forked from rpms/kernel
		
	- Fix build with CONFIG_EFI disabled, reported by Peter Bowey (rhbz 911833) - Disable debugging options.
		
			
				
	
	
		
			1435 lines
		
	
	
		
			44 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			1435 lines
		
	
	
		
			44 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From 0c5837031a4e996877930fd023a5877dd1d615ba Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:40:56 -0400
 | |
| Subject: [PATCH 01/19] Secure boot: Add new capability
 | |
| 
 | |
| Secure boot adds certain policy requirements, including that root must not
 | |
| be able to do anything that could cause the kernel to execute arbitrary code.
 | |
| The simplest way to handle this would seem to be to add a new capability
 | |
| and gate various functionality on that. We'll then strip it from the initial
 | |
| capability set if required.
 | |
| 
 | |
| Signed-off-by: Matthew Garrett <mjg@redhat.com>
 | |
| ---
 | |
|  include/uapi/linux/capability.h | 6 +++++-
 | |
|  1 file changed, 5 insertions(+), 1 deletion(-)
 | |
| 
 | |
| diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h
 | |
| index ba478fa..7109e65 100644
 | |
| --- a/include/uapi/linux/capability.h
 | |
| +++ b/include/uapi/linux/capability.h
 | |
| @@ -343,7 +343,11 @@ struct vfs_cap_data {
 | |
|  
 | |
|  #define CAP_BLOCK_SUSPEND    36
 | |
|  
 | |
| -#define CAP_LAST_CAP         CAP_BLOCK_SUSPEND
 | |
| +/* Allow things that trivially permit root to modify the running kernel */
 | |
| +
 | |
| +#define CAP_COMPROMISE_KERNEL  37
 | |
| +
 | |
| +#define CAP_LAST_CAP         CAP_COMPROMISE_KERNEL
 | |
|  
 | |
|  #define cap_valid(x) ((x) >= 0 && (x) <= CAP_LAST_CAP)
 | |
|  
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 87c8fddbcb3042fc4174b53763adbf66045a12be Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:41:05 -0400
 | |
| Subject: [PATCH 02/19] SELinux: define mapping for new Secure Boot capability
 | |
| 
 | |
| Add the name of the new Secure Boot capability.  This allows SELinux
 | |
| policies to properly map CAP_COMPROMISE_KERNEL to the appropriate
 | |
| capability class.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  security/selinux/include/classmap.h | 4 ++--
 | |
|  1 file changed, 2 insertions(+), 2 deletions(-)
 | |
| 
 | |
| diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
 | |
| index 14d04e6..ed99a2d 100644
 | |
| --- a/security/selinux/include/classmap.h
 | |
| +++ b/security/selinux/include/classmap.h
 | |
| @@ -146,8 +146,8 @@ struct security_class_mapping secclass_map[] = {
 | |
|  	{ "memprotect", { "mmap_zero", NULL } },
 | |
|  	{ "peer", { "recv", NULL } },
 | |
|  	{ "capability2",
 | |
| -	  { "mac_override", "mac_admin", "syslog", "wake_alarm", "block_suspend",
 | |
| -	    NULL } },
 | |
| +	  { "mac_override", "mac_admin", "syslog", "wake_alarm",
 | |
| +	    "block_suspend", "compromise_kernel", NULL } },
 | |
|  	{ "kernel_service", { "use_as_override", "create_files_as", NULL } },
 | |
|  	{ "tun_socket",
 | |
|  	  { COMMON_SOCK_PERMS, "attach_queue", NULL } },
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From df14b5319bf3ed2110839e233ac61e6136745be8 Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:41:02 -0400
 | |
| Subject: [PATCH 03/19] Secure boot: Add a dummy kernel parameter that will
 | |
|  switch on Secure Boot mode
 | |
| 
 | |
| This forcibly drops CAP_COMPROMISE_KERNEL from both cap_permitted and cap_bset
 | |
| in the init_cred struct, which everything else inherits from.  This works on
 | |
| any machine and can be used to develop even if the box doesn't have UEFI.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  Documentation/kernel-parameters.txt |  7 +++++++
 | |
|  kernel/cred.c                       | 17 +++++++++++++++++
 | |
|  2 files changed, 24 insertions(+)
 | |
| 
 | |
| diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
 | |
| index 6c72381..7dffdd5 100644
 | |
| --- a/Documentation/kernel-parameters.txt
 | |
| +++ b/Documentation/kernel-parameters.txt
 | |
| @@ -2654,6 +2654,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 | |
|  			Note: increases power consumption, thus should only be
 | |
|  			enabled if running jitter sensitive (HPC/RT) workloads.
 | |
|  
 | |
| +	secureboot_enable=
 | |
| +			[KNL] Enables an emulated UEFI Secure Boot mode.  This
 | |
| +			locks down various aspects of the kernel guarded by the
 | |
| +			CAP_COMPROMISE_KERNEL capability.  This includes things
 | |
| +			like /dev/mem, IO port access, and other areas.  It can
 | |
| +			be used on non-UEFI machines for testing purposes.
 | |
| +
 | |
|  	security=	[SECURITY] Choose a security module to enable at boot.
 | |
|  			If this boot parameter is not specified, only the first
 | |
|  			security module asking for security registration will be
 | |
| diff --git a/kernel/cred.c b/kernel/cred.c
 | |
| index e0573a4..c3f4e3e 100644
 | |
| --- a/kernel/cred.c
 | |
| +++ b/kernel/cred.c
 | |
| @@ -565,6 +565,23 @@ void __init cred_init(void)
 | |
|  				     0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 | |
|  }
 | |
|  
 | |
| +void __init secureboot_enable()
 | |
| +{
 | |
| +	pr_info("Secure boot enabled\n");
 | |
| +	cap_lower((&init_cred)->cap_bset, CAP_COMPROMISE_KERNEL);
 | |
| +	cap_lower((&init_cred)->cap_permitted, CAP_COMPROMISE_KERNEL);
 | |
| +}
 | |
| +
 | |
| +/* Dummy Secure Boot enable option to fake out UEFI SB=1 */
 | |
| +static int __init secureboot_enable_opt(char *str)
 | |
| +{
 | |
| +	int sb_enable = !!simple_strtol(str, NULL, 0);
 | |
| +	if (sb_enable)
 | |
| +		secureboot_enable();
 | |
| +	return 1;
 | |
| +}
 | |
| +__setup("secureboot_enable=", secureboot_enable_opt);
 | |
| +
 | |
|  /**
 | |
|   * prepare_kernel_cred - Prepare a set of credentials for a kernel service
 | |
|   * @daemon: A userspace daemon to be used as a reference
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 49c76a665e8a09da48cbe271ea40266ca1a226c0 Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:41:03 -0400
 | |
| Subject: [PATCH 04/19] efi: Enable secure boot lockdown automatically when
 | |
|  enabled in firmware
 | |
| 
 | |
| 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.  We also indicate the machine is in secure boot mode by adding the
 | |
| EFI_SECURE_BOOT bit for use with efi_enabled.
 | |
| 
 | |
| Signed-off-by: Matthew Garrett <mjg@redhat.com>
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  Documentation/x86/zero-page.txt       |  2 ++
 | |
|  arch/x86/boot/compressed/eboot.c      | 32 ++++++++++++++++++++++++++++++++
 | |
|  arch/x86/include/uapi/asm/bootparam.h |  3 ++-
 | |
|  arch/x86/kernel/setup.c               |  7 +++++++
 | |
|  include/linux/cred.h                  |  2 ++
 | |
|  include/linux/efi.h                   |  1 +
 | |
|  6 files changed, 46 insertions(+), 1 deletion(-)
 | |
| 
 | |
| diff --git a/Documentation/x86/zero-page.txt b/Documentation/x86/zero-page.txt
 | |
| index 199f453..ff651d3 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	Kernel should enable secure boot lockdowns
 | |
|  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/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
 | |
| index f8fa411..96bd86b 100644
 | |
| --- a/arch/x86/boot/compressed/eboot.c
 | |
| +++ b/arch/x86/boot/compressed/eboot.c
 | |
| @@ -849,6 +849,36 @@ 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
 | |
| @@ -1143,6 +1173,8 @@ 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);
 | |
|  
 | |
|  	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 8b24289..d74b441 100644
 | |
| --- a/arch/x86/kernel/setup.c
 | |
| +++ b/arch/x86/kernel/setup.c
 | |
| @@ -1042,6 +1042,13 @@ void __init setup_arch(char **cmdline_p)
 | |
|  
 | |
|  	io_delay_init();
 | |
|  
 | |
| +	if (boot_params.secure_boot) {
 | |
| +#ifdef CONFIG_EFI
 | |
| +		set_bit(EFI_SECURE_BOOT, &x86_efi_facility);
 | |
| +#endif
 | |
| +		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 04421e8..9e69542 100644
 | |
| --- a/include/linux/cred.h
 | |
| +++ b/include/linux/cred.h
 | |
| @@ -156,6 +156,8 @@ 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
 | |
|   */
 | |
| diff --git a/include/linux/efi.h b/include/linux/efi.h
 | |
| index 7a9498a..1ae16b6 100644
 | |
| --- a/include/linux/efi.h
 | |
| +++ b/include/linux/efi.h
 | |
| @@ -627,6 +627,7 @@ extern int __init efi_setup_pcdp_console(char *);
 | |
|  #define EFI_RUNTIME_SERVICES	3	/* Can we use runtime services? */
 | |
|  #define EFI_MEMMAP		4	/* Can we use EFI memory map? */
 | |
|  #define EFI_64BIT		5	/* Is the firmware 64-bit? */
 | |
| +#define EFI_SECURE_BOOT	6	/* Are we in Secure Boot mode? */
 | |
|  
 | |
|  #ifdef CONFIG_EFI
 | |
|  # ifdef CONFIG_X86
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From d4d1b3ad3e1a553c807b4ecafcbde4bf816e4db2 Mon Sep 17 00:00:00 2001
 | |
| From: Dave Howells <dhowells@redhat.com>
 | |
| Date: Tue, 23 Oct 2012 09:30:54 -0400
 | |
| Subject: [PATCH 05/19] Add EFI signature data types
 | |
| 
 | |
| Add the data types that are used for containing hashes, keys and certificates
 | |
| for cryptographic verification.
 | |
| 
 | |
| Signed-off-by: David Howells <dhowells@redhat.com>
 | |
| ---
 | |
|  include/linux/efi.h | 20 ++++++++++++++++++++
 | |
|  1 file changed, 20 insertions(+)
 | |
| 
 | |
| diff --git a/include/linux/efi.h b/include/linux/efi.h
 | |
| index 1ae16b6..de7021d 100644
 | |
| --- a/include/linux/efi.h
 | |
| +++ b/include/linux/efi.h
 | |
| @@ -388,6 +388,12 @@ typedef efi_status_t efi_query_capsule_caps_t(efi_capsule_header_t **capsules,
 | |
|  #define EFI_FILE_SYSTEM_GUID \
 | |
|      EFI_GUID(  0x964e5b22, 0x6459, 0x11d2, 0x8e, 0x39, 0x00, 0xa0, 0xc9, 0x69, 0x72, 0x3b )
 | |
|  
 | |
| +#define EFI_CERT_SHA256_GUID \
 | |
| +    EFI_GUID(  0xc1c41626, 0x504c, 0x4092, 0xac, 0xa9, 0x41, 0xf9, 0x36, 0x93, 0x43, 0x28 )
 | |
| +
 | |
| +#define EFI_CERT_X509_GUID \
 | |
| +    EFI_GUID(  0xa5c059a1, 0x94e4, 0x4aa7, 0x87, 0xb5, 0xab, 0x15, 0x5c, 0x2b, 0xf0, 0x72 )
 | |
| +
 | |
|  typedef struct {
 | |
|  	efi_guid_t guid;
 | |
|  	u64 table;
 | |
| @@ -523,6 +529,20 @@ typedef struct {
 | |
|  
 | |
|  #define EFI_INVALID_TABLE_ADDR		(~0UL)
 | |
|  
 | |
| +typedef struct  {
 | |
| +	efi_guid_t signature_owner;
 | |
| +	u8 signature_data[];
 | |
| +} efi_signature_data_t;
 | |
| +
 | |
| +typedef struct {
 | |
| +	efi_guid_t signature_type;
 | |
| +	u32 signature_list_size;
 | |
| +	u32 signature_header_size;
 | |
| +	u32 signature_size;
 | |
| +	u8 signature_header[];
 | |
| +	/* efi_signature_data_t signatures[][] */
 | |
| +} efi_signature_list_t;
 | |
| +
 | |
|  /*
 | |
|   * All runtime access to EFI goes through this structure:
 | |
|   */
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 3cffca89eadf7e0f0a266c370f8034f33723831a Mon Sep 17 00:00:00 2001
 | |
| From: Dave Howells <dhowells@redhat.com>
 | |
| Date: Tue, 23 Oct 2012 09:36:28 -0400
 | |
| Subject: [PATCH 06/19] Add an EFI signature blob parser and key loader.
 | |
| 
 | |
| X.509 certificates are loaded into the specified keyring as asymmetric type
 | |
| keys.
 | |
| 
 | |
| Signed-off-by: David Howells <dhowells@redhat.com>
 | |
| ---
 | |
|  crypto/asymmetric_keys/Kconfig      |   8 +++
 | |
|  crypto/asymmetric_keys/Makefile     |   1 +
 | |
|  crypto/asymmetric_keys/efi_parser.c | 108 ++++++++++++++++++++++++++++++++++++
 | |
|  include/linux/efi.h                 |   4 ++
 | |
|  4 files changed, 121 insertions(+)
 | |
|  create mode 100644 crypto/asymmetric_keys/efi_parser.c
 | |
| 
 | |
| diff --git a/crypto/asymmetric_keys/Kconfig b/crypto/asymmetric_keys/Kconfig
 | |
| index 6d2c2ea..ace9c30 100644
 | |
| --- a/crypto/asymmetric_keys/Kconfig
 | |
| +++ b/crypto/asymmetric_keys/Kconfig
 | |
| @@ -35,4 +35,12 @@ config X509_CERTIFICATE_PARSER
 | |
|  	  data and provides the ability to instantiate a crypto key from a
 | |
|  	  public key packet found inside the certificate.
 | |
|  
 | |
| +config EFI_SIGNATURE_LIST_PARSER
 | |
| +	bool "EFI signature list parser"
 | |
| +	depends on EFI
 | |
| +	select X509_CERTIFICATE_PARSER
 | |
| +	help
 | |
| +	  This option provides support for parsing EFI signature lists for
 | |
| +	  X.509 certificates and turning them into keys.
 | |
| +
 | |
|  endif # ASYMMETRIC_KEY_TYPE
 | |
| diff --git a/crypto/asymmetric_keys/Makefile b/crypto/asymmetric_keys/Makefile
 | |
| index 0727204..cd8388e 100644
 | |
| --- a/crypto/asymmetric_keys/Makefile
 | |
| +++ b/crypto/asymmetric_keys/Makefile
 | |
| @@ -8,6 +8,7 @@ asymmetric_keys-y := asymmetric_type.o signature.o
 | |
|  
 | |
|  obj-$(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE) += public_key.o
 | |
|  obj-$(CONFIG_PUBLIC_KEY_ALGO_RSA) += rsa.o
 | |
| +obj-$(CONFIG_EFI_SIGNATURE_LIST_PARSER) += efi_parser.o
 | |
|  
 | |
|  #
 | |
|  # X.509 Certificate handling
 | |
| diff --git a/crypto/asymmetric_keys/efi_parser.c b/crypto/asymmetric_keys/efi_parser.c
 | |
| new file mode 100644
 | |
| index 0000000..636feb1
 | |
| --- /dev/null
 | |
| +++ b/crypto/asymmetric_keys/efi_parser.c
 | |
| @@ -0,0 +1,108 @@
 | |
| +/* EFI signature/key/certificate list parser
 | |
| + *
 | |
| + * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
 | |
| + * Written by David Howells (dhowells@redhat.com)
 | |
| + *
 | |
| + * This program is free software; you can redistribute it and/or
 | |
| + * modify it under the terms of the GNU General Public Licence
 | |
| + * as published by the Free Software Foundation; either version
 | |
| + * 2 of the Licence, or (at your option) any later version.
 | |
| + */
 | |
| +
 | |
| +#define pr_fmt(fmt) "EFI: "fmt
 | |
| +#include <linux/module.h>
 | |
| +#include <linux/printk.h>
 | |
| +#include <linux/err.h>
 | |
| +#include <linux/efi.h>
 | |
| +#include <keys/asymmetric-type.h>
 | |
| +
 | |
| +static __initdata efi_guid_t efi_cert_x509_guid = EFI_CERT_X509_GUID;
 | |
| +
 | |
| +/**
 | |
| + * parse_efi_signature_list - Parse an EFI signature list for certificates
 | |
| + * @data: The data blob to parse
 | |
| + * @size: The size of the data blob
 | |
| + * @keyring: The keyring to add extracted keys to
 | |
| + */
 | |
| +int __init parse_efi_signature_list(const void *data, size_t size, struct key *keyring)
 | |
| +{
 | |
| +	unsigned offs = 0;
 | |
| +	size_t lsize, esize, hsize, elsize;
 | |
| +
 | |
| +	pr_devel("-->%s(,%zu)\n", __func__, size);
 | |
| +
 | |
| +	while (size > 0) {
 | |
| +		efi_signature_list_t list;
 | |
| +		const efi_signature_data_t *elem;
 | |
| +		key_ref_t key;
 | |
| +
 | |
| +		if (size < sizeof(list))
 | |
| +			return -EBADMSG;
 | |
| +
 | |
| +		memcpy(&list, data, sizeof(list));
 | |
| +		pr_devel("LIST[%04x] guid=%pUl ls=%x hs=%x ss=%x\n",
 | |
| +			 offs,
 | |
| +			 list.signature_type.b, list.signature_list_size,
 | |
| +			 list.signature_header_size, list.signature_size);
 | |
| +
 | |
| +		lsize = list.signature_list_size;
 | |
| +		hsize = list.signature_header_size;
 | |
| +		esize = list.signature_size;
 | |
| +		elsize = lsize - sizeof(list) - hsize;
 | |
| +
 | |
| +		if (lsize > size) {
 | |
| +			pr_devel("<--%s() = -EBADMSG [overrun @%x]\n",
 | |
| +				 __func__, offs);
 | |
| +			return -EBADMSG;
 | |
| +		}
 | |
| +		if (lsize < sizeof(list) ||
 | |
| +		    lsize - sizeof(list) < hsize ||
 | |
| +		    esize < sizeof(*elem) ||
 | |
| +		    elsize < esize ||
 | |
| +		    elsize % esize != 0) {
 | |
| +			pr_devel("- bad size combo @%x\n", offs);
 | |
| +			return -EBADMSG;
 | |
| +		}
 | |
| +
 | |
| +		if (efi_guidcmp(list.signature_type, efi_cert_x509_guid) != 0) {
 | |
| +			data += lsize;
 | |
| +			size -= lsize;
 | |
| +			offs += lsize;
 | |
| +			continue;
 | |
| +		}
 | |
| +
 | |
| +		data += sizeof(list) + hsize;
 | |
| +		size -= sizeof(list) + hsize;
 | |
| +		offs += sizeof(list) + hsize;
 | |
| +
 | |
| +		for (; elsize > 0; elsize -= esize) {
 | |
| +			elem = data;
 | |
| +
 | |
| +			pr_devel("ELEM[%04x]\n", offs);
 | |
| +
 | |
| +			key = key_create_or_update(
 | |
| +				make_key_ref(keyring, 1),
 | |
| +				"asymmetric",
 | |
| +				NULL,
 | |
| +				&elem->signature_data,
 | |
| +				esize - sizeof(*elem),
 | |
| +				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
 | |
| +				KEY_USR_VIEW,
 | |
| +				KEY_ALLOC_NOT_IN_QUOTA);
 | |
| +
 | |
| +			if (IS_ERR(key))
 | |
| +				pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
 | |
| +				       PTR_ERR(key));
 | |
| +			else
 | |
| +				pr_notice("Loaded cert '%s' linked to '%s'\n",
 | |
| +					  key_ref_to_ptr(key)->description,
 | |
| +					  keyring->description);
 | |
| +
 | |
| +			data += esize;
 | |
| +			size -= esize;
 | |
| +			offs += esize;
 | |
| +		}
 | |
| +	}
 | |
| +
 | |
| +	return 0;
 | |
| +}
 | |
| diff --git a/include/linux/efi.h b/include/linux/efi.h
 | |
| index de7021d..64b3e55 100644
 | |
| --- a/include/linux/efi.h
 | |
| +++ b/include/linux/efi.h
 | |
| @@ -612,6 +612,10 @@ extern int efi_set_rtc_mmss(unsigned long nowtime);
 | |
|  extern void efi_reserve_boot_services(void);
 | |
|  extern struct efi_memory_map memmap;
 | |
|  
 | |
| +struct key;
 | |
| +extern int __init parse_efi_signature_list(const void *data, size_t size,
 | |
| +					   struct key *keyring);
 | |
| +
 | |
|  /**
 | |
|   * efi_range_is_wc - check the WC bit on an address range
 | |
|   * @start: starting kvirt address
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 89ea7424726ae4f7265ab84e703cf2da77acda57 Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Fri, 26 Oct 2012 12:36:24 -0400
 | |
| Subject: [PATCH 07/19] MODSIGN: Add module certificate blacklist keyring
 | |
| 
 | |
| This adds an additional keyring that is used to store certificates that
 | |
| are blacklisted.  This keyring is searched first when loading signed modules
 | |
| and if the module's certificate is found, it will refuse to load.  This is
 | |
| useful in cases where third party certificates are used for module signing.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  init/Kconfig             |  8 ++++++++
 | |
|  kernel/modsign_pubkey.c  | 14 ++++++++++++++
 | |
|  kernel/module-internal.h |  3 +++
 | |
|  kernel/module_signing.c  | 12 ++++++++++++
 | |
|  4 files changed, 37 insertions(+)
 | |
| 
 | |
| diff --git a/init/Kconfig b/init/Kconfig
 | |
| index be8b7f5..d972b77 100644
 | |
| --- a/init/Kconfig
 | |
| +++ b/init/Kconfig
 | |
| @@ -1665,6 +1665,14 @@ config MODULE_SIG_FORCE
 | |
|  	  Reject unsigned modules or signed modules for which we don't have a
 | |
|  	  key.  Without this, such modules will simply taint the kernel.
 | |
|  
 | |
| +config MODULE_SIG_BLACKLIST
 | |
| +	bool "Support for blacklisting module signature certificates"
 | |
| +	depends on MODULE_SIG
 | |
| +	help
 | |
| +	  This adds support for keeping a blacklist of certificates that
 | |
| +	  should not pass module signature verification.  If a module is
 | |
| +	  signed with something in this keyring, the load will be rejected.
 | |
| +
 | |
|  choice
 | |
|  	prompt "Which hash algorithm should modules be signed with?"
 | |
|  	depends on MODULE_SIG
 | |
| diff --git a/kernel/modsign_pubkey.c b/kernel/modsign_pubkey.c
 | |
| index 2b6e699..4cd408d 100644
 | |
| --- a/kernel/modsign_pubkey.c
 | |
| +++ b/kernel/modsign_pubkey.c
 | |
| @@ -17,6 +17,9 @@
 | |
|  #include "module-internal.h"
 | |
|  
 | |
|  struct key *modsign_keyring;
 | |
| +#ifdef CONFIG_MODULE_SIG_BLACKLIST
 | |
| +struct key *modsign_blacklist;
 | |
| +#endif
 | |
|  
 | |
|  extern __initdata const u8 modsign_certificate_list[];
 | |
|  extern __initdata const u8 modsign_certificate_list_end[];
 | |
| @@ -43,6 +46,17 @@ static __init int module_verify_init(void)
 | |
|  	if (IS_ERR(modsign_keyring))
 | |
|  		panic("Can't allocate module signing keyring\n");
 | |
|  
 | |
| +#ifdef CONFIG_MODULE_SIG_BLACKLIST
 | |
| +	modsign_blacklist = keyring_alloc(".modsign_blacklist",
 | |
| +				    KUIDT_INIT(0), KGIDT_INIT(0),
 | |
| +				    current_cred(),
 | |
| +				    (KEY_POS_ALL & ~KEY_POS_SETATTR) |
 | |
| +				    KEY_USR_VIEW | KEY_USR_READ,
 | |
| +				    KEY_ALLOC_NOT_IN_QUOTA, NULL);
 | |
| +	if (IS_ERR(modsign_blacklist))
 | |
| +		panic("Can't allocate module signing blacklist keyring\n");
 | |
| +#endif
 | |
| +
 | |
|  	return 0;
 | |
|  }
 | |
|  
 | |
| diff --git a/kernel/module-internal.h b/kernel/module-internal.h
 | |
| index 24f9247..51a8380 100644
 | |
| --- a/kernel/module-internal.h
 | |
| +++ b/kernel/module-internal.h
 | |
| @@ -10,5 +10,8 @@
 | |
|   */
 | |
|  
 | |
|  extern struct key *modsign_keyring;
 | |
| +#ifdef CONFIG_MODULE_SIG_BLACKLIST
 | |
| +extern struct key *modsign_blacklist;
 | |
| +#endif
 | |
|  
 | |
|  extern int mod_verify_sig(const void *mod, unsigned long *_modlen);
 | |
| diff --git a/kernel/module_signing.c b/kernel/module_signing.c
 | |
| index f2970bd..5423195 100644
 | |
| --- a/kernel/module_signing.c
 | |
| +++ b/kernel/module_signing.c
 | |
| @@ -157,6 +157,18 @@ static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
 | |
|  
 | |
|  	pr_debug("Look up: \"%s\"\n", id);
 | |
|  
 | |
| +#ifdef CONFIG_MODULE_SIG_BLACKLIST
 | |
| +	key = keyring_search(make_key_ref(modsign_blacklist, 1),
 | |
| +				   &key_type_asymmetric, id);
 | |
| +	if (!IS_ERR(key)) {
 | |
| +		/* module is signed with a cert in the blacklist.  reject */
 | |
| +		pr_err("Module key '%s' is in blacklist\n", id);
 | |
| +		key_ref_put(key);
 | |
| +		kfree(id);
 | |
| +		return ERR_PTR(-EKEYREJECTED);
 | |
| +	}
 | |
| +#endif
 | |
| +
 | |
|  	key = keyring_search(make_key_ref(modsign_keyring, 1),
 | |
|  			     &key_type_asymmetric, id);
 | |
|  	if (IS_ERR(key))
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 733a5c25b896d8d5fa0051825a671911b50cb47d Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Fri, 26 Oct 2012 12:42:16 -0400
 | |
| Subject: [PATCH 08/19] MODSIGN: Import certificates from UEFI Secure Boot
 | |
| 
 | |
| Secure Boot stores a list of allowed certificates in the 'db' variable.
 | |
| This imports those certificates into the module signing keyring.  This
 | |
| allows for a third party signing certificate to be used in conjunction
 | |
| with signed modules.  By importing the public certificate into the 'db'
 | |
| variable, a user can allow a module signed with that certificate to
 | |
| load.  The shim UEFI bootloader has a similar certificate list stored
 | |
| in the 'MokListRT' variable.  We import those as well.
 | |
| 
 | |
| In the opposite case, Secure Boot maintains a list of disallowed
 | |
| certificates in the 'dbx' variable.  We load those certificates into
 | |
| the newly introduced module blacklist keyring and forbid any module
 | |
| signed with those from loading.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  include/linux/efi.h   |  6 ++++
 | |
|  init/Kconfig          |  9 ++++++
 | |
|  kernel/Makefile       |  3 ++
 | |
|  kernel/modsign_uefi.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++
 | |
|  4 files changed, 108 insertions(+)
 | |
|  create mode 100644 kernel/modsign_uefi.c
 | |
| 
 | |
| diff --git a/include/linux/efi.h b/include/linux/efi.h
 | |
| index 64b3e55..76fe526 100644
 | |
| --- a/include/linux/efi.h
 | |
| +++ b/include/linux/efi.h
 | |
| @@ -394,6 +394,12 @@ typedef efi_status_t efi_query_capsule_caps_t(efi_capsule_header_t **capsules,
 | |
|  #define EFI_CERT_X509_GUID \
 | |
|      EFI_GUID(  0xa5c059a1, 0x94e4, 0x4aa7, 0x87, 0xb5, 0xab, 0x15, 0x5c, 0x2b, 0xf0, 0x72 )
 | |
|  
 | |
| +#define EFI_IMAGE_SECURITY_DATABASE_GUID \
 | |
| +    EFI_GUID(  0xd719b2cb, 0x3d3a, 0x4596, 0xa3, 0xbc, 0xda, 0xd0, 0x0e, 0x67, 0x65, 0x6f )
 | |
| +
 | |
| +#define EFI_SHIM_LOCK_GUID \
 | |
| +    EFI_GUID(  0x605dab50, 0xe046, 0x4300, 0xab, 0xb6, 0x3d, 0xd8, 0x10, 0xdd, 0x8b, 0x23 )
 | |
| +
 | |
|  typedef struct {
 | |
|  	efi_guid_t guid;
 | |
|  	u64 table;
 | |
| diff --git a/init/Kconfig b/init/Kconfig
 | |
| index d972b77..27e3a82 100644
 | |
| --- a/init/Kconfig
 | |
| +++ b/init/Kconfig
 | |
| @@ -1673,6 +1673,15 @@ config MODULE_SIG_BLACKLIST
 | |
|  	  should not pass module signature verification.  If a module is
 | |
|  	  signed with something in this keyring, the load will be rejected.
 | |
|  
 | |
| +config MODULE_SIG_UEFI
 | |
| +	bool "Allow modules signed with certs stored in UEFI"
 | |
| +	depends on MODULE_SIG && MODULE_SIG_BLACKLIST && EFI
 | |
| +	select EFI_SIGNATURE_LIST_PARSER
 | |
| +	help
 | |
| +	  This will import certificates stored in UEFI and allow modules
 | |
| +	  signed with those to be loaded.  It will also disallow loading
 | |
| +	  of modules stored in the UEFI dbx variable.
 | |
| +
 | |
|  choice
 | |
|  	prompt "Which hash algorithm should modules be signed with?"
 | |
|  	depends on MODULE_SIG
 | |
| diff --git a/kernel/Makefile b/kernel/Makefile
 | |
| index 6c072b6..8848829 100644
 | |
| --- a/kernel/Makefile
 | |
| +++ b/kernel/Makefile
 | |
| @@ -55,6 +55,7 @@ obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
 | |
|  obj-$(CONFIG_UID16) += uid16.o
 | |
|  obj-$(CONFIG_MODULES) += module.o
 | |
|  obj-$(CONFIG_MODULE_SIG) += module_signing.o modsign_pubkey.o modsign_certificate.o
 | |
| +obj-$(CONFIG_MODULE_SIG_UEFI) += modsign_uefi.o
 | |
|  obj-$(CONFIG_KALLSYMS) += kallsyms.o
 | |
|  obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 | |
|  obj-$(CONFIG_KEXEC) += kexec.o
 | |
| @@ -114,6 +115,8 @@ obj-$(CONFIG_CONTEXT_TRACKING) += context_tracking.o
 | |
|  
 | |
|  $(obj)/configs.o: $(obj)/config_data.h
 | |
|  
 | |
| +$(obj)/modsign_uefi.o: KBUILD_CFLAGS += -fshort-wchar
 | |
| +
 | |
|  # config_data.h contains the same information as ikconfig.h but gzipped.
 | |
|  # Info from config_data can be extracted from /proc/config*
 | |
|  targets += config_data.gz
 | |
| diff --git a/kernel/modsign_uefi.c b/kernel/modsign_uefi.c
 | |
| new file mode 100644
 | |
| index 0000000..b9237d7
 | |
| --- /dev/null
 | |
| +++ b/kernel/modsign_uefi.c
 | |
| @@ -0,0 +1,90 @@
 | |
| +#include <linux/kernel.h>
 | |
| +#include <linux/sched.h>
 | |
| +#include <linux/cred.h>
 | |
| +#include <linux/err.h>
 | |
| +#include <linux/efi.h>
 | |
| +#include <keys/asymmetric-type.h>
 | |
| +#include "module-internal.h"
 | |
| +
 | |
| +static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, unsigned long *size)
 | |
| +{
 | |
| +	efi_status_t status;
 | |
| +	unsigned long lsize = 4;
 | |
| +	unsigned long tmpdb[4];
 | |
| +	void *db = NULL;
 | |
| +
 | |
| +	status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
 | |
| +	if (status != EFI_BUFFER_TOO_SMALL) {
 | |
| +		pr_err("Couldn't get size: 0x%lx\n", status);
 | |
| +		return NULL;
 | |
| +	}
 | |
| +
 | |
| +	db = kmalloc(lsize, GFP_KERNEL);
 | |
| +	if (!db) {
 | |
| +		pr_err("Couldn't allocate memory for uefi cert list\n");
 | |
| +		goto out;
 | |
| +	}
 | |
| +
 | |
| +	status = efi.get_variable(name, guid, NULL, &lsize, db);
 | |
| +	if (status != EFI_SUCCESS) {
 | |
| +		kfree(db);
 | |
| +		db = NULL;
 | |
| +		pr_err("Error reading db var: 0x%lx\n", status);
 | |
| +	}
 | |
| +out:
 | |
| +	*size = lsize;
 | |
| +	return db;
 | |
| +}
 | |
| +
 | |
| +/*
 | |
| + *  * Load the certs contained in the UEFI databases
 | |
| + *   */
 | |
| +static int __init load_uefi_certs(void)
 | |
| +{
 | |
| +	efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID;
 | |
| +	efi_guid_t mok_var = EFI_SHIM_LOCK_GUID;
 | |
| +	void *db = NULL, *dbx = NULL, *mok = NULL;
 | |
| +	unsigned long dbsize = 0, dbxsize = 0, moksize = 0;
 | |
| +	int rc = 0;
 | |
| +
 | |
| +	/* Check if SB is enabled and just return if not */
 | |
| +	if (!efi_enabled(EFI_SECURE_BOOT))
 | |
| +		return 0;
 | |
| +
 | |
| +	/* Get db, MokListRT, and dbx.  They might not exist, so it isn't
 | |
| +	 * an error if we can't get them.
 | |
| +	 */
 | |
| +	db = get_cert_list(L"db", &secure_var, &dbsize);
 | |
| +	if (!db) {
 | |
| +		pr_err("MODSIGN: Couldn't get UEFI db list\n");
 | |
| +	} else {
 | |
| +		rc = parse_efi_signature_list(db, dbsize, modsign_keyring);
 | |
| +		if (rc)
 | |
| +			pr_err("Couldn't parse db signatures: %d\n", rc);
 | |
| +		kfree(db);
 | |
| +	}
 | |
| +
 | |
| +	mok = get_cert_list(L"MokListRT", &mok_var, &moksize);
 | |
| +	if (!mok) {
 | |
| +		pr_info("MODSIGN: Couldn't get UEFI MokListRT\n");
 | |
| +	} else {
 | |
| +		rc = parse_efi_signature_list(mok, moksize, modsign_keyring);
 | |
| +		if (rc)
 | |
| +			pr_err("Couldn't parse MokListRT signatures: %d\n", rc);
 | |
| +		kfree(mok);
 | |
| +	}
 | |
| +
 | |
| +	dbx = get_cert_list(L"dbx", &secure_var, &dbxsize);
 | |
| +	if (!dbx) {
 | |
| +		pr_info("MODSIGN: Couldn't get UEFI dbx list\n");
 | |
| +	} else {
 | |
| +		rc = parse_efi_signature_list(dbx, dbxsize,
 | |
| +			modsign_blacklist);
 | |
| +		if (rc)
 | |
| +			pr_err("Couldn't parse dbx signatures: %d\n", rc);
 | |
| +		kfree(dbx);
 | |
| +	}
 | |
| +
 | |
| +	return rc;
 | |
| +}
 | |
| +late_initcall(load_uefi_certs);
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 16027d676baed34a9de804dac68d48096a688b39 Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:40:57 -0400
 | |
| Subject: [PATCH 09/19] PCI: Lock down BAR access in secure boot environments
 | |
| 
 | |
| 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 cause
 | |
| arbitrary kernel behaviour. Default to paranoid - in future we can
 | |
| potentially relax this for sufficiently IOMMU-isolated devices.
 | |
| 
 | |
| Signed-off-by: Matthew Garrett <mjg@redhat.com>
 | |
| ---
 | |
|  drivers/pci/pci-sysfs.c | 9 +++++++++
 | |
|  drivers/pci/proc.c      | 8 +++++++-
 | |
|  drivers/pci/syscall.c   | 2 +-
 | |
|  3 files changed, 17 insertions(+), 2 deletions(-)
 | |
| 
 | |
| diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
 | |
| index 9c6e9bb..b966089 100644
 | |
| --- a/drivers/pci/pci-sysfs.c
 | |
| +++ b/drivers/pci/pci-sysfs.c
 | |
| @@ -622,6 +622,9 @@ pci_write_config(struct file* filp, struct kobject *kobj,
 | |
|  	loff_t init_off = off;
 | |
|  	u8 *data = (u8*) buf;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	if (off > dev->cfg_size)
 | |
|  		return 0;
 | |
|  	if (off + count > dev->cfg_size) {
 | |
| @@ -928,6 +931,9 @@ pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr,
 | |
|  	resource_size_t start, end;
 | |
|  	int i;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	for (i = 0; i < PCI_ROM_RESOURCE; i++)
 | |
|  		if (res == &pdev->resource[i])
 | |
|  			break;
 | |
| @@ -1035,6 +1041,9 @@ pci_write_resource_io(struct file *filp, struct kobject *kobj,
 | |
|  		      struct bin_attribute *attr, char *buf,
 | |
|  		      loff_t off, size_t count)
 | |
|  {
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		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 9b8505c..35580bc 100644
 | |
| --- a/drivers/pci/proc.c
 | |
| +++ b/drivers/pci/proc.c
 | |
| @@ -139,6 +139,9 @@ proc_bus_pci_write(struct file *file, const char __user *buf, size_t nbytes, lof
 | |
|  	int size = dp->size;
 | |
|  	int cnt;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	if (pos >= size)
 | |
|  		return 0;
 | |
|  	if (nbytes >= size)
 | |
| @@ -219,6 +222,9 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd,
 | |
|  #endif /* HAVE_PCI_MMAP */
 | |
|  	int ret = 0;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	switch (cmd) {
 | |
|  	case PCIIOC_CONTROLLER:
 | |
|  		ret = pci_domain_nr(dev->bus);
 | |
| @@ -259,7 +265,7 @@ 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) || !capable(CAP_COMPROMISE_KERNEL))
 | |
|  		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..97e785f 100644
 | |
| --- a/drivers/pci/syscall.c
 | |
| +++ b/drivers/pci/syscall.c
 | |
| @@ -92,7 +92,7 @@ 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) || !capable(CAP_COMPROMISE_KERNEL))
 | |
|  		return -EPERM;
 | |
|  
 | |
|  	dev = pci_get_bus_and_slot(bus, dfn);
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 9ff1537bbe8c22bbf7f992027da43d4fe8da0860 Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:40:58 -0400
 | |
| Subject: [PATCH 10/19] x86: Lock down IO port access in secure boot
 | |
|  environments
 | |
| 
 | |
| 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 <mjg@redhat.com>
 | |
| ---
 | |
|  arch/x86/kernel/ioport.c | 4 ++--
 | |
|  drivers/char/mem.c       | 3 +++
 | |
|  2 files changed, 5 insertions(+), 2 deletions(-)
 | |
| 
 | |
| diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c
 | |
| index 8c96897..a2578c4 100644
 | |
| --- a/arch/x86/kernel/ioport.c
 | |
| +++ b/arch/x86/kernel/ioport.c
 | |
| @@ -28,7 +28,7 @@ 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) || !capable(CAP_COMPROMISE_KERNEL)))
 | |
|  		return -EPERM;
 | |
|  
 | |
|  	/*
 | |
| @@ -102,7 +102,7 @@ long sys_iopl(unsigned int level, struct pt_regs *regs)
 | |
|  		return -EINVAL;
 | |
|  	/* Trying to gain more privileges? */
 | |
|  	if (level > old) {
 | |
| -		if (!capable(CAP_SYS_RAWIO))
 | |
| +		if (!capable(CAP_SYS_RAWIO) || !capable(CAP_COMPROMISE_KERNEL))
 | |
|  			return -EPERM;
 | |
|  	}
 | |
|  	regs->flags = (regs->flags & ~X86_EFLAGS_IOPL) | (level << 12);
 | |
| diff --git a/drivers/char/mem.c b/drivers/char/mem.c
 | |
| index c6fa3bc..fc28099 100644
 | |
| --- a/drivers/char/mem.c
 | |
| +++ b/drivers/char/mem.c
 | |
| @@ -597,6 +597,9 @@ static ssize_t write_port(struct file *file, const char __user *buf,
 | |
|  	unsigned long i = *ppos;
 | |
|  	const char __user * tmp = buf;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	if (!access_ok(VERIFY_READ, buf, count))
 | |
|  		return -EFAULT;
 | |
|  	while (count-- > 0 && i < 65536) {
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 3b27408b1ced1ec83a3ce27f9d51161dbf7cea9a Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:40:59 -0400
 | |
| Subject: [PATCH 11/19] ACPI: Limit access to custom_method
 | |
| 
 | |
| It must be impossible for even root to get code executed in kernel context
 | |
| under a secure boot environment. custom_method effectively allows arbitrary
 | |
| access to system memory, so it needs to have a capability check here.
 | |
| 
 | |
| Signed-off-by: Matthew Garrett <mjg@redhat.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 5d42c24..247d58b 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 (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	if (!(*ppos)) {
 | |
|  		/* parse the table header to get the table length */
 | |
|  		if (count <= sizeof(struct acpi_table_header))
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From fb618a04089d454b7ade68c00a2b9c7dbac013f9 Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:41:00 -0400
 | |
| Subject: [PATCH 12/19] asus-wmi: Restrict debugfs interface
 | |
| 
 | |
| 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. Add a capability check to prevent that.
 | |
| 
 | |
| Signed-off-by: Matthew Garrett <mjg@redhat.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 f80ae4d..059195f 100644
 | |
| --- a/drivers/platform/x86/asus-wmi.c
 | |
| +++ b/drivers/platform/x86/asus-wmi.c
 | |
| @@ -1521,6 +1521,9 @@ static int show_dsts(struct seq_file *m, void *data)
 | |
|  	int err;
 | |
|  	u32 retval = -1;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	err = asus_wmi_get_devstate(asus, asus->debug.dev_id, &retval);
 | |
|  
 | |
|  	if (err < 0)
 | |
| @@ -1537,6 +1540,9 @@ static int show_devs(struct seq_file *m, void *data)
 | |
|  	int err;
 | |
|  	u32 retval = -1;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	err = asus_wmi_set_devstate(asus->debug.dev_id, asus->debug.ctrl_param,
 | |
|  				    &retval);
 | |
|  
 | |
| @@ -1561,6 +1567,9 @@ static int show_call(struct seq_file *m, void *data)
 | |
|  	union acpi_object *obj;
 | |
|  	acpi_status status;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	status = wmi_evaluate_method(ASUS_WMI_MGMT_GUID,
 | |
|  				     1, asus->debug.method_id,
 | |
|  				     &input, &output);
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From e515bbd5410d00835390fd8981aa9029e7b22b73 Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:41:01 -0400
 | |
| Subject: [PATCH 13/19] Restrict /dev/mem and /dev/kmem in secure boot setups
 | |
| 
 | |
| Allowing users to write to address space makes it possible for the kernel
 | |
| to be subverted. Restrict this when we need to protect the kernel.
 | |
| 
 | |
| Signed-off-by: Matthew Garrett <mjg@redhat.com>
 | |
| ---
 | |
|  drivers/char/mem.c | 6 ++++++
 | |
|  1 file changed, 6 insertions(+)
 | |
| 
 | |
| diff --git a/drivers/char/mem.c b/drivers/char/mem.c
 | |
| index fc28099..b5df7a8 100644
 | |
| --- a/drivers/char/mem.c
 | |
| +++ b/drivers/char/mem.c
 | |
| @@ -158,6 +158,9 @@ static ssize_t write_mem(struct file *file, const char __user *buf,
 | |
|  	unsigned long copied;
 | |
|  	void *ptr;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	if (!valid_phys_addr_range(p, count))
 | |
|  		return -EFAULT;
 | |
|  
 | |
| @@ -530,6 +533,9 @@ 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 (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	if (p < (unsigned long) high_memory) {
 | |
|  		unsigned long to_write = min_t(unsigned long, count,
 | |
|  					       (unsigned long)high_memory - p);
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From fe27dd192ef250abcbaba973a14d43b21d7be497 Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Thu, 20 Sep 2012 10:41:04 -0400
 | |
| Subject: [PATCH 14/19] acpi: Ignore acpi_rsdp kernel parameter in a secure
 | |
|  boot environment
 | |
| 
 | |
| This option allows userspace to pass the RSDP address to the kernel.  This
 | |
| could potentially be used to circumvent the secure boot trust model.
 | |
| We ignore the setting if we don't have the CAP_COMPROMISE_KERNEL capability.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  drivers/acpi/osl.c | 2 +-
 | |
|  1 file changed, 1 insertion(+), 1 deletion(-)
 | |
| 
 | |
| diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
 | |
| index bd22f86..88251d2 100644
 | |
| --- a/drivers/acpi/osl.c
 | |
| +++ b/drivers/acpi/osl.c
 | |
| @@ -246,7 +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 && capable(CAP_COMPROMISE_KERNEL))
 | |
|  		return acpi_rsdp;
 | |
|  #endif
 | |
|  
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From c937b2c8e179bfdadb6617c0028f558e4d701e46 Mon Sep 17 00:00:00 2001
 | |
| From: Matthew Garrett <mjg@redhat.com>
 | |
| Date: Tue, 4 Sep 2012 11:55:13 -0400
 | |
| Subject: [PATCH 15/19] kexec: Disable in a secure boot environment
 | |
| 
 | |
| kexec could be used as a vector for a malicious user to use a signed kernel
 | |
| to circumvent the secure boot trust model. In the long run we'll want to
 | |
| support signed kexec payloads, but for the moment we should just disable
 | |
| loading entirely in that situation.
 | |
| 
 | |
| Signed-off-by: Matthew Garrett <mjg@redhat.com>
 | |
| ---
 | |
|  kernel/kexec.c | 2 +-
 | |
|  1 file changed, 1 insertion(+), 1 deletion(-)
 | |
| 
 | |
| diff --git a/kernel/kexec.c b/kernel/kexec.c
 | |
| index 5e4bd78..dd464e0 100644
 | |
| --- a/kernel/kexec.c
 | |
| +++ b/kernel/kexec.c
 | |
| @@ -943,7 +943,7 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, unsigned long, nr_segments,
 | |
|  	int result;
 | |
|  
 | |
|  	/* We only trust the superuser with rebooting the system. */
 | |
| -	if (!capable(CAP_SYS_BOOT))
 | |
| +	if (!capable(CAP_SYS_BOOT) || !capable(CAP_COMPROMISE_KERNEL))
 | |
|  		return -EPERM;
 | |
|  
 | |
|  	/*
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From f08e390045266d53543a55afa16ca4be5a1c6316 Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Fri, 5 Oct 2012 10:12:48 -0400
 | |
| Subject: [PATCH 16/19] MODSIGN: Always enforce module signing in a Secure Boot
 | |
|  environment
 | |
| 
 | |
| If a machine is booted into a Secure Boot environment, we need to
 | |
| protect the trust model.  This requires that all modules be signed
 | |
| with a key that is in the kernel's _modsign keyring.  The checks for
 | |
| this are already done via the 'sig_enforce' module parameter.  Make
 | |
| this visible within the kernel and force it to be true.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  kernel/cred.c   | 8 ++++++++
 | |
|  kernel/module.c | 4 ++--
 | |
|  2 files changed, 10 insertions(+), 2 deletions(-)
 | |
| 
 | |
| diff --git a/kernel/cred.c b/kernel/cred.c
 | |
| index c3f4e3e..c5554e0 100644
 | |
| --- a/kernel/cred.c
 | |
| +++ b/kernel/cred.c
 | |
| @@ -565,11 +565,19 @@ void __init cred_init(void)
 | |
|  				     0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 | |
|  }
 | |
|  
 | |
| +#ifdef CONFIG_MODULE_SIG
 | |
| +extern bool sig_enforce;
 | |
| +#endif
 | |
| +
 | |
|  void __init secureboot_enable()
 | |
|  {
 | |
|  	pr_info("Secure boot enabled\n");
 | |
|  	cap_lower((&init_cred)->cap_bset, CAP_COMPROMISE_KERNEL);
 | |
|  	cap_lower((&init_cred)->cap_permitted, CAP_COMPROMISE_KERNEL);
 | |
| +#ifdef CONFIG_MODULE_SIG
 | |
| +	/* Enable module signature enforcing */
 | |
| +	sig_enforce = true;
 | |
| +#endif
 | |
|  }
 | |
|  
 | |
|  /* Dummy Secure Boot enable option to fake out UEFI SB=1 */
 | |
| diff --git a/kernel/module.c b/kernel/module.c
 | |
| index eab0827..93a16dc 100644
 | |
| --- a/kernel/module.c
 | |
| +++ b/kernel/module.c
 | |
| @@ -109,9 +109,9 @@ struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
 | |
|  
 | |
|  #ifdef CONFIG_MODULE_SIG
 | |
|  #ifdef CONFIG_MODULE_SIG_FORCE
 | |
| -static bool sig_enforce = true;
 | |
| +bool sig_enforce = true;
 | |
|  #else
 | |
| -static bool sig_enforce = false;
 | |
| +bool sig_enforce = false;
 | |
|  
 | |
|  static int param_set_bool_enable_only(const char *val,
 | |
|  				      const struct kernel_param *kp)
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 54ba1eec5847d964b1d458a240b50271b9a356a4 Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Fri, 26 Oct 2012 14:02:09 -0400
 | |
| Subject: [PATCH 17/19] hibernate: Disable in a Secure Boot environment
 | |
| 
 | |
| There is currently no way to verify the resume image when returning
 | |
| from hibernate.  This might compromise the secure boot trust model,
 | |
| so until we can work with signed hibernate images we disable it in
 | |
| a Secure Boot environment.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  kernel/power/hibernate.c | 15 ++++++++++++++-
 | |
|  kernel/power/main.c      |  7 ++++++-
 | |
|  kernel/power/user.c      |  3 +++
 | |
|  3 files changed, 23 insertions(+), 2 deletions(-)
 | |
| 
 | |
| diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
 | |
| index b26f5f1..7f63cb4 100644
 | |
| --- a/kernel/power/hibernate.c
 | |
| +++ b/kernel/power/hibernate.c
 | |
| @@ -28,6 +28,7 @@
 | |
|  #include <linux/syscore_ops.h>
 | |
|  #include <linux/ctype.h>
 | |
|  #include <linux/genhd.h>
 | |
| +#include <linux/efi.h>
 | |
|  
 | |
|  #include "power.h"
 | |
|  
 | |
| @@ -632,6 +633,10 @@ int hibernate(void)
 | |
|  {
 | |
|  	int error;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL)) {
 | |
| +		return -EPERM;
 | |
| +	}
 | |
| +
 | |
|  	lock_system_sleep();
 | |
|  	/* The snapshot device should not be opened while we're running */
 | |
|  	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 | |
| @@ -723,7 +728,7 @@ static int software_resume(void)
 | |
|  	/*
 | |
|  	 * If the user said "noresume".. bail out early.
 | |
|  	 */
 | |
| -	if (noresume)
 | |
| +	if (noresume || !capable(CAP_COMPROMISE_KERNEL))
 | |
|  		return 0;
 | |
|  
 | |
|  	/*
 | |
| @@ -889,6 +894,11 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
 | |
|  	int i;
 | |
|  	char *start = buf;
 | |
|  
 | |
| +	if (efi_enabled(EFI_SECURE_BOOT)) {
 | |
| +		buf += sprintf(buf, "[%s]\n", "disabled");
 | |
| +		return buf-start;
 | |
| +	}
 | |
| +
 | |
|  	for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
 | |
|  		if (!hibernation_modes[i])
 | |
|  			continue;
 | |
| @@ -923,6 +933,9 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
 | |
|  	char *p;
 | |
|  	int mode = HIBERNATION_INVALID;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	p = memchr(buf, '\n', n);
 | |
|  	len = p ? p - buf : n;
 | |
|  
 | |
| diff --git a/kernel/power/main.c b/kernel/power/main.c
 | |
| index 1c16f91..4f915fc 100644
 | |
| --- a/kernel/power/main.c
 | |
| +++ b/kernel/power/main.c
 | |
| @@ -15,6 +15,7 @@
 | |
|  #include <linux/workqueue.h>
 | |
|  #include <linux/debugfs.h>
 | |
|  #include <linux/seq_file.h>
 | |
| +#include <linux/efi.h>
 | |
|  
 | |
|  #include "power.h"
 | |
|  
 | |
| @@ -301,7 +302,11 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
 | |
|  	}
 | |
|  #endif
 | |
|  #ifdef CONFIG_HIBERNATION
 | |
| -	s += sprintf(s, "%s\n", "disk");
 | |
| +	if (!efi_enabled(EFI_SECURE_BOOT)) {
 | |
| +		s += sprintf(s, "%s\n", "disk");
 | |
| +	} else {
 | |
| +		s += sprintf(s, "\n");
 | |
| +	}
 | |
|  #else
 | |
|  	if (s != buf)
 | |
|  		/* convert the last space to a newline */
 | |
| diff --git a/kernel/power/user.c b/kernel/power/user.c
 | |
| index 4ed81e7..b11a0f4 100644
 | |
| --- a/kernel/power/user.c
 | |
| +++ b/kernel/power/user.c
 | |
| @@ -48,6 +48,9 @@ static int snapshot_open(struct inode *inode, struct file *filp)
 | |
|  	struct snapshot_data *data;
 | |
|  	int error;
 | |
|  
 | |
| +	if (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		return -EPERM;
 | |
| +
 | |
|  	lock_system_sleep();
 | |
|  
 | |
|  	if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From 686090054f6c3784218b318c7adcc3c1f0ca5069 Mon Sep 17 00:00:00 2001
 | |
| From: Josh Boyer <jwboyer@redhat.com>
 | |
| Date: Tue, 5 Feb 2013 19:25:05 -0500
 | |
| Subject: [PATCH 18/19] efi: Disable secure boot if shim is in insecure mode
 | |
| 
 | |
| A user can manually tell the shim boot loader to disable validation of
 | |
| images it loads.  When a user does this, it creates a UEFI variable called
 | |
| MokSBState that does not have the runtime attribute set.  Given that the
 | |
| user explicitly disabled validation, we can honor that and not enable
 | |
| secure boot mode if that variable is set.
 | |
| 
 | |
| Signed-off-by: Josh Boyer <jwboyer@redhat.com>
 | |
| ---
 | |
|  arch/x86/boot/compressed/eboot.c | 20 +++++++++++++++++++-
 | |
|  1 file changed, 19 insertions(+), 1 deletion(-)
 | |
| 
 | |
| diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
 | |
| index 96bd86b..6e1331c 100644
 | |
| --- a/arch/x86/boot/compressed/eboot.c
 | |
| +++ b/arch/x86/boot/compressed/eboot.c
 | |
| @@ -851,8 +851,9 @@ fail:
 | |
|  
 | |
|  static int get_secure_boot(efi_system_table_t *_table)
 | |
|  {
 | |
| -	u8 sb, setup;
 | |
| +	u8 sb, setup, moksbstate;
 | |
|  	unsigned long datasize = sizeof(sb);
 | |
| +	u32 attr;
 | |
|  	efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID;
 | |
|  	efi_status_t status;
 | |
|  
 | |
| @@ -876,6 +877,23 @@ static int get_secure_boot(efi_system_table_t *_table)
 | |
|  	if (setup == 1)
 | |
|  		return 0;
 | |
|  
 | |
| +	/* See if a user has put shim into insecure_mode.  If so, and the variable
 | |
| +	 * doesn't have the runtime attribute set, we might as well honor that.
 | |
| +	 */
 | |
| +	var_guid = EFI_SHIM_LOCK_GUID;
 | |
| +	status = efi_call_phys5(sys_table->runtime->get_variable,
 | |
| +				L"MokSBState", &var_guid, &attr, &datasize,
 | |
| +				&moksbstate);
 | |
| +
 | |
| +	/* If it fails, we don't care why.  Default to secure */
 | |
| +	if (status != EFI_SUCCESS)
 | |
| +		return 1;
 | |
| +
 | |
| +	if (!(attr & EFI_VARIABLE_RUNTIME_ACCESS)) {
 | |
| +		if (moksbstate == 1)
 | |
| +			return 0;
 | |
| +	}
 | |
| +
 | |
|  	return 1;
 | |
|  }
 | |
|  
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 | |
| 
 | |
| From df607d2d5061b04f8a686cd74edd72c1f2836d8c Mon Sep 17 00:00:00 2001
 | |
| From: Kees Cook <keescook@chromium.org>
 | |
| Date: Fri, 8 Feb 2013 11:12:13 -0800
 | |
| Subject: [PATCH 19/19] x86: Lock down MSR writing in secure boot
 | |
| 
 | |
| Writing to MSRs should not be allowed unless CAP_COMPROMISE_KERNEL is
 | |
| set since it could lead to execution of arbitrary code in kernel mode.
 | |
| 
 | |
| Signed-off-by: Kees Cook <keescook@chromium.org>
 | |
| ---
 | |
|  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 4929502..adaab3d 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 (!capable(CAP_COMPROMISE_KERNEL))
 | |
| +		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 (!capable(CAP_COMPROMISE_KERNEL)) {
 | |
| +			err = -EPERM;
 | |
| +			break;
 | |
| +		}
 | |
|  		if (copy_from_user(®s, uregs, sizeof regs)) {
 | |
|  			err = -EFAULT;
 | |
|  			break;
 | |
| -- 
 | |
| 1.8.1.2
 | |
| 
 |