From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <mjg59@coreos.com>

Date: Sun, 9 Aug 2015 16:12:39 -0700

Subject: [PATCH] Rework linux command

We want a single buffer that contains the entire kernel image in order to

perform a TPM measurement. Allocate one and copy the entire kernel into it

before pulling out the individual blocks later on.

---

 grub-core/loader/i386/linux.c | 37 ++++++++++++++++++++++++-------------

 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/grub-core/loader/i386/linux.c b/grub-core/loader/i386/linux.c

index 9b53d3168..f7186be40 100644

--- a/grub-core/loader/i386/linux.c

+++ b/grub-core/loader/i386/linux.c

@@ -685,13 +685,15 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

 {

   grub_file_t file = 0;

   struct linux_i386_kernel_header lh;

+  grub_uint8_t *linux_params_ptr;

   grub_uint8_t setup_sects;

-  grub_size_t real_size, prot_size, prot_file_size;

+  grub_size_t real_size, prot_size, prot_file_size, kernel_offset;

   grub_ssize_t len;

   int i;

   grub_size_t align, min_align;

   int relocatable;

   grub_uint64_t preferred_address = GRUB_LINUX_BZIMAGE_ADDR;

+  grub_uint8_t *kernel = NULL;

   grub_dl_ref (my_mod);

@@ -705,7 +707,15 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   if (! file)

     goto fail;

-  if (grub_file_read (file, &lh, sizeof (lh)) != sizeof (lh))

+  len = grub_file_size (file);

+  kernel = grub_malloc (len);

+  if (!kernel)

+    {

+      grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("cannot allocate kernel buffer"));

+      goto fail;

+    }

+

+  if (grub_file_read (file, kernel, len) != len)

     {

       if (!grub_errno)

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

@@ -713,6 +723,9 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

       goto fail;

     }

+  grub_memcpy (&lh, kernel, sizeof (lh));

+  kernel_offset = sizeof (lh);

+

   if (lh.boot_flag != grub_cpu_to_le16_compile_time (0xaa55))

     {

       grub_error (GRUB_ERR_BAD_OS, "invalid magic number");

@@ -804,6 +817,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

 		      preferred_address))

     goto fail;

+

   grub_memset (&linux_params, 0, sizeof (linux_params));

   grub_memcpy (&linux_params.setup_sects, &lh.setup_sects, sizeof (lh) - 0x1F1);

@@ -812,13 +826,10 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   linux_params.ps_mouse = linux_params.padding10 =  0;

   len = sizeof (linux_params) - sizeof (lh);

-  if (grub_file_read (file, (char *) &linux_params + sizeof (lh), len) != len)

-    {

-      if (!grub_errno)

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

-		    argv[0]);

-      goto fail;

-    }

+

+  linux_params_ptr = (void *)&linux_params;

+  grub_memcpy (linux_params_ptr + sizeof (lh), kernel + kernel_offset, len);

+  kernel_offset += len;

   linux_params.type_of_loader = GRUB_LINUX_BOOT_LOADER_TYPE;

@@ -877,7 +888,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   /* The other parameters are filled when booting.  */

-  grub_file_seek (file, real_size + GRUB_DISK_SECTOR_SIZE);

+  kernel_offset = real_size + GRUB_DISK_SECTOR_SIZE;

   grub_dprintf ("linux", "bzImage, setup=0x%x, size=0x%x\n",

 		(unsigned) real_size, (unsigned) prot_size);

@@ -1025,9 +1036,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

 			      - (sizeof (LINUX_IMAGE) - 1));

   len = prot_file_size;

-  if (grub_file_read (file, prot_mode_mem, len) != len && !grub_errno)

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

-		argv[0]);

+  grub_memcpy (prot_mode_mem, kernel + kernel_offset, len);

   if (grub_errno == GRUB_ERR_NONE)

     {

@@ -1038,6 +1047,8 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

  fail:

+  grub_free (kernel);

+

   if (file)

     grub_file_close (file);