mbox series

[v31,00/12] Landlock LSM

Message ID 20210324191520.125779-1-mic@digikod.net (mailing list archive)
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Series Landlock LSM | expand

Message

Mickaël Salaün March 24, 2021, 7:15 p.m. UTC 
Hi,

This updated patch series fixes minor issues in the filesystem handling,
renames a function, improves documentation, and synchronizes syscall
numbers with -next.

The SLOC count is 1327 for security/landlock/ and 2590 for
tools/testing/selftest/landlock/ .  Test coverage for security/landlock/
is 93.6% of lines.  The code not covered only deals with internal kernel
errors (e.g. memory allocation) and race conditions.  This series is
being fuzzed by syzkaller (covering internal kernel errors) that now
supports Landlock: https://github.com/google/syzkaller/pull/2380

The compiled documentation is available here:
https://landlock.io/linux-doc/landlock-v31/userspace-api/landlock.html

This series can be applied on top of v5.12-rc3 .  This can be tested with
CONFIG_SECURITY_LANDLOCK, CONFIG_SAMPLE_LANDLOCK and by prepending
"landlock," to CONFIG_LSM.  This patch series can be found in a Git
repository here:
https://github.com/landlock-lsm/linux/commits/landlock-v31
This patch series seems ready for upstream and I would really appreciate
final reviews.


Landlock LSM
------------

The goal of Landlock is to enable to restrict ambient rights (e.g.
global filesystem access) for a set of processes.  Because Landlock is a
stackable LSM [1], it makes possible to create safe security sandboxes
as new security layers in addition to the existing system-wide
access-controls. This kind of sandbox is expected to help mitigate the
security impact of bugs or unexpected/malicious behaviors in user-space
applications. Landlock empowers any process, including unprivileged
ones, to securely restrict themselves.

Landlock is inspired by seccomp-bpf but instead of filtering syscalls
and their raw arguments, a Landlock rule can restrict the use of kernel
objects like file hierarchies, according to the kernel semantic.
Landlock also takes inspiration from other OS sandbox mechanisms: XNU
Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil.

In this current form, Landlock misses some access-control features.
This enables to minimize this patch series and ease review.  This series
still addresses multiple use cases, especially with the combined use of
seccomp-bpf: applications with built-in sandboxing, init systems,
security sandbox tools and security-oriented APIs [2].

[1] https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/
[2] https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.net/

Previous versions:
v30: https://lore.kernel.org/lkml/20210316204252.427806-1-mic@digikod.net/
v29: https://lore.kernel.org/lkml/20210225190614.2181147-1-mic@digikod.net/
v28: https://lore.kernel.org/lkml/20210202162710.657398-1-mic@digikod.net/
v27: https://lore.kernel.org/lkml/20210121205119.793296-1-mic@digikod.net/
v26: https://lore.kernel.org/lkml/20201209192839.1396820-1-mic@digikod.net/
v25: https://lore.kernel.org/lkml/20201201192322.213239-1-mic@digikod.net/
v24: https://lore.kernel.org/lkml/20201112205141.775752-1-mic@digikod.net/
v23: https://lore.kernel.org/lkml/20201103182109.1014179-1-mic@digikod.net/
v22: https://lore.kernel.org/lkml/20201027200358.557003-1-mic@digikod.net/
v21: https://lore.kernel.org/lkml/20201008153103.1155388-1-mic@digikod.net/
v20: https://lore.kernel.org/lkml/20200802215903.91936-1-mic@digikod.net/
v19: https://lore.kernel.org/lkml/20200707180955.53024-1-mic@digikod.net/
v18: https://lore.kernel.org/lkml/20200526205322.23465-1-mic@digikod.net/
v17: https://lore.kernel.org/lkml/20200511192156.1618284-1-mic@digikod.net/
v16: https://lore.kernel.org/lkml/20200416103955.145757-1-mic@digikod.net/
v15: https://lore.kernel.org/lkml/20200326202731.693608-1-mic@digikod.net/
v14: https://lore.kernel.org/lkml/20200224160215.4136-1-mic@digikod.net/
v13: https://lore.kernel.org/lkml/20191104172146.30797-1-mic@digikod.net/
v12: https://lore.kernel.org/lkml/20191031164445.29426-1-mic@digikod.net/
v11: https://lore.kernel.org/lkml/20191029171505.6650-1-mic@digikod.net/
v10: https://lore.kernel.org/lkml/20190721213116.23476-1-mic@digikod.net/
v9: https://lore.kernel.org/lkml/20190625215239.11136-1-mic@digikod.net/
v8: https://lore.kernel.org/lkml/20180227004121.3633-1-mic@digikod.net/
v7: https://lore.kernel.org/lkml/20170821000933.13024-1-mic@digikod.net/
v6: https://lore.kernel.org/lkml/20170328234650.19695-1-mic@digikod.net/
v5: https://lore.kernel.org/lkml/20170222012632.4196-1-mic@digikod.net/
v4: https://lore.kernel.org/lkml/20161026065654.19166-1-mic@digikod.net/
v3: https://lore.kernel.org/lkml/20160914072415.26021-1-mic@digikod.net/
v2: https://lore.kernel.org/lkml/1472121165-29071-1-git-send-email-mic@digikod.net/
v1: https://lore.kernel.org/kernel-hardening/1458784008-16277-1-git-send-email-mic@digikod.net/

Casey Schaufler (1):
  LSM: Infrastructure management of the superblock

Mickaël Salaün (11):
  landlock: Add object management
  landlock: Add ruleset and domain management
  landlock: Set up the security framework and manage credentials
  landlock: Add ptrace restrictions
  fs,security: Add sb_delete hook
  landlock: Support filesystem access-control
  landlock: Add syscall implementations
  arch: Wire up Landlock syscalls
  selftests/landlock: Add user space tests
  samples/landlock: Add a sandbox manager example
  landlock: Add user and kernel documentation

 Documentation/security/index.rst              |    1 +
 Documentation/security/landlock.rst           |   85 +
 Documentation/userspace-api/index.rst         |    1 +
 Documentation/userspace-api/landlock.rst      |  311 ++
 MAINTAINERS                                   |   15 +
 arch/Kconfig                                  |    7 +
 arch/alpha/kernel/syscalls/syscall.tbl        |    3 +
 arch/arm/tools/syscall.tbl                    |    3 +
 arch/arm64/include/asm/unistd.h               |    2 +-
 arch/arm64/include/asm/unistd32.h             |    6 +
 arch/ia64/kernel/syscalls/syscall.tbl         |    3 +
 arch/m68k/kernel/syscalls/syscall.tbl         |    3 +
 arch/microblaze/kernel/syscalls/syscall.tbl   |    3 +
 arch/mips/kernel/syscalls/syscall_n32.tbl     |    3 +
 arch/mips/kernel/syscalls/syscall_n64.tbl     |    3 +
 arch/mips/kernel/syscalls/syscall_o32.tbl     |    3 +
 arch/parisc/kernel/syscalls/syscall.tbl       |    3 +
 arch/powerpc/kernel/syscalls/syscall.tbl      |    3 +
 arch/s390/kernel/syscalls/syscall.tbl         |    3 +
 arch/sh/kernel/syscalls/syscall.tbl           |    3 +
 arch/sparc/kernel/syscalls/syscall.tbl        |    3 +
 arch/um/Kconfig                               |    1 +
 arch/x86/entry/syscalls/syscall_32.tbl        |    3 +
 arch/x86/entry/syscalls/syscall_64.tbl        |    3 +
 arch/xtensa/kernel/syscalls/syscall.tbl       |    3 +
 fs/super.c                                    |    1 +
 include/linux/lsm_hook_defs.h                 |    1 +
 include/linux/lsm_hooks.h                     |    4 +
 include/linux/security.h                      |    4 +
 include/linux/syscalls.h                      |    7 +
 include/uapi/asm-generic/unistd.h             |    8 +-
 include/uapi/linux/landlock.h                 |  128 +
 kernel/sys_ni.c                               |    5 +
 samples/Kconfig                               |    7 +
 samples/Makefile                              |    1 +
 samples/landlock/.gitignore                   |    1 +
 samples/landlock/Makefile                     |   13 +
 samples/landlock/sandboxer.c                  |  238 ++
 security/Kconfig                              |   11 +-
 security/Makefile                             |    2 +
 security/landlock/Kconfig                     |   21 +
 security/landlock/Makefile                    |    4 +
 security/landlock/common.h                    |   20 +
 security/landlock/cred.c                      |   46 +
 security/landlock/cred.h                      |   58 +
 security/landlock/fs.c                        |  693 ++++
 security/landlock/fs.h                        |   70 +
 security/landlock/limits.h                    |   21 +
 security/landlock/object.c                    |   67 +
 security/landlock/object.h                    |   91 +
 security/landlock/ptrace.c                    |  120 +
 security/landlock/ptrace.h                    |   14 +
 security/landlock/ruleset.c                   |  473 +++
 security/landlock/ruleset.h                   |  165 +
 security/landlock/setup.c                     |   40 +
 security/landlock/setup.h                     |   18 +
 security/landlock/syscalls.c                  |  445 +++
 security/security.c                           |   51 +-
 security/selinux/hooks.c                      |   58 +-
 security/selinux/include/objsec.h             |    6 +
 security/selinux/ss/services.c                |    3 +-
 security/smack/smack.h                        |    6 +
 security/smack/smack_lsm.c                    |   35 +-
 tools/testing/selftests/Makefile              |    1 +
 tools/testing/selftests/landlock/.gitignore   |    2 +
 tools/testing/selftests/landlock/Makefile     |   24 +
 tools/testing/selftests/landlock/base_test.c  |  219 ++
 tools/testing/selftests/landlock/common.h     |  183 ++
 tools/testing/selftests/landlock/config       |    7 +
 tools/testing/selftests/landlock/fs_test.c    | 2792 +++++++++++++++++
 .../testing/selftests/landlock/ptrace_test.c  |  337 ++
 tools/testing/selftests/landlock/true.c       |    5 +
 72 files changed, 6926 insertions(+), 77 deletions(-)
 create mode 100644 Documentation/security/landlock.rst
 create mode 100644 Documentation/userspace-api/landlock.rst
 create mode 100644 include/uapi/linux/landlock.h
 create mode 100644 samples/landlock/.gitignore
 create mode 100644 samples/landlock/Makefile
 create mode 100644 samples/landlock/sandboxer.c
 create mode 100644 security/landlock/Kconfig
 create mode 100644 security/landlock/Makefile
 create mode 100644 security/landlock/common.h
 create mode 100644 security/landlock/cred.c
 create mode 100644 security/landlock/cred.h
 create mode 100644 security/landlock/fs.c
 create mode 100644 security/landlock/fs.h
 create mode 100644 security/landlock/limits.h
 create mode 100644 security/landlock/object.c
 create mode 100644 security/landlock/object.h
 create mode 100644 security/landlock/ptrace.c
 create mode 100644 security/landlock/ptrace.h
 create mode 100644 security/landlock/ruleset.c
 create mode 100644 security/landlock/ruleset.h
 create mode 100644 security/landlock/setup.c
 create mode 100644 security/landlock/setup.h
 create mode 100644 security/landlock/syscalls.c
 create mode 100644 tools/testing/selftests/landlock/.gitignore
 create mode 100644 tools/testing/selftests/landlock/Makefile
 create mode 100644 tools/testing/selftests/landlock/base_test.c
 create mode 100644 tools/testing/selftests/landlock/common.h
 create mode 100644 tools/testing/selftests/landlock/config
 create mode 100644 tools/testing/selftests/landlock/fs_test.c
 create mode 100644 tools/testing/selftests/landlock/ptrace_test.c
 create mode 100644 tools/testing/selftests/landlock/true.c


base-commit: 1e28eed17697bcf343c6743f0028cc3b5dd88bf0

Comments

Kees Cook March 26, 2021, 4:30 a.m. UTC | #1 
On Wed, Mar 24, 2021 at 08:15:18PM +0100, Mickaël Salaün wrote:
> From: Mickaël Salaün <mic@linux.microsoft.com>
> 
> Test all Landlock system calls, ptrace hooks semantic and filesystem
> access-control with multiple layouts.
> 
> Test coverage for security/landlock/ is 93.6% of lines.  The code not
> covered only deals with internal kernel errors (e.g. memory allocation)
> and race conditions.
> 
> Cc: James Morris <jmorris@namei.org>
> Cc: Jann Horn <jannh@google.com>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Serge E. Hallyn <serge@hallyn.com>
> Cc: Shuah Khan <shuah@kernel.org>
> Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>

Reviewed-by: Kees Cook <keescook@chromium.org>