mirrors/limine
1
0
Fork 0
mirror of https://github.com/limine-bootloader/limine synced 2025-02-18 10:04:23 +03:00
Code Issues Packages Projects Releases Wiki Activity

lib/elf: Add more and better sanity checks

Browse Source
This commit is contained in:
mintsuki 2024-06-03 22:34:45 +02:00
parent 65fa1a9d5c
commit 5a7052d135
2 changed files with 70 additions and 95 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

159
common/lib/elf.c
View File

@ -113,6 +113,50 @@ struct elf64_dyn {
uint64_t d_un;
};
static bool elf32_validate(struct elf32_hdr *hdr) {
if (strncmp((char *)hdr->ident, "\177ELF", 4)) {
panic(true, "elf: Not a valid ELF file.");
}
if (hdr->ident[EI_DATA] != BITS_LE) {
panic(true, "elf: Not a Little-endian ELF file.");
}
if (hdr->machine != ARCH_X86_32) {
panic(true, "elf: Not an IA-32 ELF file.");
}
return true;
}
static bool elf64_validate(struct elf64_hdr *hdr) {
if (strncmp((char *)hdr->ident, "\177ELF", 4)) {
panic(true, "elf: Not a valid ELF file.");
}
if (hdr->ident[EI_DATA] != BITS_LE) {
panic(true, "elf: Not a Little-endian ELF file.");
}
#if defined (__x86_64__) || defined (__i386__)
if (hdr->machine != ARCH_X86_64) {
panic(true, "elf: Not an x86-64 ELF file.");
}
#elif defined (__aarch64__)
if (hdr->machine != ARCH_AARCH64) {
panic(true, "elf: Not an aarch64 ELF file.");
}
#elif defined (__riscv64)
if (hdr->machine != ARCH_RISCV && hdr->ident[EI_CLASS] == ELFCLASS64) {
panic(true, "elf: Not a riscv64 ELF file.");
}
#else
#error Unknown architecture
#endif
return true;
}
int elf_bits(uint8_t *elf) {
struct elf64_hdr *hdr = (void *)elf;
@ -139,6 +183,8 @@ struct elf_section_hdr_info elf64_section_hdr_info(uint8_t *elf) {
struct elf64_hdr *hdr = (void *)elf;
elf64_validate(hdr);
info.num = hdr->sh_num;
info.section_entry_size = hdr->shdr_size;
info.str_section_idx = hdr->shstrndx;
@ -152,6 +198,8 @@ struct elf_section_hdr_info elf32_section_hdr_info(uint8_t *elf) {
struct elf32_hdr *hdr = (void *)elf;
elf32_validate(hdr);
info.num = hdr->sh_num;
info.section_entry_size = hdr->shdr_size;
info.str_section_idx = hdr->shstrndx;
@ -248,9 +296,8 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
break;
}
if (rela_ent != sizeof(struct elf64_rela)) {
print("elf: Unknown sh_entsize for RELA section!\n");
return false;
if (rela_ent < sizeof(struct elf64_rela)) {
panic(true, "elf: sh_entsize < sizeof(struct elf64_rela)");
}
for (uint16_t j = 0; j < hdr->ph_num; j++) {
@ -263,16 +310,26 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
}
}
for (uint16_t j = 0; j < hdr->ph_num; j++) {
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + j * hdr->phdr_size);
if (symtab_ent < sizeof(struct elf64_sym)) {
symtab_offset = 0;
}
if (_phdr->p_vaddr <= symtab_offset && _phdr->p_vaddr + _phdr->p_filesz > symtab_offset) {
symtab_offset -= _phdr->p_vaddr;
symtab_offset += _phdr->p_offset;
break;
if (symtab_offset != 0) {
for (uint16_t j = 0; j < hdr->ph_num; j++) {
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + j * hdr->phdr_size);
if (_phdr->p_vaddr <= symtab_offset && _phdr->p_vaddr + _phdr->p_filesz > symtab_offset) {
symtab_offset -= _phdr->p_vaddr;
symtab_offset += _phdr->p_offset;
break;
}
}
}
if (dt_pltrelsz == 0) {
dt_jmprel = 0;
}
if (dt_jmprel != 0) {
for (uint16_t j = 0; j < hdr->ph_num; j++) {
struct elf64_phdr *_phdr = (void *)elf + (hdr->phoff + j * hdr->phdr_size);
@ -385,34 +442,7 @@ static bool elf64_apply_relocations(uint8_t *elf, struct elf64_hdr *hdr, void *b
bool elf64_load_section(uint8_t *elf, void *buffer, const char *name, size_t limit, uint64_t slide) {
struct elf64_hdr *hdr = (void *)elf;
if (strncmp((char *)hdr->ident, "\177ELF", 4)) {
printv("elf: Not a valid ELF file.\n");
return false;
}
if (hdr->ident[EI_DATA] != BITS_LE) {
printv("elf: Not a Little-endian ELF file.\n");
return false;
}
#if defined (__x86_64__) || defined (__i386__)
if (hdr->machine != ARCH_X86_64) {
printv("elf: Not an x86-64 ELF file.\n");
return false;
}
#elif defined (__aarch64__)
if (hdr->machine != ARCH_AARCH64) {
printv("elf: Not an aarch64 ELF file.\n");
return false;
}
#elif defined (__riscv64)
if (hdr->machine != ARCH_RISCV && hdr->ident[EI_CLASS] == ELFCLASS64) {
printv("elf: Not a riscv64 ELF file.\n");
return false;
}
#else
#error Unknown architecture
#endif
elf64_validate(hdr);
if (hdr->sh_num == 0) {
return false;
@ -538,30 +568,7 @@ static void elf64_get_ranges(uint8_t *elf, uint64_t slide, struct elf_range **_r
bool elf64_load(uint8_t *elf, uint64_t *entry_point, uint64_t *_slide, uint32_t alloc_type, bool kaslr, struct elf_range **ranges, uint64_t *ranges_count, uint64_t *physical_base, uint64_t *virtual_base, uint64_t *_image_size, uint64_t *_image_size_before_bss, bool *is_reloc) {
struct elf64_hdr *hdr = (void *)elf;
if (strncmp((char *)hdr->ident, "\177ELF", 4)) {
printv("elf: Not a valid ELF file.\n");
return false;
}
if (hdr->ident[EI_DATA] != BITS_LE) {
panic(true, "elf: Not a Little-endian ELF file.\n");
}
#if defined (__x86_64__) || defined (__i386__)
if (hdr->machine != ARCH_X86_64) {
panic(true, "elf: Not an x86-64 ELF file.\n");
}
#elif defined (__aarch64__)
if (hdr->machine != ARCH_AARCH64) {
panic(true, "elf: Not an aarch64 ELF file.\n");
}
#elif defined (__riscv64)
if (hdr->machine != ARCH_RISCV && hdr->ident[EI_CLASS] == ELFCLASS64) {
panic(true, "elf: Not a riscv64 ELF file.\n");
}
#else
#error Unknown architecture
#endif
elf64_validate(hdr);
if (is_reloc) {
*is_reloc = false;
@ -753,20 +760,7 @@ bool elf32_load_elsewhere(uint8_t *elf, uint64_t *entry_point,
struct elsewhere_range **ranges) {
struct elf32_hdr *hdr = (void *)elf;
if (strncmp((char *)hdr->ident, "\177ELF", 4)) {
printv("elf: Not a valid ELF file.\n");
return false;
}
if (hdr->ident[EI_DATA] != BITS_LE) {
printv("elf: Not a Little-endian ELF file.\n");
return false;
}
if (hdr->machine != ARCH_X86_32) {
printv("elf: Not an x86_32 ELF file.\n");
return false;
}
elf32_validate(hdr);
*entry_point = hdr->entry;
bool entry_adjusted = false;
@ -831,20 +825,7 @@ bool elf64_load_elsewhere(uint8_t *elf, uint64_t *entry_point,
struct elsewhere_range **ranges) {
struct elf64_hdr *hdr = (void *)elf;
if (strncmp((char *)hdr->ident, "\177ELF", 4)) {
printv("elf: Not a valid ELF file.\n");
return false;
}
if (hdr->ident[EI_DATA] != BITS_LE) {
printv("elf: Not a Little-endian ELF file.\n");
return false;
}
if (hdr->machine != ARCH_X86_64) {
printv("elf: Not an x86-64 ELF file.\n");
return false;
}
elf64_validate(hdr);
*entry_point = hdr->entry;
bool entry_adjusted = false;

6
common/protos/limine.c
View File

@ -330,12 +330,6 @@ noreturn void limine_load(char *config, char *cmdline) {
if (kaslr_s != NULL && strcmp(kaslr_s, "no") == 0)
kaslr = false;
int bits = elf_bits(kernel);
if (bits == -1 || bits == 32) {
panic(true, "limine: Kernel in unrecognised format");
}
// ELF loading
uint64_t entry_point = 0;
struct elf_range *ranges;