diff options
| author | Chris Coulson <chris.coulson@canonical.com> | 2022-04-05 11:48:58 +0100 |
|---|---|---|
| committer | Daniel Kiper <daniel.kiper@oracle.com> | 2022-06-07 16:39:31 +0200 |
| commit | 04c86e0bb7b58fc2f913f798cdb18934933e532d (patch) | |
| tree | d125ceeacb30b21caee834e03bfcfe82d8647cb7 | |
| parent | 14ceb3b3ff6db664649138442b6562c114dcf56e (diff) | |
| download | grub-04c86e0bb7b58fc2f913f798cdb18934933e532d.tar.gz | |
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>
| -rw-r--r-- | grub-core/loader/efi/chainloader.c | 16 |
1 files 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); |