grub2/0266-efi-Disallow-fallback-to-legacy-Linux-loader-when-sh.patch
Leo Sandoval 5c315b462c Remove 'efi: Use shim's loader protocol for EFI image verification'
Although this patch is correct and at some point it will be
re-introduced, currently shim does not support the loader protocol so
drop it in the meanwhile.

Signed-off-by: Leo Sandoval <lsandova@redhat.com>
2024-08-06 14:30:42 -06:00

66 lines
2.2 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Mate Kukri <mate.kukri@canonical.com>
Date: Wed, 10 Jul 2024 12:07:17 -0600
Subject: [PATCH] efi: Disallow fallback to legacy Linux loader when shim says
NX is required.
Signed-off-by: Mate Kukri <mate.kukri@canonical.com>
---
grub-core/loader/efi/linux.c | 13 ++++++++-----
include/grub/efi/api.h | 2 ++
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/grub-core/loader/efi/linux.c b/grub-core/loader/efi/linux.c
index da5dcafad8b..21aad881ba0 100644
--- a/grub-core/loader/efi/linux.c
+++ b/grub-core/loader/efi/linux.c
@@ -724,6 +724,7 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
void *kernel = NULL;
grub_err_t err;
int nx_supported = 1;
+ int nx_required = 0;
grub_dl_ref (my_mod);
@@ -756,21 +757,23 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
goto fail;
}
+#if !defined(__i386__) && !defined(__x86_64__)
if (grub_arch_efi_linux_load_image_header (file, &lh) != GRUB_ERR_NONE)
-#if !defined(__i386__) && !defined(__x86_64__)
goto fail;
#else
- goto fallback;
-
- if (!initrd_use_loadfile2)
+ if (grub_arch_efi_linux_load_image_header (file, &lh) != GRUB_ERR_NONE ||
+ !initrd_use_loadfile2)
{
+ /* We cannot use the legacy loader when NX is required */
+ if (grub_efi_check_nx_required(&nx_required))
+ goto fail;
+
/*
* This is a EFI stub image but it is too old to implement the LoadFile2
* based initrd loading scheme, and Linux/x86 does not support the DT
* based method either. So fall back to the x86-specific loader that
* enters Linux in EFI mode but without going through its EFI stub.
*/
-fallback:
grub_file_close (file);
return grub_cmd_linux_x86_legacy (cmd, argc, argv);
}
diff --git a/include/grub/efi/api.h b/include/grub/efi/api.h
index da51f57fd4a..637b1272d17 100644
--- a/include/grub/efi/api.h
+++ b/include/grub/efi/api.h
@@ -2011,6 +2011,8 @@ struct grub_efi_block_io
};
typedef struct grub_efi_block_io grub_efi_block_io_t;
+#define GRUB_MOK_POLICY_NX_REQUIRED 0x1
+
struct grub_efi_shim_lock_protocol
{
/*