 0;
	Elf32_Ehdr elf32hdr;
	Elf64_Ehdr elf64hdr;
	uint16_t type, phnum, shnum, notecount;

	if (ms->flags & (MAGIC_MIME|MAGIC_APPLE|MAGIC_EXTENSION))
		return 0;
	/*
	 * ELF executables have multiple section headers in arbitrary
	 * file locations and thus file(1) cannot determine it from easily.
	 * Instead we traverse thru all section headers until a symbol table
	 * one is found or else the binary is stripped.
	 * Return immediately if it's not ELF (so we avoid pipe2file unless needed).
	 */
	if (buf[EI_MAG0] != ELFMAG0
	    || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
	    || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
		return 0;

	/*
	 * If we cannot seek, it must be a pipe, socket or fifo.
	 */
	if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
		fd = file_pipe2file(ms, fd, buf, nbytes);

	if (fstat(fd, &st) == -1) {
  		file_badread(ms);
		return -1;
	}
	if (S_ISREG(st.st_mode) || st.st_size != 0)
		fsize = st.st_size;
	else
		fsize = SIZE_UNKNOWN;

	clazz = buf[EI_CLASS];

	switch (clazz) {
	case ELFCLASS32:
#undef elf_getu
#define elf_getu(a, b)	elf_getu32(a, b)
#undef elfhdr
#define elfhdr elf32hdr
#include "elfclass.h"
	case ELFCLASS64:
#undef elf_getu
#define elf_getu(a, b)	elf_getu64(a, b)
#undef elfhdr
#define elfhdr elf64hdr
#include "elfclass.h"
	default:
	    if (file_printf(ms, ", unknown class %d", clazz) == -1)
		    return -1;
	    break;
	}
	return 0;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.