diff options
Diffstat (limited to 'Add-option-to-automatically-enforce-module-signature.patch')
| -rw-r--r-- | Add-option-to-automatically-enforce-module-signature.patch | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/Add-option-to-automatically-enforce-module-signature.patch b/Add-option-to-automatically-enforce-module-signature.patch new file mode 100644 index 000000000..9ad433cf7 --- /dev/null +++ b/Add-option-to-automatically-enforce-module-signature.patch @@ -0,0 +1,186 @@ +From acfbe6c8714da667ad980b9847edefe947f7e67e 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] 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 199f453cb4de..ec38acf00b40 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 5d0bf1aa9dcb..46392bfab57e 100644 +--- a/arch/x86/Kconfig ++++ b/arch/x86/Kconfig +@@ -1565,6 +1565,16 @@ config EFI_MIXED + + If unsure, say N. + ++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 f277184e2ac1..88edd48f03e9 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 */ + +@@ -803,6 +804,37 @@ out: + 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_early->call((unsigned long)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_early->call((unsigned long)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; ++} ++ ++ + /* + * See if we have Graphics Output Protocol + */ +@@ -1374,6 +1406,10 @@ struct boot_params *efi_main(struct efi_config *c, + else + setup_boot_services32(efi_early); + ++ sanitize_boot_params(boot_params); ++ ++ boot_params->secure_boot = get_secure_boot(); ++ + setup_graphics(boot_params); + + status = setup_efi_pci(boot_params); +diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h +index 225b0988043a..90dbfb73e11f 100644 +--- a/arch/x86/include/uapi/asm/bootparam.h ++++ b/arch/x86/include/uapi/asm/bootparam.h +@@ -133,7 +133,8 @@ 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 41ead8d3bc0b..5a5cf7395724 100644 +--- a/arch/x86/kernel/setup.c ++++ b/arch/x86/kernel/setup.c +@@ -1142,6 +1142,12 @@ 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 341a73ecea2e..cca08ac450e2 100644 +--- a/include/linux/module.h ++++ b/include/linux/module.h +@@ -188,6 +188,12 @@ 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 ++ + #ifdef CONFIG_MODULES + + extern int modules_disabled; /* for sysctl */ +diff --git a/kernel/module.c b/kernel/module.c +index 1f7b4664300e..866417ecc76a 100644 +--- a/kernel/module.c ++++ b/kernel/module.c +@@ -3843,6 +3843,13 @@ void module_layout(struct module *mod, + EXPORT_SYMBOL(module_layout); + #endif + ++#ifdef CONFIG_MODULE_SIG ++void enforce_signed_modules(void) ++{ ++ sig_enforce = true; ++} ++#endif ++ + bool secure_modules(void) + { + #ifdef CONFIG_MODULE_SIG +-- +1.9.3 + |