From: Matthew Garrett <mjg@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org,
Matthew Garrett <mjg@redhat.com>
Subject: [PATCH 09/11] efi: Enable secure boot lockdown automatically when enabled in firmware
Date: Tue, 4 Sep 2012 11:55:15 -0400 [thread overview]
Message-ID: <1346774117-2277-10-git-send-email-mjg@redhat.com> (raw)
In-Reply-To: <1346774117-2277-1-git-send-email-mjg@redhat.com>
The firmware has a set of flags that indicate whether secure boot is enabled
and enforcing. Use them to indicate whether the kernel should lock itself
down.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
Documentation/x86/zero-page.txt | 2 ++
arch/x86/boot/compressed/eboot.c | 32 ++++++++++++++++++++++++++++++++
arch/x86/include/asm/bootparam.h | 3 ++-
arch/x86/kernel/setup.c | 3 +++
include/linux/cred.h | 2 ++
5 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
index cf5437d..7f9ed48 100644
--- a/Documentation/x86/zero-page.txt
+++ b/Documentation/x86/zero-page.txt
@@ -27,6 +27,8 @@ 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 Kernel should enable secure boot lockdowns
290/040 ALL edd_mbr_sig_buffer EDD MBR signatures
2D0/A00 ALL e820_map E820 memory map table
(array of struct e820entry)
diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index b3e0227..3789356 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -724,6 +724,36 @@ fail:
return status;
}
+static int get_secure_boot(efi_system_table_t *_table)
+{
+ 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
@@ -1018,6 +1048,8 @@ struct boot_params *efi_main(void *handle, efi_system_table_t *_table,
if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
goto fail;
+ boot_params->secure_boot = get_secure_boot(sys_table);
+
setup_graphics(boot_params);
status = efi_call_phys3(sys_table->boottime->allocate_pool,
diff --git a/arch/x86/include/asm/bootparam.h b/arch/x86/include/asm/bootparam.h
index 2ad874c..c7338e0 100644
--- a/arch/x86/include/asm/bootparam.h
+++ b/arch/x86/include/asm/bootparam.h
@@ -114,7 +114,8 @@ struct boot_params {
__u8 eddbuf_entries; /* 0x1e9 */
__u8 edd_mbr_sig_buf_entries; /* 0x1ea */
__u8 kbd_status; /* 0x1eb */
- __u8 _pad6[5]; /* 0x1ec */
+ __u8 secure_boot; /* 0x1ec */
+ __u8 _pad6[4]; /* 0x1ed */
struct setup_header hdr; /* setup header */ /* 0x1f1 */
__u8 _pad7[0x290-0x1f1-sizeof(struct setup_header)];
__u32 edd_mbr_sig_buffer[EDD_MBR_SIG_MAX]; /* 0x290 */
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f4b9b80..239bf2a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -947,6 +947,9 @@ void __init setup_arch(char **cmdline_p)
io_delay_init();
+ if (boot_params.secure_boot)
+ secureboot_enable();
+
/*
* Parse the ACPI tables for possible boot-time SMP configuration.
*/
diff --git a/include/linux/cred.h b/include/linux/cred.h
index ebbed2c..a24faf1 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -170,6 +170,8 @@ extern int set_security_override_from_ctx(struct cred *, const char *);
extern int set_create_files_as(struct cred *, struct inode *);
extern void __init cred_init(void);
+extern void secureboot_enable(void);
+
/*
* check for validity of credentials
*/
--
1.7.11.4
next prev parent reply other threads:[~2012-09-04 15:56 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-04 15:55 [RFC] First attempt at kernel secure boot support Matthew Garrett
2012-09-04 15:55 ` [PATCH 01/11] Secure boot: Add new capability Matthew Garrett
2012-09-04 15:55 ` [PATCH 02/11] PCI: Lock down BAR access in secure boot environments Matthew Garrett
2012-10-01 21:00 ` Pavel Machek
2012-09-04 15:55 ` [PATCH 03/11] x86: Lock down IO port " Matthew Garrett
2012-09-04 16:16 ` Alan Cox
2012-09-04 16:16 ` Matthew Garrett
2012-09-04 15:55 ` [PATCH 04/11] ACPI: Limit access to custom_method Matthew Garrett
2012-09-04 15:55 ` [PATCH 05/11] asus-wmi: Restrict debugfs interface Matthew Garrett
2012-09-04 16:12 ` Alan Cox
2012-09-04 16:13 ` Matthew Garrett
2012-09-04 15:55 ` [PATCH 06/11] Restrict /dev/mem and /dev/kmem in secure boot setups Matthew Garrett
2012-09-04 15:55 ` [PATCH 07/11] kexec: Disable in a secure boot environment Matthew Garrett
2012-09-04 20:13 ` Eric W. Biederman
2012-09-04 20:22 ` Matthew Garrett
2012-09-04 21:13 ` Eric W. Biederman
2012-09-04 21:27 ` Matthew Garrett
2012-09-04 22:12 ` Eric W. Biederman
2012-09-04 23:25 ` Matthew Garrett
2012-09-05 4:33 ` Eric W. Biederman
2012-09-05 5:16 ` Matthew Garrett
2012-09-05 7:00 ` Eric W. Biederman
2012-09-05 7:03 ` Matthew Garrett
2012-09-04 21:39 ` Alan Cox
2012-09-04 21:40 ` Matthew Garrett
2012-09-05 15:43 ` Roland Eggner
2012-09-05 15:46 ` Matthew Garrett
2012-09-05 21:13 ` Mimi Zohar
2012-09-05 21:41 ` Matthew Garrett
2012-09-05 21:49 ` Eric Paris
2012-09-04 15:55 ` [PATCH 08/11] Secure boot: Add a dummy kernel parameter that will switch on Secure Boot mode Matthew Garrett
2012-09-04 15:55 ` Matthew Garrett [this message]
2012-09-04 15:55 ` [PATCH 10/11] acpi: Ignore acpi_rsdp kernel parameter in a secure boot environment Matthew Garrett
2012-09-04 16:30 ` Shuah Khan
2012-09-04 16:38 ` Matthew Garrett
2012-09-04 16:44 ` Shuah Khan
2012-09-04 20:37 ` Alan Cox
2012-09-04 20:37 ` Matthew Garrett
2012-09-04 20:50 ` Josh Boyer
2012-09-04 15:55 ` [PATCH 11/11] SELinux: define mapping for new Secure Boot capability Matthew Garrett
2012-09-04 16:08 ` [RFC] First attempt at kernel secure boot support Alan Cox
2012-09-04 16:12 ` Matthew Garrett
2012-10-01 21:07 ` Pavel Machek
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