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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
- Convert a __get_free_page() call into a kmalloc() call
We had some very old code that called out to __get_free_page() for
allocating a pathname. There is no reason this couldn't be done with
a call to kmalloc() so we've done the conversion and now there is one
less __get_free_page() caller in the kernel.
- Limit the number of retired/unknown DCCP netlink messages
While DCCP is gone from the kernel, there are still userspace tools
which try to talk to the kernel about DCCP sockets which were
generating SELinux related log noise (unrecognized netlink message).
This pull request both limits the log messages to just the first
instance and also explains to the user that DCCP support has been
removed.
- Convert the SELinux strlcat() calls to seq_buf_XXX() calls
As part of the effort to drop the strlcat() API from the kernel, the
SELinux/IMA code was converted over to using seq_buf_XXX() calls.
- Only calculate the SELinux IMA configuration string length once
Previously each call to generate a SELinux configuration string for
IMA would have to calculate the length of the string. While the
contents of the string will likely change over the lifetime of the
system, the length of the string will not. Calculate the string
length once at boot and reuse the length value throughout the
lifetime of the system.
- Further validation of the SELinux policy at policy load time
Perform additional sanity checks on the policy constraints and types.
- Proper cleanup and error handling for selinuxfs init failures
We were not properly cleaning up some state in the case where
selinuxfs fails to initialize properly. It's somewhat of an academic
exercise as a failure to initialize selinuxfs will cause the system
to fail on boot, but it's arguably better to make sure we do things
the proper way.
- Various code cleanups
Convert integer flags to boolean types and drop an uncessary goto
from the SELinux code.
* tag 'selinux-pr-20260814' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: validate constraint expression attr and op at load time
selinux: compute the IMA configuration settings string length once at boot
selinux: replace strlcat() with seq_buf in selinux_ima_collect_state()
selinux: suppress warning flood for retired DCCP netlink messages
selinux: tighten type validation during policy load
selinux: drop unnecessary goto and label from avc_alloc_node()
selinux: convert int flags to bool flags in ss/services.c
selinux: clean up selinuxfs resources on init failure
selinux: hooks: use kmalloc() to allocate path buffer
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As reported by Jiri Vozar, commit 7edea6e8c8e8 ("selinux: beef up
isvalid checks") introduces a new loop in mls_level_isvalid() that
causes ~89-94% throughput regression in System V IPC message queue
operations (msgsnd/msgrcv).
Move the expensive part of the ebitmap checking to policy load time
instead as the reporter suggested.
Link: https://lore.kernel.org/selinux/CAMgFczCi2Z011dNf84Amc0Q-qnTt0+VUjWY+Y7zPyXdaH35Jvw@mail.gmail.com/
Fixes: 7edea6e8c8e8 ("selinux: beef up isvalid checks")
Reported-by: Jiri Vozar <jvozar@redhat.com>
Suggested-by: Jiri Vozar <jvozar@redhat.com>
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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p_bools.nprim comes from the policy image independently of how many
booleans follow it, and cond_index_bool() fills bool_val_to_struct[] at
value - 1, so a count larger than the values present leaves NULL entries.
Every user of that array then walks it by index and dereferences each
entry: cond_evaluate_expr() on the access-vector path,
security_get_bools() and security_get_bool_value() behind selinuxfs, and
security_set_bools(). A sparse class value is absorbed by
policydb_class_isvalid() and its siblings; booleans have no such
predicate, and no consumer that could use one.
Reject a boolean value that no boolean defines, once, where the array is
built. Conforming policies define every boolean they declare and are
unaffected.
Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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security_get_classes() sizes an array by p_classes.nprim and fills it at
value - 1, so a class value the policy never defines leaves a NULL.
sel_make_classes() passes every entry to sel_make_dir(), reaching the same
d_alloc_name() dereference as the permission array. The class symbol table
is allowed to be sparse (policydb_class_isvalid() exists to absorb that),
but this getter builds its own array straight from the hash table and has
no such predicate.
Fail the lookup when a value went unclaimed instead of handing out the
NULL. Conforming policies define every class they declare and are
unaffected.
Cc: stable@vger.kernel.org
Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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security_get_permissions() sizes an array by the class's permissions.nprim
and fills it at value - 1, from the inherited common's permission table and
then the class's own. A value no permission defines leaves a NULL that
sel_make_perm_files() passes to d_alloc_name(), an oops inside
sel_write_load() that strands selinux_state.policy_mutex and leaves every
later load in uninterruptible sleep; two permissions sharing a value
overwrite the first kstrdup(). Bounding each value by nprim catches
neither, and neither would a count: the symbol table is keyed on the
permission name, so duplicates pass.
Track the values each permission table claims and require them to cover
exactly what its count declares, rejecting a count no value can reach.
Conforming policies are unaffected.
Cc: stable@vger.kernel.org
Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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sel_write_load() calls selinux_policy_cancel() when sel_make_policy_nodes()
fails, and that helper dereferences the outgoing policy to cancel its
sidtab conversion. On the first policy load there is no outgoing policy:
security_load_policy() returns early for that case, before it converts
anything, and state->policy is still NULL. A first load that fails while
building the selinuxfs tree therefore takes a NULL dereference in
selinux_policy_cancel(), reached from a write(2) to /sys/fs/selinux/load.
Skip the cancel when there is no old policy, mirroring the check
security_load_policy() already makes before it converts.
Cc: stable@vger.kernel.org
Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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security_get_permissions() maps an inherited common's permissions into
an array sized by the class's own permissions.nprim, but class_read()
takes that nprim verbatim from the policy image and never checks that it
covers the common. A class that inherits a common of N permissions while
declaring a smaller nprim is accepted, and on load the common's
permissions are written past the class-sized array -- an out-of-bounds
heap write.
Reject a class whose permission count is below its inherited common's.
Well-formed policies, where the class count already includes the
inherited permissions, are unaffected.
Cc: stable@vger.kernel.org
Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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perm_read() bounds a permission value by SEL_VEC_MAX but never by the
nprim of the owning class or common, which is taken verbatim from the
policy image. security_get_permissions() then writes perms[value - 1]
into an nprim-sized kcalloc() array, so a class declaring fewer
permissions than its largest permission value drives an out-of-bounds
heap write. The top-level symbol tables are validated this way; the
nested per-class permission table is not.
Reject a permission whose value exceeds nprim, which is already set when
perm_read() runs. Well-formed policies are unaffected.
Cc: stable@vger.kernel.org
Fixes: 55fcf09b3fe4 ("selinux: add support for querying object classes and permissions from the running policy")
Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: tweak comment for line length]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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read_cons_helper() validates the expression type and stack depth
of each constraint node but leaves e->attr and e->op unchecked,
so a policy with an invalid operator or attribute value is
accepted at load and only detected when the constraint is evaluated.
constraint_expr_eval() handles such unrecognized cases with BUG()
so the first permission check that reaches such a node oopses in
the context of the checking process or panics with panic_on_oops.
Reject these expresssions when the policy is loaded, matching what
the libsepol validator already does.
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Tighten type validation during policy load to improve robustness in
the face of ill-formed policies.
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Update security_sid_to_context_core(), security_context_to_sid_core(),
and their callers to pass boolean flags via bool rather than int.
No functional change.
Signed-off-by: Kalevi Kolttonen <kalevi@kolttonen.fi>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: minor subject and description tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
"A number of SELinux patches, almost all of which are either minor
fixes or hardening patches:
- Additional verifications when loading new SELinux policy
Multiple patches by Christian Göttsche to add additional
validations to the code responsible for loading and parsing SELinux
policy as it is loaded into the kernel.
- Avoid nontransitive comparisons comparisons in our sorting code
Done to prevent unexpected sorting results due to overflow. Qualys
documented a similar issue with glibc
https://www.qualys.com/2024/01/30/qsort.txt
- Consistently use u16 for SELinux security classes
- Move from page allocations to kmalloc() based allocations
Unfortunately one of these patches had to be reverted, but you
should see a fixed version during the next merge window.
- Move from kmalloc_objs() to kzalloc_objs() in the policy load code
- Reorder sel_kill_sb() slightly to match other pseudo filesystems
- Simplify things with QSTR() instead of QSTR_INIT()
- Minor comment typo fixes"
* tag 'selinux-pr-20260615' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: revert use of __getname() in selinux_genfs_get_sid()
selinux: comment spelling fix in ibpkey.c
selinux: comment typo fix in selinuxfs.c
selinux: hooks: use __getname() to allocate path buffer
selinux: use k[mz]alloc() to allocate temporary buffers
selinux: check for simple types
selinux: more strict bounds check
selinux: beef up isvalid checks
selinux: reorder policydb_index()
selinux: check type attr map overflows
selinux: check length fields in policies
selinux: more strict policy parsing
selinux: use u16 for security classes
selinux: avoid nontransitive comparison
selinux: switch two allocations to use kzalloc_objs()
selinux: fix sel_kill_sb()
selinux: use QSTR() instead of QSTR_INIT() in init_sel_fs
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Validate that the target of AVTAB_TYPE rules and file transitions are
simple types and not attributes.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: merge fuzz, dropped parts due to dependencies]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Validate the types used in bounds checks.
Replace the usage of BUG(), to avoid halting the system on malformed
polices.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: merge fuzz, fixed typo identified by Smalley]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Check that an ID does not refer to a gap in the global array of
definitions.
Constify parameters of isvalid() function and change return type to
bool.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: merge fixes, dropped boolean checks due to missing dependency]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Index as soon as possible to enable isvalid() checks to fail on gaps.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Validate that no types with an invalid too high ID are present in the
attribute map. Gaps are still not checked.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: changed name to ebitmap_get_highest_set_bit()]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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In multiple places the binary policy announces how many items of some
kind are to be expected next. Before reading them the kernel already
allocates enough memory for that announced size. Validate that the
remaining input size can actually fit the announced items, to avoid OOM
issues on malformed binary policies.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: manual merge fuzz fixups, style fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Be more strict during parsing of policies and reject invalid values.
Add some error messages in the case of policy parse failures, to
enhance debugging, either on a malformed policy or a too strict check.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: fixed checkpatch.pl warnings, style problems]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Security class identifiers are limited to 2^16, thus use the appropriate
type u16 consistently.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Avoid using nontransitive comparison to prevent unexpected sorting
results due to (well-defined) overflows.
See https://www.qualys.com/2024/01/30/qsort.txt for a related issue in
glibc's qsort(3).
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: use the cmp_int() macro from sort.h]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Remove the previously deprecated /sys/fs/selinux/user interface aside
from a residual stub for userspace compatibility.
Commit d7b6918e22c7 ("selinux: Deprecate /sys/fs/selinux/user") started
the deprecation process for /sys/fs/selinux/user:
The selinuxfs "user" node allows userspace to request a list
of security contexts that can be reached for a given SELinux
user from a given starting context. This was used by libselinux
when various login-style programs requested contexts for
users, but libselinux stopped using it in 2020.
Kernel support will be removed no sooner than Dec 2025.
A pr_warn() message has been in place since Linux v6.13, and a 5
second sleep was introduced since Linux v6.17 to help make it more
noticeable.
We are now past the stated deadline of Dec 2025, so remove the
underlying functionality and replace it with a stub that returns a
'0\0' buffer to avoid breaking userspace. This also avoids a local DoS
from logspam and an uninterruptible sleep delay.
Cc: stable@vger.kernel.org
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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These were the only two allocations in the policy loading logic
that were not already using kzalloc_objs() for the policy
data structures. Fix these to be consistent with the rest and
to protect against ill-formed policy.
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Conversion performed via this Coccinelle script:
// SPDX-License-Identifier: GPL-2.0-only
// Options: --include-headers-for-types --all-includes --include-headers --keep-comments
virtual patch
@gfp depends on patch && !(file in "tools") && !(file in "samples")@
identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex,
kzalloc_obj,kzalloc_objs,kzalloc_flex,
kvmalloc_obj,kvmalloc_objs,kvmalloc_flex,
kvzalloc_obj,kvzalloc_objs,kvzalloc_flex};
@@
ALLOC(...
- , GFP_KERNEL
)
$ make coccicheck MODE=patch COCCI=gfp.cocci
Build and boot tested x86_64 with Fedora 42's GCC and Clang:
Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
- Improve the granularity of SELinux labeling for memfd files
Currently when creating a memfd file, SELinux treats it the same as
any other tmpfs, or hugetlbfs, file. While simple, the drawback is
that it is not possible to differentiate between memfd and tmpfs
files.
This adds a call to the security_inode_init_security_anon() LSM hook
and wires up SELinux to provide a set of memfd specific access
controls, including the ability to control the execution of memfds.
As usual, the commit message has more information.
- Improve the SELinux AVC lookup performance
Adopt MurmurHash3 for the SELinux AVC hash function instead of the
custom hash function currently used. MurmurHash3 is already used for
the SELinux access vector table so the impact to the code is minimal,
and performance tests have shown improvements in both hash
distribution and latency.
See the commit message for the performance measurments.
- Introduce a Kconfig option for the SELinux AVC bucket/slot size
While we have the ability to grow the number of AVC hash buckets
today, the size of the buckets (slot size) is fixed at 512. This pull
request makes that slot size configurable at build time through a new
Kconfig knob, CONFIG_SECURITY_SELINUX_AVC_HASH_BITS.
* tag 'selinux-pr-20251201' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: improve bucket distribution uniformity of avc_hash()
selinux: Move avtab_hash() to a shared location for future reuse
selinux: Introduce a new config to make avc cache slot size adjustable
memfd,selinux: call security_inode_init_security_anon()
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Reuse the already implemented MurmurHash3 algorithm. Under heavy stress
testing (on an 8-core system sustaining over 50,000 authentication events
per second), sample once per second and take the mean of 1800 samples:
1. Bucket utilization rate and length of longest chain
+--------------------------+-----------------------------------------+
| | bucket utilization rate / longest chain |
| +--------------------+--------------------+
| | no-patch | with-patch |
+--------------------------+--------------------+--------------------+
| 512 nodes, 512 buckets | 52.5%/7.5 | 60.2%/5.7 |
+--------------------------+--------------------+--------------------+
| 1024 nodes, 512 buckets | 68.9%/12.1 | 80.2%/9.7 |
+--------------------------+--------------------+--------------------+
| 2048 nodes, 512 buckets | 83.7%/19.4 | 93.4%/16.3 |
+--------------------------+--------------------+--------------------+
| 8192 nodes, 8192 buckets | 49.5%/11.4 | 60.3%/7.4 |
+--------------------------+--------------------+--------------------+
2. avc_search_node latency (total latency of hash operation and table
lookup)
+--------------------------+-----------------------------------------+
| | latency of function avc_search_node |
| +--------------------+--------------------+
| | no-patch | with-patch |
+--------------------------+--------------------+--------------------+
| 512 nodes, 512 buckets | 87ns | 84ns |
+--------------------------+--------------------+--------------------+
| 1024 nodes, 512 buckets | 97ns | 96ns |
+--------------------------+--------------------+--------------------+
| 2048 nodes, 512 buckets | 118ns | 113ns |
+--------------------------+--------------------+--------------------+
| 8192 nodes, 8192 buckets | 106ns | 99ns |
+--------------------------+--------------------+--------------------+
Although MurmurHash3 has higher overhead than the bitwise operations in
the original algorithm, the data shows that the MurmurHash3 achieves
better distribution, reducing average lookup time. Consequently, the
total latency of hashing and table lookup is lower than before.
Signed-off-by: Hongru Zhang <zhanghongru@xiaomi.com>
[PM: whitespace fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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This is a preparation patch, no functional change.
Signed-off-by: Hongru Zhang <zhanghongru@xiaomi.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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SELinux currently has a number of initcalls so we've created a new
function, selinux_initcall(), which wraps all of these initcalls so
that we have a single initcall function that can be registered with the
LSM framework.
Signed-off-by: Paul Moore <paul@paul-moore.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
- Introduce the concept of a SELinux "neveraudit" type which prevents
all auditing of the given type/domain.
Taken by itself, the benefit of marking a SELinux domain with the
"neveraudit" tag is likely not very interesting, especially given the
significant overlap with the "dontaudit" tag.
However, given that the "neveraudit" tag applies to *all* auditing of
the tagged domain, we can do some fairly interesting optimizations
when a SELinux domain is marked as both "permissive" and "dontaudit"
(think of the unconfined_t domain).
While this pull request includes optimized inode permission and
getattr hooks, these optimizations require SELinux policy changes,
therefore the improvements may not be visible on standard downstream
Linux distos for a period of time.
- Continue the deprecation process of /sys/fs/selinux/user.
After removing the associated userspace code in 2020, we marked the
/sys/fs/selinux/user interface as deprecated in Linux v6.13 with
pr_warn() and the usual documention update.
This adds a five second sleep after the pr_warn(), following a
previous deprecation process pattern that has worked well for us in
the past in helping identify any existing users that we haven't yet
reached.
- Add a __GFP_NOWARN flag to our initial hash table allocation.
Fuzzers such a syzbot often attempt abnormally large SELinux policy
loads, which the SELinux code gracefully handles by checking for
allocation failures, but not before the allocator emits a warning
which causes the automated fuzzing to flag this as an error and
report it to the list. While we want to continue to support the work
done by the fuzzing teams, we want to focus on proper issues and not
an error case that is already handled safely. Add a NOWARN flag to
quiet the allocator and prevent syzbot from tripping on this again.
- Remove some unnecessary selinuxfs cleanup code, courtesy of Al.
- Update the SELinux in-kernel documentation with pointers to
additional information.
* tag 'selinux-pr-20250725' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: don't bother with selinuxfs_info_free() on failures
selinux: add __GFP_NOWARN to hashtab_init() allocations
selinux: optimize selinux_inode_getattr/permission() based on neveraudit|permissive
selinux: introduce neveraudit types
documentation: add links to SELinux resources
selinux: add a 5 second sleep to /sys/fs/selinux/user
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As reported by syzbot, hashtab_init() can be affected by abnormally
large policy loads which would cause the kernel's allocator to emit
a warning in some configurations. Since the SELinux hashtab_init()
code handles the case where the allocation fails, due to a large
request or some other reason, we can safely add the __GFP_NOWARN flag
to squelch these abnormally large allocation warnings.
Reported-by: syzbot+bc2c99c2929c3d219fb3@syzkaller.appspotmail.com
Tested-by: syzbot+bc2c99c2929c3d219fb3@syzkaller.appspotmail.com
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Introduce neveraudit types i.e. types that should never trigger
audit messages. This allows the AVC to skip all audit-related
processing for such types. Note that neveraudit differs from
dontaudit not only wrt being applied for all checks with a given
source type but also in that it disables all auditing, not just
permission denials.
When a type is both a permissive type and a neveraudit type,
the security server can short-circuit the security_compute_av()
logic, allowing all permissions and not auditing any permissions.
This change just introduces the basic support but does not yet
further optimize the AVC or hook function logic when a type
is both a permissive type and a dontaudit type.
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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If the end result of a security_compute_sid() computation matches the
ssid or tsid, return that SID rather than looking it up again. This
avoids the problem of multiple initial SIDs that map to the same
context.
Cc: stable@vger.kernel.org
Reported-by: Guido Trentalancia <guido@trentalancia.com>
Fixes: ae254858ce07 ("selinux: introduce an initial SID for early boot processes")
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Guido Trentalancia <guido@trentalancia.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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The "linux/parser.h" header was included twice, we only need it once.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202504121945.Q0GDD0sG-lkp@intel.com/
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Currently, genfscon only supports string prefix match to label files.
Thus, labeling numerous dynamic sysfs entries requires many specific
path rules. For example, labeling device paths such as
`/sys/devices/pci0000:00/0000:00:03.1/<...>/0000:04:00.1/wakeup`
requires listing all specific PCI paths, which is challenging to
maintain. While user-space restorecon can handle these paths with
regular expression rules, relabeling thousands of paths under sysfs
after it is mounted is inefficient compared to using genfscon.
This commit adds wildcard matching to genfscon to make rules more
efficient and expressive. This new behavior is enabled by
genfs_seclabel_wildcard capability. With this capability, genfscon does
wildcard matching instead of prefix matching. When multiple wildcard
rules match against a path, then the longest rule (determined by the
length of the rule string) will be applied. If multiple rules of the
same length match, the first matching rule encountered in the given
genfscon policy will be applied. Users are encouraged to write longer,
more explicit path rules to avoid relying on this behavior.
This change resulted in nice real-world performance improvements. For
example, boot times on test Android devices were reduced by 15%. This
improvement is due to the elimination of the "restorecon -R /sys" step
during boot, which takes more than two seconds in the worst case.
Signed-off-by: Takaya Saeki <takayas@chromium.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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The network address, either an IPv4 or IPv6 one, is not modified.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Retrieve the netif_wildcard policy capability in security_netif_sid()
from the locked active policy instead of the cached value in
selinux_state.
Fixes: 8af43b61c17e ("selinux: support wildcard network interface names")
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: /netlabel/netif/ due to a typo in the description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Add support for wildcard matching of network interface names. This is
useful for auto-generated interfaces, for example podman creates network
interfaces for containers with the naming scheme podman0, podman1,
podman2, ...
To maintain backward compatibility guard this feature with a new policy
capability 'netif_wildcard'.
Netifcon definitions are compared against in the order given by the
policy, so userspace tools should sort them in a reasonable order.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
- Extended permissions supported in conditional policy
The SELinux extended permissions, aka "xperms", allow security admins
to target individuals ioctls, and recently netlink messages, with
their SELinux policy. Adding support for conditional policies allows
admins to toggle the granular xperms using SELinux booleans, helping
pave the way for greater use of xperms in general purpose SELinux
policies. This change bumps the maximum SELinux policy version to 34.
- Fix a SCTP/SELinux error return code inconsistency
Depending on the loaded SELinux policy, specifically it's
EXTSOCKCLASS support, the bind(2) LSM/SELinux hook could return
different error codes due to the SELinux code checking the socket's
SELinux object class (which can vary depending on EXTSOCKCLASS) and
not the socket's sk_protocol field. We fix this by doing the obvious,
and looking at the sock->sk_protocol field instead of the object
class.
- Makefile fixes to properly cleanup av_permissions.h
Add av_permissions.h to "targets" so that it is properly cleaned up
using the kbuild infrastructure.
- A number of smaller improvements by Christian Göttsche
A variety of straightforward changes to reduce code duplication,
reduce pointer lookups, migrate void pointers to defined types,
simplify code, constify function parameters, and correct iterator
types.
* tag 'selinux-pr-20250121' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: make more use of str_read() when loading the policy
selinux: avoid unnecessary indirection in struct level_datum
selinux: use known type instead of void pointer
selinux: rename comparison functions for clarity
selinux: rework match_ipv6_addrmask()
selinux: constify and reconcile function parameter names
selinux: avoid using types indicating user space interaction
selinux: supply missing field initializers
selinux: add netlink nlmsg_type audit message
selinux: add support for xperms in conditional policies
selinux: Fix SCTP error inconsistency in selinux_socket_bind()
selinux: use native iterator types
selinux: add generated av_permissions.h to targets
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Simplify the call sites, and enable future string validation in a single
place.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Store the owned member of type struct mls_level directly in the parent
struct instead of an extra heap allocation.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Improve type safety and readability by using the known type.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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The functions context_cmp(), mls_context_cmp() and ebitmap_cmp() are not
traditional C style compare functions returning -1, 0, and 1 for less
than, equal, and greater than; they only return whether their arguments
are equal.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Constify parameters, add size hints, and simplify control flow.
According to godbolt the same assembly is generated.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Align the parameter names between declarations and definitions, and
constify read-only parameters.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: tweak the subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>
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Integer types starting with a double underscore, like __u32, are
intended for usage of variables interacting with user-space.
Just use the plain variant.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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In commit d1d991efaf34 ("selinux: Add netlink xperm support") a new
extended permission was added ("nlmsg"). This was the second extended
permission implemented in selinux ("ioctl" being the first one).
Extended permissions are associated with a base permission. It was found
that, in the access vector cache (avc), the extended permission did not
keep track of its base permission. This is an issue for a domain that is
using both extended permissions (i.e., a domain calling ioctl() on a
netlink socket). In this case, the extended permissions were
overlapping.
Keep track of the base permission in the cache. A new field "base_perm"
is added to struct extended_perms_decision to make sure that the
extended permission refers to the correct policy permission. A new field
"base_perms" is added to struct extended_perms to quickly decide if
extended permissions apply.
While it is in theory possible to retrieve the base permission from the
access vector, the same base permission may not be mapped to the same
bit for each class (e.g., "nlmsg" is mapped to a different bit for
"netlink_route_socket" and "netlink_audit_socket"). Instead, use a
constant (AVC_EXT_IOCTL or AVC_EXT_NLMSG) provided by the caller.
Fixes: d1d991efaf34 ("selinux: Add netlink xperm support")
Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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When evaluating extended permissions, ignore unknown permissions instead
of calling BUG(). This commit ensures that future permissions can be
added without interfering with older kernels.
Cc: stable@vger.kernel.org
Fixes: fa1aa143ac4a ("selinux: extended permissions for ioctls")
Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
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