integ/grub/grub2/debian/patches/0026-loader-efi-chainloader-Use-grub_loader_set_ex.patch
Li Zhou 8e6824ec91 grub2/grub-efi: fix CVE-2022-28736
We add patches to fix CVEs for grub instead of upgrading because
grub2/grub-efi is ported from yocto for secure boot bringing up.

The patches for CVE-2022-28736 have conflicts with the patches for
secure boot. So refer to below link to fix this CVE:
(1) https://patchwork.yoctoproject.org/project/oe-core/patch/
20221207034254.58292-1-xiangyu.chen@eng.windriver.com/
(2)https://github.com/jiazhang0/meta-secure-core/pull/257

The special patches for grub-efi are from layers meta-lat and
meta-secure-core of yocto upstream, which are based on the patches
for grub-efi in oe-core layer (including CVE patches). We used to mix
all the patches together. Now we will move the patches from meta-lat
and meta-secure-core to the end of sequence for applying patches,
so that we can keep align with yocto upstream and make it easier
to maintain the grub here.
Since there are many patches involved here, we don't change the number
in patches' name in case confusion is caused if we rename many files.

Below commits are added for the CVE:
<loader/efi/chainloader: Simplify the loader state>
<commands/boot: Add API to pass context to loader>
<loader/efi/chainloader: Use grub_loader_set_ex()>

Below patches for secure boot are adapted for conflicts with above:
secure-core/0009 <efi: chainloader: port shim to grub>
secure-core/0010 <efi: chainloader: use shim to load and verify an image>
secure-core/0012 <efi: chainloader: take care of unload undershim>

All of them are aligned with upstream and no changes here.

Test plan:
 - PASS: build grub2/grub-efi.
 - PASS: build-image and install and boot up on lab/qemu.
 - PASS: check that the "stx.N" version number is right for both
         bios(grub2 ver) and uefi(grub-efi ver) boot.
 - PASS: the tests are done on lab with secure boot disabled and
         enabled.

Closes-Bug: #2034119

Signed-off-by: Li Zhou <li.zhou@windriver.com>
Change-Id: I9a37cd8b804b238407f8ac6528f087a2eb0cf2de
2023-09-07 02:00:19 -04:00

87 lines
2.7 KiB
Diff

From 04c86e0bb7b58fc2f913f798cdb18934933e532d Mon Sep 17 00:00:00 2001
From: Chris Coulson <chris.coulson@canonical.com>
Date: Tue, 5 Apr 2022 11:48:58 +0100
Subject: [PATCH] loader/efi/chainloader: Use grub_loader_set_ex()
This ports the EFI chainloader to use grub_loader_set_ex() in order to fix
a use-after-free bug that occurs when grub_cmd_chainloader() is executed
more than once before a boot attempt is performed.
Fixes: CVE-2022-28736
Signed-off-by: Chris Coulson <chris.coulson@canonical.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Upstream-Status: Backport
CVE: CVE-2022-28736
Reference to upstream patch:
https://git.savannah.gnu.org/cgit/grub.git/commit/?id=04c86e0bb7b58fc2f913f798cdb18934933e532d
Signed-off-by: Xiangyu Chen <xiangyu.chen@windriver.com>
---
grub-core/loader/efi/chainloader.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/grub-core/loader/efi/chainloader.c b/grub-core/loader/efi/chainloader.c
index d1602c89b..7557eb269 100644
--- a/grub-core/loader/efi/chainloader.c
+++ b/grub-core/loader/efi/chainloader.c
@@ -44,11 +44,10 @@ GRUB_MOD_LICENSE ("GPLv3+");
static grub_dl_t my_mod;
-static grub_efi_handle_t image_handle;
-
static grub_err_t
-grub_chainloader_unload (void)
+grub_chainloader_unload (void *context)
{
+ grub_efi_handle_t image_handle = (grub_efi_handle_t) context;
grub_efi_loaded_image_t *loaded_image;
grub_efi_boot_services_t *b;
@@ -64,8 +63,9 @@ grub_chainloader_unload (void)
}
static grub_err_t
-grub_chainloader_boot (void)
+grub_chainloader_boot (void *context)
{
+ grub_efi_handle_t image_handle = (grub_efi_handle_t) context;
grub_efi_boot_services_t *b;
grub_efi_status_t status;
grub_efi_uintn_t exit_data_size;
@@ -225,6 +225,7 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),
grub_efi_physical_address_t address = 0;
grub_efi_uintn_t pages = 0;
grub_efi_char16_t *cmdline = NULL;
+ grub_efi_handle_t image_handle = NULL;
if (argc == 0)
return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("filename expected"));
@@ -405,7 +406,7 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),
efi_call_2 (b->free_pages, address, pages);
grub_free (file_path);
- grub_loader_set (grub_chainloader_boot, grub_chainloader_unload, 0);
+ grub_loader_set_ex (grub_chainloader_boot, grub_chainloader_unload, image_handle, 0);
return 0;
fail:
@@ -423,10 +424,7 @@ grub_cmd_chainloader (grub_command_t cmd __attribute__ ((unused)),
efi_call_2 (b->free_pages, address, pages);
if (image_handle != NULL)
- {
- efi_call_1 (b->unload_image, image_handle);
- image_handle = NULL;
- }
+ efi_call_1 (b->unload_image, image_handle);
grub_dl_unref (my_mod);
--
2.34.1