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Commit Graph

25 Commits

Author SHA1 Message Date
Paul Moore
c5e3cdbf2a tomoyo: revert CONFIG_SECURITY_TOMOYO_LKM support
This patch reverts two TOMOYO patches that were merged into Linus' tree
during the v6.12 merge window:

8b985bbfab ("tomoyo: allow building as a loadable LSM module")
268225a1de ("tomoyo: preparation step for building as a loadable LSM module")

Together these two patches introduced the CONFIG_SECURITY_TOMOYO_LKM
Kconfig build option which enabled a TOMOYO specific dynamic LSM loading
mechanism (see the original commits for more details).  Unfortunately,
this approach was widely rejected by the LSM community as well as some
members of the general kernel community.  Objections included concerns
over setting a bad precedent regarding individual LSMs managing their
LSM callback registrations as well as general kernel symbol exporting
practices.  With little to no support for the CONFIG_SECURITY_TOMOYO_LKM
approach outside of Tetsuo, and multiple objections, we need to revert
these changes.

Link: https://lore.kernel.org/all/0c4b443a-9c72-4800-97e8-a3816b6a9ae2@I-love.SAKURA.ne.jp
Link: https://lore.kernel.org/all/CAHC9VhR=QjdoHG3wJgHFJkKYBg7vkQH2MpffgVzQ0tAByo_wRg@mail.gmail.com
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-10-04 11:41:22 -04:00
Tetsuo Handa
8b985bbfab tomoyo: allow building as a loadable LSM module
One of concerns for enabling TOMOYO in prebuilt kernels is that distributor
wants to avoid bloating kernel packages. Although boot-time kernel command
line options allows selecting built-in LSMs to enable, file size increase
of vmlinux and memory footprint increase of vmlinux caused by builtin-but-
not-enabled LSMs remains. If it becomes possible to make LSMs dynamically
appendable after boot using loadable kernel modules, these problems will
go away.

Another of concerns for enabling TOMOYO in prebuilt kernels is that who can
provide support when distributor cannot provide support. Due to "those who
compiled kernel code is expected to provide support for that kernel code"
spell, TOMOYO is failing to get enabled in Fedora distribution [1]. The
point of loadable kernel module is to share the workload. If it becomes
possible to make LSMs dynamically appendable after boot using loadable
kernel modules, as with people can use device drivers not supported by
distributors but provided by third party device vendors, we can break
this spell and can lower the barrier for using TOMOYO.

This patch is intended for demonstrating that there is nothing difficult
for supporting TOMOYO-like loadable LSM modules. For now we need to live
with a mixture of built-in part and loadable part because fully loadable
LSM modules are not supported since Linux 2.6.24 [2] and number of LSMs
which can reserve static call slots is determined at compile time in
Linux 6.12.

Major changes in this patch are described below.
There are no behavior changes as long as TOMOYO is built into vmlinux.

Add CONFIG_SECURITY_TOMOYO_LKM as "bool" instead of changing
CONFIG_SECURITY_TOMOYO from "bool" to "tristate", for something went
wrong with how Makefile is evaluated if I choose "tristate".

Add proxy.c for serving as a bridge between vmlinux and tomoyo.ko .
Move callback functions from init.c to proxy.c when building as a loadable
LSM module. init.c is built-in part and remains for reserving static call
slots. proxy.c contains module's init function and tells init.c location of
callback functions, making it possible to use static call for tomoyo.ko .

By deferring initialization of "struct tomoyo_task" until tomoyo.ko is
loaded, threads created between init.c reserved LSM hooks and proxy.c
updates LSM hooks will have NULL "struct tomoyo_task" instances. Assuming
that tomoyo.ko is loaded by the moment when the global init process starts,
initialize "struct tomoyo_task" instance for current thread as a kernel
thread when tomoyo_task(current) is called for the first time.

There is a hack for exporting currently not-exported functions.
This hack will be removed after all relevant functions are exported.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=542986 [1]
Link: https://lkml.kernel.org/r/caafb609-8bef-4840-a080-81537356fc60@I-love.SAKURA.ne.jp [2]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2024-09-24 22:35:30 +09:00
Tetsuo Handa
268225a1de tomoyo: preparation step for building as a loadable LSM module
In order to allow Makefile to generate tomoyo.ko as output, rename
tomoyo.c to hooks.h and cut out LSM hook registration part that will be
built into vmlinux from hooks.h to init.c . Also, update comments and
relocate some variables. No behavior changes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2024-09-23 19:00:21 +09:00
Masahiro Yamada
b1992c3772 kbuild: use $(src) instead of $(srctree)/$(src) for source directory
Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

    src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

  $(obj)     - directory in the object tree
  $(src)     - directory in the source tree  (changed by this commit)
  $(objtree) - the top of the kernel object tree
  $(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2024-05-10 04:34:52 +09:00
Masahiro Yamada
80f8be7af0 tomoyo: Omit use of bin2c
bin2c was, as its name implies, introduced to convert a binary file to
C code.

However, I did not see any good reason ever for using this tool because
using the .incbin directive is much faster, and often results in simpler
code.

Most of the uses of bin2c have been killed, for example:

  - 13610aa908 ("kernel/configs: use .incbin directive to embed config_data.gz")
  - 4c0f032d49 ("s390/purgatory: Omit use of bin2c")

security/tomoyo/Makefile has even less reason for using bin2c because
the policy files are text data. So, sed is enough for converting them
to C string literals, and what is nicer, generates human-readable
builtin-policy.h.

This is the last user of bin2c. After this commit lands, bin2c will be
removed.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
[penguin-kernel: Update sed script to also escape backslash and quote ]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2023-01-09 21:46:50 +09:00
Masahiro Yamada
df4840c1b8 tomoyo: avoid unneeded creation of builtin-policy.h
When CONFIG_SECURITY_TOMOYO_INSECURE_BUILTIN_SETTING=y,
builtin-policy.h is unneeded.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2023-01-07 21:31:35 +09:00
Masahiro Yamada
eaf2213ba5 tomoyo: fix broken dependency on *.conf.default
If *.conf.default is updated, builtin-policy.h should be rebuilt,
but this does not work when compiled with O= option.

[Without this commit]

  $ touch security/tomoyo/policy/exception_policy.conf.default
  $ make O=/tmp security/tomoyo/
  make[1]: Entering directory '/tmp'
    GEN     Makefile
    CALL    /home/masahiro/ref/linux/scripts/checksyscalls.sh
    DESCEND objtool
  make[1]: Leaving directory '/tmp'

[With this commit]

  $ touch security/tomoyo/policy/exception_policy.conf.default
  $ make O=/tmp security/tomoyo/
  make[1]: Entering directory '/tmp'
    GEN     Makefile
    CALL    /home/masahiro/ref/linux/scripts/checksyscalls.sh
    DESCEND objtool
    POLICY  security/tomoyo/builtin-policy.h
    CC      security/tomoyo/common.o
    AR      security/tomoyo/built-in.a
  make[1]: Leaving directory '/tmp'

$(srctree)/ is essential because $(wildcard ) does not follow VPATH.

Fixes: f02dee2d14 ("tomoyo: Do not generate empty policy files")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2023-01-07 21:30:48 +09:00
Masahiro Yamada
c417fbce98 kbuild: move bin2c back to scripts/ from scripts/basic/
Commit 8370edea81 ("bin2c: move bin2c in scripts/basic") moved bin2c
to the scripts/basic/ directory, incorrectly stating "Kexec wants to
use bin2c and it wants to use it really early in the build process.
See arch/x86/purgatory/ code in later patches."

Commit bdab125c93 ("Revert "kexec/purgatory: Add clean-up for
purgatory directory"") and commit d6605b6bbe ("x86/build: Remove
unnecessary preparation for purgatory") removed the redundant
purgatory build magic entirely.

That means that the move of bin2c was unnecessary in the first place.

fixdep is the only host program that deserves to sit in the
scripts/basic/ directory.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-07-18 01:18:05 +09:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Michal Marek
f02dee2d14 tomoyo: Do not generate empty policy files
The Makefile automatically generates the tomoyo policy files, which are
not removed by make clean (because they could have been provided by the
user). Instead of generating the missing files, use /dev/null if a
given file is not provided. Store the default exception_policy in
exception_policy.conf.default.

Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-04-07 21:27:45 +02:00
Michal Marek
bf7a9ab43c tomoyo: Use if_changed when generating builtin-policy.h
Combine the generation of builtin-policy.h into a single command and use
if_changed, so that the file is regenerated each time the command
changes. The next patch will make use of this.

Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-04-07 21:27:45 +02:00
Michal Marek
7e114bbf51 tomoyo: Use bin2c to generate builtin-policy.h
Simplify the Makefile by using a readily available tool instead of a
custom sed script. The downside is that builtin-policy.h becomes
unreadable for humans, but it is only a generated file.

Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Michal Marek <mmarek@suse.cz>
2015-04-07 21:27:45 +02:00
Tetsuo Handa
843d183cdd TOMOYO: Bump version.
Tell userland tools that this is TOMOYO 2.5.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2011-09-15 08:14:21 +10:00
Tetsuo Handa
059d84dbb3 TOMOYO: Add socket operation restriction support.
This patch adds support for permission checks for PF_INET/PF_INET6/PF_UNIX
socket's bind()/listen()/connect()/send() operations.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2011-09-14 08:27:05 +10:00
Tetsuo Handa
d58e0da854 TOMOYO: Add environment variable name restriction support.
This patch adds support for checking environment variable's names.
Although TOMOYO already provides ability to check argv[]/envp[] passed to
execve() requests,

  file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="bar"

will reject execution of /bin/sh if environment variable LD_LIBRARY_PATH is not
defined. To grant execution of /bin/sh if LD_LIBRARY_PATH is not defined,
administrators have to specify like

  file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]="/system/lib"
  file execute /bin/sh exec.envp["LD_LIBRARY_PATH"]=NULL

. Since there are many environment variables whereas conditional checks are
applied as "&&", it is difficult to cover all combinations. Therefore, this
patch supports conditional checks that are applied as "||", by specifying like

  file execute /bin/sh
  misc env LD_LIBRARY_PATH exec.envp["LD_LIBRARY_PATH"]="/system/lib"

which means "grant execution of /bin/sh if environment variable is not defined
or is defined and its value is /system/lib".

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2011-09-14 08:27:05 +10:00
Tetsuo Handa
2066a36125 TOMOYO: Allow using UID/GID etc. of current thread as conditions.
This patch adds support for permission checks using current thread's UID/GID
etc. in addition to pathnames.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2011-07-11 11:05:32 +10:00
Tetsuo Handa
efe836ab2b TOMOYO: Add built-in policy support.
To be able to start using enforcing mode from the early stage of boot sequence,
this patch adds support for built-in policy configuration (and next patch adds
support for activating access control without calling external policy loader
program).

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2011-06-29 09:31:22 +10:00
Tetsuo Handa
eadd99cc85 TOMOYO: Add auditing interface.
Add /sys/kernel/security/tomoyo/audit interface. This interface generates audit
logs in the form of domain policy so that /usr/sbin/tomoyo-auditd can reuse
audit logs for appending to /sys/kernel/security/tomoyo/domain_policy
interface.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2011-06-29 09:31:20 +10:00
Tetsuo Handa
7c2ea22e3c TOMOYO: Merge path_group and number_group.
Use common code for "path_group" and "number_group".

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:34:42 +10:00
Tetsuo Handa
c3ef1500ec TOMOYO: Split files into some pieces.
security/tomoyo/common.c became too large to read.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:33:39 +10:00
Tetsuo Handa
2106ccd972 TOMOYO: Add mount restriction.
mount(2) has three string and one numeric parameters.
Split mount restriction code from security/tomoyo/file.c .

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:33:37 +10:00
Tetsuo Handa
4c3e9e2ded TOMOYO: Add numeric values grouping support.
This patch adds numeric values grouping support, which is useful for grouping
numeric values such as file's UID, DAC's mode, ioctl()'s cmd number.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:33:35 +10:00
Tetsuo Handa
7762fbfffd TOMOYO: Add pathname grouping support.
This patch adds pathname grouping support, which is useful for grouping
pathnames that cannot be represented using /\{dir\}/ pattern.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-05-17 09:25:57 +10:00
Tetsuo Handa
847b173ea3 TOMOYO: Add garbage collector.
This patch adds garbage collector support to TOMOYO.
Elements are protected by "struct srcu_struct tomoyo_ss".

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-02-15 09:00:24 +11:00
Kentaro Takeda
00d7d6f840 Kconfig and Makefile
TOMOYO uses LSM hooks for pathname based access control and securityfs support.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 15:19:00 +11:00