Pull Landlock update from Mickaël Salaün:
"This adds a new Landlock access right for pathname UNIX domain sockets
thanks to a new LSM hook, and a few fixes"
* tag 'landlock-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux: (23 commits)
landlock: Document fallocate(2) as another truncation corner case
landlock: Document FS access right for pathname UNIX sockets
selftests/landlock: Simplify ruleset creation and enforcement in fs_test
selftests/landlock: Check that coredump sockets stay unrestricted
selftests/landlock: Audit test for LANDLOCK_ACCESS_FS_RESOLVE_UNIX
selftests/landlock: Test LANDLOCK_ACCESS_FS_RESOLVE_UNIX
selftests/landlock: Replace access_fs_16 with ACCESS_ALL in fs_test
samples/landlock: Add support for named UNIX domain socket restrictions
landlock: Clarify BUILD_BUG_ON check in scoping logic
landlock: Control pathname UNIX domain socket resolution by path
landlock: Use mem_is_zero() in is_layer_masks_allowed()
lsm: Add LSM hook security_unix_find
landlock: Fix kernel-doc warning for pointer-to-array parameters
landlock: Fix formatting in tsync.c
landlock: Improve kernel-doc "Return:" section consistency
landlock: Add missing kernel-doc "Return:" sections
selftests/landlock: Fix format warning for __u64 in net_test
selftests/landlock: Skip stale records in audit_match_record()
selftests/landlock: Drain stale audit records on init
selftests/landlock: Fix socket file descriptor leaks in audit helpers
...
Pull LSM updates from Paul Moore:
"We only have five patches in the LSM tree, but three of the five are
for an important bugfix relating to overlayfs and the mmap() and
mprotect() access controls for LSMs. Highlights below:
- Fix problems with the mmap() and mprotect() LSM hooks on overlayfs
As we are dealing with problems both in mmap() and mprotect() there
are essentially two components to this fix, spread across three
patches with all marked for stable.
The simplest portion of the fix is the creation of a new LSM hook,
security_mmap_backing_file(), that is used to enforce LSM mmap()
access controls on backing files in the stacked/overlayfs case. The
existing security_mmap_file() does not have visibility past the
user file. You can see from the associated SELinux hook callback
the code is fairly straightforward.
The mprotect() fix is a bit more complicated as there is no way in
the mprotect() code path to inspect both the user and backing
files, and bolting on a second file reference to vm_area_struct
wasn't really an option.
The solution taken here adds a LSM security blob and associated
hooks to the backing_file struct that LSMs can use to capture and
store relevant information from the user file. While the necessary
SELinux information is relatively small, a single u32, I expect
other LSMs to require more than that, and a dedicated backing_file
LSM blob provides a storage mechanism without negatively impacting
other filesystems.
I want to note that other LSMs beyond SELinux have been involved in
the discussion of the fixes presented here and they are working on
their own related changes using these new hooks, but due to other
issues those patches will be coming at a later date.
- Use kstrdup_const()/kfree_const() for securityfs symlink targets
- Resolve a handful of kernel-doc warnings in cred.h"
* tag 'lsm-pr-20260410' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
selinux: fix overlayfs mmap() and mprotect() access checks
lsm: add backing_file LSM hooks
fs: prepare for adding LSM blob to backing_file
securityfs: use kstrdup_const() to manage symlink targets
cred: fix kernel-doc warnings in cred.h
Add an LSM hook security_unix_find.
This hook is called to check the path of a named UNIX socket before a
connection is initiated. The peer socket may be inspected as well.
Why existing hooks are unsuitable:
Existing socket hooks, security_unix_stream_connect(),
security_unix_may_send(), and security_socket_connect() don't provide
TOCTOU-free / namespace independent access to the paths of sockets.
(1) We cannot resolve the path from the struct sockaddr in existing hooks.
This requires another path lookup. A change in the path between the
two lookups will cause a TOCTOU bug.
(2) We cannot use the struct path from the listening socket, because it
may be bound to a path in a different namespace than the caller,
resulting in a path that cannot be referenced at policy creation time.
Consumers of the hook wishing to reference @other are responsible
for acquiring the unix_state_lock and checking for the SOCK_DEAD flag
therein, ensuring the socket hasn't died since lookup.
Cc: Günther Noack <gnoack3000@gmail.com>
Cc: Tingmao Wang <m@maowtm.org>
Cc: Mickaël Salaün <mic@digikod.net>
Cc: Paul Moore <paul@paul-moore.com>
Signed-off-by: Justin Suess <utilityemal77@gmail.com>
Signed-off-by: Günther Noack <gnoack3000@gmail.com>
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20260327164838.38231-2-gnoack3000@gmail.com
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Stacked filesystems such as overlayfs do not currently provide the
necessary mechanisms for LSMs to properly enforce access controls on the
mmap() and mprotect() operations. In order to resolve this gap, a LSM
security blob is being added to the backing_file struct and the following
new LSM hooks are being created:
security_backing_file_alloc()
security_backing_file_free()
security_mmap_backing_file()
The first two hooks are to manage the lifecycle of the LSM security blob
in the backing_file struct, while the third provides a new mmap() access
control point for the underlying backing file. It is also expected that
LSMs will likely want to update their security_file_mprotect() callback
to address issues with their mprotect() controls, but that does not
require a change to the security_file_mprotect() LSM hook.
There are a three other small changes to support these new LSM hooks:
* Pass the user file associated with a backing file down to
alloc_empty_backing_file() so it can be included in the
security_backing_file_alloc() hook.
* Add getter and setter functions for the backing_file struct LSM blob
as the backing_file struct remains private to fs/file_table.c.
* Constify the file struct field in the LSM common_audit_data struct to
better support LSMs that need to pass a const file struct pointer into
the common LSM audit code.
Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL()
and supplying a fixup.
Cc: stable@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-unionfs@vger.kernel.org
Cc: linux-erofs@lists.ozlabs.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
When running in an unprivileged domU under Xen, the privcmd driver
is restricted to allow only hypercalls against a target domain, for
which the current domU is acting as a device model.
Add a boot parameter "unrestricted" to allow all hypercalls (the
hypervisor will still refuse destructive hypercalls affecting other
guests).
Make this new parameter effective only in case the domU wasn't started
using secure boot, as otherwise hypercalls targeting the domU itself
might result in violating the secure boot functionality.
This is achieved by adding another lockdown reason, which can be
tested to not being set when applying the "unrestricted" option.
This is part of XSA-482
Signed-off-by: Juergen Gross <jgross@suse.com>
---
V2:
- new patch
The key use for static-branches are not refrenced by name outside
of the security/security.c file, so make them static. This stops
the sparse warnings about "Should it be static?" such as:
security/security.c: note: in included file:
./include/linux/lsm_hook_defs.h:29:1: warning: symbol
'security_hook_active_binder_set_context_mgr_0' was not declared.
Should it be static?
./include/linux/lsm_hook_defs.h:29:1: warning: symbol
'security_hook_active_binder_set_context_mgr_1' was not declared.
Should it be static?
...
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
[PM: trimmed sparse output for line-length, readability]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Move away from an init specific init_debug() macro to a more general
lsm_pr()/lsm_pr_cont()/lsm_pr_dbg() set of macros that are available
both before and after init. In the process we do a number of minor
changes to improve the LSM initialization output and cleanup the code
somewhat.
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johhansen@canonical.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Move the LSM active count and lsm_id list declarations out of a header
that is visible across the kernel and into a header that is limited to
the LSM framework. This not only helps keep the include/linux headers
smaller and cleaner, it helps prevent misuse of these variables.
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johhansen@canonical.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Continue to pull code out of security/security.c to help improve
readability by pulling all of the LSM framework initialization
code out into a new file.
No code changes.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
In an effort to decompose security/security.c somewhat to make it less
twisted and unwieldy, pull out the LSM notifier code into a new file
as it is fairly well self-contained.
No code changes.
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull d_name audit update from Al Viro:
"Simplifying ->d_name audits, easy part.
Turn dentry->d_name into an anon union of const struct qsrt (d_name
itself) and a writable alias (__d_name).
With constification of some struct qstr * arguments of functions that
get &dentry->d_name passed to them, that ends up with all
modifications provably done only in fs/dcache.c (and a fairly small
part of it).
Any new places doing modifications will be easy to find - grep for
__d_name will suffice"
* tag 'pull-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
make it easier to catch those who try to modify ->d_name
generic_ci_validate_strict_name(): constify name argument
afs_dir_search: constify qstr argument
afs_edit_dir_{add,remove}(): constify qstr argument
exfat_find(): constify qstr argument
security_dentry_init_security(): constify qstr argument
Pull lsm updates from Paul Moore:
- Move the management of the LSM BPF security blobs into the framework
In order to enable multiple LSMs we need to allocate and free the
various security blobs in the LSM framework and not the individual
LSMs as they would end up stepping all over each other.
- Leverage the lsm_bdev_alloc() helper in lsm_bdev_alloc()
Make better use of our existing helper functions to reduce some code
duplication.
- Update the Rust cred code to use 'sync::aref'
Part of a larger effort to move the Rust code over to the 'sync'
module.
- Make CONFIG_LSM dependent on CONFIG_SECURITY
As the CONFIG_LSM Kconfig setting is an ordered list of the LSMs to
enable a boot, it obviously doesn't make much sense to enable this
when CONFIG_SECURITY is disabled.
- Update the LSM and CREDENTIALS sections in MAINTAINERS with Rusty
bits
Add the Rust helper files to the associated LSM and CREDENTIALS
entries int the MAINTAINERS file. We're trying to improve the
communication between the two groups and making sure we're all aware
of what is going on via cross-posting to the relevant lists is a good
way to start.
* tag 'lsm-pr-20250926' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
lsm: CONFIG_LSM can depend on CONFIG_SECURITY
MAINTAINERS: add the associated Rust helper to the CREDENTIALS section
MAINTAINERS: add the associated Rust helper to the LSM section
rust,cred: update AlwaysRefCounted import to sync::aref
security: use umax() to improve code
lsm,selinux: Add LSM blob support for BPF objects
lsm: use lsm_blob_alloc() in lsm_bdev_alloc()
Pull audit updates from Paul Moore:
- Proper audit support for multiple LSMs
As the audit subsystem predated the work to enable multiple LSMs,
some additional work was needed to support logging the different LSM
labels for the subjects/tasks and objects on the system. Casey's
patches add new auxillary records for subjects and objects that
convey the additional labels.
- Ensure fanotify audit events are always generated
Generally speaking security relevant subsystems always generate audit
events, unless explicitly ignored. However, up to this point fanotify
events had been ignored by default, but starting with this pull
request fanotify follows convention and generates audit events by
default.
- Replace an instance of strcpy() with strscpy()
- Minor indentation, style, and comment fixes
* tag 'audit-pr-20250926' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: fix skb leak when audit rate limit is exceeded
audit: init ab->skb_list earlier in audit_buffer_alloc()
audit: add record for multiple object contexts
audit: add record for multiple task security contexts
lsm: security_lsmblob_to_secctx module selection
audit: create audit_stamp structure
audit: add a missing tab
audit: record fanotify event regardless of presence of rules
audit: fix typo in auditfilter.c comment
audit: Replace deprecated strcpy() with strscpy()
audit: fix indentation in audit_log_exit()
Nothing outside of fs/dcache.c has any business modifying
dentry names; passing &dentry->d_name as an argument should
have that argument declared as a const pointer.
Acked-by: Casey Schaufler <casey@schaufler-ca.com> # smack part
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
With the introduction of clone3 in commit 7f192e3cd3 ("fork: add
clone3") the effective bit width of clone_flags on all architectures was
increased from 32-bit to 64-bit, with a new type of u64 for the flags.
However, for most consumers of clone_flags the interface was not
changed from the previous type of unsigned long.
While this works fine as long as none of the new 64-bit flag bits
(CLONE_CLEAR_SIGHAND and CLONE_INTO_CGROUP) are evaluated, this is still
undesirable in terms of the principle of least surprise.
Thus, this commit fixes all relevant interfaces of callees to
sys_clone3/copy_process (excluding the architecture-specific
copy_thread) to consistently pass clone_flags as u64, so that
no truncation to 32-bit integers occurs on 32-bit architectures.
Signed-off-by: Simon Schuster <schuster.simon@siemens-energy.com>
Link: https://lore.kernel.org/20250901-nios2-implement-clone3-v2-2-53fcf5577d57@siemens-energy.com
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add a parameter lsmid to security_lsmblob_to_secctx() to identify which
of the security modules that may be active should provide the security
context. If the value of lsmid is LSM_ID_UNDEF the first LSM providing
a hook is used. security_secid_to_secctx() is unchanged, and will
always report the first LSM providing a hook.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subj tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
This patch introduces LSM blob support for BPF maps, programs, and
tokens to enable LSM stacking and multiplexing of LSM modules that
govern BPF objects. Additionally, the existing BPF hooks used by
SELinux have been updated to utilize the new blob infrastructure,
removing the assumption of exclusive ownership of the security
pointer.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
[PM: dropped local variable init, style fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Convert the lsm_bdev_alloc() function to use the lsm_blob_alloc() helper
like all of the other LSM security blob allocators.
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull lsm updates from Paul Moore:
- Add Nicolas Bouchinet and Xiu Jianfeng as Lockdown maintainers
The Lockdown LSM has been without a dedicated mantainer since its
original acceptance upstream, and it has suffered as a result.
Thankfully we have two new volunteers who together I believe have the
background and desire to help ensure Lockdown is properly supported.
- Remove the unused cap_mmap_file() declaration
* tag 'lsm-pr-20250725' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
MAINTAINERS: Add Xiu and myself as Lockdown maintainers
security: Remove unused declaration cap_mmap_file()
lsm: trivial comment fix
Fix a typo in the security_inode_mkdir() comment block.
Signed-off-by: Kalevi Kolttonen <kalevi@kolttonen.fi>
[PM: subject tweak, add description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
security_netlink_send() is a networking hook, so it fits better under
CONFIG_SECURITY_NETWORK.
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull bpf updates from Alexei Starovoitov:
"For this merge window we're splitting BPF pull request into three for
higher visibility: main changes, res_spin_lock, try_alloc_pages.
These are the main BPF changes:
- Add DFA-based live registers analysis to improve verification of
programs with loops (Eduard Zingerman)
- Introduce load_acquire and store_release BPF instructions and add
x86, arm64 JIT support (Peilin Ye)
- Fix loop detection logic in the verifier (Eduard Zingerman)
- Drop unnecesary lock in bpf_map_inc_not_zero() (Eric Dumazet)
- Add kfunc for populating cpumask bits (Emil Tsalapatis)
- Convert various shell based tests to selftests/bpf/test_progs
format (Bastien Curutchet)
- Allow passing referenced kptrs into struct_ops callbacks (Amery
Hung)
- Add a flag to LSM bpf hook to facilitate bpf program signing
(Blaise Boscaccy)
- Track arena arguments in kfuncs (Ihor Solodrai)
- Add copy_remote_vm_str() helper for reading strings from remote VM
and bpf_copy_from_user_task_str() kfunc (Jordan Rome)
- Add support for timed may_goto instruction (Kumar Kartikeya
Dwivedi)
- Allow bpf_get_netns_cookie() int cgroup_skb programs (Mahe Tardy)
- Reduce bpf_cgrp_storage_busy false positives when accessing cgroup
local storage (Martin KaFai Lau)
- Introduce bpf_dynptr_copy() kfunc (Mykyta Yatsenko)
- Allow retrieving BTF data with BTF token (Mykyta Yatsenko)
- Add BPF kfuncs to set and get xattrs with 'security.bpf.' prefix
(Song Liu)
- Reject attaching programs to noreturn functions (Yafang Shao)
- Introduce pre-order traversal of cgroup bpf programs (Yonghong
Song)"
* tag 'bpf-next-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (186 commits)
selftests/bpf: Add selftests for load-acquire/store-release when register number is invalid
bpf: Fix out-of-bounds read in check_atomic_load/store()
libbpf: Add namespace for errstr making it libbpf_errstr
bpf: Add struct_ops context information to struct bpf_prog_aux
selftests/bpf: Sanitize pointer prior fclose()
selftests/bpf: Migrate test_xdp_vlan.sh into test_progs
selftests/bpf: test_xdp_vlan: Rename BPF sections
bpf: clarify a misleading verifier error message
selftests/bpf: Add selftest for attaching fexit to __noreturn functions
bpf: Reject attaching fexit/fmod_ret to __noreturn functions
bpf: Only fails the busy counter check in bpf_cgrp_storage_get if it creates storage
bpf: Make perf_event_read_output accessible in all program types.
bpftool: Using the right format specifiers
bpftool: Add -Wformat-signedness flag to detect format errors
selftests/bpf: Test freplace from user namespace
libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID
bpf: Return prog btf_id without capable check
bpf: BPF token support for BPF_BTF_GET_FD_BY_ID
bpf, x86: Fix objtool warning for timed may_goto
bpf: Check map->record at the beginning of check_and_free_fields()
...
Certain bpf syscall subcommands are available for usage from both
userspace and the kernel. LSM modules or eBPF gatekeeper programs may
need to take a different course of action depending on whether or not
a BPF syscall originated from the kernel or userspace.
Additionally, some of the bpf_attr struct fields contain pointers to
arbitrary memory. Currently the functionality to determine whether or
not a pointer refers to kernel memory or userspace memory is exposed
to the bpf verifier, but that information is missing from various LSM
hooks.
Here we augment the LSM hooks to provide this data, by simply passing
a boolean flag indicating whether or not the call originated in the
kernel, in any hook that contains a bpf_attr struct that corresponds
to a subcommand that may be called from the kernel.
Signed-off-by: Blaise Boscaccy <bboscaccy@linux.microsoft.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/r/20250310221737.821889-2-bboscaccy@linux.microsoft.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Linus Torvalds
Justin SuessandMickaël Salaün
Paul Moore
Juergen Gross
Ben DooksandPaul Moore
Al Viro
Simon SchusterandChristian Brauner
Casey SchauflerandPaul Moore
Blaise BoscaccyandPaul Moore
Andrey AlbershteynandChristian Brauner
Kalevi KolttonenandPaul Moore
Song LiuandPaul Moore
