linux-stable.git/include/linux/efi.h, branch v5.0.4

efi/arm: Revert "Defer persistent reservations until after paging_init()"

2019-02-16T14:02:03+00:00

This reverts commit eff896288872d687d9662000ec9ae11b6d61766f, which
deferred the processing of persistent memory reservations to a point
where the memory may have already been allocated and overwritten,
defeating the purpose.

Signed-off-by: Ard Biesheuvel 
Acked-by: Will Deacon 
Cc: Linus Torvalds 
Cc: Marc Zyngier 
Cc: Mike Rapoport 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20190215123333.21209-3-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar

Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2019-01-02T17:43:14+00:00

Pull integrity updates from James Morris:
 "In Linux 4.19, a new LSM hook named security_kernel_load_data was
  upstreamed, allowing LSMs and IMA to prevent the kexec_load syscall.
  Different signature verification methods exist for verifying the
  kexec'ed kernel image. This adds additional support in IMA to prevent
  loading unsigned kernel images via the kexec_load syscall,
  independently of the IMA policy rules, based on the runtime "secure
  boot" flag. An initial IMA kselftest is included.

  In addition, this pull request defines a new, separate keyring named
  ".platform" for storing the preboot/firmware keys needed for verifying
  the kexec'ed kernel image's signature and includes the associated IMA
  kexec usage of the ".platform" keyring.

  (David Howell's and Josh Boyer's patches for reading the
  preboot/firmware keys, which were previously posted for a different
  use case scenario, are included here)"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  integrity: Remove references to module keyring
  ima: Use inode_is_open_for_write
  ima: Support platform keyring for kernel appraisal
  efi: Allow the "db" UEFI variable to be suppressed
  efi: Import certificates from UEFI Secure Boot
  efi: Add an EFI signature blob parser
  efi: Add EFI signature data types
  integrity: Load certs to the platform keyring
  integrity: Define a trusted platform keyring
  selftests/ima: kexec_load syscall test
  ima: don't measure/appraise files on efivarfs
  x86/ima: retry detecting secure boot mode
  docs: Extend trusted keys documentation for TPM 2.0
  x86/ima: define arch_get_ima_policy() for x86
  ima: add support for arch specific policies
  ima: refactor ima_init_policy()
  ima: prevent kexec_load syscall based on runtime secureboot flag
  x86/ima: define arch_ima_get_secureboot
  integrity: support new struct public_key_signature encoding field

Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next-integrity

2018-12-17T19:26:46+00:00

From Mimi:

In Linux 4.19, a new LSM hook named security_kernel_load_data was
upstreamed, allowing LSMs and IMA to prevent the kexec_load
syscall.  Different signature verification methods exist for verifying
the kexec'ed kernel image.  This pull request adds additional support
in IMA to prevent loading unsigned kernel images via the kexec_load
syscall, independently of the IMA policy rules, based on the runtime
"secure boot" flag.  An initial IMA kselftest is included.

In addition, this pull request defines a new, separate keyring named
".platform" for storing the preboot/firmware keys needed for verifying
the kexec'ed kernel image's signature and includes the associated IMA
kexec usage of the ".platform" keyring.

(David Howell's and Josh Boyer's patches for reading the
preboot/firmware keys, which were previously posted for a different
use case scenario, are included here.)

efi: Add an EFI signature blob parser

2018-12-13T03:04:29+00:00

Add a function to parse an EFI signature blob looking for elements of
interest. A list is made up of a series of sublists, where all the
elements in a sublist are of the same type, but sublists can be of
different types.

For each sublist encountered, the function pointed to by the
get_handler_for_guid argument is called with the type specifier GUID and
returns either a pointer to a function to handle elements of that type or
NULL if the type is not of interest.

If the sublist is of interest, each element is passed to the handler
function in turn.

Signed-off-by: David Howells 
Signed-off-by: Nayna Jain 
Acked-by: Serge Hallyn 
Signed-off-by: Mimi Zohar

efi: Add EFI signature data types

2018-12-13T03:03:36+00:00

Add the data types that are used for containing hashes, keys and
certificates for cryptographic verification along with their corresponding
type GUIDs.

Signed-off-by: David Howells 
Acked-by: Nayna Jain 
Acked-by: Serge Hallyn 
Reviewed-by: James Morris 
Signed-off-by: Mimi Zohar

efi: Reduce the amount of memblock reservations for persistent allocations

2018-11-30T08:37:57+00:00

The current implementation of efi_mem_reserve_persistent() is rather
naive, in the sense that for each invocation, it creates a separate
linked list entry to describe the reservation. Since the linked list
entries themselves need to persist across subsequent kexec reboots,
every reservation created this way results in two memblock_reserve()
calls at the next boot.

On arm64 systems with 100s of CPUs, this may result in a excessive
number of memblock reservations, and needless fragmentation.

So instead, make use of the newly updated struct linux_efi_memreserve
layout to put multiple reservations into a single linked list entry.
This should get rid of the numerous tiny memblock reservations, and
effectively cut the total number of reservations in half on arm64
systems with many CPUs.

 [ mingo: build warning fix. ]

Tested-by: Marc Zyngier 
Signed-off-by: Ard Biesheuvel 
Cc: Andy Lutomirski 
Cc: Arend van Spriel 
Cc: Bhupesh Sharma 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Eric Snowberg 
Cc: Hans de Goede 
Cc: Joe Perches 
Cc: Jon Hunter 
Cc: Julien Thierry 
Cc: Linus Torvalds 
Cc: Matt Fleming 
Cc: Nathan Chancellor 
Cc: Peter Zijlstra 
Cc: Sai Praneeth Prakhya 
Cc: Sedat Dilek 
Cc: Thomas Gleixner 
Cc: YiFei Zhu 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-11-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar

efi: Permit multiple entries in persistent memreserve data structure

2018-11-30T08:10:31+00:00

In preparation of updating efi_mem_reserve_persistent() to cause less
fragmentation when dealing with many persistent reservations, update
the struct definition and the code that handles it currently so it
can describe an arbitrary number of reservations using a single linked
list entry. The actual optimization will be implemented in a subsequent
patch.

Tested-by: Marc Zyngier 
Signed-off-by: Ard Biesheuvel 
Cc: Andy Lutomirski 
Cc: Arend van Spriel 
Cc: Bhupesh Sharma 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Eric Snowberg 
Cc: Hans de Goede 
Cc: Joe Perches 
Cc: Jon Hunter 
Cc: Julien Thierry 
Cc: Linus Torvalds 
Cc: Matt Fleming 
Cc: Nathan Chancellor 
Cc: Peter Zijlstra 
Cc: Sai Praneeth Prakhya 
Cc: Sedat Dilek 
Cc: Thomas Gleixner 
Cc: YiFei Zhu 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-10-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar

x86/efi: Move efi__boot_services() to arch/x86

2018-11-30T08:10:31+00:00

efi__boot_services() are x86 specific quirks and as such
should be in asm/efi.h, so move them from linux/efi.h. Also, call
efi_free_boot_services() from __efi_enter_virtual_mode() as it is x86
specific call and ideally shouldn't be part of init/main.c

Signed-off-by: Sai Praneeth Prakhya 
Signed-off-by: Ard Biesheuvel 
Acked-by: Thomas Gleixner 
Cc: Andy Lutomirski 
Cc: Arend van Spriel 
Cc: Bhupesh Sharma 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Eric Snowberg 
Cc: Hans de Goede 
Cc: Joe Perches 
Cc: Jon Hunter 
Cc: Julien Thierry 
Cc: Linus Torvalds 
Cc: Marc Zyngier 
Cc: Matt Fleming 
Cc: Nathan Chancellor 
Cc: Peter Zijlstra 
Cc: Sedat Dilek 
Cc: YiFei Zhu 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181129171230.18699-7-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar

efi/arm: Defer persistent reservations until after paging_init()

2018-11-15T09:04:46+00:00

The new memory EFI reservation feature we introduced to allow memory
reservations to persist across kexec may trigger an unbounded number
of calls to memblock_reserve(). The memblock subsystem can deal with
this fine, but not before memblock resizing is enabled, which we can
only do after paging_init(), when the memory we reallocate the array
into is actually mapped.

So break out the memreserve table processing into a separate routine
and call it after paging_init() on arm64. On ARM, because of limited
reviewing bandwidth of the maintainer, we cannot currently fix this,
so instead, disable the EFI persistent memreserve entirely on ARM so
we can fix it later.

Tested-by: Marc Zyngier 
Signed-off-by: Ard Biesheuvel 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181114175544.12860-5-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar

efi/x86: Handle page faults occurring while running EFI runtime services

2018-09-26T10:14:55+00:00

Memory accesses performed by UEFI runtime services should be limited to:
- reading/executing from EFI_RUNTIME_SERVICES_CODE memory regions
- reading/writing from/to EFI_RUNTIME_SERVICES_DATA memory regions
- reading/writing by-ref arguments
- reading/writing from/to the stack.

Accesses outside these regions may cause the kernel to hang because the
memory region requested by the firmware isn't mapped in efi_pgd, which
causes a page fault in ring 0 and the kernel fails to handle it, leading
to die(). To save kernel from hanging, add an EFI specific page fault
handler which recovers from such faults by
1. If the efi runtime service is efi_reset_system(), reboot the machine
   through BIOS.
2. If the efi runtime service is _not_ efi_reset_system(), then freeze
   efi_rts_wq and schedule a new process.

The EFI page fault handler offers us two advantages:
1. Avoid potential hangs caused by buggy firmware.
2. Shout loud that the firmware is buggy and hence is not a kernel bug.

Tested-by: Bhupesh Sharma 
Suggested-by: Matt Fleming 
Based-on-code-from: Ricardo Neri 
Signed-off-by: Sai Praneeth Prakhya 
Reviewed-by: Thomas Gleixner 
[ardb: clarify commit log]
Signed-off-by: Ard Biesheuvel