1 // SPDX-License-Identifier: GPL-2.0+
5 * based partly on wine code
7 * Copyright (c) 2016 Alexander Graf
12 #include <efi_loader.h>
16 #include "crypto/pkcs7_parser.h"
17 #include <linux/err.h>
19 const efi_guid_t efi_global_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
20 const efi_guid_t efi_guid_device_path = EFI_DEVICE_PATH_PROTOCOL_GUID;
21 const efi_guid_t efi_guid_loaded_image = EFI_LOADED_IMAGE_PROTOCOL_GUID;
22 const efi_guid_t efi_guid_loaded_image_device_path =
23 EFI_LOADED_IMAGE_DEVICE_PATH_PROTOCOL_GUID;
24 const efi_guid_t efi_simple_file_system_protocol_guid =
25 EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID;
26 const efi_guid_t efi_file_info_guid = EFI_FILE_INFO_GUID;
28 static int machines[] = {
29 #if defined(__aarch64__)
30 IMAGE_FILE_MACHINE_ARM64,
31 #elif defined(__arm__)
32 IMAGE_FILE_MACHINE_ARM,
33 IMAGE_FILE_MACHINE_THUMB,
34 IMAGE_FILE_MACHINE_ARMNT,
37 #if defined(__x86_64__)
38 IMAGE_FILE_MACHINE_AMD64,
39 #elif defined(__i386__)
40 IMAGE_FILE_MACHINE_I386,
43 #if defined(__riscv) && (__riscv_xlen == 32)
44 IMAGE_FILE_MACHINE_RISCV32,
47 #if defined(__riscv) && (__riscv_xlen == 64)
48 IMAGE_FILE_MACHINE_RISCV64,
53 * efi_print_image_info() - print information about a loaded image
55 * If the program counter is located within the image the offset to the base
59 * @image: loaded image
60 * @pc: program counter (use NULL to suppress offset output)
63 static efi_status_t efi_print_image_info(struct efi_loaded_image_obj *obj,
64 struct efi_loaded_image *image,
68 printf(" [0x%p:0x%p]",
69 image->image_base, image->image_base + image->image_size - 1);
70 if (pc && pc >= image->image_base &&
71 pc < image->image_base + image->image_size)
72 printf(" pc=0x%zx", pc - image->image_base);
74 printf(" '%pD'", image->file_path);
80 * efi_print_image_infos() - print information about all loaded images
82 * @pc: program counter (use NULL to suppress offset output)
84 void efi_print_image_infos(void *pc)
86 struct efi_object *efiobj;
87 struct efi_handler *handler;
89 list_for_each_entry(efiobj, &efi_obj_list, link) {
90 list_for_each_entry(handler, &efiobj->protocols, link) {
91 if (!guidcmp(handler->guid, &efi_guid_loaded_image)) {
93 (struct efi_loaded_image_obj *)efiobj,
94 handler->protocol_interface, pc);
101 * efi_loader_relocate() - relocate UEFI binary
103 * @rel: pointer to the relocation table
104 * @rel_size: size of the relocation table in bytes
105 * @efi_reloc: actual load address of the image
106 * @pref_address: preferred load address of the image
107 * Return: status code
109 static efi_status_t efi_loader_relocate(const IMAGE_BASE_RELOCATION *rel,
110 unsigned long rel_size, void *efi_reloc,
111 unsigned long pref_address)
113 unsigned long delta = (unsigned long)efi_reloc - pref_address;
114 const IMAGE_BASE_RELOCATION *end;
120 end = (const IMAGE_BASE_RELOCATION *)((const char *)rel + rel_size);
121 while (rel < end && rel->SizeOfBlock) {
122 const uint16_t *relocs = (const uint16_t *)(rel + 1);
123 i = (rel->SizeOfBlock - sizeof(*rel)) / sizeof(uint16_t);
125 uint32_t offset = (uint32_t)(*relocs & 0xfff) +
127 int type = *relocs >> EFI_PAGE_SHIFT;
128 uint64_t *x64 = efi_reloc + offset;
129 uint32_t *x32 = efi_reloc + offset;
130 uint16_t *x16 = efi_reloc + offset;
133 case IMAGE_REL_BASED_ABSOLUTE:
135 case IMAGE_REL_BASED_HIGH:
136 *x16 += ((uint32_t)delta) >> 16;
138 case IMAGE_REL_BASED_LOW:
139 *x16 += (uint16_t)delta;
141 case IMAGE_REL_BASED_HIGHLOW:
142 *x32 += (uint32_t)delta;
144 case IMAGE_REL_BASED_DIR64:
145 *x64 += (uint64_t)delta;
148 case IMAGE_REL_BASED_RISCV_HI20:
149 *x32 = ((*x32 & 0xfffff000) + (uint32_t)delta) |
152 case IMAGE_REL_BASED_RISCV_LOW12I:
153 case IMAGE_REL_BASED_RISCV_LOW12S:
154 /* We know that we're 4k aligned */
156 printf("Unsupported reloc offset\n");
157 return EFI_LOAD_ERROR;
162 printf("Unknown Relocation off %x type %x\n",
164 return EFI_LOAD_ERROR;
168 rel = (const IMAGE_BASE_RELOCATION *)relocs;
173 void __weak invalidate_icache_all(void)
175 /* If the system doesn't support icache_all flush, cross our fingers */
179 * efi_set_code_and_data_type() - determine the memory types to be used for code
182 * @loaded_image_info: image descriptor
183 * @image_type: field Subsystem of the optional header for
184 * Windows specific field
186 static void efi_set_code_and_data_type(
187 struct efi_loaded_image *loaded_image_info,
190 switch (image_type) {
191 case IMAGE_SUBSYSTEM_EFI_APPLICATION:
192 loaded_image_info->image_code_type = EFI_LOADER_CODE;
193 loaded_image_info->image_data_type = EFI_LOADER_DATA;
195 case IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER:
196 loaded_image_info->image_code_type = EFI_BOOT_SERVICES_CODE;
197 loaded_image_info->image_data_type = EFI_BOOT_SERVICES_DATA;
199 case IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER:
200 case IMAGE_SUBSYSTEM_EFI_ROM:
201 loaded_image_info->image_code_type = EFI_RUNTIME_SERVICES_CODE;
202 loaded_image_info->image_data_type = EFI_RUNTIME_SERVICES_DATA;
205 printf("%s: invalid image type: %u\n", __func__, image_type);
206 /* Let's assume it is an application */
207 loaded_image_info->image_code_type = EFI_LOADER_CODE;
208 loaded_image_info->image_data_type = EFI_LOADER_DATA;
213 #ifdef CONFIG_EFI_SECURE_BOOT
215 * cmp_pe_section - compare two sections
216 * @arg1: Pointer to pointer to first section
217 * @arg2: Pointer to pointer to second section
219 * Compare two sections in PE image.
221 * Return: -1, 0, 1 respectively if arg1 < arg2, arg1 == arg2 or
224 static int cmp_pe_section(const void *arg1, const void *arg2)
226 const IMAGE_SECTION_HEADER *section1, *section2;
228 section1 = *((const IMAGE_SECTION_HEADER **)arg1);
229 section2 = *((const IMAGE_SECTION_HEADER **)arg2);
231 if (section1->VirtualAddress < section2->VirtualAddress)
233 else if (section1->VirtualAddress == section2->VirtualAddress)
240 * efi_image_parse - parse a PE image
241 * @efi: Pointer to image
243 * @regp: Pointer to a list of regions
244 * @auth: Pointer to a pointer to authentication data in PE
245 * @auth_len: Size of @auth
247 * Parse image binary in PE32(+) format, assuming that sanity of PE image
248 * has been checked by a caller.
249 * On success, an address of authentication data in @efi and its size will
250 * be returned in @auth and @auth_len, respectively.
252 * Return: true on success, false on error
254 bool efi_image_parse(void *efi, size_t len, struct efi_image_regions **regp,
255 WIN_CERTIFICATE **auth, size_t *auth_len)
257 struct efi_image_regions *regs;
258 IMAGE_DOS_HEADER *dos;
259 IMAGE_NT_HEADERS32 *nt;
260 IMAGE_SECTION_HEADER *sections, **sorted;
261 int num_regions, num_sections, i;
262 int ctidx = IMAGE_DIRECTORY_ENTRY_SECURITY;
263 u32 align, size, authsz, authoff;
267 nt = (void *)(efi + dos->e_lfanew);
270 * Count maximum number of regions to be digested.
271 * We don't have to have an exact number here.
272 * See efi_image_region_add()'s in parsing below.
274 num_regions = 3; /* for header */
275 num_regions += nt->FileHeader.NumberOfSections;
276 num_regions++; /* for extra */
278 regs = calloc(sizeof(*regs) + sizeof(struct image_region) * num_regions,
282 regs->max = num_regions;
285 * Collect data regions for hash calculation
288 if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
289 IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
290 IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
293 efi_image_region_add(regs, efi, &opt->CheckSum, 0);
294 if (nt64->OptionalHeader.NumberOfRvaAndSizes <= ctidx) {
295 efi_image_region_add(regs,
297 efi + opt->SizeOfHeaders, 0);
299 /* Skip Certificates Table */
300 efi_image_region_add(regs,
302 &opt->DataDirectory[ctidx], 0);
303 efi_image_region_add(regs,
304 &opt->DataDirectory[ctidx] + 1,
305 efi + opt->SizeOfHeaders, 0);
308 bytes_hashed = opt->SizeOfHeaders;
309 align = opt->FileAlignment;
310 authoff = opt->DataDirectory[ctidx].VirtualAddress;
311 authsz = opt->DataDirectory[ctidx].Size;
312 } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
313 IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
315 efi_image_region_add(regs, efi, &opt->CheckSum, 0);
316 efi_image_region_add(regs, &opt->CheckSum + 1,
317 &opt->DataDirectory[ctidx], 0);
318 efi_image_region_add(regs, &opt->DataDirectory[ctidx] + 1,
319 efi + opt->SizeOfHeaders, 0);
321 bytes_hashed = opt->SizeOfHeaders;
322 align = opt->FileAlignment;
323 authoff = opt->DataDirectory[ctidx].VirtualAddress;
324 authsz = opt->DataDirectory[ctidx].Size;
326 debug("%s: Invalid optional header magic %x\n", __func__,
327 nt->OptionalHeader.Magic);
332 num_sections = nt->FileHeader.NumberOfSections;
333 sections = (void *)((uint8_t *)&nt->OptionalHeader +
334 nt->FileHeader.SizeOfOptionalHeader);
335 sorted = calloc(sizeof(IMAGE_SECTION_HEADER *), num_sections);
337 debug("%s: Out of memory\n", __func__);
342 * Make sure the section list is in ascending order.
344 for (i = 0; i < num_sections; i++)
345 sorted[i] = §ions[i];
346 qsort(sorted, num_sections, sizeof(sorted[0]), cmp_pe_section);
348 for (i = 0; i < num_sections; i++) {
349 if (!sorted[i]->SizeOfRawData)
352 size = (sorted[i]->SizeOfRawData + align - 1) & ~(align - 1);
353 efi_image_region_add(regs, efi + sorted[i]->PointerToRawData,
354 efi + sorted[i]->PointerToRawData + size,
356 debug("section[%d](%s): raw: 0x%x-0x%x, virt: %x-%x\n",
358 sorted[i]->PointerToRawData,
359 sorted[i]->PointerToRawData + size,
360 sorted[i]->VirtualAddress,
361 sorted[i]->VirtualAddress
362 + sorted[i]->Misc.VirtualSize);
364 bytes_hashed += size;
368 /* 3. Extra data excluding Certificates Table */
369 if (bytes_hashed + authsz < len) {
370 debug("extra data for hash: %lu\n",
371 len - (bytes_hashed + authsz));
372 efi_image_region_add(regs, efi + bytes_hashed,
373 efi + len - authsz, 0);
376 /* Return Certificates Table */
378 if (len < authoff + authsz) {
379 debug("%s: Size for auth too large: %u >= %zu\n",
380 __func__, authsz, len - authoff);
383 if (authsz < sizeof(*auth)) {
384 debug("%s: Size for auth too small: %u < %zu\n",
385 __func__, authsz, sizeof(*auth));
388 *auth = efi + authoff;
390 debug("WIN_CERTIFICATE: 0x%x, size: 0x%x\n", authoff, authsz);
407 * efi_image_unsigned_authenticate - authenticate unsigned image with
409 * @regs: List of regions to be verified
411 * If an image is not signed, it doesn't have a signature. In this case,
412 * its message digest is calculated and it will be compared with one of
413 * hash values stored in signature databases.
415 * Return: true if authenticated, false if not
417 static bool efi_image_unsigned_authenticate(struct efi_image_regions *regs)
419 struct efi_signature_store *db = NULL, *dbx = NULL;
422 dbx = efi_sigstore_parse_sigdb(L"dbx");
424 debug("Getting signature database(dbx) failed\n");
428 db = efi_sigstore_parse_sigdb(L"db");
430 debug("Getting signature database(db) failed\n");
434 /* try black-list first */
435 if (efi_signature_verify_with_sigdb(regs, NULL, dbx, NULL)) {
436 debug("Image is not signed and rejected by \"dbx\"\n");
441 if (efi_signature_verify_with_sigdb(regs, NULL, db, NULL))
444 debug("Image is not signed and not found in \"db\" or \"dbx\"\n");
447 efi_sigstore_free(db);
448 efi_sigstore_free(dbx);
454 * efi_image_authenticate - verify a signature of signed image
455 * @efi: Pointer to image
456 * @efi_size: Size of @efi
458 * A signed image should have its signature stored in a table of its PE header.
459 * So if an image is signed and only if if its signature is verified using
460 * signature databases, an image is authenticated.
461 * If an image is not signed, its validity is checked by using
462 * efi_image_unsigned_authenticated().
464 * When AuditMode==0, if the image's signature is not found in
465 * the authorized database, or is found in the forbidden database,
466 * the image will not be started and instead, information about it
467 * will be placed in this table.
468 * When AuditMode==1, an EFI_IMAGE_EXECUTION_INFO element is created
469 * in the EFI_IMAGE_EXECUTION_INFO_TABLE for every certificate found
470 * in the certificate table of every image that is validated.
472 * Return: true if authenticated, false if not
474 static bool efi_image_authenticate(void *efi, size_t efi_size)
476 struct efi_image_regions *regs = NULL;
477 WIN_CERTIFICATE *wincerts = NULL, *wincert;
479 struct pkcs7_message *msg = NULL;
480 struct efi_signature_store *db = NULL, *dbx = NULL;
481 struct x509_certificate *cert = NULL;
482 void *new_efi = NULL;
486 if (!efi_secure_boot_enabled())
490 * Size must be 8-byte aligned and the trailing bytes must be
491 * zero'ed. Otherwise hash value may be incorrect.
493 if (efi_size & 0x7) {
494 new_efi_size = (efi_size + 0x7) & ~0x7ULL;
495 new_efi = calloc(new_efi_size, 1);
498 memcpy(new_efi, efi, efi_size);
500 efi_size = new_efi_size;
503 if (!efi_image_parse(efi, efi_size, ®s, &wincerts,
505 debug("Parsing PE executable image failed\n");
510 /* The image is not signed */
511 ret = efi_image_unsigned_authenticate(regs);
517 * verify signature using db and dbx
519 db = efi_sigstore_parse_sigdb(L"db");
521 debug("Getting signature database(db) failed\n");
525 dbx = efi_sigstore_parse_sigdb(L"dbx");
527 debug("Getting signature database(dbx) failed\n");
531 /* go through WIN_CERTIFICATE list */
532 for (wincert = wincerts;
533 (void *)wincert < (void *)wincerts + wincerts_len;
534 wincert = (void *)wincert + ALIGN(wincert->dwLength, 8)) {
535 if (wincert->dwLength < sizeof(*wincert)) {
536 debug("%s: dwLength too small: %u < %zu\n",
537 __func__, wincert->dwLength, sizeof(*wincert));
540 msg = pkcs7_parse_message((void *)wincert + sizeof(*wincert),
541 wincert->dwLength - sizeof(*wincert));
543 debug("Parsing image's signature failed\n");
548 /* try black-list first */
549 if (efi_signature_verify_with_sigdb(regs, msg, dbx, NULL)) {
550 debug("Signature was rejected by \"dbx\"\n");
554 if (!efi_signature_verify_signers(msg, dbx)) {
555 debug("Signer was rejected by \"dbx\"\n");
562 if (!efi_signature_verify_with_sigdb(regs, msg, db, &cert)) {
563 debug("Verifying signature with \"db\" failed\n");
569 if (!efi_signature_verify_cert(cert, dbx)) {
570 debug("Certificate was rejected by \"dbx\"\n");
578 x509_free_certificate(cert);
579 efi_sigstore_free(db);
580 efi_sigstore_free(dbx);
581 pkcs7_free_message(msg);
588 static bool efi_image_authenticate(void *efi, size_t efi_size)
592 #endif /* CONFIG_EFI_SECURE_BOOT */
595 * efi_load_pe() - relocate EFI binary
597 * This function loads all sections from a PE binary into a newly reserved
598 * piece of memory. On success the entry point is returned as handle->entry.
600 * @handle: loaded image handle
601 * @efi: pointer to the EFI binary
602 * @efi_size: size of @efi binary
603 * @loaded_image_info: loaded image protocol
604 * Return: status code
606 efi_status_t efi_load_pe(struct efi_loaded_image_obj *handle,
607 void *efi, size_t efi_size,
608 struct efi_loaded_image *loaded_image_info)
610 IMAGE_NT_HEADERS32 *nt;
611 IMAGE_DOS_HEADER *dos;
612 IMAGE_SECTION_HEADER *sections;
616 const IMAGE_BASE_RELOCATION *rel;
617 unsigned long rel_size;
618 int rel_idx = IMAGE_DIRECTORY_ENTRY_BASERELOC;
620 unsigned long virt_size = 0;
624 /* Sanity check for a file header */
625 if (efi_size < sizeof(*dos)) {
626 printf("%s: Truncated DOS Header\n", __func__);
627 ret = EFI_LOAD_ERROR;
632 if (dos->e_magic != IMAGE_DOS_SIGNATURE) {
633 printf("%s: Invalid DOS Signature\n", __func__);
634 ret = EFI_LOAD_ERROR;
638 /* assume sizeof(IMAGE_NT_HEADERS32) <= sizeof(IMAGE_NT_HEADERS64) */
639 if (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS32)) {
640 printf("%s: Invalid offset for Extended Header\n", __func__);
641 ret = EFI_LOAD_ERROR;
645 nt = (void *) ((char *)efi + dos->e_lfanew);
646 if ((nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) &&
647 (efi_size < dos->e_lfanew + sizeof(IMAGE_NT_HEADERS64))) {
648 printf("%s: Invalid offset for Extended Header\n", __func__);
649 ret = EFI_LOAD_ERROR;
653 if (nt->Signature != IMAGE_NT_SIGNATURE) {
654 printf("%s: Invalid NT Signature\n", __func__);
655 ret = EFI_LOAD_ERROR;
659 for (i = 0; machines[i]; i++)
660 if (machines[i] == nt->FileHeader.Machine) {
666 printf("%s: Machine type 0x%04x is not supported\n",
667 __func__, nt->FileHeader.Machine);
668 ret = EFI_LOAD_ERROR;
672 num_sections = nt->FileHeader.NumberOfSections;
673 sections = (void *)&nt->OptionalHeader +
674 nt->FileHeader.SizeOfOptionalHeader;
676 if (efi_size < ((void *)sections + sizeof(sections[0]) * num_sections
678 printf("%s: Invalid number of sections: %d\n",
679 __func__, num_sections);
680 ret = EFI_LOAD_ERROR;
684 /* Authenticate an image */
685 if (efi_image_authenticate(efi, efi_size))
686 handle->auth_status = EFI_IMAGE_AUTH_PASSED;
688 handle->auth_status = EFI_IMAGE_AUTH_FAILED;
690 /* Calculate upper virtual address boundary */
691 for (i = num_sections - 1; i >= 0; i--) {
692 IMAGE_SECTION_HEADER *sec = §ions[i];
693 virt_size = max_t(unsigned long, virt_size,
694 sec->VirtualAddress + sec->Misc.VirtualSize);
697 /* Read 32/64bit specific header bits */
698 if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR64_MAGIC) {
699 IMAGE_NT_HEADERS64 *nt64 = (void *)nt;
700 IMAGE_OPTIONAL_HEADER64 *opt = &nt64->OptionalHeader;
701 image_base = opt->ImageBase;
702 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
703 handle->image_type = opt->Subsystem;
704 efi_reloc = efi_alloc(virt_size,
705 loaded_image_info->image_code_type);
707 printf("%s: Could not allocate %lu bytes\n",
708 __func__, virt_size);
709 ret = EFI_OUT_OF_RESOURCES;
712 handle->entry = efi_reloc + opt->AddressOfEntryPoint;
713 rel_size = opt->DataDirectory[rel_idx].Size;
714 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
715 virt_size = ALIGN(virt_size, opt->SectionAlignment);
716 } else if (nt->OptionalHeader.Magic == IMAGE_NT_OPTIONAL_HDR32_MAGIC) {
717 IMAGE_OPTIONAL_HEADER32 *opt = &nt->OptionalHeader;
718 image_base = opt->ImageBase;
719 efi_set_code_and_data_type(loaded_image_info, opt->Subsystem);
720 handle->image_type = opt->Subsystem;
721 efi_reloc = efi_alloc(virt_size,
722 loaded_image_info->image_code_type);
724 printf("%s: Could not allocate %lu bytes\n",
725 __func__, virt_size);
726 ret = EFI_OUT_OF_RESOURCES;
729 handle->entry = efi_reloc + opt->AddressOfEntryPoint;
730 rel_size = opt->DataDirectory[rel_idx].Size;
731 rel = efi_reloc + opt->DataDirectory[rel_idx].VirtualAddress;
732 virt_size = ALIGN(virt_size, opt->SectionAlignment);
734 printf("%s: Invalid optional header magic %x\n", __func__,
735 nt->OptionalHeader.Magic);
736 ret = EFI_LOAD_ERROR;
740 /* Copy PE headers */
741 memcpy(efi_reloc, efi,
744 + nt->FileHeader.SizeOfOptionalHeader
745 + num_sections * sizeof(IMAGE_SECTION_HEADER));
747 /* Load sections into RAM */
748 for (i = num_sections - 1; i >= 0; i--) {
749 IMAGE_SECTION_HEADER *sec = §ions[i];
750 memset(efi_reloc + sec->VirtualAddress, 0,
751 sec->Misc.VirtualSize);
752 memcpy(efi_reloc + sec->VirtualAddress,
753 efi + sec->PointerToRawData,
757 /* Run through relocations */
758 if (efi_loader_relocate(rel, rel_size, efi_reloc,
759 (unsigned long)image_base) != EFI_SUCCESS) {
760 efi_free_pages((uintptr_t) efi_reloc,
761 (virt_size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT);
762 ret = EFI_LOAD_ERROR;
767 flush_cache((ulong)efi_reloc,
768 ALIGN(virt_size, EFI_CACHELINE_SIZE));
769 invalidate_icache_all();
771 /* Populate the loaded image interface bits */
772 loaded_image_info->image_base = efi_reloc;
773 loaded_image_info->image_size = virt_size;
775 if (handle->auth_status == EFI_IMAGE_AUTH_PASSED)
778 return EFI_SECURITY_VIOLATION;