From 8dea807503a1ba88d9e27595daae7f86ec968711 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Fri, 9 Aug 2013 17:58:15 -0400

Subject: [PATCH 01/14] Add secure_modules() call

Provide a single call to allow kernel code to determine whether the system

has been configured to either disable module loading entirely or to load

only modules signed with a trusted key.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 include/linux/module.h |  7 +++++++

 kernel/module.c        | 10 ++++++++++

 2 files changed, 17 insertions(+)

diff --git a/include/linux/module.h b/include/linux/module.h

index 46f1ea0..0c266b2 100644

--- a/include/linux/module.h

+++ b/include/linux/module.h

@@ -509,6 +509,8 @@ int unregister_module_notifier(struct notifier_block * nb);

 extern void print_modules(void);

+extern bool secure_modules(void);

+

 #else /* !CONFIG_MODULES... */

 /* Given an address, look for it in the exception tables. */

@@ -619,6 +621,11 @@ static inline int unregister_module_notifier(struct notifier_block * nb)

 static inline void print_modules(void)

 {

 }

+

+static inline bool secure_modules(void)

+{

+	return false;

+}

 #endif /* CONFIG_MODULES */

 #ifdef CONFIG_SYSFS

diff --git a/kernel/module.c b/kernel/module.c

index 2069158..0e94acf 100644

--- a/kernel/module.c

+++ b/kernel/module.c

@@ -3852,3 +3852,13 @@ void module_layout(struct module *mod,

 }

 EXPORT_SYMBOL(module_layout);

 #endif

+

+bool secure_modules(void)

+{

+#ifdef CONFIG_MODULE_SIG

+	return (sig_enforce || modules_disabled);

+#else

+	return modules_disabled;

+#endif

+}

+EXPORT_SYMBOL(secure_modules);

-- 

1.8.3.1

From 9b7b3f6283bf784e4ea1c34e52646b12971b2823 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Thu, 8 Mar 2012 10:10:38 -0500

Subject: [PATCH 02/14] PCI: Lock down BAR access when module security is

 enabled

Any hardware that can potentially generate DMA has to be locked down from

userspace in order to avoid it being possible for an attacker to modify

kernel code, allowing them to circumvent disabled module loading or module

signing. Default to paranoid - in future we can potentially relax this for

sufficiently IOMMU-isolated devices.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 drivers/pci/pci-sysfs.c | 10 ++++++++++

 drivers/pci/proc.c      |  8 +++++++-

 drivers/pci/syscall.c   |  3 ++-

 3 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c

index c0dbe1f..cd4e35f 100644

--- a/drivers/pci/pci-sysfs.c

+++ b/drivers/pci/pci-sysfs.c

@@ -29,6 +29,7 @@

 #include <linux/slab.h>

 #include <linux/vgaarb.h>

 #include <linux/pm_runtime.h>

+#include <linux/module.h>

 #include "pci.h"

 static int sysfs_initialized;	/* = 0 */

@@ -624,6 +625,9 @@ pci_write_config(struct file* filp, struct kobject *kobj,

 	loff_t init_off = off;

 	u8 *data = (u8*) buf;

+	if (secure_modules())

+		return -EPERM;

+

 	if (off > dev->cfg_size)

 		return 0;

 	if (off + count > dev->cfg_size) {

@@ -930,6 +934,9 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,

 	resource_size_t start, end;

 	int i;

+	if (secure_modules())

+		return -EPERM;

+

 	for (i = 0; i < PCI_ROM_RESOURCE; i++)

 		if (res == &pdev->resource[i])

 			break;

@@ -1037,6 +1044,9 @@ pci_write_resource_io(struct file *filp, struct kobject *kobj,

 		      struct bin_attribute *attr, char *buf,

 		      loff_t off, size_t count)

 {

+	if (secure_modules())

+		return -EPERM;

+

 	return pci_resource_io(filp, kobj, attr, buf, off, count, true);

 }

diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c

index cdc7836..e3d498b 100644

--- a/drivers/pci/proc.c

+++ b/drivers/pci/proc.c

@@ -117,6 +117,9 @@ proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, lof

 	int size = dev->cfg_size;

 	int cnt;

+	if (secure_modules())

+		return -EPERM;

+

 	if (pos >= size)

 		return 0;

 	if (nbytes >= size)

@@ -196,6 +199,9 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,

 #endif /* HAVE_PCI_MMAP */

 	int ret = 0;

+	if (secure_modules())

+		return -EPERM;

+

 	switch (cmd) {

 	case PCIIOC_CONTROLLER:

 		ret = pci_domain_nr(dev->bus);

@@ -234,7 +240,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma)

 	struct pci_filp_private *fpriv = file->private_data;

 	int i, ret;

-	if (!capable(CAP_SYS_RAWIO))

+	if (!capable(CAP_SYS_RAWIO) || secure_modules())

 		return -EPERM;

 	/* Make sure the caller is mapping a real resource for this device */

diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c

index e1c1ec5..bffbf71 100644

--- a/drivers/pci/syscall.c

+++ b/drivers/pci/syscall.c

@@ -10,6 +10,7 @@

 #include <linux/errno.h>

 #include <linux/pci.h>

 #include <linux/syscalls.h>

+#include <linux/module.h>

 #include <asm/uaccess.h>

 #include "pci.h"

@@ -92,7 +93,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn,

 	u32 dword;

 	int err = 0;

-	if (!capable(CAP_SYS_ADMIN))

+	if (!capable(CAP_SYS_ADMIN) || secure_modules())

 		return -EPERM;

 	dev = pci_get_bus_and_slot(bus, dfn);

-- 

1.8.3.1

From aac2425a2664c09c2a369e1eec6e7a5bc2713cb1 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Thu, 8 Mar 2012 10:35:59 -0500

Subject: [PATCH 03/14] x86: Lock down IO port access when module security is

 enabled

IO port access would permit users to gain access to PCI configuration

registers, which in turn (on a lot of hardware) give access to MMIO register

space. This would potentially permit root to trigger arbitrary DMA, so lock

it down by default.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 arch/x86/kernel/ioport.c | 5 +++--

 drivers/char/mem.c       | 4 ++++

 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c

index 4ddaf66..00b4403 100644

--- a/arch/x86/kernel/ioport.c

+++ b/arch/x86/kernel/ioport.c

@@ -15,6 +15,7 @@

 #include <linux/thread_info.h>

 #include <linux/syscalls.h>

 #include <linux/bitmap.h>

+#include <linux/module.h>

 #include <asm/syscalls.h>

 /*

@@ -28,7 +29,7 @@ asmlinkage long sys_ioperm(unsigned long from, unsigned long num, int turn_on)

 	if ((from + num <= from) || (from + num > IO_BITMAP_BITS))

 		return -EINVAL;

-	if (turn_on && !capable(CAP_SYS_RAWIO))

+	if (turn_on && (!capable(CAP_SYS_RAWIO) || secure_modules()))

 		return -EPERM;

 	/*

@@ -103,7 +104,7 @@ SYSCALL_DEFINE1(iopl, unsigned int, level)

 		return -EINVAL;

 	/* Trying to gain more privileges? */

 	if (level > old) {

-		if (!capable(CAP_SYS_RAWIO))

+		if (!capable(CAP_SYS_RAWIO) || secure_modules())

 			return -EPERM;

 	}

 	regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);

diff --git a/drivers/char/mem.c b/drivers/char/mem.c

index f895a8c..1af8664 100644

--- a/drivers/char/mem.c

+++ b/drivers/char/mem.c

@@ -28,6 +28,7 @@

 #include <linux/export.h>

 #include <linux/io.h>

 #include <linux/aio.h>

+#include <linux/module.h>

 #include <asm/uaccess.h>

@@ -563,6 +564,9 @@ static ssize_t write_port(struct file *file, const char __user *buf,

 	unsigned long i = *ppos;

 	const char __user *tmp = buf;

+	if (secure_modules())

+		return -EPERM;

+

 	if (!access_ok(VERIFY_READ, buf, count))

 		return -EFAULT;

 	while (count-- > 0 && i < 65536) {

-- 

1.8.3.1

From e7f9789c7eedf291972666befee726ff8e7126f6 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Fri, 9 Mar 2012 08:39:37 -0500

Subject: [PATCH 04/14] ACPI: Limit access to custom_method

custom_method effectively allows arbitrary access to system memory, making

it possible for an attacker to circumvent restrictions on module loading.

Disable it if any such restrictions have been enabled.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 drivers/acpi/custom_method.c | 3 +++

 1 file changed, 3 insertions(+)

diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c

index 12b62f2..50647b3 100644

--- a/drivers/acpi/custom_method.c

+++ b/drivers/acpi/custom_method.c

@@ -29,6 +29,9 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf,

 	struct acpi_table_header table;

 	acpi_status status;

+	if (secure_modules())

+		return -EPERM;

+

 	if (!(*ppos)) {

 		/* parse the table header to get the table length */

 		if (count <= sizeof(struct acpi_table_header))

-- 

1.8.3.1

From d81cd6628c821d47bd086354cbc57b1474f3c1a8 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Fri, 9 Mar 2012 08:46:50 -0500

Subject: [PATCH 05/14] asus-wmi: Restrict debugfs interface when module

 loading is restricted

We have no way of validating what all of the Asus WMI methods do on a

given machine, and there's a risk that some will allow hardware state to

be manipulated in such a way that arbitrary code can be executed in the

kernel, circumventing module loading restrictions. Prevent that if any of

these features are enabled.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 drivers/platform/x86/asus-wmi.c | 9 +++++++++

 1 file changed, 9 insertions(+)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c

index 19c313b..db18ef66 100644

--- a/drivers/platform/x86/asus-wmi.c

+++ b/drivers/platform/x86/asus-wmi.c

@@ -1618,6 +1618,9 @@ static int show_dsts(struct seq_file *m, void *data)

 	int err;

 	u32 retval = -1;

+	if (secure_modules())

+		return -EPERM;

+

 	err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval);

 	if (err < 0)

@@ -1634,6 +1637,9 @@ static int show_devs(struct seq_file *m, void *data)

 	int err;

 	u32 retval = -1;

+	if (secure_modules())

+		return -EPERM;

+

 	err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param,

 				    &retval);

@@ -1658,6 +1664,9 @@ static int show_call(struct seq_file *m, void *data)

 	union acpi_object *obj;

 	acpi_status status;

+	if (secure_modules())

+		return -EPERM;

+

 	status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID,

 				     1, asus->debug.method_id,

 				     &input, &output);

-- 

1.8.3.1

From df75e984729ef50bb691b4d15472529fcd81580b Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Fri, 9 Mar 2012 09:28:15 -0500

Subject: [PATCH 06/14] Restrict /dev/mem and /dev/kmem when module loading is

 restricted

Allowing users to write to address space makes it possible for the kernel

to be subverted, avoiding module loading restrictions. Prevent this when

any restrictions have been imposed on loading modules.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 drivers/char/mem.c | 6 ++++++

 1 file changed, 6 insertions(+)

diff --git a/drivers/char/mem.c b/drivers/char/mem.c

index 1af8664..61406c8 100644

--- a/drivers/char/mem.c

+++ b/drivers/char/mem.c

@@ -159,6 +159,9 @@ static ssize_t write_mem(struct file *file, const char __user *buf,

 	unsigned long copied;

 	void *ptr;

+	if (secure_modules())

+		return -EPERM;

+

 	if (!valid_phys_addr_range(p, count))

 		return -EFAULT;

@@ -497,6 +500,9 @@ static ssize_t write_kmem(struct file *file, const char __user *buf,

 	char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */

 	int err = 0;

+	if (secure_modules())

+		return -EPERM;

+

 	if (p < (unsigned long) high_memory) {

 		unsigned long to_write = min_t(unsigned long, count,

 					       (unsigned long)high_memory - p);

-- 

1.8.3.1

From 78955913cc46cc5e5c7f2c71c1b07a5c18e06456 Mon Sep 17 00:00:00 2001

From: Josh Boyer <jwboyer@redhat.com>

Date: Mon, 25 Jun 2012 19:57:30 -0400

Subject: [PATCH 07/14] acpi: Ignore acpi_rsdp kernel parameter when module

 loading is restricted

This option allows userspace to pass the RSDP address to the kernel, which

makes it possible for a user to circumvent any restrictions imposed on

loading modules. Disable it in that case.

Signed-off-by: Josh Boyer <jwboyer@redhat.com>

---

 drivers/acpi/osl.c | 3 ++-

 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c

index 6ab2c35..e4c4410 100644

--- a/drivers/acpi/osl.c

+++ b/drivers/acpi/osl.c

@@ -45,6 +45,7 @@

 #include <linux/list.h>

 #include <linux/jiffies.h>

 #include <linux/semaphore.h>

+#include <linux/module.h>

 #include <asm/io.h>

 #include <asm/uaccess.h>

@@ -245,7 +246,7 @@ early_param("acpi_rsdp", setup_acpi_rsdp);

 acpi_physical_address __init acpi_os_get_root_pointer(void)

 {

 #ifdef CONFIG_KEXEC

-	if (acpi_rsdp)

+	if (acpi_rsdp && !secure_modules())

 		return acpi_rsdp;

 #endif

-- 

1.8.3.1

From 23aae9143fbece326b3a26bf5ba48956c99cabe4 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Fri, 9 Aug 2013 03:33:56 -0400

Subject: [PATCH 08/14] kexec: Disable at runtime if the kernel enforces module

 loading restrictions

kexec permits the loading and execution of arbitrary code in ring 0, which

is something that module signing enforcement is meant to prevent. It makes

sense to disable kexec in this situation.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 kernel/kexec.c | 8 ++++++++

 1 file changed, 8 insertions(+)

diff --git a/kernel/kexec.c b/kernel/kexec.c

index 59f7b55..3e2b63a 100644

--- a/kernel/kexec.c

+++ b/kernel/kexec.c

@@ -32,6 +32,7 @@

 #include <linux/vmalloc.h>

 #include <linux/swap.h>

 #include <linux/syscore_ops.h>

+#include <linux/module.h>

 #include <asm/page.h>

 #include <asm/uaccess.h>

@@ -943,6 +944,13 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,

 		return -EPERM;

 	/*

+	 * kexec can be used to circumvent module loading restrictions, so

+	 * prevent loading in that case

+	 */

+	if (secure_modules())

+		return -EPERM;

+

+	/*

 	 * Verify we have a legal set of flags

 	 * This leaves us room for future extensions.

 	 */

-- 

1.8.3.1

From 218cd49aa2d6a085c5c4edc0396200864f0b54ad Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Tue, 3 Sep 2013 11:23:29 -0400

Subject: [PATCH 09/14] uswsusp: Disable when module loading is restricted

uswsusp allows a user process to dump and then restore kernel state, which

makes it possible to avoid module loading restrictions. Prevent this when

any restrictions have been imposed on loading modules.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 kernel/power/user.c | 4 ++++

 1 file changed, 4 insertions(+)

diff --git a/kernel/power/user.c b/kernel/power/user.c

index 4ed81e7..15cb72f 100644

--- a/kernel/power/user.c

+++ b/kernel/power/user.c

@@ -24,6 +24,7 @@

 #include <linux/console.h>

 #include <linux/cpu.h>

 #include <linux/freezer.h>

+#include <linux/module.h>

 #include <asm/uaccess.h>

@@ -48,6 +49,9 @@ static int snapshot_open(struct inode *inode, struct file *filp)

 	struct snapshot_data *data;

 	int error;

+	if (secure_modules())

+		return -EPERM;

+

 	lock_system_sleep();

 	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {

-- 

1.8.3.1

From beeaac053d4ae57dc65be1da8b46e5d4bc6542b8 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Fri, 8 Feb 2013 11:12:13 -0800

Subject: [PATCH 10/14] x86: Restrict MSR access when module loading is

 restricted

Writing to MSRs should not be allowed if module loading is restricted,

since it could lead to execution of arbitrary code in kernel mode. Based

on a patch by Kees Cook.

Cc: Kees Cook <keescook@chromium.org>

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 arch/x86/kernel/msr.c | 7 +++++++

 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c

index 88458fa..d08f7e3 100644

--- a/arch/x86/kernel/msr.c

+++ b/arch/x86/kernel/msr.c

@@ -103,6 +103,9 @@ static ssize_t msr_write(struct file *file, const char __user *buf,

 	int err = 0;

 	ssize_t bytes = 0;

+	if (secure_modules())

+		return -EPERM;

+

 	if (count % 8)

 		return -EINVAL;	/* Invalid chunk size */

@@ -150,6 +153,10 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg)

 			err = -EBADF;

 			break;

 		}

+		if (secure_modules()) {

+			err = -EPERM;

+			break;

+		}

 		if (copy_from_user(&regs, uregs, sizeof regs)) {

 			err = -EFAULT;

 			break;

-- 

1.8.3.1

From b4331711c52aff0a6a9cef0f4b52fe261874d6f2 Mon Sep 17 00:00:00 2001

From: Matthew Garrett <matthew.garrett@nebula.com>

Date: Fri, 9 Aug 2013 18:36:30 -0400

Subject: [PATCH 11/14] Add option to automatically enforce module signatures

 when in Secure Boot mode

UEFI Secure Boot provides a mechanism for ensuring that the firmware will

only load signed bootloaders and kernels. Certain use cases may also

require that all kernel modules also be signed. Add a configuration option

that enforces this automatically when enabled.

Signed-off-by: Matthew Garrett <matthew.garrett@nebula.com>

---

 Documentation/x86/zero-page.txt       |  2 ++

 arch/x86/Kconfig                      | 10 ++++++++++

 arch/x86/boot/compressed/eboot.c      | 36 +++++++++++++++++++++++++++++++++++

 arch/x86/include/uapi/asm/bootparam.h |  3 ++-

 arch/x86/kernel/setup.c               |  6 ++++++

 include/linux/module.h                |  6 ++++++

 kernel/module.c                       |  7 +++++++

 7 files changed, 69 insertions(+), 1 deletion(-)

diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt

index 199f453..ec38acf 100644

--- a/Documentation/x86/zero-page.txt

+++ b/Documentation/x86/zero-page.txt

@@ -30,6 +30,8 @@ Offset	Proto	Name		Meaning

 1E9/001	ALL	eddbuf_entries	Number of entries in eddbuf (below)

 1EA/001	ALL	edd_mbr_sig_buf_entries	Number of entries in edd_mbr_sig_buffer

 				(below)

+1EB/001	ALL     kbd_status      Numlock is enabled

+1EC/001	ALL     secure_boot	Secure boot is enabled in the firmware

 1EF/001	ALL	sentinel	Used to detect broken bootloaders

 290/040	ALL	edd_mbr_sig_buffer EDD MBR signatures

 2D0/A00	ALL	e820_map	E820 memory map table

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig

index b32ebf9..6a6c19b 100644

--- a/arch/x86/Kconfig

+++ b/arch/x86/Kconfig

@@ -1581,6 +1581,16 @@ config EFI_STUB

 	  See Documentation/x86/efi-stub.txt for more information.

+config EFI_SECURE_BOOT_SIG_ENFORCE

+        def_bool n

+	prompt "Force module signing when UEFI Secure Boot is enabled"

+	---help---

+	  UEFI Secure Boot provides a mechanism for ensuring that the

+	  firmware will only load signed bootloaders and kernels. Certain

+	  use cases may also require that all kernel modules also be signed.

+	  Say Y here to automatically enable module signature enforcement

+	  when a system boots with UEFI Secure Boot enabled.

+

 config SECCOMP

 	def_bool y

 	prompt "Enable seccomp to safely compute untrusted bytecode"

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c

index b7388a4..53bfe4f 100644

--- a/arch/x86/boot/compressed/eboot.c

+++ b/arch/x86/boot/compressed/eboot.c

@@ -12,6 +12,7 @@

 #include <asm/efi.h>

 #include <asm/setup.h>

 #include <asm/desc.h>

+#include <asm/bootparam_utils.h>

 #undef memcpy			/* Use memcpy from misc.c */

@@ -861,6 +862,37 @@ fail:

 	return status;

 }

+static int get_secure_boot(void)

+{

+	u8 sb, setup;

+	unsigned long datasize = sizeof(sb);

+	efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID;

+	efi_status_t status;

+

+	status = efi_call_phys5(sys_table->runtime->get_variable,

+				L"SecureBoot", &var_guid, NULL, &datasize, &sb);

+

+	if (status != EFI_SUCCESS)

+		return 0;

+

+	if (sb == 0)

+		return 0;

+

+

+	status = efi_call_phys5(sys_table->runtime->get_variable,

+				L"SetupMode", &var_guid, NULL, &datasize,

+				&setup);

+

+	if (status != EFI_SUCCESS)

+		return 0;

+

+	if (setup == 1)

+		return 0;

+

+	return 1;

+}

+

+

 /*

  * Because the x86 boot code expects to be passed a boot_params we

  * need to create one ourselves (usually the bootloader would create

@@ -1169,6 +1201,10 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table,

 	if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)

 		goto fail;

+	sanitize_boot_params(boot_params);

+

+	boot_params->secure_boot = get_secure_boot();

+

 	setup_graphics(boot_params);

 	setup_efi_pci(boot_params);

diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h

index c15ddaf..85d7685 100644

--- a/arch/x86/include/uapi/asm/bootparam.h

+++ b/arch/x86/include/uapi/asm/bootparam.h

@@ -131,7 +131,8 @@ struct boot_params {

 	__u8  eddbuf_entries;				/* 0x1e9 */

 	__u8  edd_mbr_sig_buf_entries;			/* 0x1ea */

 	__u8  kbd_status;				/* 0x1eb */

-	__u8  _pad5[3];					/* 0x1ec */

+	__u8  secure_boot;				/* 0x1ec */

+	__u8  _pad5[2];					/* 0x1ed */

 	/*

 	 * The sentinel is set to a nonzero value (0xff) in header.S.

 	 *

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c

index f8ec578..deeb7bc 100644

--- a/arch/x86/kernel/setup.c

+++ b/arch/x86/kernel/setup.c

@@ -1129,6 +1129,12 @@ void __init setup_arch(char **cmdline_p)

 	io_delay_init();

+#ifdef CONFIG_EFI_SECURE_BOOT_SIG_ENFORCE

+	if (boot_params.secure_boot) {

+		enforce_signed_modules();

+	}

+#endif

+

 	/*

 	 * Parse the ACPI tables for possible boot-time SMP configuration.

 	 */

diff --git a/include/linux/module.h b/include/linux/module.h

index 0c266b2..5a6374a 100644

--- a/include/linux/module.h

+++ b/include/linux/module.h

@@ -184,6 +184,12 @@ const struct exception_table_entry *search_exception_tables(unsigned long add);

 struct notifier_block;

+#ifdef CONFIG_MODULE_SIG

+extern void enforce_signed_modules(void);

+#else

+static inline void enforce_signed_modules(void) {};

+#endif