From: Scott Wood <swood@xxxxxxxxxx> commit 558b523d46289f111d53d7c42211069063be5985 upstream. Checking efi_enabled(EFI_BOOT) is not sufficient to ensure that EFI runtime services are available, e.g. if efi=noruntime is used. Without this, I get an oops on a PREEMPT_RT kernel where efi=noruntime is the default. Fixes: 399574c64eaf94e8 ("x86/ima: retry detecting secure boot mode") Cc: stable@xxxxxxxxxxxxxxx (linux-5.0) Signed-off-by: Scott Wood <swood@xxxxxxxxxx> Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/ima_arch.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/arch/x86/kernel/ima_arch.c +++ b/arch/x86/kernel/ima_arch.c @@ -17,6 +17,11 @@ static enum efi_secureboot_mode get_sb_m size = sizeof(secboot); + if (!efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_info("ima: secureboot mode unknown, no efi\n"); + return efi_secureboot_mode_unknown; + } + /* Get variable contents into buffer */ status = efi.get_variable(efi_SecureBoot_name, &efi_variable_guid, NULL, &size, &secboot);