int64_t
private_check_section(struct bfelf_shdr *shdr,
bfelf64_word type,
bfelf64_xword flags,
bfelf64_xword addralign,
bfelf64_xword entsize)
{
/*
* All of the section types that we support exist in the lower 8 bits.
* The exception to that is SHT_X86_64_UNWIND which is a processor
* specific type for SHT_PROGBITS defined in the 64bit System V ABI.
* Since we look for SHT_PROGBITS when we see SHT_X86_64_UNWIND, the below
* mask fixes the issue.
*/
if ((shdr->sh_type & 0xFF) != type)
return invalid_section("type mismatch");
if ((shdr->sh_flags & ~flags) != 0)
return invalid_section("flags mismatch");
if (shdr->sh_addralign != addralign)
return invalid_section("address alignment mismatch");
if (shdr->sh_entsize != 0 && shdr->sh_entsize != entsize)
return invalid_section("entry size mismatch");
return BFELF_SUCCESS;
}
static bfelf64_sword
private_check_sections(struct bfelf_file_t *ef)
{
bfelf64_sword i = 0;
bfelf64_sword j = 0;
struct bfelf_shdr *shstrtab = private_get_section(ef, ef->ehdr->e_shstrndx);
for (i = 0; i < ef->ehdr->e_shnum; i++)
{
bfelf64_sword valid_addr = 0;
struct bfelf_shdr *shdr = private_get_section(ef, i);
if (shdr->sh_type != bfsht_nobits)
{
if (shdr->sh_offset + shdr->sh_size > ef->fsize)
return invalid_section("section offset / size is corrupt");
}
if (shdr->sh_name >= shstrtab->sh_size)
return invalid_section("invalid section name offset");
if (shdr->sh_link >= ef->ehdr->e_shnum)
return invalid_section("invalid section link");
for (j = 0; j < ef->ehdr->e_phnum; j++)
{
struct bfelf_phdr *phdr = private_get_segment(ef, j);
if (shdr->sh_addr >= phdr->p_vaddr &&
shdr->sh_addr + shdr->sh_size <= phdr->p_vaddr + phdr->p_memsz)
{
valid_addr = 1;
break;
}
}
if (shdr->sh_addr != 0 && valid_addr == 0)
return invalid_section("section address is out of bounds");
}
return BFELF_SUCCESS;
}
static bfelf64_sword
private_check_section(struct bfelf_shdr *shdr,
bfelf64_word type,
bfelf64_xword flags,
bfelf64_xword addralign,
bfelf64_xword entsize)
{
if (shdr->sh_type != type)
return invalid_section("type mismatch");
if ((shdr->sh_flags & ~flags) != 0)
return invalid_section("flags mismatch");
if (shdr->sh_addralign != addralign)
return invalid_section("address alignment mismatch");
if (shdr->sh_entsize != entsize)
return invalid_section("entry size mismatch");
return BFELF_SUCCESS;
}
static bfelf64_sword
private_get_hash_table(struct bfelf_file_t *ef)
{
if (ef->hashtab)
{
bfelf64_word total = 0;
bfelf64_word *p = (bfelf64_word *)(ef->hashtab->sh_offset + ef->file);
if (sizeof(bfelf64_word) * 2 > ef->hashtab->sh_size)
return invalid_section("hash table contents corrupt");
ef->nbucket = p[0];
ef->nchain = p[1];
total = (ef->nbucket + ef->nchain + 2) * sizeof(bfelf64_word);
if (total > ef->hashtab->sh_size)
return invalid_section("hash table contents corrupt");
ef->bucket = &(p[2]);
ef->chain = &(p[2 + ef->nbucket]);
}
return BFELF_SUCCESS;
}
