boot/grub2: add patches to fix numerous CVEs

This patch brings the entire stack of Debian patches on grub2 titled
"cve-2025-jan" and available at:

  https://salsa.debian.org/grub-team/grub/-/tree/debian/2.12-9/debian/patches/cve-2025-jan?ref_type=tags

As of this exact Debian grub2 version 2.12-9. Some minor conflicts had
to be fixed. All patches are in upstream Grub master, but mixed with
hundreds of other changes, which is why Debian's effort to backport
them has been leveraged here.

In addition to those patches, 2 extra patches are added:

 0073-net-drivers-ieee1275-ofnet-Add-missing-grub_malloc.patch
 0074-Constant-time-grub_crypto_memcmp.patch

The first one fixes an issue in one of the earlier patches. The fix is
not in Debian, but is in upstream Grub.

The second one fixes another CVE, not fixed in Debian, but fixed in
OpenSUSE. This fix is not upstream as upstream has decided to move to
libgcrypt instead to avoid the problem, but that's a fairly large
change.

Overall, this patch fixes all CVEs currently reported by pkg-stats
against our grub2 package, namely:

CVE-2024-45777
CVE-2024-45778
CVE-2024-45779
CVE-2024-45780
CVE-2024-45782
CVE-2024-56737
CVE-2024-56738
CVE-2025-0678
CVE-2025-0684
CVE-2025-0685
CVE-2025-0686
CVE-2025-0689
CVE-2025-1125

With the previous fixes on runtime tests added (to use glibc
toolchains to build grub2 tests), this commit successfully passes all
tests:

- The ISO9660 tests that use grub2:
  https://gitlab.com/tpetazzoni/buildroot/-/pipelines/1985234563

- The grub2 tests:
  https://gitlab.com/tpetazzoni/buildroot/-/pipelines/1985234685

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[Julien: also tested by building and booting
 - qemu_aarch64_sbsa_defconfig
 - qemu_arm_ebbr_defconfig
 - qemu_loongarch64_virt_efi_defconfig
 - qemu_riscv64_virt_efi_defconfig
 - pc_x86_64_bios_defconfig
 - pc_x86_64_efi_defconfig
]
Tested-by: Julien Olivain <ju.o@free.fr>
[Julien:
 - fix patch #72 upstream link to point to the initial patch
   sumbission rather than a reply
 - merge two _IGNORE_CVES blocks for patch #50 into a single one
 - order _IGNORE_CVES blocks by numerical patch order
 - order numerically the CVE list in commit log
 - add a "Fixes:" tag in patch #74 since its commit log does not
   mention the CVE.
]
Signed-off-by: Julien Olivain <ju.o@free.fr>

boot/grub2/0043-fs-bfs-Disable-under-lockdown.patch

@@ -0,0 +1,57 @@
+From 71487b0cf0f7c3fa45f450ed1f3ea4cedd8002a1 Mon Sep 17 00:00:00 2001
+From: Daniel Axtens <dja@axtens.net>
+Date: Sat, 23 Mar 2024 15:59:43 +1100
+Subject: [PATCH] fs/bfs: Disable under lockdown
+
+The BFS is not fuzz-clean. Don't allow it to be loaded under lockdown.
+This will also disable the AFS.
+
+Fixes: CVE-2024-45778
+Fixes: CVE-2024-45779
+
+Reported-by: Nils Langius <nils@langius.de>
+Signed-off-by: Daniel Axtens <dja@axtens.net>
+Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
+Upstream: 26db6605036bd9e5b16d9068a8cc75be63b8b630
+Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
+---
+ grub-core/fs/bfs.c | 11 ++++++++---
+ 1 file changed, 8 insertions(+), 3 deletions(-)
+
+diff --git a/grub-core/fs/bfs.c b/grub-core/fs/bfs.c
+index f37b16895..c92fd7916 100644
+--- a/grub-core/fs/bfs.c
++++ b/grub-core/fs/bfs.c
+@@ -30,6 +30,7 @@
+ #include <grub/types.h>
+ #include <grub/i18n.h>
+ #include <grub/fshelp.h>
++#include <grub/lockdown.h>
+ 
+ GRUB_MOD_LICENSE ("GPLv3+");
+ 
+@@ -1106,8 +1107,11 @@ GRUB_MOD_INIT (bfs)
+ {
+   COMPILE_TIME_ASSERT (1 << LOG_EXTENT_SIZE ==
+ 		       sizeof (struct grub_bfs_extent));
+-  grub_bfs_fs.mod = mod;
+-  grub_fs_register (&grub_bfs_fs);
++  if (!grub_is_lockdown ())
++    {
++      grub_bfs_fs.mod = mod;
++      grub_fs_register (&grub_bfs_fs);
++    }
+ }
+ 
+ #ifdef MODE_AFS
+@@ -1116,5 +1120,6 @@ GRUB_MOD_FINI (afs)
+ GRUB_MOD_FINI (bfs)
+ #endif
+ {
+-  grub_fs_unregister (&grub_bfs_fs);
++  if (!grub_is_lockdown ())
++    grub_fs_unregister (&grub_bfs_fs);
+ }
+-- 
+2.50.1
+