Commit Graph

12 Commits

Author SHA1 Message Date
Eric Snowberg 45fcd5e521 integrity: add new keyring handler for mok keys
Currently both Secure Boot DB and Machine Owner Keys (MOK) go through
the same keyring handler (get_handler_for_db). With the addition of the
new machine keyring, the end-user may choose to trust MOK keys.

Introduce a new keyring handler specific for MOK keys.  If MOK keys are
trusted by the end-user, use the new keyring handler instead.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2022-03-08 13:55:52 +02:00
Lee, Chun-Yi 92ad19559e integrity: Do not load MOK and MOKx when secure boot be disabled
The security of Machine Owner Key (MOK) relies on secure boot. When
secure boot is disabled, EFI firmware will not verify binary code. Then
arbitrary efi binary code can modify MOK when rebooting.

This patch prevents MOK/MOKx be loaded when secure boot be disabled.

Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-12-24 10:25:24 -05:00
Eric Snowberg ebd9c2ae36 integrity: Load mokx variables into the blacklist keyring
During boot the Secure Boot Forbidden Signature Database, dbx,
is loaded into the blacklist keyring.  Systems booted with shim
have an equivalent Forbidden Signature Database called mokx.
Currently mokx is only used by shim and grub, the contents are
ignored by the kernel.

Add the ability to load mokx into the blacklist keyring during boot.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
cc: keyrings@vger.kernel.org
Link: https://lore.kernel.org/r/c33c8e3839a41e9654f41cc92c7231104931b1d7.camel@HansenPartnership.com/
Link: https://lore.kernel.org/r/20210122181054.32635-5-eric.snowberg@oracle.com/ # v5
Link: https://lore.kernel.org/r/161428674320.677100.12637282414018170743.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/161433313205.902181.2502803393898221637.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161529607422.163428.13530426573612578854.stgit@warthog.procyon.org.uk/ # v3
2021-03-11 16:34:48 +00:00
Lenny Szubowicz 726bd8965a integrity: Load certs from the EFI MOK config table
Because of system-specific EFI firmware limitations, EFI volatile
variables may not be capable of holding the required contents of
the Machine Owner Key (MOK) certificate store when the certificate
list grows above some size. Therefore, an EFI boot loader may pass
the MOK certs via a EFI configuration table created specifically for
this purpose to avoid this firmware limitation.

An EFI configuration table is a much more primitive mechanism
compared to EFI variables and is well suited for one-way passage
of static information from a pre-OS environment to the kernel.

This patch adds the support to load certs from the MokListRT
entry in the MOK variable configuration table, if it's present.
The pre-existing support to load certs from the MokListRT EFI
variable remains and is used if the EFI MOK configuration table
isn't present or can't be successfully used.

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Link: https://lore.kernel.org/r/20200905013107.10457-4-lszubowi@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-16 18:53:42 +03:00
Lenny Szubowicz 38a1f03aa2 integrity: Move import of MokListRT certs to a separate routine
Move the loading of certs from the UEFI MokListRT into a separate
routine to facilitate additional MokList functionality.

There is no visible functional change as a result of this patch.
Although the UEFI dbx certs are now loaded before the MokList certs,
they are loaded onto different key rings. So the order of the keys
on their respective key rings is the same.

Signed-off-by: Lenny Szubowicz <lszubowi@redhat.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20200905013107.10457-3-lszubowi@redhat.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-09-16 18:53:42 +03:00
Ingo Molnar e9765680a3 EFI updates for v5.7:
This time, the set of changes for the EFI subsystem is much larger than
 usual. The main reasons are:
 - Get things cleaned up before EFI support for RISC-V arrives, which will
   increase the size of the validation matrix, and therefore the threshold to
   making drastic changes,
 - After years of defunct maintainership, the GRUB project has finally started
   to consider changes from the distros regarding UEFI boot, some of which are
   highly specific to the way x86 does UEFI secure boot and measured boot,
   based on knowledge of both shim internals and the layout of bootparams and
   the x86 setup header. Having this maintenance burden on other architectures
   (which don't need shim in the first place) is hard to justify, so instead,
   we are introducing a generic Linux/UEFI boot protocol.
 
 Summary of changes:
 - Boot time GDT handling changes (Arvind)
 - Simplify handling of EFI properties table on arm64
 - Generic EFI stub cleanups, to improve command line handling, file I/O,
   memory allocation, etc.
 - Introduce a generic initrd loading method based on calling back into
   the firmware, instead of relying on the x86 EFI handover protocol or
   device tree.
 - Introduce a mixed mode boot method that does not rely on the x86 EFI
   handover protocol either, and could potentially be adopted by other
   architectures (if another one ever surfaces where one execution mode
   is a superset of another)
 - Clean up the contents of struct efi, and move out everything that
   doesn't need to be stored there.
 - Incorporate support for UEFI spec v2.8A changes that permit firmware
   implementations to return EFI_UNSUPPORTED from UEFI runtime services at
   OS runtime, and expose a mask of which ones are supported or unsupported
   via a configuration table.
 - Various documentation updates and minor code cleanups (Heinrich)
 - Partial fix for the lack of by-VA cache maintenance in the decompressor
   on 32-bit ARM. Note that these patches were deliberately put at the
   beginning so they can be used as a stable branch that will be shared with
   a PR containing the complete fix, which I will send to the ARM tree.
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Merge tag 'efi-next' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi into efi/core

Pull EFI updates for v5.7 from Ard Biesheuvel:

This time, the set of changes for the EFI subsystem is much larger than
usual. The main reasons are:

 - Get things cleaned up before EFI support for RISC-V arrives, which will
   increase the size of the validation matrix, and therefore the threshold to
   making drastic changes,

 - After years of defunct maintainership, the GRUB project has finally started
   to consider changes from the distros regarding UEFI boot, some of which are
   highly specific to the way x86 does UEFI secure boot and measured boot,
   based on knowledge of both shim internals and the layout of bootparams and
   the x86 setup header. Having this maintenance burden on other architectures
   (which don't need shim in the first place) is hard to justify, so instead,
   we are introducing a generic Linux/UEFI boot protocol.

Summary of changes:

 - Boot time GDT handling changes (Arvind)

 - Simplify handling of EFI properties table on arm64

 - Generic EFI stub cleanups, to improve command line handling, file I/O,
   memory allocation, etc.

 - Introduce a generic initrd loading method based on calling back into
   the firmware, instead of relying on the x86 EFI handover protocol or
   device tree.

 - Introduce a mixed mode boot method that does not rely on the x86 EFI
   handover protocol either, and could potentially be adopted by other
   architectures (if another one ever surfaces where one execution mode
   is a superset of another)

 - Clean up the contents of struct efi, and move out everything that
   doesn't need to be stored there.

 - Incorporate support for UEFI spec v2.8A changes that permit firmware
   implementations to return EFI_UNSUPPORTED from UEFI runtime services at
   OS runtime, and expose a mask of which ones are supported or unsupported
   via a configuration table.

 - Various documentation updates and minor code cleanups (Heinrich)

 - Partial fix for the lack of by-VA cache maintenance in the decompressor
   on 32-bit ARM. Note that these patches were deliberately put at the
   beginning so they can be used as a stable branch that will be shared with
   a PR containing the complete fix, which I will send to the ARM tree.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2020-02-26 15:21:22 +01:00
Ard Biesheuvel 6b75d54d52 integrity: Check properly whether EFI GetVariable() is available
Testing the value of the efi.get_variable function pointer is not
the right way to establish whether the platform supports EFI
variables at runtime. Instead, use the newly added granular check
that can test for the presence of each EFI runtime service
individually.

Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-02-23 21:59:42 +01:00
Javier Martinez Canillas 3be54d558c efi: Only print errors about failing to get certs if EFI vars are found
If CONFIG_LOAD_UEFI_KEYS is enabled, the kernel attempts to load the certs
from the db, dbx and MokListRT EFI variables into the appropriate keyrings.

But it just assumes that the variables will be present and prints an error
if the certs can't be loaded, even when is possible that the variables may
not exist. For example the MokListRT variable will only be present if shim
is used.

So only print an error message about failing to get the certs list from an
EFI variable if this is found. Otherwise these printed errors just pollute
the kernel log ring buffer with confusing messages like the following:

[    5.427251] Couldn't get size: 0x800000000000000e
[    5.427261] MODSIGN: Couldn't get UEFI db list
[    5.428012] Couldn't get size: 0x800000000000000e
[    5.428023] Couldn't get UEFI MokListRT

Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-02-18 07:35:48 -05:00
YueHaibing 6f090192f8 x86/efi: remove unused variables
commit ad723674d6 ("x86/efi: move common keyring handler functions
to new file") leave this unused.

Fixes: ad723674d6 ("x86/efi: move common keyring handler functions to new file")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20191115130830.13320-1-yuehaibing@huawei.com
2019-11-29 22:23:46 +11:00
Nayna Jain ad723674d6 x86/efi: move common keyring handler functions to new file
The handlers to add the keys to the .platform keyring and blacklisted
hashes to the .blacklist keyring is common for both the uefi and powerpc
mechanisms of loading the keys/hashes from the firmware.

This patch moves the common code from load_uefi.c to keyring_handler.c

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573441836-3632-4-git-send-email-nayna@linux.ibm.com
2019-11-13 00:33:23 +11:00
Josh Boyer 386b49f51d efi: Allow the "db" UEFI variable to be suppressed
If a user tells shim to not use the certs/hashes in the UEFI db variable
for verification purposes, shim will set a UEFI variable called
MokIgnoreDB. Have the uefi import code look for this and ignore the db
variable if it is found.

[zohar@linux.ibm.com: removed reference to "secondary" keyring comment]
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-12 22:09:10 -05:00
Josh Boyer 15ea0e1e3e efi: Import certificates from UEFI Secure Boot
Secure Boot stores a list of allowed certificates in the 'db' variable.
This patch imports those certificates into the platform keyring. The shim
UEFI bootloader has a similar certificate list stored in the 'MokListRT'
variable. We import those as well.

Secure Boot also maintains a list of disallowed certificates in the 'dbx'
variable. We load those certificates into the system blacklist keyring
and forbid any kernel signed with those from loading.

[zohar@linux.ibm.com: dropped Josh's original patch description]
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-12 22:04:33 -05:00