From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: Mate Kukri 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 --- 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 fe48001442a..0d1804b602d 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); @@ -772,21 +773,23 @@ 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 76c88fbdcb0..2376182d735 100644 --- a/include/grub/efi/api.h +++ b/include/grub/efi/api.h @@ -2006,6 +2006,8 @@ 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 { /*