From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Wed, 9 Feb 2022 16:08:20 -0500

Subject: [PATCH] EFI: allocate kernel in EFI_RUNTIME_SERVICES_CODE instead of

 EFI_LOADER_DATA.

On some of the firmwares with more security mitigations, EFI_LOADER_DATA

doesn't get you executable memory, and we take a fault and reboot when

we enter kernel.

This patch correctly allocates the kernel code as EFI_RUNTIME_SERVICES_CODE

rather than EFI_LOADER_DATA.

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

[rharwood: use kernel_size]

Signed-off-by: Robbie Harwood <rharwood@redhat.com>

---

 grub-core/loader/i386/efi/linux.c | 19 +++++++++++++------

 1 file changed, 13 insertions(+), 6 deletions(-)

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

index 9e5c11ac69..92b2fb5091 100644

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

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

@@ -86,7 +86,9 @@ kernel_free(void *addr, grub_efi_uintn_t size)

 }

 static void *

-kernel_alloc(grub_efi_uintn_t size, const char * const errmsg)

+kernel_alloc(grub_efi_uintn_t size,

+	     grub_efi_memory_type_t memtype,

+	     const char * const errmsg)

 {

   void *addr = 0;

   unsigned int i;

@@ -112,7 +114,7 @@ kernel_alloc(grub_efi_uintn_t size, const char * const errmsg)

       prev_max = max;

       addr = grub_efi_allocate_pages_real (max, pages,

 					   max_addresses[i].alloc_type,

-					   GRUB_EFI_LOADER_DATA);

+					   memtype);

       if (addr)

 	grub_dprintf ("linux", "Allocated at %p\n", addr);

     }

@@ -242,7 +244,8 @@ grub_cmd_initrd (grub_command_t cmd, int argc, char *argv[])

 	}

     }

-  initrd_mem = kernel_alloc(size, N_("can't allocate initrd"));

+  initrd_mem = kernel_alloc(size, GRUB_EFI_RUNTIME_SERVICES_DATA,

+			    N_("can't allocate initrd"));

   if (initrd_mem == NULL)

     goto fail;

   grub_dprintf ("linux", "initrd_mem = %p\n", initrd_mem);

@@ -393,7 +396,8 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

     }

 #endif

-  params = kernel_alloc (sizeof(*params), "cannot allocate kernel parameters");

+  params = kernel_alloc (sizeof(*params), GRUB_EFI_RUNTIME_SERVICES_DATA,

+			 "cannot allocate kernel parameters");

   if (!params)

     goto fail;

   grub_dprintf ("linux", "params = %p\n", params);

@@ -415,7 +419,9 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   grub_dprintf ("linux", "new lh is at %p\n", lh);

   grub_dprintf ("linux", "setting up cmdline\n");

-  cmdline = kernel_alloc (lh->cmdline_size + 1, N_("can't allocate cmdline"));

+  cmdline = kernel_alloc (lh->cmdline_size + 1,

+			  GRUB_EFI_RUNTIME_SERVICES_DATA,

+			  N_("can't allocate cmdline"));

   if (!cmdline)

     goto fail;

   grub_dprintf ("linux", "cmdline = %p\n", cmdline);

@@ -461,7 +467,8 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),

   max_addresses[1].addr = GRUB_EFI_MAX_ALLOCATION_ADDRESS;

   max_addresses[2].addr = GRUB_EFI_MAX_ALLOCATION_ADDRESS;

   kernel_size = lh->init_size;

-  kernel_mem = kernel_alloc (kernel_size, N_("can't allocate kernel"));

+  kernel_mem = kernel_alloc (kernel_size, GRUB_EFI_RUNTIME_SERVICES_CODE,

+			     N_("can't allocate kernel"));

   restore_addresses();

   if (!kernel_mem)

     goto fail;