[PATCH v29 00/12] Landlock LSM
From: Mickaël Salaün
Date: Thu Feb 25 2021 - 14:09:42 EST
Hi,
This patch series mainly fixes race condition issues, explains specific
lock rules and improves code related to concurrent calls of
hook_sb_delete() and release_inode(). I exploited these races to
validate the fixes. Userspace tests are also improved along with some
commit messages and comments. Serge Hallyn's review is taken into
account and his Acked-by are added to the corresponding patches.
The SLOC count is 1328 for security/landlock/ and 2539 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 (which may cover internal kernel errors), and
patches are on their way: https://github.com/google/syzkaller/pull/2380
The compiled documentation is available here:
https://landlock.io/linux-doc/landlock-v29/userspace-api/landlock.html
This series can be applied on top of v5.11-7592-g1a3a9ffb27bb (Linus's
master branch from Sunday). 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-v29
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].
Previous version:
https://lore.kernel.org/lkml/20210202162710.657398-1-mic@xxxxxxxxxxx/
[1] https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@xxxxxxxxxxxxxxxx/
[2] https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@xxxxxxxxxxx/
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 | 79 +
Documentation/userspace-api/index.rst | 1 +
Documentation/userspace-api/landlock.rst | 307 ++
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 | 686 +++++
security/landlock/fs.h | 56 +
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 | 2724 +++++++++++++++++
.../testing/selftests/landlock/ptrace_test.c | 337 ++
tools/testing/selftests/landlock/true.c | 5 +
72 files changed, 6827 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: 31caf8b2a847214be856f843e251fc2ed2cd1075
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2.30.0