From bbf98517303e438cea398bb74306b6553c880ac3 Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Tue, 6 Oct 2015 13:04:37 -0400

Subject: [PATCH 151/229] Add secureboot support on efi chainloader

Expand the chainloader to be able to verify the image by means of shim

lock protocol. The PE/COFF image is loaded and relocated by the

chainloader instead of calling LoadImage and StartImage UEFI boot

Service as they require positive verification result from keys enrolled

in KEK or DB. The shim will use MOK in addition to firmware enrolled

keys to verify the image.

The chainloader module could be used to load other UEFI bootloaders,

such as xen.efi, and could be signed by any of MOK, KEK or DB.

Based on https://build.opensuse.org/package/view_file/openSUSE:Factory/grub2/grub2-secureboot-chainloader.patch

Signed-off-by: Peter Jones <pjones@redhat.com>

---

 grub-core/loader/efi/chainloader.c | 612 ++++++++++++++++++++++++++++++++++---

 include/grub/efi/pe32.h            |  20 +-

 2 files changed, 595 insertions(+), 37 deletions(-)

diff --git a/grub-core/loader/efi/chainloader.c b/grub-core/loader/efi/chainloader.c

index 14ce6ddd7ad..87a91e16f17 100644

--- a/grub-core/loader/efi/chainloader.c

+++ b/grub-core/loader/efi/chainloader.c

@@ -32,6 +32,8 @@

 #include <grub/efi/api.h>

 #include <grub/efi/efi.h>

 #include <grub/efi/disk.h>

+#include <grub/efi/pe32.h>

+#include <grub/efi/linux.h>

 #include <grub/command.h>

 #include <grub/i18n.h>

 #include <grub/net.h>

@@ -46,9 +48,14 @@ static grub_dl_t my_mod;

 static grub_efi_physical_address_t address;

 static grub_efi_uintn_t pages;

+static grub_ssize_t fsize;

 static grub_efi_device_path_t *file_path;

 static grub_efi_handle_t image_handle;

 static grub_efi_char16_t *cmdline;

+static grub_ssize_t cmdline_len;

+static grub_efi_handle_t dev_handle;

+

+static grub_efi_status_t (*entry_point) (grub_efi_handle_t image_handle, grub_efi_system_table_t *system_table);

 static grub_err_t

 grub_chainloader_unload (void)

@@ -63,6 +70,7 @@ grub_chainloader_unload (void)

   grub_free (cmdline);

   cmdline = 0;

   file_path = 0;

+  dev_handle = 0;

   grub_dl_unref (my_mod);

   return GRUB_ERR_NONE;

@@ -191,12 +199,523 @@ make_file_path (grub_efi_device_path_t *dp, const char *filename)

   return file_path;

 }

+#define SHIM_LOCK_GUID \

+  { 0x605dab50, 0xe046, 0x4300, { 0xab,0xb6,0x3d,0xd8,0x10,0xdd,0x8b,0x23 } }

+

+typedef union

+{

+  struct grub_pe32_header_32 pe32;

+  struct grub_pe32_header_64 pe32plus;

+} grub_pe_header_t;

+

+struct pe_coff_loader_image_context

+{

+  grub_efi_uint64_t image_address;

+  grub_efi_uint64_t image_size;

+  grub_efi_uint64_t entry_point;

+  grub_efi_uintn_t size_of_headers;

+  grub_efi_uint16_t image_type;

+  grub_efi_uint16_t number_of_sections;

+  grub_efi_uint32_t section_alignment;

+  struct grub_pe32_section_table *first_section;

+  struct grub_pe32_data_directory *reloc_dir;

+  struct grub_pe32_data_directory *sec_dir;

+  grub_efi_uint64_t number_of_rva_and_sizes;

+  grub_pe_header_t *pe_hdr;

+};

+

+typedef struct pe_coff_loader_image_context pe_coff_loader_image_context_t;

+

+struct grub_efi_shim_lock

+{

+  grub_efi_status_t (*verify)(void *buffer,

+                              grub_efi_uint32_t size);

+  grub_efi_status_t (*hash)(void *data,

+                            grub_efi_int32_t datasize,

+                            pe_coff_loader_image_context_t *context,

+                            grub_efi_uint8_t *sha256hash,

+                            grub_efi_uint8_t *sha1hash);

+  grub_efi_status_t (*context)(void *data,

+                               grub_efi_uint32_t size,

+                               pe_coff_loader_image_context_t *context);

+};

+

+typedef struct grub_efi_shim_lock grub_efi_shim_lock_t;

+

+static grub_efi_boolean_t

+read_header (void *data, grub_efi_uint32_t size,

+	     pe_coff_loader_image_context_t *context)

+{

+  grub_efi_guid_t guid = SHIM_LOCK_GUID;

+  grub_efi_shim_lock_t *shim_lock;

+  grub_efi_status_t status;

+

+  shim_lock = grub_efi_locate_protocol (&guid, NULL);

+

+  if (!shim_lock)

+    {

+      grub_error (GRUB_ERR_BAD_ARGUMENT, "no shim lock protocol");

+      return 0;

+    }

+

+  status = shim_lock->context (data, size, context);

+

+  if (status == GRUB_EFI_SUCCESS)

+    {

+      grub_dprintf ("chain", "context success\n");

+      return 1;

+    }

+

+  switch (status)

+    {

+      case GRUB_EFI_UNSUPPORTED:

+      grub_error (GRUB_ERR_BAD_ARGUMENT, "context error unsupported");

+      break;

+      case GRUB_EFI_INVALID_PARAMETER:

+      grub_error (GRUB_ERR_BAD_ARGUMENT, "context error invalid parameter");

+      break;

+      default:

+      grub_error (GRUB_ERR_BAD_ARGUMENT, "context error code");

+      break;

+    }

+

+  return 0;

+}

+

+static void*

+image_address (void *image, grub_efi_uint64_t sz, grub_efi_uint64_t adr)

+{

+  if (adr > sz)

+    return NULL;

+

+  return ((grub_uint8_t*)image + adr);

+}

+

+static int

+image_is_64_bit (grub_pe_header_t *pe_hdr)

+{

+  /* .Magic is the same offset in all cases */

+  if (pe_hdr->pe32plus.optional_header.magic == GRUB_PE32_PE64_MAGIC)

+    return 1;

+  return 0;

+}

+

+static const grub_uint16_t machine_type =

+#if defined(__x86_64__)

+  GRUB_PE32_MACHINE_X86_64;

+#elif defined(__aarch64__)

+  GRUB_PE32_MACHINE_ARM64;

+#elif defined(__arm__)

+  GRUB_PE32_MACHINE_ARMTHUMB_MIXED;

+#elif defined(__i386__) || defined(__i486__) || defined(__i686__)

+  GRUB_PE32_MACHINE_I386;

+#elif defined(__ia64__)

+  GRUB_PE32_MACHINE_IA64;

+#else

+#error this architecture is not supported by grub2

+#endif

+

+static grub_efi_status_t

+relocate_coff (pe_coff_loader_image_context_t *context,

+	       struct grub_pe32_section_table *section,

+	       void *orig, void *data)

+{

+  struct grub_pe32_data_directory *reloc_base, *reloc_base_end;

+  grub_efi_uint64_t adjust;

+  struct grub_pe32_fixup_block *reloc, *reloc_end;

+  char *fixup, *fixup_base, *fixup_data = NULL;

+  grub_efi_uint16_t *fixup_16;

+  grub_efi_uint32_t *fixup_32;

+  grub_efi_uint64_t *fixup_64;

+  grub_efi_uint64_t size = context->image_size;

+  void *image_end = (char *)orig + size;

+  int n = 0;

+

+  if (image_is_64_bit (context->pe_hdr))

+    context->pe_hdr->pe32plus.optional_header.image_base =

+      (grub_uint64_t)(unsigned long)data;

+  else

+    context->pe_hdr->pe32.optional_header.image_base =

+      (grub_uint32_t)(unsigned long)data;

+

+  /* Alright, so here's how this works:

+   *

+   * context->reloc_dir gives us two things:

+   * - the VA the table of base relocation blocks are (maybe) to be

+   *   mapped at (reloc_dir->rva)

+   * - the virtual size (reloc_dir->size)

+   *

+   * The .reloc section (section here) gives us some other things:

+   * - the name! kind of. (section->name)

+   * - the virtual size (section->virtual_size), which should be the same

+   *   as RelocDir->Size

+   * - the virtual address (section->virtual_address)

+   * - the file section size (section->raw_data_size), which is

+   *   a multiple of optional_header->file_alignment.  Only useful for image

+   *   validation, not really useful for iteration bounds.

+   * - the file address (section->raw_data_offset)

+   * - a bunch of stuff we don't use that's 0 in our binaries usually

+   * - Flags (section->characteristics)

+   *

+   * and then the thing that's actually at the file address is an array

+   * of struct grub_pe32_fixup_block structs with some values packed behind

+   * them.  The block_size field of this structure includes the

+   * structure itself, and adding it to that structure's address will

+   * yield the next entry in the array.

+   */

+

+  reloc_base = image_address (orig, size, section->raw_data_offset);

+  reloc_base_end = image_address (orig, size, section->raw_data_offset

+				  + section->virtual_size - 1);

+

+  grub_dprintf ("chain", "reloc_base %p reloc_base_end %p\n", reloc_base,

+		reloc_base_end);

+

+  if (!reloc_base && !reloc_base_end)

+    return GRUB_EFI_SUCCESS;

+

+  if (!reloc_base || !reloc_base_end)

+    {

+      grub_error (GRUB_ERR_BAD_ARGUMENT, "Reloc table overflows binary");

+      return GRUB_EFI_UNSUPPORTED;

+    }

+

+  adjust = (grub_uint64_t)data - context->image_address;

+  if (adjust == 0)

+    return GRUB_EFI_SUCCESS;

+

+  while (reloc_base < reloc_base_end)

+    {

+      grub_uint16_t *entry;

+      reloc = (struct grub_pe32_fixup_block *)((char*)reloc_base);

+

+      if ((reloc_base->size == 0) ||

+	  (reloc_base->size > context->reloc_dir->size))

+	{

+	  grub_error (GRUB_ERR_BAD_ARGUMENT,

+		      "Reloc %d block size %d is invalid\n", n,

+		      reloc_base->size);

+	  return GRUB_EFI_UNSUPPORTED;

+	}

+

+      entry = &reloc->entries[0];

+      reloc_end = (struct grub_pe32_fixup_block *)

+	((char *)reloc_base + reloc_base->size);

+

+      if ((void *)reloc_end < data || (void *)reloc_end > image_end)

+        {

+          grub_error (GRUB_ERR_BAD_ARGUMENT, "Reloc entry %d overflows binary",

+		      n);

+          return GRUB_EFI_UNSUPPORTED;

+        }

+

+      fixup_base = image_address(data, size, reloc_base->rva);

+

+      if (!fixup_base)

+        {

+          grub_error (GRUB_ERR_BAD_ARGUMENT, "Reloc %d Invalid fixupbase", n);

+          return GRUB_EFI_UNSUPPORTED;

+        }

+

+      while ((void *)entry < (void *)reloc_end)

+        {

+          fixup = fixup_base + (*entry & 0xFFF);

+          switch ((*entry) >> 12)

+            {

+              case GRUB_PE32_REL_BASED_ABSOLUTE:

+                break;

+              case GRUB_PE32_REL_BASED_HIGH:

+                fixup_16 = (grub_uint16_t *)fixup;

+                *fixup_16 = (grub_uint16_t)

+		  (*fixup_16 + ((grub_uint16_t)((grub_uint32_t)adjust >> 16)));

+                if (fixup_data != NULL)

+                  {

+                    *(grub_uint16_t *) fixup_data = *fixup_16;

+                    fixup_data = fixup_data + sizeof (grub_uint16_t);

+                  }

+                break;

+              case GRUB_PE32_REL_BASED_LOW:

+                fixup_16 = (grub_uint16_t *)fixup;

+                *fixup_16 = (grub_uint16_t) (*fixup_16 + (grub_uint16_t)adjust);

+                if (fixup_data != NULL)

+                  {

+                    *(grub_uint16_t *) fixup_data = *fixup_16;

+                    fixup_data = fixup_data + sizeof (grub_uint16_t);

+                  }

+                break;

+              case GRUB_PE32_REL_BASED_HIGHLOW:

+                fixup_32 = (grub_uint32_t *)fixup;

+                *fixup_32 = *fixup_32 + (grub_uint32_t)adjust;

+                if (fixup_data != NULL)

+                  {

+                    fixup_data = (char *)ALIGN_UP ((grub_addr_t)fixup_data, sizeof (grub_uint32_t));

+                    *(grub_uint32_t *) fixup_data = *fixup_32;

+                    fixup_data += sizeof (grub_uint32_t);

+                  }

+                break;

+              case GRUB_PE32_REL_BASED_DIR64:

+                fixup_64 = (grub_uint64_t *)fixup;

+                *fixup_64 = *fixup_64 + (grub_uint64_t)adjust;

+                if (fixup_data != NULL)

+                  {

+                    fixup_data = (char *)ALIGN_UP ((grub_addr_t)fixup_data, sizeof (grub_uint64_t));

+                    *(grub_uint64_t *) fixup_data = *fixup_64;

+                    fixup_data += sizeof (grub_uint64_t);

+                  }

+                break;

+              default:

+                grub_error (GRUB_ERR_BAD_ARGUMENT,

+			    "Reloc %d unknown relocation type %d",

+			    n, (*entry) >> 12);

+                return GRUB_EFI_UNSUPPORTED;

+            }

+          entry += 1;

+        }

+      reloc_base = (struct grub_pe32_data_directory *)reloc_end;

+      n++;

+    }

+

+  return GRUB_EFI_SUCCESS;

+}

+

+static grub_efi_device_path_t *

+grub_efi_get_media_file_path (grub_efi_device_path_t *dp)

+{

+  while (1)

+    {

+      grub_efi_uint8_t type = GRUB_EFI_DEVICE_PATH_TYPE (dp);

+      grub_efi_uint8_t subtype = GRUB_EFI_DEVICE_PATH_SUBTYPE (dp);

+

+      if (type == GRUB_EFI_END_DEVICE_PATH_TYPE)

+        break;

+      else if (type == GRUB_EFI_MEDIA_DEVICE_PATH_TYPE

+            && subtype == GRUB_EFI_FILE_PATH_DEVICE_PATH_SUBTYPE)

+      return dp;

+

+      dp = GRUB_EFI_NEXT_DEVICE_PATH (dp);

+    }

+

+    return NULL;

+}

+

+static grub_efi_boolean_t

+handle_image (void *data, grub_efi_uint32_t datasize)

+{

+  grub_efi_boot_services_t *b;

+  grub_efi_loaded_image_t *li, li_bak;

+  grub_efi_status_t efi_status;

+  char *buffer = NULL;

+  char *buffer_aligned = NULL;

+  grub_efi_uint32_t i, size;

+  struct grub_pe32_section_table *section;

+  char *base, *end;

+  pe_coff_loader_image_context_t context;

+  grub_uint32_t section_alignment;

+  grub_uint32_t buffer_size;

+

+  b = grub_efi_system_table->boot_services;

+

+  if (read_header (data, datasize, &context))

+    {

+      grub_dprintf ("chain", "Succeed to read header\n");

+    }

+  else

+    {

+      grub_dprintf ("chain", "Failed to read header\n");

+      goto error_exit;

+    }

+

+  section_alignment = context.section_alignment;

+  buffer_size = context.image_size + section_alignment;

+

+  efi_status = efi_call_3 (b->allocate_pool, GRUB_EFI_LOADER_DATA,

+			   buffer_size, &buffer);

+

+  if (efi_status != GRUB_EFI_SUCCESS)

+    {

+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));

+      goto error_exit;

+    }

+

+  buffer_aligned = (char *)ALIGN_UP ((grub_addr_t)buffer, section_alignment);

+

+  if (!buffer_aligned)

+    {

+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("out of memory"));

+      goto error_exit;

+    }

+

+  grub_memcpy (buffer_aligned, data, context.size_of_headers);

+

+  char *reloc_base, *reloc_base_end;

+  reloc_base = image_address (buffer_aligned, datasize,

+			      context.reloc_dir->rva);

+  /* RelocBaseEnd here is the address of the last byte of the table */

+  reloc_base_end = image_address (buffer_aligned, datasize,

+				  context.reloc_dir->rva

+				  + context.reloc_dir->size - 1);

+  struct grub_pe32_section_table *reloc_section = NULL;

+

+  section = context.first_section;

+  for (i = 0; i < context.number_of_sections; i++, section++)

+    {

+      size = section->virtual_size;

+      if (size > section->raw_data_size)

+        size = section->raw_data_size;

+

+      base = image_address (buffer_aligned, context.image_size,

+			    section->virtual_address);

+      end = image_address (buffer_aligned, context.image_size,

+			   section->virtual_address + size - 1);

+

+

+      /* We do want to process .reloc, but it's often marked

+       * discardable, so we don't want to memcpy it. */

+      if (grub_memcmp (section->name, ".reloc\0\0", 8) == 0)

+	{

+	  if (reloc_section)

+	    {

+	      grub_error (GRUB_ERR_BAD_ARGUMENT,

+			  "Image has multiple relocation sections");

+	      goto error_exit;

+	    }

+

+	  /* If it has nonzero sizes, and our bounds check

+	   * made sense, and the VA and size match RelocDir's

+	   * versions, then we believe in this section table. */

+	  if (section->raw_data_size && section->virtual_size &&

+	      base && end && reloc_base == base && reloc_base_end == end)

+	    {

+	      reloc_section = section;

+	    }

+	}

+

+      if (section->characteristics && GRUB_PE32_SCN_MEM_DISCARDABLE)

+	continue;

+

+      if (!base || !end)

+        {

+          grub_error (GRUB_ERR_BAD_ARGUMENT, "Invalid section size");

+          goto error_exit;

+        }

+

+      if (section->virtual_address < context.size_of_headers ||

+	  section->raw_data_offset < context.size_of_headers)

+	{

+	  grub_error (GRUB_ERR_BAD_ARGUMENT,

+		      "Section %d is inside image headers", i);

+	  goto error_exit;

+	}

+

+      if (section->raw_data_size > 0)

+        grub_memcpy (base, (grub_efi_uint8_t*)data + section->raw_data_offset,

+		     size);

+

+      if (size < section->virtual_size)

+        grub_memset (base + size, 0, section->virtual_size - size);

+

+      grub_dprintf ("chain", "copied section %s\n", section->name);

+    }

+

+  /* 5 == EFI_IMAGE_DIRECTORY_ENTRY_BASERELOC */

+  if (context.number_of_rva_and_sizes <= 5)

+    {

+      grub_dprintf ("chain", "image has no relocation entry\n");

+      goto error_exit;

+    }

+

+  if (context.reloc_dir->size && reloc_section)

+    {

+      /* run the relocation fixups */

+      efi_status = relocate_coff (&context, reloc_section, data,

+				  buffer_aligned);

+

+      if (efi_status != GRUB_EFI_SUCCESS)

+	{

+	  grub_error (GRUB_ERR_BAD_ARGUMENT, "relocation failed");

+	  goto error_exit;

+	}

+    }

+

+  entry_point = image_address (buffer_aligned, context.image_size,

+			       context.entry_point);

+

+  if (!entry_point)

+    {

+      grub_error (GRUB_ERR_BAD_ARGUMENT, "invalid entry point");

+      goto error_exit;

+    }

+

+  li = grub_efi_get_loaded_image (grub_efi_image_handle);

+  if (!li)

+    {

+      grub_error (GRUB_ERR_BAD_ARGUMENT, "no loaded image available");

+      goto error_exit;

+    }

+

+  grub_memcpy (&li_bak, li, sizeof (grub_efi_loaded_image_t));

+  li->image_base = buffer_aligned;

+  li->image_size = context.image_size;

+  li->load_options = cmdline;

+  li->load_options_size = cmdline_len;

+  li->file_path = grub_efi_get_media_file_path (file_path);

+  li->device_handle = dev_handle;

+  if (li->file_path)

+    {

+      grub_printf ("file path: ");

+      grub_efi_print_device_path (li->file_path);

+    }

+  else

+    {

+      grub_error (GRUB_ERR_UNKNOWN_DEVICE, "no matching file path found");

+      goto error_exit;

+    }

+

+  efi_status = efi_call_2 (entry_point, grub_efi_image_handle,

+			   grub_efi_system_table);

+

+  grub_memcpy (li, &li_bak, sizeof (grub_efi_loaded_image_t));

+  efi_status = efi_call_1 (b->free_pool, buffer);

+

+  return 1;

+

+error_exit:

+  if (buffer)

+      efi_call_1 (b->free_pool, buffer);

+

+  return 0;

+}

+

+static grub_err_t

+grub_secureboot_chainloader_unload (void)

+{

+  grub_efi_boot_services_t *b;

+

+  b = grub_efi_system_table->boot_services;

+  efi_call_2 (b->free_pages, address, pages);

+  grub_free (file_path);

+  grub_free (cmdline);

+  cmdline = 0;

+  file_path = 0;

+  dev_handle = 0;

+

+  grub_dl_unref (my_mod);

+  return GRUB_ERR_NONE;

+}

+

+static grub_err_t

+grub_secureboot_chainloader_boot (void)

+{

+  handle_image ((void *)address, fsize);

+  grub_loader_unset ();

+  return grub_errno;

+}

+

 static grub_err_t

 grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

 		      int argc, char *argv[])

 {

   grub_file_t file = 0;

-  grub_ssize_t size;

   grub_efi_status_t status;

   grub_efi_boot_services_t *b;

   grub_device_t dev = 0;

@@ -204,7 +723,6 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

   grub_efi_loaded_image_t *loaded_image;

   char *filename;

   void *boot_image = 0;

-  grub_efi_handle_t dev_handle = 0;

   if (argc == 0)

     return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));

@@ -216,9 +734,36 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

   address = 0;

   image_handle = 0;

   file_path = 0;

+  dev_handle = 0;

   b = grub_efi_system_table->boot_services;

+  if (argc > 1)

+    {

+      int i;

+      grub_efi_char16_t *p16;

+

+      for (i = 1, cmdline_len = 0; i < argc; i++)

+        cmdline_len += grub_strlen (argv[i]) + 1;

+

+      cmdline_len *= sizeof (grub_efi_char16_t);

+      cmdline = p16 = grub_malloc (cmdline_len);

+      if (! cmdline)

+        goto fail;

+

+      for (i = 1; i < argc; i++)

+        {

+          char *p8;

+

+          p8 = argv[i];

+          while (*p8)

+            *(p16++) = *(p8++);

+

+          *(p16++) = ' ';

+        }

+      *(--p16) = 0;

+    }

+

   file = grub_file_open (filename);

   if (! file)

     goto fail;

@@ -267,14 +812,14 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

   grub_printf ("file path: ");

   grub_efi_print_device_path (file_path);

-  size = grub_file_size (file);

-  if (!size)

+  fsize = grub_file_size (file);

+  if (!fsize)

     {

       grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),

 		  filename);

       goto fail;

     }

-  pages = (((grub_efi_uintn_t) size + ((1 << 12) - 1)) >> 12);

+  pages = (((grub_efi_uintn_t) fsize + ((1 << 12) - 1)) >> 12);

   status = efi_call_4 (b->allocate_pages, GRUB_EFI_ALLOCATE_ANY_PAGES,

 			      GRUB_EFI_LOADER_CODE,

@@ -288,7 +833,7 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

     }

   boot_image = (void *) ((grub_addr_t) address);

-  if (grub_file_read (file, boot_image, size) != size)

+  if (grub_file_read (file, boot_image, fsize) != fsize)

     {

       if (grub_errno == GRUB_ERR_NONE)

 	grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),

@@ -298,7 +843,7 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

     }

 #if defined (__i386__) || defined (__x86_64__)

-  if (size >= (grub_ssize_t) sizeof (struct grub_macho_fat_header))

+  if (fsize >= (grub_ssize_t) sizeof (struct grub_macho_fat_header))

     {

       struct grub_macho_fat_header *head = boot_image;

       if (head->magic

@@ -307,6 +852,14 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

 	  grub_uint32_t i;

 	  struct grub_macho_fat_arch *archs

 	    = (struct grub_macho_fat_arch *) (head + 1);

+

+	  if (grub_efi_secure_boot())

+	    {

+	      grub_error (GRUB_ERR_BAD_OS,

+			  "MACHO binaries are forbidden with Secure Boot");

+	      goto fail;

+	    }

+

 	  for (i = 0; i < grub_cpu_to_le32 (head->nfat_arch); i++)

 	    {

 	      if (GRUB_MACHO_CPUTYPE_IS_HOST_CURRENT (archs[i].cputype))

@@ -321,21 +874,28 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

 	      > ~grub_cpu_to_le32 (archs[i].size)

 	      || grub_cpu_to_le32 (archs[i].offset)

 	      + grub_cpu_to_le32 (archs[i].size)

-	      > (grub_size_t) size)

+	      > (grub_size_t) fsize)

 	    {

 	      grub_error (GRUB_ERR_BAD_OS, N_("premature end of file %s"),

 			  filename);

 	      goto fail;

 	    }

 	  boot_image = (char *) boot_image + grub_cpu_to_le32 (archs[i].offset);

-	  size = grub_cpu_to_le32 (archs[i].size);

+	  fsize = grub_cpu_to_le32 (archs[i].size);

 	}

     }

 #endif

+  if (grub_linuxefi_secure_validate((void *)address, fsize))

+    {

+      grub_file_close (file);

+      grub_loader_set (grub_secureboot_chainloader_boot,

+		       grub_secureboot_chainloader_unload, 0);

+      return 0;

+    }

+

   status = efi_call_6 (b->load_image, 0, grub_efi_image_handle, file_path,

-		       boot_image, size,

-		       &image_handle);

+		       boot_image, fsize, &image_handle);

   if (status != GRUB_EFI_SUCCESS)

     {

       if (status == GRUB_EFI_OUT_OF_RESOURCES)

@@ -357,33 +917,10 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),

     }

   loaded_image->device_handle = dev_handle;