[PATCH 5.2 52/85] x86/ima: check EFI SetupMode too

[Greg Kroah-Hartman]

From: Mimi Zohar <zohar@xxxxxxxxxxxxx>

commit 980ef4d22a95a3cd84a9b8ffaa7b81b391d173c6 upstream.

Checking "SecureBoot" mode is not sufficient, also check "SetupMode".

Fixes: 399574c64eaf ("x86/ima: retry detecting secure boot mode")
Reported-by: Matthew Garrett <mjg59@xxxxxxxxxx>
Signed-off-by: Mimi Zohar <zohar@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kernel/ima_arch.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/ima_arch.c
+++ b/arch/x86/kernel/ima_arch.c
@@ -11,10 +11,11 @@ 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;
-	u8 secboot;
+	u8 secboot, setupmode;
 
 	size = sizeof(secboot);
 
@@ -36,7 +37,14 @@ static enum efi_secureboot_mode get_sb_m
 		return efi_secureboot_mode_unknown;
 	}
 
-	if (secboot == 0) {
+	size = sizeof(setupmode);
+	status = efi.get_variable(efi_SetupMode_name, &efi_variable_guid,
+				  NULL, &size, &setupmode);
+
+	if (status != EFI_SUCCESS)	/* ignore unknown SetupMode */
+		setupmode = 0;
+
+	if (secboot == 0 || setupmode == 1) {
 		pr_info("ima: secureboot mode disabled\n");
 		return efi_secureboot_mode_disabled;
 	}