From: Ard Biesheuvel ardb@kernel.org
commit ff5ac61ee83c13f516544d29847d28be093a40ee upstream.
The IMA arch code attempts to inspect the "SetupMode" EFI variable by populating a variable called efi_SetupMode_name with the string "SecureBoot" and passing that to the EFI GetVariable service, which obviously does not yield the expected result.
Given that the string is only referenced a single time, let's get rid of the intermediate variable, and pass the correct string as an immediate argument. While at it, do the same for "SecureBoot".
Fixes: 399574c64eaf ("x86/ima: retry detecting secure boot mode") Fixes: 980ef4d22a95 ("x86/ima: check EFI SetupMode too") Cc: Matthew Garrett mjg59@google.com Signed-off-by: Ard Biesheuvel ardb@kernel.org Cc: stable@vger.kernel.org # v5.3 Signed-off-by: Mimi Zohar zohar@linux.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/ima_arch.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
--- a/arch/x86/kernel/ima_arch.c +++ b/arch/x86/kernel/ima_arch.c @@ -10,8 +10,6 @@ extern struct boot_params boot_params;
static enum efi_secureboot_mode get_sb_mode(void) { - efi_char16_t efi_SecureBoot_name[] = L"SecureBoot"; - efi_char16_t efi_SetupMode_name[] = L"SecureBoot"; efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID; efi_status_t status; unsigned long size; @@ -25,7 +23,7 @@ static enum efi_secureboot_mode get_sb_m }
/* Get variable contents into buffer */ - status = efi.get_variable(efi_SecureBoot_name, &efi_variable_guid, + status = efi.get_variable(L"SecureBoot", &efi_variable_guid, NULL, &size, &secboot); if (status == EFI_NOT_FOUND) { pr_info("ima: secureboot mode disabled\n"); @@ -38,7 +36,7 @@ static enum efi_secureboot_mode get_sb_m }
size = sizeof(setupmode); - status = efi.get_variable(efi_SetupMode_name, &efi_variable_guid, + status = efi.get_variable(L"SetupMode", &efi_variable_guid, NULL, &size, &setupmode);
if (status != EFI_SUCCESS) /* ignore unknown SetupMode */