Ventoy/GRUB2/MOD_SRC/grub-2.04/util/grub-module-verifierXX.c

447 lines
14 KiB
C

#include <string.h>
#include <grub/elf.h>
#include <grub/module_verifier.h>
#include <grub/util/misc.h>
#if defined(MODULEVERIFIER_ELF32)
# define SUFFIX(x) x ## 32
# define ELFCLASSXX ELFCLASS32
# define Elf_Ehdr Elf32_Ehdr
# define Elf_Phdr Elf32_Phdr
# define Elf_Nhdr Elf32_Nhdr
# define Elf_Addr Elf32_Addr
# define Elf_Sym Elf32_Sym
# define Elf_Off Elf32_Off
# define Elf_Shdr Elf32_Shdr
# define Elf_Rela Elf32_Rela
# define Elf_Rel Elf32_Rel
# define Elf_Word Elf32_Word
# define Elf_Half Elf32_Half
# define Elf_Section Elf32_Section
# define ELF_R_SYM(val) ELF32_R_SYM(val)
# define ELF_R_TYPE(val) ELF32_R_TYPE(val)
# define ELF_ST_TYPE(val) ELF32_ST_TYPE(val)
#elif defined(MODULEVERIFIER_ELF64)
# define SUFFIX(x) x ## 64
# define ELFCLASSXX ELFCLASS64
# define Elf_Ehdr Elf64_Ehdr
# define Elf_Phdr Elf64_Phdr
# define Elf_Nhdr Elf64_Nhdr
# define Elf_Addr Elf64_Addr
# define Elf_Sym Elf64_Sym
# define Elf_Off Elf64_Off
# define Elf_Shdr Elf64_Shdr
# define Elf_Rela Elf64_Rela
# define Elf_Rel Elf64_Rel
# define Elf_Word Elf64_Word
# define Elf_Half Elf64_Half
# define Elf_Section Elf64_Section
# define ELF_R_SYM(val) ELF64_R_SYM(val)
# define ELF_R_TYPE(val) ELF64_R_TYPE(val)
# define ELF_ST_TYPE(val) ELF64_ST_TYPE(val)
#else
#error "I'm confused"
#endif
#define grub_target_to_host32(x) (grub_target_to_host32_real (arch, (x)))
#define grub_host_to_target32(x) (grub_host_to_target32_real (arch, (x)))
#define grub_target_to_host64(x) (grub_target_to_host64_real (arch, (x)))
#define grub_host_to_target64(x) (grub_host_to_target64_real (arch, (x)))
#define grub_host_to_target_addr(x) (grub_host_to_target_addr_real (arch, (x)))
#define grub_target_to_host16(x) (grub_target_to_host16_real (arch, (x)))
#define grub_host_to_target16(x) (grub_host_to_target16_real (arch, (x)))
#define grub_target_to_host(val) grub_target_to_host_real(arch, (val))
static inline grub_uint32_t
grub_target_to_host32_real (const struct grub_module_verifier_arch *arch,
grub_uint32_t in)
{
if (arch->bigendian)
return grub_be_to_cpu32 (in);
else
return grub_le_to_cpu32 (in);
}
static inline grub_uint64_t
grub_target_to_host64_real (const struct grub_module_verifier_arch *arch,
grub_uint64_t in)
{
if (arch->bigendian)
return grub_be_to_cpu64 (in);
else
return grub_le_to_cpu64 (in);
}
static inline grub_uint64_t
grub_host_to_target64_real (const struct grub_module_verifier_arch *arch,
grub_uint64_t in)
{
if (arch->bigendian)
return grub_cpu_to_be64 (in);
else
return grub_cpu_to_le64 (in);
}
static inline grub_uint32_t
grub_host_to_target32_real (const struct grub_module_verifier_arch *arch,
grub_uint32_t in)
{
if (arch->bigendian)
return grub_cpu_to_be32 (in);
else
return grub_cpu_to_le32 (in);
}
static inline grub_uint16_t
grub_target_to_host16_real (const struct grub_module_verifier_arch *arch,
grub_uint16_t in)
{
if (arch->bigendian)
return grub_be_to_cpu16 (in);
else
return grub_le_to_cpu16 (in);
}
static inline grub_uint16_t
grub_host_to_target16_real (const struct grub_module_verifier_arch *arch,
grub_uint16_t in)
{
if (arch->bigendian)
return grub_cpu_to_be16 (in);
else
return grub_cpu_to_le16 (in);
}
static inline grub_uint64_t
grub_host_to_target_addr_real (const struct grub_module_verifier_arch *arch, grub_uint64_t in)
{
if (arch->voidp_sizeof == 8)
return grub_host_to_target64_real (arch, in);
else
return grub_host_to_target32_real (arch, in);
}
static inline grub_uint64_t
grub_target_to_host_real (const struct grub_module_verifier_arch *arch, grub_uint64_t in)
{
if (arch->voidp_sizeof == 8)
return grub_target_to_host64_real (arch, in);
else
return grub_target_to_host32_real (arch, in);
}
static Elf_Shdr *
find_section (const struct grub_module_verifier_arch *arch, Elf_Ehdr *e, const char *name)
{
Elf_Shdr *s;
const char *str;
unsigned i;
s = (Elf_Shdr *) ((char *) e + grub_target_to_host (e->e_shoff) + grub_target_to_host16 (e->e_shstrndx) * grub_target_to_host16 (e->e_shentsize));
str = (char *) e + grub_target_to_host (s->sh_offset);
for (i = 0, s = (Elf_Shdr *) ((char *) e + grub_target_to_host (e->e_shoff));
i < grub_target_to_host16 (e->e_shnum);
i++, s = (Elf_Shdr *) ((char *) s + grub_target_to_host16 (e->e_shentsize)))
if (strcmp (str + grub_target_to_host32 (s->sh_name), name) == 0)
return s;
return NULL;
}
static void
check_license (const char * const filename,
const struct grub_module_verifier_arch *arch, Elf_Ehdr *e)
{
Elf_Shdr *s = find_section (arch, e, ".module_license");
if (s && (strcmp ((char *) e + grub_target_to_host(s->sh_offset), "LICENSE=GPLv3") == 0
|| strcmp ((char *) e + grub_target_to_host(s->sh_offset), "LICENSE=GPLv3+") == 0
|| strcmp ((char *) e + grub_target_to_host(s->sh_offset), "LICENSE=GPLv2+") == 0))
return;
grub_util_error ("%s: incompatible license", filename);
}
static Elf_Sym *
get_symtab (const struct grub_module_verifier_arch *arch, Elf_Ehdr *e, Elf_Word *size, Elf_Word *entsize)
{
unsigned i;
Elf_Shdr *s, *sections;
Elf_Sym *sym;
sections = (Elf_Shdr *) ((char *) e + grub_target_to_host (e->e_shoff));
for (i = 0, s = sections;
i < grub_target_to_host16 (e->e_shnum);
i++, s = (Elf_Shdr *) ((char *) s + grub_target_to_host16 (e->e_shentsize)))
if (grub_target_to_host32 (s->sh_type) == SHT_SYMTAB)
break;
if (i == grub_target_to_host16 (e->e_shnum))
return NULL;
sym = (Elf_Sym *) ((char *) e + grub_target_to_host (s->sh_offset));
*size = grub_target_to_host (s->sh_size);
*entsize = grub_target_to_host (s->sh_entsize);
return sym;
}
static int
is_whitelisted (const char *modname, const char **whitelist)
{
const char **ptr;
if (!whitelist)
return 0;
if (!modname)
return 0;
for (ptr = whitelist; *ptr; ptr++)
if (strcmp (modname, *ptr) == 0)
return 1;
return 0;
}
static void
check_symbols (const struct grub_module_verifier_arch *arch,
Elf_Ehdr *e, const char *modname,
const char **whitelist_empty)
{
Elf_Sym *sym;
Elf_Word size, entsize;
unsigned i;
/* Module without symbol table and without .moddeps section is useless
at boot time, so catch it early to prevent build errors */
sym = get_symtab (arch, e, &size, &entsize);
if (!sym)
{
Elf_Shdr *s;
/* However some modules are dependencies-only,
e.g. insmod all_video pulls in all video drivers.
Some platforms e.g. xen have no video drivers, so
the module does nothing. */
if (is_whitelisted (modname, whitelist_empty))
return;
s = find_section (arch, e, ".moddeps");
if (!s)
grub_util_error ("%s: no symbol table and no .moddeps section", modname);
if (!s->sh_size)
grub_util_error ("%s: no symbol table and empty .moddeps section", modname);
return;
}
for (i = 0;
i < size / entsize;
i++, sym = (Elf_Sym *) ((char *) sym + entsize))
{
unsigned char type = ELF_ST_TYPE (sym->st_info);
switch (type)
{
case STT_NOTYPE:
case STT_OBJECT:
case STT_FUNC:
case STT_SECTION:
case STT_FILE:
break;
default:
return grub_util_error ("%s: unknown symbol type `%d'", modname, (int) type);
}
}
}
static int
is_symbol_local(Elf_Sym *sym)
{
switch (ELF_ST_TYPE (sym->st_info))
{
case STT_NOTYPE:
case STT_OBJECT:
if (sym->st_name != 0 && sym->st_shndx == 0)
return 0;
return 1;
case STT_FUNC:
case STT_SECTION:
return 1;
default:
return 0;
}
}
static void
section_check_relocations (const char * const modname,
const struct grub_module_verifier_arch *arch, void *ehdr,
Elf_Shdr *s, size_t target_seg_size)
{
Elf_Rel *rel, *max;
Elf_Sym *symtab;
Elf_Word symtabsize, symtabentsize;
symtab = get_symtab (arch, ehdr, &symtabsize, &symtabentsize);
if (!symtab)
grub_util_error ("%s: relocation without symbol table", modname);
for (rel = (Elf_Rel *) ((char *) ehdr + grub_target_to_host (s->sh_offset)),
max = (Elf_Rel *) ((char *) rel + grub_target_to_host (s->sh_size));
rel < max;
rel = (Elf_Rel *) ((char *) rel + grub_target_to_host (s->sh_entsize)))
{
Elf_Sym *sym;
unsigned i;
if (target_seg_size < grub_target_to_host (rel->r_offset))
grub_util_error ("%s: reloc offset is out of the segment", modname);
grub_size_t r_info;
if (arch->machine == EM_MIPS && arch->voidp_sizeof == 8)
r_info = ((grub_uint64_t) rel->r_info << 32) |
(grub_uint32_t) grub_be_to_cpu64 (rel->r_info);
else
r_info = grub_target_to_host (rel->r_info);
grub_uint32_t type = ELF_R_TYPE (r_info);
if (arch->machine == EM_SPARCV9)
type &= 0xff;
for (i = 0; arch->supported_relocations[i] != -1; i++)
if (type == arch->supported_relocations[i])
break;
if (arch->supported_relocations[i] != -1)
continue;
if (!arch->short_relocations)
grub_util_error ("%s: unsupported relocation 0x%x", modname, type);
for (i = 0; arch->short_relocations[i] != -1; i++)
if (type == arch->short_relocations[i])
break;
if (arch->short_relocations[i] == -1)
grub_util_error ("%s: unsupported relocation 0x%x", modname, type);
sym = (Elf_Sym *) ((char *) symtab + symtabentsize * ELF_R_SYM (r_info));
if (is_symbol_local (sym))
continue;
grub_util_error ("%s: relocation 0x%x is not module-local", modname, type);
}
#if defined(MODULEVERIFIER_ELF64)
if (arch->machine == EM_AARCH64)
{
unsigned unmatched_adr_got_page = 0;
Elf_Rela *rel2;
for (rel = (Elf_Rel *) ((char *) ehdr + grub_target_to_host (s->sh_offset)),
max = (Elf_Rel *) ((char *) rel + grub_target_to_host (s->sh_size));
rel < max;
rel = (Elf_Rel *) ((char *) rel + grub_target_to_host (s->sh_entsize)))
{
switch (ELF_R_TYPE (grub_target_to_host (rel->r_info)))
{
case R_AARCH64_ADR_GOT_PAGE:
unmatched_adr_got_page++;
for (rel2 = (Elf_Rela *) ((char *) rel + grub_target_to_host (s->sh_entsize));
rel2 < (Elf_Rela *) max;
rel2 = (Elf_Rela *) ((char *) rel2 + grub_target_to_host (s->sh_entsize)))
if (ELF_R_SYM (rel2->r_info)
== ELF_R_SYM (rel->r_info)
&& ((Elf_Rela *) rel)->r_addend == rel2->r_addend
&& ELF_R_TYPE (rel2->r_info) == R_AARCH64_LD64_GOT_LO12_NC)
break;
if (rel2 >= (Elf_Rela *) max)
grub_util_error ("%s: ADR_GOT_PAGE without matching LD64_GOT_LO12_NC", modname);
break;
case R_AARCH64_LD64_GOT_LO12_NC:
if (unmatched_adr_got_page == 0)
grub_util_error ("%s: LD64_GOT_LO12_NC without matching ADR_GOT_PAGE", modname);
unmatched_adr_got_page--;
break;
}
}
}
#endif
}
static void
check_relocations (const char * const modname,
const struct grub_module_verifier_arch *arch, Elf_Ehdr *e)
{
Elf_Shdr *s;
unsigned i;
for (i = 0, s = (Elf_Shdr *) ((char *) e + grub_target_to_host (e->e_shoff));
i < grub_target_to_host16 (e->e_shnum);
i++, s = (Elf_Shdr *) ((char *) s + grub_target_to_host16 (e->e_shentsize)))
if (grub_target_to_host32 (s->sh_type) == SHT_REL || grub_target_to_host32 (s->sh_type) == SHT_RELA)
{
Elf_Shdr *ts;
if (grub_target_to_host32 (s->sh_type) == SHT_REL && !(arch->flags & GRUB_MODULE_VERIFY_SUPPORTS_REL))
grub_util_error ("%s: unsupported SHT_REL", modname);
if (grub_target_to_host32 (s->sh_type) == SHT_RELA && !(arch->flags & GRUB_MODULE_VERIFY_SUPPORTS_RELA))
grub_util_error ("%s: unsupported SHT_RELA", modname);
/* Find the target segment. */
if (grub_target_to_host32 (s->sh_info) >= grub_target_to_host16 (e->e_shnum))
grub_util_error ("%s: orphaned reloc section", modname);
ts = (Elf_Shdr *) ((char *) e + grub_target_to_host (e->e_shoff) + grub_target_to_host32 (s->sh_info) * grub_target_to_host16 (e->e_shentsize));
section_check_relocations (modname, arch, e, s, grub_target_to_host (ts->sh_size));
}
}
void
SUFFIX(grub_module_verify) (const char * const filename,
void *module_img, size_t size,
const struct grub_module_verifier_arch *arch,
const char **whitelist_empty)
{
Elf_Ehdr *e = module_img;
/* Check the header size. */
if (size < sizeof (Elf_Ehdr))
grub_util_error ("%s: ELF header smaller than expected", filename);
/* Check the magic numbers. */
if (e->e_ident[EI_MAG0] != ELFMAG0
|| e->e_ident[EI_MAG1] != ELFMAG1
|| e->e_ident[EI_MAG2] != ELFMAG2
|| e->e_ident[EI_MAG3] != ELFMAG3
|| e->e_ident[EI_VERSION] != EV_CURRENT
|| grub_target_to_host32 (e->e_version) != EV_CURRENT)
grub_util_error ("%s: invalid arch-independent ELF magic", filename);
if (e->e_ident[EI_CLASS] != ELFCLASSXX
|| e->e_ident[EI_DATA] != (arch->bigendian ? ELFDATA2MSB : ELFDATA2LSB)
|| grub_target_to_host16 (e->e_machine) != arch->machine)
grub_util_error ("%s: invalid arch-dependent ELF magic", filename);
if (grub_target_to_host16 (e->e_type) != ET_REL)
{
grub_util_error ("%s: this ELF file is not of the right type", filename);
}
/* Make sure that every section is within the core. */
if (size < grub_target_to_host (e->e_shoff)
+ (grub_uint32_t) grub_target_to_host16 (e->e_shentsize) * grub_target_to_host16(e->e_shnum))
{
grub_util_error ("%s: ELF sections outside core", filename);
}
check_license (filename, arch, e);
Elf_Shdr *s;
const char *modname;
s = find_section (arch, e, ".modname");
if (!s)
grub_util_error ("%s: no module name found", filename);
modname = (const char *) e + grub_target_to_host (s->sh_offset);
check_symbols(arch, e, modname, whitelist_empty);
check_relocations(modname, arch, e);
}