[ Upstream commit e1a57c3359 ]
Remove bind() call on a client socket that doesn't make sense.
Since strlen(cli_un.sun_path) returns a random value depending on stack
garbage, that many uninitialized bytes are read from the stack as an
unix socket address. This creates random test failures due to the bind
address being invalid or already in use if the same stack value comes up
twice.
Fixes: f83d51a5bd ("selftests/landlock: Check IOCTL restrictions for named UNIX domain sockets")
Signed-off-by: Matthieu Buffet <matthieu@buffet.re>
Reviewed-by: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20251201003631.190817-1-matthieu@buffet.re
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit bd09d9a05c ]
The nominal error code for bind(AF_UNSPEC) on an IPv6 socket
is -EAFNOSUPPORT, not -EINVAL. -EINVAL is only returned when
the supplied address struct is too short, which happens to be
the case in current selftests because they treat AF_UNSPEC
like IPv4 sockets do: as an alias for AF_INET (which is a
16-byte struct instead of the 24 bytes required by IPv6
sockets).
Make the union large enough for any address (by adding struct
sockaddr_storage to the union), and make AF_UNSPEC addresses
large enough for any family.
Test for -EAFNOSUPPORT instead, and add a dedicated test case
for truncated inputs with -EINVAL.
Fixes: a549d055a2 ("selftests/landlock: Add network tests")
Signed-off-by: Matthieu Buffet <matthieu@buffet.re>
Link: https://lore.kernel.org/r/20251027190726.626244-2-matthieu@buffet.re
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit c5efa393d8 upstream.
The new signal_scoping_thread_setuid tests check that the libc's
setuid() function works as expected even when a thread is sandboxed with
scoped signal restrictions.
Before the signal scoping fix, this test would have failed with the
setuid() call:
[pid 65] getpid() = 65
[pid 65] tgkill(65, 66, SIGRT_1) = -1 EPERM (Operation not permitted)
[pid 65] futex(0x40a66cdc, FUTEX_WAKE_PRIVATE, 1) = 0
[pid 65] setuid(1001) = 0
After the fix, tgkill(2) is successfully leveraged to synchronize
credentials update across threads:
[pid 65] getpid() = 65
[pid 65] tgkill(65, 66, SIGRT_1) = 0
[pid 66] <... read resumed>0x40a65eb7, 1) = ? ERESTARTSYS (To be restarted if SA_RESTART is set)
[pid 66] --- SIGRT_1 {si_signo=SIGRT_1, si_code=SI_TKILL, si_pid=65, si_uid=1000} ---
[pid 66] getpid() = 65
[pid 66] setuid(1001) = 0
[pid 66] futex(0x40a66cdc, FUTEX_WAKE_PRIVATE, 1) = 0
[pid 66] rt_sigreturn({mask=[]}) = 0
[pid 66] read(3, <unfinished ...>
[pid 65] setuid(1001) = 0
Test coverage for security/landlock is 92.9% of 1137 lines according to
gcc/gcov-14.
Fixes: c899496501 ("selftests/landlock: Test signal scoping for threads")
Cc: Günther Noack <gnoack@google.com>
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250318161443.279194-8-mic@digikod.net
[mic: Update test coverage]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 18eb75f3af upstream.
Because Linux credentials are managed per thread, user space relies on
some hack to synchronize credential update across threads from the same
process. This is required by the Native POSIX Threads Library and
implemented by set*id(2) wrappers and libcap(3) to use tgkill(2) to
synchronize threads. See nptl(7) and libpsx(3). Furthermore, some
runtimes like Go do not enable developers to have control over threads
[1].
To avoid potential issues, and because threads are not security
boundaries, let's relax the Landlock (optional) signal scoping to always
allow signals sent between threads of the same process. This exception
is similar to the __ptrace_may_access() one.
hook_file_set_fowner() now checks if the target task is part of the same
process as the caller. If this is the case, then the related signal
triggered by the socket will always be allowed.
Scoping of abstract UNIX sockets is not changed because kernel objects
(e.g. sockets) should be tied to their creator's domain at creation
time.
Note that creating one Landlock domain per thread puts each of these
threads (and their future children) in their own scope, which is
probably not what users expect, especially in Go where we do not control
threads. However, being able to drop permissions on all threads should
not be restricted by signal scoping. We are working on a way to make it
possible to atomically restrict all threads of a process with the same
domain [2].
Add erratum for signal scoping.
Closes: https://github.com/landlock-lsm/go-landlock/issues/36
Fixes: 54a6e6bbf3 ("landlock: Add signal scoping")
Fixes: c899496501 ("selftests/landlock: Test signal scoping for threads")
Depends-on: 26f204380a ("fs: Fix file_set_fowner LSM hook inconsistencies")
Link: https://pkg.go.dev/kernel.org/pub/linux/libs/security/libcap/psx [1]
Link: https://github.com/landlock-lsm/linux/issues/2 [2]
Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20250318161443.279194-6-mic@digikod.net
[mic: Add extra pointer check and RCU guard, and ease backport]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 15383a0d63 upstream.
Some fixes may require user space to check if they are applied on the
running kernel before using a specific feature. For instance, this
applies when a restriction was previously too restrictive and is now
getting relaxed (e.g. for compatibility reasons). However, non-visible
changes for legitimate use (e.g. security fixes) do not require an
erratum.
Because fixes are backported down to a specific Landlock ABI, we need a
way to avoid cherry-pick conflicts. The solution is to only update a
file related to the lower ABI impacted by this issue. All the ABI files
are then used to create a bitmask of fixes.
The new errata interface is similar to the one used to get the supported
Landlock ABI version, but it returns a bitmask instead because the order
of fixes may not match the order of versions, and not all fixes may
apply to all versions.
The actual errata will come with dedicated commits. The description is
not actually used in the code but serves as documentation.
Create the landlock_abi_version symbol and use its value to check errata
consistency.
Update test_base's create_ruleset_checks_ordering tests and add errata
tests.
This commit is backportable down to the first version of Landlock.
Fixes: 3532b0b435 ("landlock: Enable user space to infer supported features")
Cc: Günther Noack <gnoack@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250318161443.279194-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a test to verify that the SIGURG signal created by an out-of-bound
message in UNIX sockets is well controlled by the file_send_sigiotask
hook.
Test coverage for security/landlock is 92.2% of 1046 lines according to
gcc/gcov-14.
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/50daeed4d4f60d71e9564d0f24004a373fc5f7d5.1725657728.git.fahimitahera@gmail.com
[mic: Improve commit message and add test coverage, improve test with
four variants to fully cover the hook, use abstract unix socket to avoid
managing a file, use dedicated variable per process, add comments, avoid
negative ASSERT, move close calls]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Provide tests for the signal scoping. If the signal is 0, no signal
will be sent, but the permission of a process to send a signal will be
checked. Likewise, this test consider one signal for each signal
category: SIGTRAP, SIGURG, SIGHUP, and SIGTSTP.
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/15dc202bb7f0a462ddeaa0c1cd630d2a7c6fa5c5.1725657728.git.fahimitahera@gmail.com
[mic: Fix commit message, use dedicated variables per process, properly
close FDs, extend send_sig_to_parent to make sure scoping works as
expected]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Currently, a sandbox process is not restricted to sending a signal (e.g.
SIGKILL) to a process outside the sandbox environment. The ability to
send a signal for a sandboxed process should be scoped the same way
abstract UNIX sockets are scoped. Therefore, we extend the "scoped"
field in a ruleset with LANDLOCK_SCOPE_SIGNAL to specify that a ruleset
will deny sending any signal from within a sandbox process to its parent
(i.e. any parent sandbox or non-sandboxed processes).
This patch adds file_set_fowner and file_free_security hooks to set and
release a pointer to the file owner's domain. This pointer, fown_domain
in landlock_file_security will be used in file_send_sigiotask to check
if the process can send a signal.
The ruleset_with_unknown_scope test is updated to support
LANDLOCK_SCOPE_SIGNAL.
This depends on two new changes:
- commit 1934b21261 ("file: reclaim 24 bytes from f_owner"): replace
container_of(fown, struct file, f_owner) with fown->file .
- commit 26f204380a ("fs: Fix file_set_fowner LSM hook
inconsistencies"): lock before calling the hook.
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Closes: https://github.com/landlock-lsm/linux/issues/8
Link: https://lore.kernel.org/r/df2b4f880a2ed3042992689a793ea0951f6798a5.1725657727.git.fahimitahera@gmail.com
[mic: Update landlock_get_current_domain()'s return type, improve and
fix locking in hook_file_set_fowner(), simplify and fix sleepable call
and locking issue in hook_file_send_sigiotask() and rebase on the latest
VFS tree, simplify hook_task_kill() and quickly return when not
sandboxed, improve comments, rename LANDLOCK_SCOPED_SIGNAL]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
A socket can be shared between multiple processes, so it can connect and
send data to them. Provide a test scenario where a sandboxed process
inherits a socket's file descriptor. The process cannot connect or send
data to the inherited socket since the process is scoped.
Test coverage for security/landlock is 92.0% of 1013 lines according to
gcc/gcov-14.
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/1428574deec13603b6ab2f2ed68ecbfa3b63bcb3.1725494372.git.fahimitahera@gmail.com
[mic: Remove negative ASSERT, fix potential race condition because of
closed connections, remove useless buffer, add test coverage]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Expand abstract UNIX socket restriction tests by examining different
scenarios for UNIX sockets with pathname or unnamed address formats
connection with scoped domain.
The various_address_sockets tests ensure that UNIX sockets bound to a
filesystem pathname and unnamed sockets created by socketpair can still
connect to a socket outside of their scoped domain, meaning that even if
the domain is scoped with LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET, the
socket can connect to a socket outside the scoped domain.
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/a9e8016aaa5846252623b158c8f1ce0d666944f4.1725494372.git.fahimitahera@gmail.com
[mic: Remove useless clang-format tags, fix unlink/rmdir calls, drop
capabilities, rename variables, remove useless mknod/unlink calls, clean
up fixture, test write/read on sockets, test sendto() on datagram
sockets, close sockets as soon as possible]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Add three tests that examine different scenarios for abstract UNIX
socket:
1) scoped_domains: Base tests of the abstract socket scoping mechanism
for a landlocked process, same as the ptrace test.
2) scoped_vs_unscoped: Generates three processes with different domains
and tests if a process with a non-scoped domain can connect to other
processes.
3) outside_socket: Since the socket's creator credentials are used
for scoping sockets, this test examines the cases where the socket's
credentials are different from the process using it.
Move protocol_variant, service_fixture, and sys_gettid() from net_test.c
to common.h, and factor out code into a new set_unix_address() helper.
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/9321c3d3bcd9212ceb4b50693e29349f8d625e16.1725494372.git.fahimitahera@gmail.com
[mic: Fix commit message, remove useless clang-format tags, move
drop_caps() calls, move and rename variables, rename variants, use more
EXPECT, improve comments, simplify the outside_socket test]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Introduces the LANDLOCK_ACCESS_FS_IOCTL_DEV right
and increments the Landlock ABI version to 5.
This access right applies to device-custom IOCTL commands
when they are invoked on block or character device files.
Like the truncate right, this right is associated with a file
descriptor at the time of open(2), and gets respected even when the
file descriptor is used outside of the thread which it was originally
opened in.
Therefore, a newly enabled Landlock policy does not apply to file
descriptors which are already open.
If the LANDLOCK_ACCESS_FS_IOCTL_DEV right is handled, only a small
number of safe IOCTL commands will be permitted on newly opened device
files. These include FIOCLEX, FIONCLEX, FIONBIO and FIOASYNC, as well
as other IOCTL commands for regular files which are implemented in
fs/ioctl.c.
Noteworthy scenarios which require special attention:
TTY devices are often passed into a process from the parent process,
and so a newly enabled Landlock policy does not retroactively apply to
them automatically. In the past, TTY devices have often supported
IOCTL commands like TIOCSTI and some TIOCLINUX subcommands, which were
letting callers control the TTY input buffer (and simulate
keypresses). This should be restricted to CAP_SYS_ADMIN programs on
modern kernels though.
Known limitations:
The LANDLOCK_ACCESS_FS_IOCTL_DEV access right is a coarse-grained
control over IOCTL commands.
Landlock users may use path-based restrictions in combination with
their knowledge about the file system layout to control what IOCTLs
can be done.
Cc: Paul Moore <paul@paul-moore.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20240419161122.2023765-2-gnoack@google.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Setting the time namespace with CLONE_NEWTIME returns -EUSERS if the
calling thread shares memory with another thread (because of the shared
vDSO), which is the case when it is created with vfork().
Fix pidfd_setns_test by replacing test harness's vfork() call with a
clone3() call with CLONE_VFORK, and an explicit sharing of the
_metadata and self objects.
Replace _metadata->teardown_parent with a new FIXTURE_TEARDOWN_PARENT()
helper that can replace FIXTURE_TEARDOWN(). This is a cleaner approach
and it enables to selectively share the fixture data between the child
process running tests and the parent process running the fixture
teardown. This also avoids updating several tests to not rely on the
self object's copy-on-write property (e.g. storing the returned value of
a fork() call).
Cc: Christian Brauner <brauner@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Günther Noack <gnoack@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202403291015.1fcfa957-oliver.sang@intel.com
Fixes: 0710a1a73f ("selftests/harness: Merge TEST_F_FORK() into TEST_F()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240511171445.904356-10-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Pull landlock updates from Mickaël Salaün:
"Some miscellaneous improvements, including new KUnit tests, extended
documentation and boot help, and some cosmetic cleanups.
Additional test changes already went through the net tree"
* tag 'landlock-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
samples/landlock: Don't error out if a file path cannot be opened
landlock: Use f_cred in security_file_open() hook
landlock: Rename "ptrace" files to "task"
landlock: Simplify current_check_access_socket()
landlock: Warn once if a Landlock action is requested while disabled
landlock: Extend documentation for kernel support
landlock: Add support for KUnit tests
selftests/landlock: Clean up error logs related to capabilities
Always run fixture setup in the grandchild process, and by default also
run the teardown in the same process. However, this change makes it
possible to run the teardown in a parent process when
_metadata->teardown_parent is set to true (e.g. in fixture setup).
Fix TEST_SIGNAL() by forwarding grandchild's signal to its parent. Fix
seccomp tests by running the test setup in the parent of the test
thread, as expected by the related test code. Fix Landlock tests by
waiting for the grandchild before processing _metadata.
Use of exit(3) in tests should be OK because the environment in which
the vfork(2) call happen is already dedicated to the running test (with
flushed stdio, setpgrp() call), see __run_test() and the call to fork(2)
just before running the setup/test/teardown. Even if the test
configures its own exit handlers, they will not be run by the parent
because it never calls exit(3), and the test function either ends with a
call to _exit(2) or a signal.
Cc: Günther Noack <gnoack@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Fixes: 0710a1a73f ("selftests/harness: Merge TEST_F_FORK() into TEST_F()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Reported-by: Mark Brown <broonie@kernel.org>
Tested-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240305201029.1331333-1-mic@digikod.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Instead of tracking passed = 0/1 rename the field to exit_code
and invert the values so that they match the KSFT_* exit codes.
This will allow us to fold SKIP / XFAIL into the same value.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace Landlock-specific TEST_F_FORK() with an improved TEST_F() which
brings four related changes:
Run TEST_F()'s tests in a grandchild process to make it possible to
drop privileges and delegate teardown to the parent.
Compared to TEST_F_FORK(), simplify handling of the test grandchild
process thanks to vfork(2), and makes it generic (e.g. no explicit
conversion between exit code and _metadata).
Compared to TEST_F_FORK(), run teardown even when tests failed with an
assert thanks to commit 63e6b2a423 ("selftests/harness: Run TEARDOWN
for ASSERT failures").
Simplify the test harness code by removing the no_print and step fields
which are not used. I added this feature just after I made
kselftest_harness.h more broadly available but this step counter
remained even though it wasn't needed after all. See commit 369130b631
("selftests: Enhance kselftest_harness.h to print which assert failed").
Replace spaces with tabs in one line of __TEST_F_IMPL().
Cc: Günther Noack <gnoack@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This has the effect of creating a new test process for either TEST_F()
or TEST_F_FORK(), which doesn't change tests but will ease potential
backports. See next commit for the TEST_F_FORK() merge into TEST_F().
Cc: Günther Noack <gnoack@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
CAP_NET_ADMIN allows to configure network interfaces, not CAP_SYS_ADMIN
which only allows to call unshare(2). Without this change, running
network tests as a non-root user but with all capabilities would fail at
the setup_loopback() step with "RTNETLINK answers: Operation not
permitted".
The issue is only visible when running tests with non-root users (i.e.
only relying on ambient capabilities). Indeed, when configuring the
network interface, the "ip" command is called, which may lead to the
special handling of capabilities for the root user by execve(2). If
root is the caller, then the inherited, permitted and effective
capabilities are all reset, which then includes CAP_NET_ADMIN. However,
if a non-root user is the caller, then ambient capabilities are masked
by the inherited ones, which were explicitly dropped.
To make execution deterministic whatever users are running the tests,
set the noroot secure bit for each test, and set the inheritable and
ambient capabilities to CAP_NET_ADMIN, the only capability that may be
required after an execve(2).
Factor out _effective_cap() into _change_cap(), and use it to manage
ambient capabilities with the new set_ambient_cap() and
clear_ambient_cap() helpers.
This makes it possible to run all Landlock tests with check-linux.sh
from https://github.com/landlock-lsm/landlock-test-tools
Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Fixes: a549d055a2 ("selftests/landlock: Add network tests")
Link: https://lore.kernel.org/r/20240125153230.3817165-2-mic@digikod.net
[mic: Make sure SECBIT_NOROOT_LOCKED is set]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
One issue comes up while building selftest/landlock/fs_test on my side
(gcc 7.3/glibc-2.28/kernel-4.19).
gcc -Wall -O2 -isystem fs_test.c -lcap -o selftests/landlock/fs_test
fs_test.c:4575:9: error: initializer element is not constant
.mnt = mnt_tmp,
^~~~~~~
Signed-off-by: Hu Yadi <hu.yadi@h3c.com>
Suggested-by: Jiao <jiaoxupo@h3c.com>
Reviewed-by: Berlin <berlin@h3c.com>
Link: https://lore.kernel.org/r/20240124022908.42100-1-hu.yadi@h3c.com
Fixes: 04f9070e99 ("selftests/landlock: Add tests for pseudo filesystems")
[mic: Factor out mount's data string and make mnt_tmp static]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
One issue comes up while building selftest/landlock/net_test on my side
(gcc 7.3/glibc-2.28/kernel-4.19).
net_test.c: In function ‘set_service’:
net_test.c:91:45: warning: implicit declaration of function ‘gettid’; [-Wimplicit-function-declaration]
"_selftests-landlock-net-tid%d-index%d", gettid(),
^~~~~~
getgid
net_test.c:(.text+0x4e0): undefined reference to `gettid'
Signed-off-by: Hu Yadi <hu.yadi@h3c.com>
Suggested-by: Jiao <jiaoxupo@h3c.com>
Reviewed-by: Berlin <berlin@h3c.com>
Fixes: a549d055a2 ("selftests/landlock: Add network tests")
Link: https://lore.kernel.org/r/20240123062621.25082-1-hu.yadi@h3c.com
[mic: Cosmetic fixes]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Add 2 tests to the layout1 fixture:
* topology_changes_with_net_only: Checks that FS topology
changes are not denied by network-only restrictions.
* topology_changes_with_net_and_fs: Make sure that FS topology
changes are still denied with FS and network restrictions.
This specifically test commit d722036403 ("landlock: Allow FS topology
changes for domains without such rule type").
Cc: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Link: https://lore.kernel.org/r/20231027154615.815134-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Add 82 test suites to check edge cases related to bind() and connect()
actions. They are defined with 6 fixtures and their variants:
The "protocol" fixture is extended with 12 variants defined as a matrix
of: sandboxed/not-sandboxed, IPv4/IPv6/unix network domain, and
stream/datagram socket. 4 related tests suites are defined:
* bind: Tests bind action.
* connect: Tests connect action.
* bind_unspec: Tests bind action with the AF_UNSPEC socket family.
* connect_unspec: Tests connect action with the AF_UNSPEC socket family.
The "ipv4" fixture is extended with 4 variants defined as a matrix
of: sandboxed/not-sandboxed, and stream/datagram socket. 1 related test
suite is defined:
* from_unix_to_inet: Tests to make sure unix sockets' actions are not
restricted by Landlock rules applied to TCP ones.
The "tcp_layers" fixture is extended with 8 variants defined as a matrix
of: IPv4/IPv6 network domain, and different number of landlock rule
layers. 2 related tests suites are defined:
* ruleset_overlap: Tests nested layers with less constraints.
* ruleset_expand: Tests nested layers with more constraints.
In the "mini" fixture 4 tests suites are defined:
* network_access_rights: Tests handling of known access rights.
* unknown_access_rights: Tests handling of unknown access rights.
* inval: Tests unhandled allowed access and zero access value.
* tcp_port_overflow: Tests with port values greater than 65535.
The "ipv4_tcp" fixture supports IPv4 network domain with stream socket.
2 tests suites are defined:
* port_endianness: Tests with big/little endian port formats.
* with_fs: Tests a ruleset with both filesystem and network
restrictions.
The "port_specific" fixture is extended with 4 variants defined
as a matrix of: sandboxed/not-sandboxed, IPv4/IPv6 network domain,
and stream socket. 2 related tests suites are defined:
* bind_connect_zero: Tests with port 0.
* bind_connect_1023: Tests with port 1023.
Test coverage for security/landlock is 92.4% of 710 lines according to
gcc/gcov-13.
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Link: https://lore.kernel.org/r/20231026014751.414649-11-konstantin.meskhidze@huawei.com
[mic: Extend commit message, update test coverage, clean up capability
use, fix useless TEST_F_FORK, and improve ipv4_tcp.with_fs]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Add network rules support in the ruleset management helpers and the
landlock_create_ruleset() syscall. Extend user space API to support
network actions:
* Add new network access rights: LANDLOCK_ACCESS_NET_BIND_TCP and
LANDLOCK_ACCESS_NET_CONNECT_TCP.
* Add a new network rule type: LANDLOCK_RULE_NET_PORT tied to struct
landlock_net_port_attr. The allowed_access field contains the network
access rights, and the port field contains the port value according to
the controlled protocol. This field can take up to a 64-bit value
but the maximum value depends on the related protocol (e.g. 16-bit
value for TCP). Network port is in host endianness [1].
* Add a new handled_access_net field to struct landlock_ruleset_attr
that contains network access rights.
* Increment the Landlock ABI version to 4.
Implement socket_bind() and socket_connect() LSM hooks, which enable
to control TCP socket binding and connection to specific ports.
Expand access_masks_t from u16 to u32 to be able to store network access
rights alongside filesystem access rights for rulesets' handled access
rights.
Access rights are not tied to socket file descriptors but checked at
bind() or connect() call time against the caller's Landlock domain. For
the filesystem, a file descriptor is a direct access to a file/data.
However, for network sockets, we cannot identify for which data or peer
a newly created socket will give access to. Indeed, we need to wait for
a connect or bind request to identify the use case for this socket.
Likewise a directory file descriptor may enable to open another file
(i.e. a new data item), but this opening is also restricted by the
caller's domain, not the file descriptor's access rights [2].
[1] https://lore.kernel.org/r/278ab07f-7583-a4e0-3d37-1bacd091531d@digikod.net
[2] https://lore.kernel.org/r/263c1eb3-602f-57fe-8450-3f138581bee7@digikod.net
Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Link: https://lore.kernel.org/r/20231026014751.414649-9-konstantin.meskhidze@huawei.com
[mic: Extend commit message, fix typo in comments, and specify
endianness in the documentation]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
