[PATCH v17 00/10] Landlock LSM
Mickaël Salaün
mic at digikod.net
Mon May 11 19:21:46 UTC 2020
Hi,
This new patch series brings some improvements and add new tests:
Use smaller userspace structures (attributes) to save space, and check
at built time that every attribute don't contain hole and are 8-bits
aligned.
Allow enforcement of empty ruleset, which enables deny-all policies
(useful for strict sandboxes).
I found that UML may not keep the same internal struct inode for an open
file. Because the Landlock filesystem access-control relies on internal
kernel states, special architectures such as UML can't support Landlock.
Add a new ARCH_EPHEMERAL_STATES to identify such architectures.
Add a size_attr_features field to struct landlock_attr_features for
self-introspection
Switch syscall attribute pointer and size arguments to follow similar
syscalls argument order (e.g. bpf, clone3, openat2).
The SLOC count is 1288 for security/landlock/ and 1740 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.
The compiled documentation is available here:
https://landlock.io/linux-doc/landlock-v17/security/landlock/index.html
This series can be applied on top of v5.7-rc5. This can be tested with
CONFIG_SECURITY_LANDLOCK and CONFIG_SAMPLE_LANDLOCK. This patch series
can be found in a Git repository here:
https://github.com/landlock-lsm/linux/commits/landlock-v17
I would really appreciate constructive comments on this patch series.
# 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 [2], 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.
Previous version:
https://lore.kernel.org/lkml/20200416103955.145757-1-mic@digikod.net/
[1] https://lore.kernel.org/lkml/e07fe473-1801-01cc-12ae-b3167f95250e@digikod.net/
[2] https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler-ca.com/
Regards,
Mickaël Salaün (10):
landlock: Add object management
landlock: Add ruleset and domain management
landlock: Set up the security framework and manage credentials
landlock: Add ptrace restrictions
fs,landlock: Support filesystem access-control
landlock: Add syscall implementation
arch: Wire up landlock() syscall
selftests/landlock: Add initial tests
samples/landlock: Add a sandbox manager example
landlock: Add user and kernel documentation
Documentation/security/index.rst | 1 +
Documentation/security/landlock/index.rst | 18 +
Documentation/security/landlock/kernel.rst | 69 +
Documentation/security/landlock/user.rst | 268 +++
MAINTAINERS | 12 +
arch/Kconfig | 7 +
arch/alpha/kernel/syscalls/syscall.tbl | 1 +
arch/arm/tools/syscall.tbl | 1 +
arch/arm64/include/asm/unistd.h | 2 +-
arch/arm64/include/asm/unistd32.h | 2 +
arch/ia64/kernel/syscalls/syscall.tbl | 1 +
arch/m68k/kernel/syscalls/syscall.tbl | 1 +
arch/microblaze/kernel/syscalls/syscall.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n32.tbl | 1 +
arch/mips/kernel/syscalls/syscall_n64.tbl | 1 +
arch/mips/kernel/syscalls/syscall_o32.tbl | 1 +
arch/parisc/kernel/syscalls/syscall.tbl | 1 +
arch/powerpc/kernel/syscalls/syscall.tbl | 1 +
arch/s390/kernel/syscalls/syscall.tbl | 1 +
arch/sh/kernel/syscalls/syscall.tbl | 1 +
arch/sparc/kernel/syscalls/syscall.tbl | 1 +
arch/um/Kconfig | 1 +
arch/x86/entry/syscalls/syscall_32.tbl | 1 +
arch/x86/entry/syscalls/syscall_64.tbl | 1 +
arch/xtensa/kernel/syscalls/syscall.tbl | 1 +
fs/super.c | 2 +
include/linux/fs.h | 5 +
include/linux/landlock.h | 22 +
include/linux/syscalls.h | 3 +
include/uapi/asm-generic/unistd.h | 4 +-
include/uapi/linux/landlock.h | 302 +++
kernel/sys_ni.c | 3 +
samples/Kconfig | 7 +
samples/Makefile | 1 +
samples/landlock/.gitignore | 1 +
samples/landlock/Makefile | 15 +
samples/landlock/sandboxer.c | 228 +++
security/Kconfig | 11 +-
security/Makefile | 2 +
security/landlock/Kconfig | 18 +
security/landlock/Makefile | 4 +
security/landlock/common.h | 20 +
security/landlock/cred.c | 46 +
security/landlock/cred.h | 58 +
security/landlock/fs.c | 601 ++++++
security/landlock/fs.h | 42 +
security/landlock/object.c | 66 +
security/landlock/object.h | 91 +
security/landlock/ptrace.c | 120 ++
security/landlock/ptrace.h | 14 +
security/landlock/ruleset.c | 342 ++++
security/landlock/ruleset.h | 161 ++
security/landlock/setup.c | 39 +
security/landlock/setup.h | 18 +
security/landlock/syscall.c | 532 +++++
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/landlock/.gitignore | 2 +
tools/testing/selftests/landlock/Makefile | 29 +
tools/testing/selftests/landlock/base_test.c | 170 ++
tools/testing/selftests/landlock/common.h | 108 +
tools/testing/selftests/landlock/config | 5 +
tools/testing/selftests/landlock/fs_test.c | 1729 +++++++++++++++++
.../testing/selftests/landlock/ptrace_test.c | 293 +++
tools/testing/selftests/landlock/true.c | 5 +
64 files changed, 5509 insertions(+), 7 deletions(-)
create mode 100644 Documentation/security/landlock/index.rst
create mode 100644 Documentation/security/landlock/kernel.rst
create mode 100644 Documentation/security/landlock/user.rst
create mode 100644 include/linux/landlock.h
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/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/syscall.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
--
2.26.2
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