From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Howells Subject: Re: [PATCH 5/7] efi: Get the secure boot status [ver #3] Date: Fri, 25 Nov 2016 13:00:55 +0000 Message-ID: <31374.1480078855@warthog.procyon.org.uk> References: <147990561294.7576.6464430479448167484.stgit@warthog.procyon.org.uk> <147990565051.7576.9673287945782426886.stgit@warthog.procyon.org.uk> <1480016487.2444.18.camel@HansenPartnership.com> <15173.1480066220@warthog.procyon.org.uk> <16661.1480075392@warthog.procyon.org.uk> <17565.1480077303@warthog.procyon.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: Content-ID: <31373.1480078855.1-S6HVgzuS8uM4Awkfq6JHfwNdhmdF6hFW@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ard Biesheuvel Cc: dhowells-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, James Bottomley , "linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , linux-security-module , Lukas Wunner , keyrings-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: linux-efi@vger.kernel.org Okay, how about the attached? Can these variables every be anything other than 1 or 0? E.g. should the check on SetupMode be that it isn't 0 rather than it is 1? David --- commit 6d4bb08e376045e27706c2740c0fdff0a6ec43f7 Author: David Howells Date: Fri Nov 25 11:52:05 2016 +0000 efi: Handle secure boot from UEFI-2.6 UEFI-2.6 adds a new variable, DeployedMode. If it exists, this must be 1 if we're to engage lockdown mode. Reported-by: James Bottomley Signed-off-by: David Howells diff --git a/drivers/firmware/efi/libstub/secureboot.c b/drivers/firmware/efi/libstub/secureboot.c index ca643eba5a4b..157782d1c552 100644 --- a/drivers/firmware/efi/libstub/secureboot.c +++ b/drivers/firmware/efi/libstub/secureboot.c @@ -22,6 +22,9 @@ static const efi_char16_t const efi_SecureBoot_name[] = { static const efi_char16_t const efi_SetupMode_name[] = { 'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0 }; +static const efi_char16_t const efi_DeployedMode_name[] = { + 'D', 'e', 'p', 'l', 'o', 'y', 'e', 'd', 'M', 'o', 'd', 'e', 0 +}; /* SHIM variables */ static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID; @@ -62,6 +65,17 @@ int efi_get_secureboot(efi_system_table_t *sys_table_arg) if (val == 1) return 0; + /* UEFI-2.6 requires DeployedMode to be 1. */ + if (sys_table_arg->hdr.revision == EFI_2_60_SYSTEM_TABLE_REVISION) { + status = get_efi_var(efi_DeployedMode_name, &efi_variable_guid, + NULL, &size, &val); + if (status != EFI_SUCCESS) + goto out_efi_err; + + if (val != 1) + return 0; + } + /* See if a user has put shim into insecure mode. If so, and if the * variable doesn't have the runtime attribute set, we might as well * honor that. diff --git a/include/linux/efi.h b/include/linux/efi.h index 333d31bf55bf..563abb37f03f 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -645,6 +645,10 @@ typedef struct { #define EFI_SYSTEM_TABLE_SIGNATURE ((u64)0x5453595320494249ULL) +#define EFI_2_60_SYSTEM_TABLE_REVISION ((2 << 16) | (60)) +#define EFI_2_50_SYSTEM_TABLE_REVISION ((2 << 16) | (50)) +#define EFI_2_40_SYSTEM_TABLE_REVISION ((2 << 16) | (40)) +#define EFI_2_31_SYSTEM_TABLE_REVISION ((2 << 16) | (31)) #define EFI_2_30_SYSTEM_TABLE_REVISION ((2 << 16) | (30)) #define EFI_2_20_SYSTEM_TABLE_REVISION ((2 << 16) | (20)) #define EFI_2_10_SYSTEM_TABLE_REVISION ((2 << 16) | (10))