Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752932Ab3IEDM3 (ORCPT ); Wed, 4 Sep 2013 23:12:29 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:53803 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752158Ab3IEDM1 (ORCPT ); Wed, 4 Sep 2013 23:12:27 -0400 Subject: Re: [PATCH V3 11/11] Add option to automatically enforce module signatures when in Secure Boot mode From: joeyli To: Matthew Garrett Cc: linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, keescook@chromium.org, hpa@zytor.com In-Reply-To: <1378252218-18798-12-git-send-email-matthew.garrett@nebula.com> References: <1378252218-18798-1-git-send-email-matthew.garrett@nebula.com> <1378252218-18798-12-git-send-email-matthew.garrett@nebula.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 05 Sep 2013 11:13:16 +0800 Message-ID: <1378350796.6380.78.camel@linux-s257.site> Mime-Version: 1.0 X-Mailer: Evolution 2.28.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6237 Lines: 191 於 二，2013-09-03 於 19:50 -0400，Matthew Garrett 提到： > 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 Tested-by: Lee, Chun-Yi Thanks Joey Lee > --- > 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 > #include > #include > +#include > > #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 > + > #ifdef CONFIG_MODULES > > extern int modules_disabled; /* for sysctl */ > diff --git a/kernel/module.c b/kernel/module.c > index 0e94acf..974139b 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -3853,6 +3853,13 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/