Commit Graph

118 Commits

Author SHA1 Message Date
Linus Torvalds
509d3f4584 Merge tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:

 - "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
   fixes a build issue and does some cleanup in ib/sys_info.c

 - "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
   enhances the 64-bit math code on behalf of a PWM driver and beefs up
   the test module for these library functions

 - "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
   makes BPF symbol names, sizes, and line numbers available to the GDB
   debugger

 - "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
   adds a sysctl which can be used to cause additional info dumping when
   the hung-task and lockup detectors fire

 - "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
   adds a general base64 encoder/decoder to lib/ and migrates several
   users away from their private implementations

 - "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
   makes TCP a little faster

 - "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
   reworks the KEXEC Handover interfaces in preparation for Live Update
   Orchestrator (LUO), and possibly for other future clients

 - "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
   increases the flexibility of KEXEC Handover. Also preparation for LUO

 - "Live Update Orchestrator" (Pasha Tatashin)
   is a major new feature targeted at cloud environments. Quoting the
   cover letter:

      This series introduces the Live Update Orchestrator, a kernel
      subsystem designed to facilitate live kernel updates using a
      kexec-based reboot. This capability is critical for cloud
      environments, allowing hypervisors to be updated with minimal
      downtime for running virtual machines. LUO achieves this by
      preserving the state of selected resources, such as memory,
      devices and their dependencies, across the kernel transition.

      As a key feature, this series includes support for preserving
      memfd file descriptors, which allows critical in-memory data, such
      as guest RAM or any other large memory region, to be maintained in
      RAM across the kexec reboot.

   Mike Rappaport merits a mention here, for his extensive review and
   testing work.

 - "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
   moves the kexec and kdump sysfs entries from /sys/kernel/ to
   /sys/kernel/kexec/ and adds back-compatibility symlinks which can
   hopefully be removed one day

 - "kho: fixes for vmalloc restoration" (Mike Rapoport)
   fixes a BUG which was being hit during KHO restoration of vmalloc()
   regions

* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
  calibrate: update header inclusion
  Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
  vmcoreinfo: track and log recoverable hardware errors
  kho: fix restoring of contiguous ranges of order-0 pages
  kho: kho_restore_vmalloc: fix initialization of pages array
  MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
  init: replace simple_strtoul with kstrtoul to improve lpj_setup
  KHO: fix boot failure due to kmemleak access to non-PRESENT pages
  Documentation/ABI: new kexec and kdump sysfs interface
  Documentation/ABI: mark old kexec sysfs deprecated
  kexec: move sysfs entries to /sys/kernel/kexec
  test_kho: always print restore status
  kho: free chunks using free_page() instead of kfree()
  selftests/liveupdate: add kexec test for multiple and empty sessions
  selftests/liveupdate: add simple kexec-based selftest for LUO
  selftests/liveupdate: add userspace API selftests
  docs: add documentation for memfd preservation via LUO
  mm: memfd_luo: allow preserving memfd
  liveupdate: luo_file: add private argument to store runtime state
  mm: shmem: export some functions to internal.h
  ...
2025-12-06 14:01:20 -08:00
Mickaël Salaün
54f9baf537 selftests/landlock: Add disconnected leafs and branch test suites
Test disconnected directories with two test suites
(layout4_disconnected_leafs and layout5_disconnected_branch) and 43
variants to cover the main corner cases.

These tests are complementary to the previous commit.

Add test_renameat() and test_exchangeat() helpers.

Test coverage for security/landlock is 92.1% of 1927 lines according to
LLVM 20.

Cc: Günther Noack <gnoack@google.com>
Cc: Song Liu <song@kernel.org>
Cc: Tingmao Wang <m@maowtm.org>
Link: https://lore.kernel.org/r/20251128172200.760753-5-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-11-28 18:27:07 +01:00
Tingmao Wang
a18ee3f31f selftests/landlock: Add tests for access through disconnected paths
This adds tests for the edge case discussed in [1], with specific ones
for rename and link operations when the operands are through
disconnected paths, as that go through a separate code path in Landlock.

This has resulted in a warning, due to collect_domain_accesses() not
expecting to reach a different root from path->mnt:

  #  RUN           layout1_bind.path_disconnected ...
  #            OK  layout1_bind.path_disconnected
  ok 96 layout1_bind.path_disconnected
  #  RUN           layout1_bind.path_disconnected_rename ...
  [..] ------------[ cut here ]------------
  [..] WARNING: CPU: 3 PID: 385 at security/landlock/fs.c:1065 collect_domain_accesses
  [..] ...
  [..] RIP: 0010:collect_domain_accesses (security/landlock/fs.c:1065 (discriminator 2) security/landlock/fs.c:1031 (discriminator 2))
  [..] current_check_refer_path (security/landlock/fs.c:1205)
  [..] ...
  [..] hook_path_rename (security/landlock/fs.c:1526)
  [..] security_path_rename (security/security.c:2026 (discriminator 1))
  [..] do_renameat2 (fs/namei.c:5264)
  #            OK  layout1_bind.path_disconnected_rename
  ok 97 layout1_bind.path_disconnected_rename

Move the const char definitions a bit above so that we can use the path
for s4d1 in cleanup code.

Cc: Günther Noack <gnoack@google.com>
Cc: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/027d5190-b37a-40a8-84e9-4ccbc352bcdf@maowtm.org [1]
Signed-off-by: Tingmao Wang <m@maowtm.org>
Link: https://lore.kernel.org/r/20251128172200.760753-4-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-11-28 18:27:06 +01:00
Bala-Vignesh-Reddy
e6fbd1759c selftests: complete kselftest include centralization
This follow-up patch completes centralization of kselftest.h and
ksefltest_harness.h includes in remaining seltests files, replacing all
relative paths with a non-relative paths using shared -I include path in
lib.mk

Tested with gcc-13.3 and clang-18.1, and cross-compiled successfully on
riscv, arm64, x86_64 and powerpc arch.

[reddybalavignesh9979@gmail.com: add selftests include path for kselftest.h]
  Link: https://lkml.kernel.org/r/20251017090201.317521-1-reddybalavignesh9979@gmail.com
Link: https://lkml.kernel.org/r/20251016104409.68985-1-reddybalavignesh9979@gmail.com
Signed-off-by: Bala-Vignesh-Reddy <reddybalavignesh9979@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Günther Noack <gnoack@google.com>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mickael Salaun <mic@digikod.net>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-27 14:24:31 -08:00
Matthieu Buffet
e61462232a selftests/landlock: Fix makefile header list
Make all headers part of make's dependencies computations.
Otherwise, updating audit.h, common.h, scoped_base_variants.h,
scoped_common.h, scoped_multiple_domain_variants.h, or wrappers.h,
re-running make and running selftests could lead to testing stale headers.

Fixes: 6a500b2297 ("selftests/landlock: Add tests for audit flags and domain IDs")
Fixes: fefcf0f7cf ("selftests/landlock: Test abstract UNIX socket scoping")
Fixes: 5147779d5e ("selftests/landlock: Add wrappers.h")
Signed-off-by: Matthieu Buffet <matthieu@buffet.re>
Link: https://lore.kernel.org/r/20251027011440.1838514-1-matthieu@buffet.re
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-11-26 20:20:23 +01:00
Bala-Vignesh-Reddy
a7498388b0 selftests: centralise maybe-unused definition in kselftest.h
Several selftests subdirectories duplicated the define __maybe_unused,
leading to redundant code.  Move to kselftest.h header and remove other
definitions.

This addresses the duplication noted in the proc-pid-vm warning fix

Link: https://lkml.kernel.org/r/20250821101159.2238-1-reddybalavignesh9979@gmail.com
Signed-off-by: Bala-Vignesh-Reddy <reddybalavignesh9979@gmail.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Link:https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Mickal Salan <mic@digikod.net>	[landlock]
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13 16:55:16 -07:00
Mickaël Salaün
dae01387e6 selftests/landlock: Add test to check rule tied to covered mount point
This test checks that a rule on a directory used as a mount point does
not grant access to the mount covering it.  It is a generalization of
the bind mount case in layout3_fs.hostfs.release_inodes [1] that tests
hidden mount points.

Cc: Günther Noack <gnoack@google.com>
Cc: Song Liu <song@kernel.org>
Cc: Tingmao Wang <m@maowtm.org>
Link: https://lore.kernel.org/r/20250606.zo5aekae6Da6@digikod.net [1]
Link: https://lore.kernel.org/r/20250606110811.211297-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-06-19 13:55:41 +02:00
Song Liu
dc58130bc3 selftests/landlock: Fix build of audit_test
We are hitting build error on CentOS 9:

audit_test.c:232:40: error: ‘O_CLOEXEC’ undeclared (...)

Fix this by including fcntl.h.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20250605214416.1885878-1-song@kernel.org
Fixes: 6b4566400a ("selftests/landlock: Add PID tests for audit records")
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-06-19 13:55:40 +02:00
Mickaël Salaün
94a7ce2642 selftests/landlock: Fix readlink check
The audit_init_filter_exe() helper incorrectly checks the readlink(2)
error because an unsigned integer is used to store the result.  Use a
signed integer for this check.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/aDbFwyZ_fM-IO7sC@stanley.mountain
Fixes: 6a500b2297 ("selftests/landlock: Add tests for audit flags and domain IDs")
Reviewed-by: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20250528144426.1709063-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-06-19 13:55:38 +02:00
Mickaël Salaün
6b4566400a selftests/landlock: Add PID tests for audit records
Add audit.thread tests to check that the PID tied to a domain is not a
thread ID but the thread group ID.  These new tests would not pass
without the previous TGID fix.

Extend matches_log_domain_allocated() to check against the PID that
created the domain.

Test coverage for security/landlock is 93.6% of 1524 lines according to
gcc/gcov-14.

Cc: Christian Brauner <brauner@kernel.org>
Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250410171725.1265860-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-04-11 12:53:22 +02:00
Mickaël Salaün
e4a0f9e0ca selftests/landlock: Factor out audit fixture in audit_test
The audit fixture needlessly stores and manages domain_stack.  Move it
to the audit.layers tests.  This will be useful to reuse the audit
fixture with the next patch.

Cc: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20250410171725.1265860-2-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-04-11 12:53:20 +02:00
Mickaël Salaün
a5c369e45b selftests/landlock: Add audit tests for network
Test all network blockers:
- net.bind_tcp
- net.connect_tcp

Test coverage for security/landlock is 94.0% of 1525 lines according to
gcc/gcov-14.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-28-mic@digikod.net
[mic: Update test coverage]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:48 +01:00
Mickaël Salaün
316d06b011 selftests/landlock: Add audit tests for filesystem
Test all filesystem blockers, including events with several records, and
record with several blockers:
- fs.execute
- fs.write_file
- fs.read_file
- fs_read_dir
- fs.remove_dir
- fs.remove_file
- fs.make_char
- fs.make_dir
- fs.make_reg
- fs.make_sock
- fs.make_fifo
- fs.make_block
- fs.make_sym
- fs.refer
- fs.truncate
- fs.ioctl_dev
- fs.change_topology

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-27-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:48 +01:00
Mickaël Salaün
e1156872ef selftests/landlock: Add audit tests for abstract UNIX socket scoping
Add a new scoped_audit.connect_to_child test to check the abstract UNIX
socket blocker.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-26-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:47 +01:00
Mickaël Salaün
e2893c0a69 selftests/landlock: Add audit tests for ptrace
Add tests for all ptrace actions checking "blockers=ptrace" records.

This also improves PTRACE_TRACEME and PTRACE_ATTACH tests by making sure
that the restrictions comes from Landlock, and with the expected
process.  These extended tests are like enhanced errno checks that make
sure Landlock enforcement is consistent.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-25-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:47 +01:00
Mickaël Salaün
960ed6ca4c selftests/landlock: Test audit with restrict flags
Add audit_exec tests to filter Landlock denials according to
cross-execution or muted subdomains.

Add a wait-pipe-sandbox.c test program to sandbox itself and send a
(denied) signals to its parent.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-24-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:46 +01:00
Mickaël Salaün
6a500b2297 selftests/landlock: Add tests for audit flags and domain IDs
Add audit_test.c to check with and without LANDLOCK_RESTRICT_SELF_*
flags against the two Landlock audit record types:
AUDIT_LANDLOCK_ACCESS and AUDIT_LANDLOCK_DOMAIN.

Check consistency of domain IDs per layer in AUDIT_LANDLOCK_ACCESS and
AUDIT_LANDLOCK_DOMAIN messages: denied access, domain allocation, and
domain deallocation.

These tests use signal scoping to make it simple.  They are not in the
scoped_signal_test.c file but in the new dedicated audit_test.c file.

Tests are run with audit filters to ensure the audit records come from
the test program.  Moreover, because there can only be one audit
process, tests would failed if run in parallel.  Because of audit
limitations, tests can only be run in the initial namespace.

The audit test helpers were inspired by libaudit and
tools/testing/selftests/net/netfilter/audit_logread.c

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Phil Sutter <phil@nwl.cc>
Link: https://lore.kernel.org/r/20250320190717.2287696-23-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:45 +01:00
Mickaël Salaün
e178b404ea selftests/landlock: Extend tests for landlock_restrict_self(2)'s flags
Add the base_test's restrict_self_fd_flags tests to align with previous
restrict_self_fd tests but with the new
LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF flag.

Add the restrict_self_flags tests to check that
LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF,
LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON, and
LANDLOCK_RESTRICT_SELF_LOG_SUBDOMAINS_OFF are valid but not the next
bit.  Some checks are similar to restrict_self_checks_ordering's ones.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-22-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:45 +01:00
Mickaël Salaün
ec12a8d4c1 selftests/landlock: Add test for invalid ruleset file descriptor
To align with fs_test's layout1.inval and layout0.proc_nsfs which test
EBADFD for landlock_add_rule(2), create a new base_test's
restrict_self_fd which test EBADFD for landlock_restrict_self(2).

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-21-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:44 +01:00
Mickaël Salaün
12bfcda73a landlock: Add LANDLOCK_RESTRICT_SELF_LOG_*_EXEC_* flags
Most of the time we want to log denied access because they should not
happen and such information helps diagnose issues.  However, when
sandboxing processes that we know will try to access denied resources
(e.g. unknown, bogus, or malicious binary), we might want to not log
related access requests that might fill up logs.

By default, denied requests are logged until the task call execve(2).

If the LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF flag is set, denied
requests will not be logged for the same executed file.

If the LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON flag is set, denied
requests from after an execve(2) call will be logged.

The rationale is that a program should know its own behavior, but not
necessarily the behavior of other programs.

Because LANDLOCK_RESTRICT_SELF_LOG_SAME_EXEC_OFF is set for a specific
Landlock domain, it makes it possible to selectively mask some access
requests that would be logged by a parent domain, which might be handy
for unprivileged processes to limit logs.  However, system
administrators should still use the audit filtering mechanism.  There is
intentionally no audit nor sysctl configuration to re-enable these logs.
This is delegated to the user space program.

Increment the Landlock ABI version to reflect this interface change.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250320190717.2287696-18-mic@digikod.net
[mic: Rename variables and fix __maybe_unused]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:42 +01:00
Mickaël Salaün
c5efa393d8 selftests/landlock: Add a new test for setuid()
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>
2025-03-26 13:59:32 +01:00
Mickaël Salaün
bbe7227403 selftests/landlock: Split signal_scoping_threads tests
Split signal_scoping_threads tests into signal_scoping_thread_before
and signal_scoping_thread_after.

Use local variables for thread synchronization.  Fix exported function.
Replace some asserts with expects.

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/20250318161443.279194-7-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-03-26 13:59:32 +01:00
Mickaël Salaün
18eb75f3af landlock: Always allow signals between threads of the same process
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>
2025-03-26 13:59:29 +01:00
Mickaël Salaün
15383a0d63 landlock: Add the errata interface
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>
2025-03-21 12:12:19 +01:00
Bharadwaj Raju
78332fdb95 selftests/landlock: Add binaries to .gitignore
Building the test creates binaries 'wait-pipe' and
'sandbox-and-launch' which need to be gitignore'd.

Signed-off-by: Bharadwaj Raju <bharadwaj.raju777@gmail.com>
Link: https://lore.kernel.org/r/20250210161101.6024-1-bharadwaj.raju777@gmail.com
[mic: Sort entries]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-02-14 09:23:11 +01:00
Mikhail Ivanov
3d4033985f selftests/landlock: Test that MPTCP actions are not restricted
Extend protocol fixture with test suits for MPTCP protocol.
Add CONFIG_MPTCP and CONFIG_MPTCP_IPV6 options in config.

Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
Link: https://lore.kernel.org/r/20250205093651.1424339-4-ivanov.mikhail1@huawei-partners.com
Cc: <stable@vger.kernel.org> # 6.7.x
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-02-14 09:23:10 +01:00
Mikhail Ivanov
f5534d511b selftests/landlock: Test TCP accesses with protocol=IPPROTO_TCP
Extend protocol_variant structure with protocol field (Cf. socket(2)).

Extend protocol fixture with TCP test suits with protocol=IPPROTO_TCP
which can be used as an alias for IPPROTO_IP (=0) in socket(2).

Signed-off-by: Mikhail Ivanov <ivanov.mikhail1@huawei-partners.com>
Link: https://lore.kernel.org/r/20250205093651.1424339-3-ivanov.mikhail1@huawei-partners.com
Cc: <stable@vger.kernel.org> # 6.7.x
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-02-14 09:23:09 +01:00
Mickaël Salaün
89cb121e94 selftests/landlock: Enable the new CONFIG_AF_UNIX_OOB
Since commit 5155cbcdbf ("af_unix: Add a prompt to
CONFIG_AF_UNIX_OOB"), the Landlock selftests's configuration is not
enough to build a minimal kernel.  Because scoped_signal_test checks
with the MSG_OOB flag, we need to enable CONFIG_AF_UNIX_OOB for tests:

 #  RUN           fown.no_sandbox.sigurg_socket ...
 # scoped_signal_test.c:420:sigurg_socket:Expected 1 (1) == send(client_socket, ".", 1, MSG_OOB) (-1)
 # sigurg_socket: Test terminated by assertion
 #          FAIL  fown.no_sandbox.sigurg_socket
 ...

Cc: Günther Noack <gnoack@google.com>
Acked-by: Florent Revest <revest@chromium.org>
Link: https://lore.kernel.org/r/20250211132531.1625566-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-02-14 09:23:06 +01:00
Linus Torvalds
bdd4f86c97 Merge tag 'AT_EXECVE_CHECK-v6.14-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull AT_EXECVE_CHECK selftest fix from Kees Cook:
 "Fixes the AT_EXECVE_CHECK selftests which didn't run on old versions
  of glibc"

* tag 'AT_EXECVE_CHECK-v6.14-rc1-fix1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  selftests: Handle old glibc without execveat(2)
2025-01-31 17:12:31 -08:00
Mickaël Salaün
38567b972a selftests: Handle old glibc without execveat(2)
Add an execveat(2) wrapper because glibc < 2.34 does not have one.  This
fixes the check-exec tests and samples.

Cc: Günther Noack <gnoack@google.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: Kees Cook <kees@kernel.org>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Stefan Berger <stefanb@linux.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/r/20250114205645.GA2825031@ax162
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20250115144753.311152-1-mic@digikod.net
Signed-off-by: Kees Cook <kees@kernel.org>
2025-01-27 11:37:18 -08:00
Linus Torvalds
21266b8df5 Merge tag 'AT_EXECVE_CHECK-v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull AT_EXECVE_CHECK from Kees Cook:

 - Implement AT_EXECVE_CHECK flag to execveat(2) (Mickaël Salaün)

 - Implement EXEC_RESTRICT_FILE and EXEC_DENY_INTERACTIVE securebits
   (Mickaël Salaün)

 - Add selftests and samples for AT_EXECVE_CHECK (Mickaël Salaün)

* tag 'AT_EXECVE_CHECK-v6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  ima: instantiate the bprm_creds_for_exec() hook
  samples/check-exec: Add an enlighten "inc" interpreter and 28 tests
  selftests: ktap_helpers: Fix uninitialized variable
  samples/check-exec: Add set-exec
  selftests/landlock: Add tests for execveat + AT_EXECVE_CHECK
  selftests/exec: Add 32 tests for AT_EXECVE_CHECK and exec securebits
  security: Add EXEC_RESTRICT_FILE and EXEC_DENY_INTERACTIVE securebits
  exec: Add a new AT_EXECVE_CHECK flag to execveat(2)
2025-01-22 20:34:42 -08:00
Mickaël Salaün
2a794ee613 selftests/landlock: Add layout1.umount_sandboxer tests
Check that a domain is not tied to the executable file that created it.
For instance, that could happen if a Landlock domain took a reference to
a struct path.

Move global path names to common.h and replace copy_binary() with a more
generic copy_file() helper.

Test coverage for security/landlock is 92.7% of 1133 lines according to
gcc/gcov-14.

Cc: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20250108154338.1129069-23-mic@digikod.net
[mic: Update date and add test coverage]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-01-17 19:05:38 +01:00
Mickaël Salaün
5147779d5e selftests/landlock: Add wrappers.h
Extract syscall wrappers to make them usable by standalone binaries (see
next commit).

Cc: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20250108154338.1129069-22-mic@digikod.net
[mic: Fix comments]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-01-17 19:05:38 +01:00
Mickaël Salaün
2107c35128 selftests/landlock: Fix error message
The global variable errno may not be set in test_execute().  Do not use
it in related error message.

Cc: Günther Noack <gnoack@google.com>
Fixes: e1199815b4 ("selftests/landlock: Add user space tests")
Link: https://lore.kernel.org/r/20250108154338.1129069-21-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-01-17 19:05:37 +01:00
Mickaël Salaün
12264f721f selftests/landlock: Add test to check partial access in a mount tree
Add layout1.refer_part_mount_tree_is_allowed to test the masked logical
issue regarding collect_domain_accesses() calls followed by the
is_access_to_paths_allowed() check in current_check_refer_path().  See
previous commit.

This test should work without the previous fix as well, but it enables
us to make sure future changes will not have impact regarding this
behavior.

Cc: Günther Noack <gnoack@google.com>
Link: https://lore.kernel.org/r/20250108154338.1129069-13-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-01-17 19:05:36 +01:00
Mickaël Salaün
0e4db4f843 selftests/landlock: Fix build with non-default pthread linking
Old toolchains require explicit -lpthread (e.g. on Debian 11).

Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Tahera Fahimi <fahimitahera@gmail.com>
Fixes: c899496501 ("selftests/landlock: Test signal scoping for threads")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20250115145409.312226-1-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-01-17 19:05:31 +01:00
Ba Jing
b665ee5f08 selftests/landlock: Remove unused macros in ptrace_test.c
After reviewing the code, it was found that these macros are never
referenced in the code. Just remove them.

Signed-off-by: Ba Jing <bajing@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20241118042407.12900-1-bajing@cmss.chinamobile.com
[mic: Reword subject]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2025-01-10 12:12:37 +01:00
Mickaël Salaün
0e7f90f34c selftests/landlock: Add tests for execveat + AT_EXECVE_CHECK
Extend layout1.execute with the new AT_EXECVE_CHECK flag.  The semantic
with AT_EXECVE_CHECK is the same as with a simple execve(2),
LANDLOCK_ACCESS_FS_EXECUTE is enforced the same way.

Cc: Günther Noack <gnoack@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Link: https://lore.kernel.org/r/20241212174223.389435-5-mic@digikod.net
Signed-off-by: Kees Cook <kees@kernel.org>
2024-12-18 17:00:29 -08:00
Tahera Fahimi
f34e9ce5f4 selftests/landlock: Test signal created by out-of-bound message
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>
2024-09-16 23:50:54 +02:00
Tahera Fahimi
c899496501 selftests/landlock: Test signal scoping for threads
Expand the signal scoping tests with pthread_kill(3).  Test if a scoped
thread can send signal to a process in the same scoped domain, or a
non-sandboxed thread.

Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/c15e9eafbb2da1210e46ba8db7b8907f5ea11009.1725657728.git.fahimitahera@gmail.com
[mic: Improve commit message]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2024-09-16 23:50:53 +02:00
Tahera Fahimi
ea292363c3 selftests/landlock: Test signal scoping
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>
2024-09-16 23:50:53 +02:00
Tahera Fahimi
54a6e6bbf3 landlock: Add signal scoping
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>
2024-09-16 23:50:52 +02:00
Tahera Fahimi
644a728506 selftests/landlock: Test inherited restriction of abstract UNIX socket
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>
2024-09-16 23:50:50 +02:00
Tahera Fahimi
d1cc0ef80f selftests/landlock: Test connected and unconnected datagram UNIX socket
Check the specific case where a scoped datagram socket is connected and
send(2) works, whereas sendto(2) is denied if the datagram socket is not
connected.

Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/c28c9cd8feef67dd25e115c401a2389a75f9983b.1725494372.git.fahimitahera@gmail.com
[mic: Use more EXPECT and avoid negative ASSERT, use variables dedicated
per process, remove useless buffer]
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2024-09-16 23:50:50 +02:00
Tahera Fahimi
4f9a5b50d3 selftests/landlock: Test UNIX sockets with any address formats
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>
2024-09-16 23:50:49 +02:00
Tahera Fahimi
fefcf0f7cf selftests/landlock: Test abstract UNIX socket scoping
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>
2024-09-16 23:50:48 +02:00
Tahera Fahimi
5b6b63cd64 selftests/landlock: Test handling of unknown scope
Add a new ruleset_with_unknown_scope test designed to validate the
behaviour of landlock_create_ruleset(2) when called with an unsupported
or unknown scope mask.

Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/74b363aaa7ddf80e1e5e132ce3d550a3a8bbf6da.1725494372.git.fahimitahera@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2024-09-16 23:50:48 +02:00
Tahera Fahimi
21d52e295a landlock: Add abstract UNIX socket scoping
Introduce a new "scoped" member to landlock_ruleset_attr that can
specify LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET to restrict connection to
abstract UNIX sockets from a process outside of the socket's domain.

Two hooks are implemented to enforce these restrictions:
unix_stream_connect and unix_may_send.

Closes: https://github.com/landlock-lsm/linux/issues/7
Signed-off-by: Tahera Fahimi <fahimitahera@gmail.com>
Link: https://lore.kernel.org/r/5f7ad85243b78427242275b93481cfc7c127764b.1725494372.git.fahimitahera@gmail.com
[mic: Fix commit message formatting, improve documentation, simplify
hook_unix_may_send(), and cosmetic fixes including rename of
LANDLOCK_SCOPED_ABSTRACT_UNIX_SOCKET]
Co-developed-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2024-09-16 23:50:45 +02:00
Mickaël Salaün
cc374782b6 selftests/landlock: Add cred_transfer test
Check that keyctl(KEYCTL_SESSION_TO_PARENT) preserves the parent's
restrictions.

Fixes: e1199815b4 ("selftests/landlock: Add user space tests")
Co-developed-by: Jann Horn <jannh@google.com>
Signed-off-by: Jann Horn <jannh@google.com>
Link: https://lore.kernel.org/r/20240724.Ood5aige9she@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2024-07-24 17:34:56 +02:00
Mickaël Salaün
0055f53aac selftests/landlock: Add layout1.refer_mount_root
Add tests to check error codes when linking or renaming a mount root
directory.  This previously triggered a kernel warning, but it is fixed
with the previous commit.

Cc: Günther Noack <gnoack@google.com>
Cc: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20240516181935.1645983-3-mic@digikod.net
Signed-off-by: Mickaël Salaün <mic@digikod.net>
2024-05-31 16:41:54 +02:00