linux-toradex.git/drivers/acpi/custom_method.c, branch v5.5-rc3

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

2019-09-28T15:14:15+00:00

Pull kernel lockdown mode from James Morris:
"This is the latest iteration of the kernel lockdown patchset, from
Matthew Garrett, David Howells and others.

From the original description:

This patchset introduces an optional kernel lockdown feature,
intended to strengthen the boundary between UID 0 and the kernel.
When enabled, various pieces of kernel functionality are restricted.
Applications that rely on low-level access to either hardware or the
kernel may cease working as a result - therefore this should not be
enabled without appropriate evaluation beforehand.

The majority of mainstream distributions have been carrying variants
of this patchset for many years now, so there's value in providing a
doesn't meet every distribution requirement, but gets us much closer
to not requiring external patches.

There are two major changes since this was last proposed for mainline:

- Separating lockdown from EFI secure boot. Background discussion is
covered here: https://lwn.net/Articles/751061/

- Implementation as an LSM, with a default stackable lockdown LSM
module. This allows the lockdown feature to be policy-driven,
rather than encoding an implicit policy within the mechanism.

The new locked_down LSM hook is provided to allow LSMs to make a
policy decision around whether kernel functionality that would allow
tampering with or examining the runtime state of the kernel should be
permitted.

The included lockdown LSM provides an implementation with a simple
policy intended for general purpose use. This policy provides a coarse
level of granularity, controllable via the kernel command line:

lockdown={integrity|confidentiality}

Enable the kernel lockdown feature. If set to integrity, kernel features
that allow userland to modify the running kernel are disabled. If set to
confidentiality, kernel features that allow userland to extract
confidential information from the kernel are also disabled.

This may also be controlled via /sys/kernel/security/lockdown and
overriden by kernel configuration.

New or existing LSMs may implement finer-grained controls of the
lockdown features. Refer to the lockdown_reason documentation in
include/linux/security.h for details.

The lockdown feature has had signficant design feedback and review
across many subsystems. This code has been in linux-next for some
weeks, with a few fixes applied along the way.

Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf
when kernel lockdown is in confidentiality mode") is missing a
Signed-off-by from its author. Matthew responded that he is providing
this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
kexec: Fix file verification on S390
security: constify some arrays in lockdown LSM
lockdown: Print current->comm in restriction messages
efi: Restrict efivar_ssdt_load when the kernel is locked down
tracefs: Restrict tracefs when the kernel is locked down
debugfs: Restrict debugfs when the kernel is locked down
kexec: Allow kexec_file() with appropriate IMA policy when locked down
lockdown: Lock down perf when in confidentiality mode
bpf: Restrict bpf when kernel lockdown is in confidentiality mode
lockdown: Lock down tracing and perf kprobes when in confidentiality mode
lockdown: Lock down /proc/kcore
x86/mmiotrace: Lock down the testmmiotrace module
lockdown: Lock down module params that specify hardware parameters (eg. ioport)
lockdown: Lock down TIOCSSERIAL
lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
acpi: Disable ACPI table override if the kernel is locked down
acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
ACPI: Limit access to custom_method when the kernel is locked down
x86/msr: Restrict MSR access when the kernel is locked down
x86: Lock down IO port access when the kernel is locked down
...

ACPI: custom_method: fix memory leaks

2019-09-02T21:17:22+00:00

In cm_write(), 'buf' is allocated through kzalloc(). In the following
execution, if an error occurs, 'buf' is not deallocated, leading to memory
leaks. To fix this issue, free 'buf' before returning the error.

Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver")
Signed-off-by: Wenwen Wang 
Signed-off-by: Rafael J. Wysocki

ACPI: Limit access to custom_method when the kernel is locked down

2019-08-20T04:54:16+00:00

custom_method effectively allows arbitrary access to system memory, making
it possible for an attacker to circumvent restrictions on module loading.
Disable it if the kernel is locked down.

Signed-off-by: Matthew Garrett 
Signed-off-by: David Howells 
Reviewed-by: Kees Cook 
cc: linux-acpi@vger.kernel.org
Signed-off-by: James Morris

treewide: Add SPDX license identifier for more missed files

2019-05-21T08:50:45+00:00

Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have MODULE_LICENCE("GPL*") inside which was used in the initial
   scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

ACPI: no need to check return value of debugfs_create functions

2019-01-22T18:45:52+00:00

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Rafael J. Wysocki

ACPI: custom_method: remove meaningless null check before debugfs_remove()

2018-09-10T10:46:51+00:00

debugfs_remove() has taken null pointer into account. So it is safe
to remove the check before debugfs_remove().

Signed-off-by: zhong jiang 
Signed-off-by: Rafael J. Wysocki

treewide: Align function definition open/close braces

2018-03-26T09:13:09+00:00

Some functions definitions have either the initial open brace and/or
the closing brace outside of column 1.

Move those braces to column 1.

This allows various function analyzers like gnu complexity to work
properly for these modified functions.

Signed-off-by: Joe Perches 
Acked-by: Andy Shevchenko 
Acked-by: Paul Moore 
Acked-by: Alex Deucher 
Acked-by: Dave Chinner 
Reviewed-by: Darrick J. Wong 
Acked-by: Alexandre Belloni 
Acked-by: Martin K. Petersen 
Acked-by: Takashi Iwai 
Acked-by: Mauro Carvalho Chehab 
Acked-by: Rafael J. Wysocki 
Acked-by: Nicolin Chen 
Acked-by: Martin K. Petersen 
Acked-by: Steven Rostedt (VMware) 
Signed-off-by: Jiri Kosina

ACPI: Clean up inclusions of ACPI header files

2013-12-07T00:03:14+00:00

Replace direct inclusions of ,  and
, which are incorrect, with 
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, ,  and 
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds.  For CONFIG_ACPI set,
 includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met.  Namely, it is required that  be included
prior to  so that the acpi_pci_root declarations the
latter depends on are always there.  And  which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds.  That also is taken care of including
 as appropriate.

Signed-off-by: Lv Zheng 
Cc: Greg Kroah-Hartman 
Cc: Matthew Garrett 
Cc: Tony Luck 
Cc: "H. Peter Anvin" 
Acked-by: Bjorn Helgaas  (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk  (Xen stuff)
Signed-off-by: Rafael J. Wysocki

Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

2013-02-25T23:41:43+00:00

Pull module update from Rusty Russell:
 "The sweeping change is to make add_taint() explicitly indicate whether
  to disable lockdep, but it's a mechanical change."

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  MODSIGN: Add option to not sign modules during modules_install
  MODSIGN: Add -s  option to sign-file
  MODSIGN: Specify the hash algorithm on sign-file command line
  MODSIGN: Simplify Makefile with a Kconfig helper
  module: clean up load_module a little more.
  modpost: Ignore ARC specific non-alloc sections
  module: constify within_module_*
  taint: add explicit flag to show whether lock dep is still OK.
  module: printk message when module signature fail taints kernel.

ACPI: fix obsolete comment in custom_method.c

2013-01-25T23:34:22+00:00

The comment describing the contents of the custom_method.c file is
obsolete, so update it.

[rjw: Subject and changelog]
Signed-off-by: Zhang Rui 
Signed-off-by: Rafael J. Wysocki