Commit Graph

410 Commits (edcef667070f7dbddca403e6331c86940407dae0)

Author SHA1 Message Date
Linus Torvalds 690ffcd817 selinux/stable-6.14 PR 20250121
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Merge tag 'selinux-pr-20250121' of 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
2025-01-21 20:09:14 -08:00
Christian Göttsche 9090308510 selinux: constify and reconcile function parameter names
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>
2025-01-07 23:14:38 -05:00
Christian Göttsche 9d8d094fa3 selinux: supply missing field initializers
Please clang by supplying the missing field initializers in the
secclass_map variable and sel_fill_super() function.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: tweak subj and commit description]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-01-07 23:14:37 -05:00
Thiébaud Weksteen 5e7f0efd23 selinux: match extended permissions to their base permissions
In commit d1d991efaf ("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: d1d991efaf ("selinux: Add netlink xperm support")
Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2025-01-04 20:58:46 -05:00
Christian Göttsche 4aa1761934 selinux: add support for xperms in conditional policies
Add support for extended permission rules in conditional policies.
Currently the kernel accepts such rules already, but evaluating a
security decision will hit a BUG() in
services_compute_xperms_decision().  Thus reject extended permission
rules in conditional policies for current policy versions.

Add a new policy version for this feature.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Tested-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-12-13 16:35:38 -05:00
Linus Torvalds 5591fd5e03 lsm/stable-6.13 PR 20241112
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Merge tag 'lsm-pr-20241112' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

Pull lsm updates from Paul Moore:
 "Thirteen patches, all focused on moving away from the current 'secid'
  LSM identifier to a richer 'lsm_prop' structure.

  This move will help reduce the translation that is necessary in many
  LSMs, offering better performance, and make it easier to support
  different LSMs in the future"

* tag 'lsm-pr-20241112' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
  lsm: remove lsm_prop scaffolding
  netlabel,smack: use lsm_prop for audit data
  audit: change context data from secid to lsm_prop
  lsm: create new security_cred_getlsmprop LSM hook
  audit: use an lsm_prop in audit_names
  lsm: use lsm_prop in security_inode_getsecid
  lsm: use lsm_prop in security_current_getsecid
  audit: update shutdown LSM data
  lsm: use lsm_prop in security_ipc_getsecid
  audit: maintain an lsm_prop in audit_context
  lsm: add lsmprop_to_secctx hook
  lsm: use lsm_prop in security_audit_rule_match
  lsm: add the lsm_prop data structure
2024-11-18 17:34:05 -08:00
Casey Schaufler 6f2f724f0e lsm: add lsmprop_to_secctx hook
Add a new hook security_lsmprop_to_secctx() and its LSM specific
implementations. The LSM specific code will use the lsm_prop element
allocated for that module. This allows for the possibility that more
than one module may be called upon to translate a secid to a string,
as can occur in the audit code.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-10-11 14:34:12 -04:00
Casey Schaufler 870b7fdc66 lsm: use lsm_prop in security_audit_rule_match
Change the secid parameter of security_audit_rule_match
to a lsm_prop structure pointer. Pass the entry from the
lsm_prop structure for the approprite slot to the LSM hook.

Change the users of security_audit_rule_match to use the
lsm_prop instead of a u32. The scaffolding function lsmprop_init()
fills the structure with the value of the old secid, ensuring that
it is available to the appropriate module hook. The sources of
the secid, security_task_getsecid() and security_inode_getsecid(),
will be converted to use the lsm_prop structure later in the series.
At that point the use of lsmprop_init() is dropped.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject line tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-10-11 14:34:12 -04:00
Thiébaud Weksteen d1d991efaf selinux: Add netlink xperm support
Reuse the existing extended permissions infrastructure to support
policies based on the netlink message types.

A new policy capability "netlink_xperm" is introduced. When disabled,
the previous behaviour is preserved. That is, netlink_send will rely on
the permission mappings defined in nlmsgtab.c (e.g, nlmsg_read for
RTM_GETADDR on NETLINK_ROUTE). When enabled, the mappings are ignored
and the generic "nlmsg" permission is used instead.

The new "nlmsg" permission is an extended permission. The 16 bits of the
extended permission are mapped to the nlmsg_type field.

Example policy on Android, preventing regular apps from accessing the
device's MAC address and ARP table, but allowing this access to
privileged apps, looks as follows:

allow netdomain self:netlink_route_socket {
	create read getattr write setattr lock append connect getopt
	setopt shutdown nlmsg
};
allowxperm netdomain self:netlink_route_socket nlmsg ~{
	RTM_GETLINK RTM_GETNEIGH RTM_GETNEIGHTBL
};
allowxperm priv_app self:netlink_route_socket nlmsg {
	RTM_GETLINK RTM_GETNEIGH RTM_GETNEIGHTBL
};

The constants in the example above (e.g., RTM_GETLINK) are explicitly
defined in the policy.

It is possible to generate policies to support kernels that may or
may not have the capability enabled by generating a rule for each
scenario. For instance:

allow domain self:netlink_audit_socket nlmsg_read;
allow domain self:netlink_audit_socket nlmsg;
allowxperm domain self:netlink_audit_socket nlmsg { AUDIT_GET };

The approach of defining a new permission ("nlmsg") instead of relying
on the existing permissions (e.g., "nlmsg_read", "nlmsg_readpriv" or
"nlmsg_tty_audit") has been preferred because:
  1. This is similar to the other extended permission ("ioctl");
  2. With the new extended permission, the coarse-grained mapping is not
     necessary anymore. It could eventually be removed, which would be
     impossible if the extended permission was defined below these.
  3. Having a single extra extended permission considerably simplifies
     the implementation here and in libselinux.

Signed-off-by: Thiébaud Weksteen <tweek@google.com>
Signed-off-by: Bram Bonné <brambonne@google.com>
[PM: manual merge fixes for sock_skip_has_perm()]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-10-07 16:28:11 -04:00
Masahiro Yamada 541b57e313 selinux: do not include <linux/*.h> headers from host programs
The header, security/selinux/include/classmap.h, is included not only
from kernel space but also from host programs.

It includes <linux/capability.h> and <linux/socket.h>, which pull in
more <linux/*.h> headers. This makes the host programs less portable,
specifically causing build errors on macOS.

Those headers are included for the following purposes:

 - <linux/capability.h> for checking CAP_LAST_CAP
 - <linux/socket.h> for checking PF_MAX

These checks can be guarded by __KERNEL__ so they are skipped when
building host programs. Testing them when building the kernel should
be sufficient.

The header, security/selinux/include/initial_sid_to_string.h, includes
<linux/stddef.h> for the NULL definition, but this is not portable
either. Instead, <stddef.h> should be included for host programs.

Reported-by: Daniel Gomez <da.gomez@samsung.com>
Closes: https://lore.kernel.org/lkml/20240807-macos-build-support-v1-6-4cd1ded85694@samsung.com/
Closes: https://lore.kernel.org/lkml/20240807-macos-build-support-v1-7-4cd1ded85694@samsung.com/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-10-03 15:34:24 -04:00
Linus Torvalds a430d95c5e lsm/stable-6.12 PR 20240911
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Merge tag 'lsm-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm

Pull lsm updates from Paul Moore:

 - Move the LSM framework to static calls

   This transitions the vast majority of the LSM callbacks into static
   calls. Those callbacks which haven't been converted were left as-is
   due to the general ugliness of the changes required to support the
   static call conversion; we can revisit those callbacks at a future
   date.

 - Add the Integrity Policy Enforcement (IPE) LSM

   This adds a new LSM, Integrity Policy Enforcement (IPE). There is
   plenty of documentation about IPE in this patches, so I'll refrain
   from going into too much detail here, but the basic motivation behind
   IPE is to provide a mechanism such that administrators can restrict
   execution to only those binaries which come from integrity protected
   storage, e.g. a dm-verity protected filesystem. You will notice that
   IPE requires additional LSM hooks in the initramfs, dm-verity, and
   fs-verity code, with the associated patches carrying ACK/review tags
   from the associated maintainers. We couldn't find an obvious
   maintainer for the initramfs code, but the IPE patchset has been
   widely posted over several years.

   Both Deven Bowers and Fan Wu have contributed to IPE's development
   over the past several years, with Fan Wu agreeing to serve as the IPE
   maintainer moving forward. Once IPE is accepted into your tree, I'll
   start working with Fan to ensure he has the necessary accounts, keys,
   etc. so that he can start submitting IPE pull requests to you
   directly during the next merge window.

 - Move the lifecycle management of the LSM blobs to the LSM framework

   Management of the LSM blobs (the LSM state buffers attached to
   various kernel structs, typically via a void pointer named "security"
   or similar) has been mixed, some blobs were allocated/managed by
   individual LSMs, others were managed by the LSM framework itself.

   Starting with this pull we move management of all the LSM blobs,
   minus the XFRM blob, into the framework itself, improving consistency
   across LSMs, and reducing the amount of duplicated code across LSMs.
   Due to some additional work required to migrate the XFRM blob, it has
   been left as a todo item for a later date; from a practical
   standpoint this omission should have little impact as only SELinux
   provides a XFRM LSM implementation.

 - Fix problems with the LSM's handling of F_SETOWN

   The LSM hook for the fcntl(F_SETOWN) operation had a couple of
   problems: it was racy with itself, and it was disconnected from the
   associated DAC related logic in such a way that the LSM state could
   be updated in cases where the DAC state would not. We fix both of
   these problems by moving the security_file_set_fowner() hook into the
   same section of code where the DAC attributes are updated. Not only
   does this resolve the DAC/LSM synchronization issue, but as that code
   block is protected by a lock, it also resolve the race condition.

 - Fix potential problems with the security_inode_free() LSM hook

   Due to use of RCU to protect inodes and the placement of the LSM hook
   associated with freeing the inode, there is a bit of a challenge when
   it comes to managing any LSM state associated with an inode. The VFS
   folks are not open to relocating the LSM hook so we have to get
   creative when it comes to releasing an inode's LSM state.
   Traditionally we have used a single LSM callback within the hook that
   is triggered when the inode is "marked for death", but not actually
   released due to RCU.

   Unfortunately, this causes problems for LSMs which want to take an
   action when the inode's associated LSM state is actually released; so
   we add an additional LSM callback, inode_free_security_rcu(), that is
   called when the inode's LSM state is released in the RCU free
   callback.

 - Refactor two LSM hooks to better fit the LSM return value patterns

   The vast majority of the LSM hooks follow the "return 0 on success,
   negative values on failure" pattern, however, there are a small
   handful that have unique return value behaviors which has caused
   confusion in the past and makes it difficult for the BPF verifier to
   properly vet BPF LSM programs. This includes patches to
   convert two of these"special" LSM hooks to the common 0/-ERRNO pattern.

 - Various cleanups and improvements

   A handful of patches to remove redundant code, better leverage the
   IS_ERR_OR_NULL() helper, add missing "static" markings, and do some
   minor style fixups.

* tag 'lsm-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (40 commits)
  security: Update file_set_fowner documentation
  fs: Fix file_set_fowner LSM hook inconsistencies
  lsm: Use IS_ERR_OR_NULL() helper function
  lsm: remove LSM_COUNT and LSM_CONFIG_COUNT
  ipe: Remove duplicated include in ipe.c
  lsm: replace indirect LSM hook calls with static calls
  lsm: count the LSMs enabled at compile time
  kernel: Add helper macros for loop unrolling
  init/main.c: Initialize early LSMs after arch code, static keys and calls.
  MAINTAINERS: add IPE entry with Fan Wu as maintainer
  documentation: add IPE documentation
  ipe: kunit test for parser
  scripts: add boot policy generation program
  ipe: enable support for fs-verity as a trust provider
  fsverity: expose verified fsverity built-in signatures to LSMs
  lsm: add security_inode_setintegrity() hook
  ipe: add support for dm-verity as a trust provider
  dm-verity: expose root hash digest and signature data to LSMs
  block,lsm: add LSM blob and new LSM hooks for block devices
  ipe: add permissive toggle
  ...
2024-09-16 18:19:47 +02:00
Paul Moore d19a9e25a7 selinux: fix style problems in security/selinux/include/audit.h
Remove the needless indent in the function comment header blocks.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-09-03 18:54:38 -04:00
Casey Schaufler 61a1dcdceb lsm: infrastructure management of the perf_event security blob
Move management of the perf_event->security blob out of the individual
security modules and into the security infrastructure. Instead of
allocating the blobs from within the modules the modules tell the
infrastructure how much space is required, and the space is allocated
there.  There are no longer any modules that require the perf_event_free()
hook.  The hook definition has been removed.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-07-29 16:54:52 -04:00
Casey Schaufler 66de33a0bb lsm: infrastructure management of the infiniband blob
Move management of the infiniband security blob out of the individual
security modules and into the LSM infrastructure.  The security modules
tell the infrastructure how much space they require at initialization.
There are no longer any modules that require the ib_free() hook.
The hook definition has been removed.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak, selinux style fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-07-29 16:54:52 -04:00
Casey Schaufler a39c0f77db lsm: infrastructure management of the dev_tun blob
Move management of the dev_tun security blob out of the individual
security modules and into the LSM infrastructure.  The security modules
tell the infrastructure how much space they require at initialization.
There are no longer any modules that require the dev_tun_free hook.
The hook definition has been removed.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak, selinux style fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-07-29 16:54:51 -04:00
Casey Schaufler 5f8d28f6d7 lsm: infrastructure management of the key security blob
Move management of the key->security blob out of the individual security
modules and into the security infrastructure. Instead of allocating the
blobs from within the modules the modules tell the infrastructure how
much space is required, and the space is allocated there.  There are
no existing modules that require a key_free hook, so the call to it and
the definition for it have been removed.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-07-29 16:54:51 -04:00
Casey Schaufler 2aff9d20d5 lsm: infrastructure management of the sock security
Move management of the sock->sk_security blob out
of the individual security modules and into the security
infrastructure. Instead of allocating the blobs from within
the modules the modules tell the infrastructure how much
space is required, and the space is allocated there.

Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: subject tweak]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-07-29 16:54:50 -04:00
GUO Zihua 9a95c5bfbf ima: Avoid blocking in RCU read-side critical section
A panic happens in ima_match_policy:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 42f873067 P4D 0
Oops: 0000 [#1] SMP NOPTI
CPU: 5 PID: 1286325 Comm: kubeletmonit.sh
Kdump: loaded Tainted: P
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
               BIOS 0.0.0 02/06/2015
RIP: 0010:ima_match_policy+0x84/0x450
Code: 49 89 fc 41 89 cf 31 ed 89 44 24 14 eb 1c 44 39
      7b 18 74 26 41 83 ff 05 74 20 48 8b 1b 48 3b 1d
      f2 b9 f4 00 0f 84 9c 01 00 00 <44> 85 73 10 74 ea
      44 8b 6b 14 41 f6 c5 01 75 d4 41 f6 c5 02 74 0f
RSP: 0018:ff71570009e07a80 EFLAGS: 00010207
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000200
RDX: ffffffffad8dc7c0 RSI: 0000000024924925 RDI: ff3e27850dea2000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffffabfce739
R10: ff3e27810cc42400 R11: 0000000000000000 R12: ff3e2781825ef970
R13: 00000000ff3e2785 R14: 000000000000000c R15: 0000000000000001
FS:  00007f5195b51740(0000)
GS:ff3e278b12d40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000626d24002 CR4: 0000000000361ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ima_get_action+0x22/0x30
 process_measurement+0xb0/0x830
 ? page_add_file_rmap+0x15/0x170
 ? alloc_set_pte+0x269/0x4c0
 ? prep_new_page+0x81/0x140
 ? simple_xattr_get+0x75/0xa0
 ? selinux_file_open+0x9d/0xf0
 ima_file_check+0x64/0x90
 path_openat+0x571/0x1720
 do_filp_open+0x9b/0x110
 ? page_counter_try_charge+0x57/0xc0
 ? files_cgroup_alloc_fd+0x38/0x60
 ? __alloc_fd+0xd4/0x250
 ? do_sys_open+0x1bd/0x250
 do_sys_open+0x1bd/0x250
 do_syscall_64+0x5d/0x1d0
 entry_SYSCALL_64_after_hwframe+0x65/0xca

Commit c7423dbdbc ("ima: Handle -ESTALE returned by
ima_filter_rule_match()") introduced call to ima_lsm_copy_rule within a
RCU read-side critical section which contains kmalloc with GFP_KERNEL.
This implies a possible sleep and violates limitations of RCU read-side
critical sections on non-PREEMPT systems.

Sleeping within RCU read-side critical section might cause
synchronize_rcu() returning early and break RCU protection, allowing a
UAF to happen.

The root cause of this issue could be described as follows:
|	Thread A	|	Thread B	|
|			|ima_match_policy	|
|			|  rcu_read_lock	|
|ima_lsm_update_rule	|			|
|  synchronize_rcu	|			|
|			|    kmalloc(GFP_KERNEL)|
|			|      sleep		|
==> synchronize_rcu returns early
|  kfree(entry)		|			|
|			|    entry = entry->next|
==> UAF happens and entry now becomes NULL (or could be anything).
|			|    entry->action	|
==> Accessing entry might cause panic.

To fix this issue, we are converting all kmalloc that is called within
RCU read-side critical section to use GFP_ATOMIC.

Fixes: c7423dbdbc ("ima: Handle -ESTALE returned by ima_filter_rule_match()")
Cc: stable@vger.kernel.org
Signed-off-by: GUO Zihua <guozihua@huawei.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: fixed missing comment, long lines, !CONFIG_IMA_LSM_RULES case]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2024-06-13 14:26:50 -04:00
Paul Moore cc2a734199 selinux: fix style issues in security/selinux/include/initial_sid_to_string.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:31 -05:00
Paul Moore cea9216338 selinux: fix style issues in security/selinux/include/xfrm.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:30 -05:00
Paul Moore 7d1464bd11 selinux: fix style issues in security/selinux/include/security.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:30 -05:00
Paul Moore 376ef14d62 selinux: fix style issues with security/selinux/include/policycap_names.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:30 -05:00
Paul Moore db896a0061 selinux: fix style issues in security/selinux/include/policycap.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:29 -05:00
Paul Moore c787022036 selinux: fix style issues in security/selinux/include/objsec.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:29 -05:00
Paul Moore 3e7773f8da selinux: fix style issues with security/selinux/include/netlabel.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:28 -05:00
Paul Moore e04f8585d0 selinux: fix style issues in security/selinux/include/netif.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:28 -05:00
Paul Moore e5a4cc30cb selinux: fix style issues in security/selinux/include/ima.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:28 -05:00
Paul Moore ce4a781bae selinux: fix style issues in security/selinux/include/conditional.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:27 -05:00
Paul Moore 27283b3118 selinux: fix style issues in security/selinux/include/classmap.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:27 -05:00
Paul Moore 1d08fa8b95 selinux: fix style issues in security/selinux/include/avc_ss.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:26 -05:00
Paul Moore bb4e5993f1 selinux: align avc_has_perm_noaudit() prototype with definition
A trivial correction to convert an 'unsigned' parameter into an
'unsigned int' parameter so the prototype matches the function
definition.

I really thought that someone submitted a patch for this a few years
ago but sadly I can't find it now.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:26 -05:00
Paul Moore bdaaf515ba selinux: fix style issues in security/selinux/include/avc.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:26 -05:00
Paul Moore e9b0748b6b selinux: fix style issues in security/selinux/include/audit.h
As part of on ongoing effort to perform more automated testing and
provide more tools for individual developers to validate their
patches before submitting, we are trying to make our code
"clang-format clean".  My hope is that once we have fixed all of our
style "quirks", developers will be able to run clang-format on their
patches to help avoid silly formatting problems and ensure their
changes fit in well with the rest of the SELinux kernel code.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-12-22 18:09:25 -05:00
Ondrej Mosnacek ae254858ce selinux: introduce an initial SID for early boot processes
Currently, SELinux doesn't allow distinguishing between kernel threads
and userspace processes that are started before the policy is first
loaded - both get the label corresponding to the kernel SID. The only
way a process that persists from early boot can get a meaningful label
is by doing a voluntary dyntransition or re-executing itself.

Reusing the kernel label for userspace processes is problematic for
several reasons:
1. The kernel is considered to be a privileged domain and generally
   needs to have a wide range of permissions allowed to work correctly,
   which prevents the policy writer from effectively hardening against
   early boot processes that might remain running unintentionally after
   the policy is loaded (they represent a potential extra attack surface
   that should be mitigated).
2. Despite the kernel being treated as a privileged domain, the policy
   writer may want to impose certain special limitations on kernel
   threads that may conflict with the requirements of intentional early
   boot processes. For example, it is a good hardening practice to limit
   what executables the kernel can execute as usermode helpers and to
   confine the resulting usermode helper processes. However, a
   (legitimate) process surviving from early boot may need to execute a
   different set of executables.
3. As currently implemented, overlayfs remembers the security context of
   the process that created an overlayfs mount and uses it to bound
   subsequent operations on files using this context. If an overlayfs
   mount is created before the SELinux policy is loaded, these "mounter"
   checks are made against the kernel context, which may clash with
   restrictions on the kernel domain (see 2.).

To resolve this, introduce a new initial SID (reusing the slot of the
former "init" initial SID) that will be assigned to any userspace
process started before the policy is first loaded. This is easy to do,
as we can simply label any process that goes through the
bprm_creds_for_exec LSM hook with the new init-SID instead of
propagating the kernel SID from the parent.

To provide backwards compatibility for existing policies that are
unaware of this new semantic of the "init" initial SID, introduce a new
policy capability "userspace_initial_context" and set the "init" SID to
the same context as the "kernel" SID unless this capability is set by
the policy.

Another small backwards compatibility measure is needed in
security_sid_to_context_core() for before the initial SELinux policy
load - see the code comment for explanation.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: edited comments based on feedback/discussion]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-11-21 18:39:59 -05:00
Paul Moore 817199e006 selinux: revert SECINITSID_INIT support
This commit reverts 5b0eea835d ("selinux: introduce an initial SID
for early boot processes") as it was found to cause problems on
distros with old SELinux userspace tools/libraries, specifically
Ubuntu 16.04.

Hopefully we will be able to re-add this functionality at a later
date, but let's revert this for now to help ensure a stable and
backwards compatible SELinux tree.

Link: https://lore.kernel.org/selinux/87edkseqf8.fsf@mail.lhotse
Acked-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-08-09 10:51:13 -04:00
Christian Göttsche c50e125d05 selinux: avoid implicit conversions in services code
Use u32 as the output parameter type in security_get_classes() and
security_get_permissions(), based on the type of the symtab nprim
member.

Declare the read-only class string parameter of
security_get_permissions() const.

Avoid several implicit conversions by using the identical type for the
destination.

Use the type identical to the source for local variables.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: cleanup extra whitespace in subject]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-08-03 22:19:57 -04:00
Stephen Smalley 0fe53224bf selinux: update my email address
Update my email address; MAINTAINERS was updated some time ago.

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-07-19 11:27:02 -04:00
Stephen Smalley 90aa4f5e92 selinux: de-brand SELinux
Change "NSA SELinux" to just "SELinux" in Kconfig help text and
comments. While NSA was the original primary developer and continues to
help maintain SELinux, SELinux has long since transitioned to a wide
community of developers and maintainers. SELinux has been part of the
mainline Linux kernel for nearly 20 years now [1] and has received
contributions from many individuals and organizations.

[1] https://lore.kernel.org/lkml/Pine.LNX.4.44.0308082228470.1852-100000@home.osdl.org/

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-07-18 18:42:57 -04:00
Christian Göttsche c867248cf4 selinux: avoid implicit conversions regarding enforcing status
Use the type bool as parameter type in
selinux_status_update_setenforce().  The related function
enforcing_enabled() returns the type bool, while the struct
selinux_kernel_status member enforcing uses an u32.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: subject line tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-07-18 18:29:50 -04:00
Christian Göttsche 1f270f1c34 selinux: consistently use u32 as sequence number type in the status code
Align the type with the one used in selinux_notify_policy_change() and
the sequence member of struct selinux_kernel_status.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
[PM: subject line tweaks]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-07-18 18:29:47 -04:00
Ondrej Mosnacek 5b0eea835d selinux: introduce an initial SID for early boot processes
Currently, SELinux doesn't allow distinguishing between kernel threads
and userspace processes that are started before the policy is first
loaded - both get the label corresponding to the kernel SID. The only
way a process that persists from early boot can get a meaningful label
is by doing a voluntary dyntransition or re-executing itself.

Reusing the kernel label for userspace processes is problematic for
several reasons:
1. The kernel is considered to be a privileged domain and generally
   needs to have a wide range of permissions allowed to work correctly,
   which prevents the policy writer from effectively hardening against
   early boot processes that might remain running unintentionally after
   the policy is loaded (they represent a potential extra attack surface
   that should be mitigated).
2. Despite the kernel being treated as a privileged domain, the policy
   writer may want to impose certain special limitations on kernel
   threads that may conflict with the requirements of intentional early
   boot processes. For example, it is a good hardening practice to limit
   what executables the kernel can execute as usermode helpers and to
   confine the resulting usermode helper processes. However, a
   (legitimate) process surviving from early boot may need to execute a
   different set of executables.
3. As currently implemented, overlayfs remembers the security context of
   the process that created an overlayfs mount and uses it to bound
   subsequent operations on files using this context. If an overlayfs
   mount is created before the SELinux policy is loaded, these "mounter"
   checks are made against the kernel context, which may clash with
   restrictions on the kernel domain (see 2.).

To resolve this, introduce a new initial SID (reusing the slot of the
former "init" initial SID) that will be assigned to any userspace
process started before the policy is first loaded. This is easy to do,
as we can simply label any process that goes through the
bprm_creds_for_exec LSM hook with the new init-SID instead of
propagating the kernel SID from the parent.

To provide backwards compatibility for existing policies that are
unaware of this new semantic of the "init" initial SID, introduce a new
policy capability "userspace_initial_context" and set the "init" SID to
the same context as the "kernel" SID unless this capability is set by
the policy.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-07-10 14:23:56 -04:00
Paul Moore d91c1ab470 selinux: cleanup the policycap accessor functions
In the process of reverting back to directly accessing the global
selinux_state pointer we left behind some artifacts in the
selinux_policycap_XXX() helper functions.  This patch cleans up
some of that left-behind cruft.

Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-07-10 14:23:56 -04:00
Ondrej Mosnacek cec5fe7007 selinux: make labeled NFS work when mounted before policy load
Currently, when an NFS filesystem that supports passing LSM/SELinux
labels is mounted during early boot (before the SELinux policy is
loaded), it ends up mounted without the labeling support (i.e. with
Fedora policy all files get the generic NFS label
system_u:object_r:nfs_t:s0).

This is because the information that the NFS mount supports passing
labels (communicated to the LSM layer via the kern_flags argument of
security_set_mnt_opts()) gets lost and when the policy is loaded the
mount is initialized as if the passing is not supported.

Fix this by noting the "native labeling" in newsbsec->flags (using a new
SE_SBNATIVE flag) on the pre-policy-loaded call of
selinux_set_mnt_opts() and then making sure it is respected on the
second call from delayed_superblock_init().

Additionally, make inode_doinit_with_dentry() initialize the inode's
label from its extended attributes whenever it doesn't find it already
intitialized by the filesystem. This is needed to properly initialize
pre-existing inodes when delayed_superblock_init() is called. It should
not trigger in any other cases (and if it does, it's still better to
initialize the correct label instead of leaving the inode unlabeled).

Fixes: eb9ae68650 ("SELinux: Add new labeling type native labels")
Tested-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: fixed 'Fixes' tag format]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-05-30 17:44:34 -04:00
Xiu Jianfeng 29cd55fe69 selinux: cleanup exit_sel_fs() declaration
exit_sel_fs() has been removed since commit f22f9aaf6c ("selinux:
remove the runtime disable functionality").

Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-05-30 16:43:25 -04:00
Christian Göttsche eb14232fb7 selinux: make header files self-including
Include all necessary headers in header files to enable third party
applications, like LSP servers, to resolve all used symbols.

ibpkey.h: include "flask.h" for SECINITSID_UNLABELED
initial_sid_to_string.h: include <linux/stddef.h> for NULL

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-05-18 14:12:43 -04:00
Christian Göttsche 757010002b selinux: avc: drop unused function avc_disable()
Since commit f22f9aaf6c ("selinux: remove the runtime disable
functionality") the function avc_disable() is no longer used.

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-05-08 16:45:36 -04:00
Christian Göttsche 3d9047a064 selinux: adjust typos in comments
Found by codespell(1)

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-05-08 16:44:01 -04:00
Paul Moore f22f9aaf6c selinux: remove the runtime disable functionality
After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable functionality.  The existing kernel deprecation
notice explains the functionality and why we want to remove it:

  The selinuxfs "disable" node allows SELinux to be disabled at
  runtime prior to a policy being loaded into the kernel.  If
  disabled via this mechanism, SELinux will remain disabled until
  the system is rebooted.

  The preferred method of disabling SELinux is via the "selinux=0"
  boot parameter, but the selinuxfs "disable" node was created to
  make it easier for systems with primitive bootloaders that did not
  allow for easy modification of the kernel command line.
  Unfortunately, allowing for SELinux to be disabled at runtime makes
  it difficult to secure the kernel's LSM hooks using the
  "__ro_after_init" feature.

It is that last sentence, mentioning the '__ro_after_init' hardening,
which is the real motivation for this change, and if you look at the
diffstat you'll see that the impact of this patch reaches across all
the different LSMs, helping prevent tampering at the LSM hook level.

From a SELinux perspective, it is important to note that if you
continue to disable SELinux via "/etc/selinux/config" it may appear
that SELinux is disabled, but it is simply in an uninitialized state.
If you load a policy with `load_policy -i`, you will see SELinux
come alive just as if you had loaded the policy during early-boot.

It is also worth noting that the "/sys/fs/selinux/disable" file is
always writable now, regardless of the Kconfig settings, but writing
to the file has no effect on the system, other than to display an
error on the console if a non-zero/true value is written.

Finally, in the several years where we have been working on
deprecating this functionality, there has only been one instance of
someone mentioning any user visible breakage.  In this particular
case it was an individual's kernel test system, and the workaround
documented in the deprecation notice ("selinux=0" on the kernel
command line) resolved the issue without problem.

Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-03-20 12:34:23 -04:00
Paul Moore a7e4676e8e selinux: remove the 'checkreqprot' functionality
We originally promised that the SELinux 'checkreqprot' functionality
would be removed no sooner than June 2021, and now that it is March
2023 it seems like it is a good time to do the final removal.  The
deprecation notice in the kernel provides plenty of detail on why
'checkreqprot' is not desirable, with the key point repeated below:

  This was a compatibility mechanism for legacy userspace and
  for the READ_IMPLIES_EXEC personality flag.  However, if set to
  1, it weakens security by allowing mappings to be made executable
  without authorization by policy.  The default value of checkreqprot
  at boot was changed starting in Linux v4.4 to 0 (i.e. check the
  actual protection), and Android and Linux distributions have been
  explicitly writing a "0" to /sys/fs/selinux/checkreqprot during
  initialization for some time.

Along with the official deprecation notice, we have been discussing
this on-list and directly with several of the larger SELinux-based
distros and everyone is happy to see this feature finally removed.
In an attempt to catch all of the smaller, and DIY, Linux systems
we have been writing a deprecation notice URL into the kernel log,
along with a growing ssleep() penalty, when admins enabled
checkreqprot at runtime or via the kernel command line.  We have
yet to have anyone come to us and raise an objection to the
deprecation or planned removal.

It is worth noting that while this patch removes the checkreqprot
functionality, it leaves the user visible interfaces (kernel command
line and selinuxfs file) intact, just inert.  This should help
prevent breakages with existing userspace tools that correctly, but
unnecessarily, disable checkreqprot at boot or runtime.  Admins
that attempt to enable checkreqprot will be met with a removal
message in the kernel log.

Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-03-20 12:33:50 -04:00
Stephen Smalley e67b79850f selinux: stop passing selinux_state pointers and their offspring
Linus observed that the pervasive passing of selinux_state pointers
introduced by me in commit aa8e712cee ("selinux: wrap global selinux
state") adds overhead and complexity without providing any
benefit. The original idea was to pave the way for SELinux namespaces
but those have not yet been implemented and there isn't currently
a concrete plan to do so. Remove the passing of the selinux_state
pointers, reverting to direct use of the single global selinux_state,
and likewise remove passing of child pointers like the selinux_avc.
The selinux_policy pointer remains as it is needed for atomic switching
of policies.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202303101057.mZ3Gv5fK-lkp@intel.com/
Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2023-03-14 15:22:45 -04:00