Commit Graph

807 Commits

Author SHA1 Message Date
Linus Torvalds
5825a95fe9 selinux/stable-5.4 PR 20190917
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Merge tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:

 - Add LSM hooks, and SELinux access control hooks, for dnotify,
   fanotify, and inotify watches. This has been discussed with both the
   LSM and fs/notify folks and everybody is good with these new hooks.

 - The LSM stacking changes missed a few calls to current_security() in
   the SELinux code; we fix those and remove current_security() for
   good.

 - Improve our network object labeling cache so that we always return
   the object's label, even when under memory pressure. Previously we
   would return an error if we couldn't allocate a new cache entry, now
   we always return the label even if we can't create a new cache entry
   for it.

 - Convert the sidtab atomic_t counter to a normal u32 with
   READ/WRITE_ONCE() and memory barrier protection.

 - A few patches to policydb.c to clean things up (remove forward
   declarations, long lines, bad variable names, etc)

* tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  lsm: remove current_security()
  selinux: fix residual uses of current_security() for the SELinux blob
  selinux: avoid atomic_t usage in sidtab
  fanotify, inotify, dnotify, security: add security hook for fs notifications
  selinux: always return a secid from the network caches if we find one
  selinux: policydb - rename type_val_to_struct_array
  selinux: policydb - fix some checkpatch.pl warnings
  selinux: shuffle around policydb.c to get rid of forward declarations
2019-09-23 11:21:04 -07:00
Stephen Smalley
169ce0c081 selinux: fix residual uses of current_security() for the SELinux blob
We need to use selinux_cred() to fetch the SELinux cred blob instead
of directly using current->security or current_security().  There
were a couple of lingering uses of current_security() in the SELinux code
that were apparently missed during the earlier conversions. IIUC, this
would only manifest as a bug if multiple security modules including
SELinux are enabled and SELinux is not first in the lsm order. After
this change, there appear to be no other users of current_security()
in-tree; perhaps we should remove it altogether.

Fixes: bbd3662a83 ("Infrastructure management of the cred security blob")
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-09-04 18:41:12 -04:00
Aaron Goidel
ac5656d8a4 fanotify, inotify, dnotify, security: add security hook for fs notifications
As of now, setting watches on filesystem objects has, at most, applied a
check for read access to the inode, and in the case of fanotify, requires
CAP_SYS_ADMIN. No specific security hook or permission check has been
provided to control the setting of watches. Using any of inotify, dnotify,
or fanotify, it is possible to observe, not only write-like operations, but
even read access to a file. Modeling the watch as being merely a read from
the file is insufficient for the needs of SELinux. This is due to the fact
that read access should not necessarily imply access to information about
when another process reads from a file. Furthermore, fanotify watches grant
more power to an application in the form of permission events. While
notification events are solely, unidirectional (i.e. they only pass
information to the receiving application), permission events are blocking.
Permission events make a request to the receiving application which will
then reply with a decision as to whether or not that action may be
completed. This causes the issue of the watching application having the
ability to exercise control over the triggering process. Without drawing a
distinction within the permission check, the ability to read would imply
the greater ability to control an application. Additionally, mount and
superblock watches apply to all files within the same mount or superblock.
Read access to one file should not necessarily imply the ability to watch
all files accessed within a given mount or superblock.

In order to solve these issues, a new LSM hook is implemented and has been
placed within the system calls for marking filesystem objects with inotify,
fanotify, and dnotify watches. These calls to the hook are placed at the
point at which the target path has been resolved and are provided with the
path struct, the mask of requested notification events, and the type of
object on which the mark is being set (inode, superblock, or mount). The
mask and obj_type have already been translated into common FS_* values
shared by the entirety of the fs notification infrastructure. The path
struct is passed rather than just the inode so that the mount is available,
particularly for mount watches. This also allows for use of the hook by
pathname-based security modules. However, since the hook is intended for
use even by inode based security modules, it is not placed under the
CONFIG_SECURITY_PATH conditional. Otherwise, the inode-based security
modules would need to enable all of the path hooks, even though they do not
use any of them.

This only provides a hook at the point of setting a watch, and presumes
that permission to set a particular watch implies the ability to receive
all notification about that object which match the mask. This is all that
is required for SELinux. If other security modules require additional hooks
or infrastructure to control delivery of notification, these can be added
by them. It does not make sense for us to propose hooks for which we have
no implementation. The understanding that all notifications received by the
requesting application are all strictly of a type for which the application
has been granted permission shows that this implementation is sufficient in
its coverage.

Security modules wishing to provide complete control over fanotify must
also implement a security_file_open hook that validates that the access
requested by the watching application is authorized. Fanotify has the issue
that it returns a file descriptor with the file mode specified during
fanotify_init() to the watching process on event. This is already covered
by the LSM security_file_open hook if the security module implements
checking of the requested file mode there. Otherwise, a watching process
can obtain escalated access to a file for which it has not been authorized.

The selinux_path_notify hook implementation works by adding five new file
permissions: watch, watch_mount, watch_sb, watch_reads, and watch_with_perm
(descriptions about which will follow), and one new filesystem permission:
watch (which is applied to superblock checks). The hook then decides which
subset of these permissions must be held by the requesting application
based on the contents of the provided mask and the obj_type. The
selinux_file_open hook already checks the requested file mode and therefore
ensures that a watching process cannot escalate its access through
fanotify.

The watch, watch_mount, and watch_sb permissions are the baseline
permissions for setting a watch on an object and each are a requirement for
any watch to be set on a file, mount, or superblock respectively. It should
be noted that having either of the other two permissions (watch_reads and
watch_with_perm) does not imply the watch, watch_mount, or watch_sb
permission. Superblock watches further require the filesystem watch
permission to the superblock. As there is no labeled object in view for
mounts, there is no specific check for mount watches beyond watch_mount to
the inode. Such a check could be added in the future, if a suitable labeled
object existed representing the mount.

The watch_reads permission is required to receive notifications from
read-exclusive events on filesystem objects. These events include accessing
a file for the purpose of reading and closing a file which has been opened
read-only. This distinction has been drawn in order to provide a direct
indication in the policy for this otherwise not obvious capability. Read
access to a file should not necessarily imply the ability to observe read
events on a file.

Finally, watch_with_perm only applies to fanotify masks since it is the
only way to set a mask which allows for the blocking, permission event.
This permission is needed for any watch which is of this type. Though
fanotify requires CAP_SYS_ADMIN, this is insufficient as it gives implicit
trust to root, which we do not do, and does not support least privilege.

Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-08-12 17:45:39 -04:00
Linus Torvalds
028db3e290 Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs"
This reverts merge 0f75ef6a9c (and thus
effectively commits

   7a1ade8475 ("keys: Provide KEYCTL_GRANT_PERMISSION")
   2e12256b9a ("keys: Replace uid/gid/perm permissions checking with an ACL")

that the merge brought in).

It turns out that it breaks booting with an encrypted volume, and Eric
biggers reports that it also breaks the fscrypt tests [1] and loading of
in-kernel X.509 certificates [2].

The root cause of all the breakage is likely the same, but David Howells
is off email so rather than try to work it out it's getting reverted in
order to not impact the rest of the merge window.

 [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/
 [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/

Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-10 18:43:43 -07:00
Linus Torvalds
8b68150883 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
Pull integrity updates from Mimi Zohar:
 "Bug fixes, code clean up, and new features:

   - IMA policy rules can be defined in terms of LSM labels, making the
     IMA policy dependent on LSM policy label changes, in particular LSM
     label deletions. The new environment, in which IMA-appraisal is
     being used, frequently updates the LSM policy and permits LSM label
     deletions.

   - Prevent an mmap'ed shared file opened for write from also being
     mmap'ed execute. In the long term, making this and other similar
     changes at the VFS layer would be preferable.

   - The IMA per policy rule template format support is needed for a
     couple of new/proposed features (eg. kexec boot command line
     measurement, appended signatures, and VFS provided file hashes).

   - Other than the "boot-aggregate" record in the IMA measuremeent
     list, all other measurements are of file data. Measuring and
     storing the kexec boot command line in the IMA measurement list is
     the first buffer based measurement included in the measurement
     list"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  integrity: Introduce struct evm_xattr
  ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition
  KEXEC: Call ima_kexec_cmdline to measure the boot command line args
  IMA: Define a new template field buf
  IMA: Define a new hook to measure the kexec boot command line arguments
  IMA: support for per policy rule template formats
  integrity: Fix __integrity_init_keyring() section mismatch
  ima: Use designated initializers for struct ima_event_data
  ima: use the lsm policy update notifier
  LSM: switch to blocking policy update notifiers
  x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY
  ima: Make arch_policy_entry static
  ima: prevent a file already mmap'ed write to be mmap'ed execute
  x86/ima: check EFI SetupMode too
2019-07-08 20:28:59 -07:00
Linus Torvalds
0f75ef6a9c Keyrings ACL
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Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull keyring ACL support from David Howells:
 "This changes the permissions model used by keys and keyrings to be
  based on an internal ACL by the following means:

   - Replace the permissions mask internally with an ACL that contains a
     list of ACEs, each with a specific subject with a permissions mask.
     Potted default ACLs are available for new keys and keyrings.

     ACE subjects can be macroised to indicate the UID and GID specified
     on the key (which remain). Future commits will be able to add
     additional subject types, such as specific UIDs or domain
     tags/namespaces.

     Also split a number of permissions to give finer control. Examples
     include splitting the revocation permit from the change-attributes
     permit, thereby allowing someone to be granted permission to revoke
     a key without allowing them to change the owner; also the ability
     to join a keyring is split from the ability to link to it, thereby
     stopping a process accessing a keyring by joining it and thus
     acquiring use of possessor permits.

   - Provide a keyctl to allow the granting or denial of one or more
     permits to a specific subject. Direct access to the ACL is not
     granted, and the ACL cannot be viewed"

* tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  keys: Provide KEYCTL_GRANT_PERMISSION
  keys: Replace uid/gid/perm permissions checking with an ACL
2019-07-08 19:56:57 -07:00
Linus Torvalds
7c0f896348 selinux/stable-5.3 PR 20190702
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Merge tag 'selinux-pr-20190702' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "Like the audit pull request this is a little early due to some
  upcoming vacation plans and uncertain network access while I'm away.
  Also like the audit PR, the list of patches here is pretty minor, the
  highlights include:

   - Explicitly use __le variables to make sure "sparse" can verify
     proper byte endian handling.

   - Remove some BUG_ON()s that are no longer needed.

   - Allow zero-byte writes to the "keycreate" procfs attribute without
     requiring key:create to make it easier for userspace to reset the
     keycreate label.

   - Consistently log the "invalid_context" field as an untrusted string
     in the AUDIT_SELINUX_ERR audit records"

* tag 'selinux-pr-20190702' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: format all invalid context as untrusted
  selinux: fix empty write to keycreate file
  selinux: remove some no-op BUG_ONs
  selinux: provide __le variables explicitly
2019-07-08 18:59:56 -07:00
David Howells
2e12256b9a keys: Replace uid/gid/perm permissions checking with an ACL
Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split.  This will also allow a
greater range of subjects to represented.

============
WHY DO THIS?
============

The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.

For SETATTR, this includes actions that are about controlling access to a
key:

 (1) Changing a key's ownership.

 (2) Changing a key's security information.

 (3) Setting a keyring's restriction.

And actions that are about managing a key's lifetime:

 (4) Setting an expiry time.

 (5) Revoking a key.

and (proposed) managing a key as part of a cache:

 (6) Invalidating a key.

Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.

Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission.  It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.

As for SEARCH permission, that currently covers:

 (1) Finding keys in a keyring tree during a search.

 (2) Permitting keyrings to be joined.

 (3) Invalidation.

But these don't really belong together either, since these actions really
need to be controlled separately.

Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.


===============
WHAT IS CHANGED
===============

The SETATTR permission is split to create two new permissions:

 (1) SET_SECURITY - which allows the key's owner, group and ACL to be
     changed and a restriction to be placed on a keyring.

 (2) REVOKE - which allows a key to be revoked.

The SEARCH permission is split to create:

 (1) SEARCH - which allows a keyring to be search and a key to be found.

 (2) JOIN - which allows a keyring to be joined as a session keyring.

 (3) INVAL - which allows a key to be invalidated.

The WRITE permission is also split to create:

 (1) WRITE - which allows a key's content to be altered and links to be
     added, removed and replaced in a keyring.

 (2) CLEAR - which allows a keyring to be cleared completely.  This is
     split out to make it possible to give just this to an administrator.

 (3) REVOKE - see above.


Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together.  An ACE specifies a subject, such as:

 (*) Possessor - permitted to anyone who 'possesses' a key
 (*) Owner - permitted to the key owner
 (*) Group - permitted to the key group
 (*) Everyone - permitted to everyone

Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.

Further subjects may be made available by later patches.

The ACE also specifies a permissions mask.  The set of permissions is now:

	VIEW		Can view the key metadata
	READ		Can read the key content
	WRITE		Can update/modify the key content
	SEARCH		Can find the key by searching/requesting
	LINK		Can make a link to the key
	SET_SECURITY	Can change owner, ACL, expiry
	INVAL		Can invalidate
	REVOKE		Can revoke
	JOIN		Can join this keyring
	CLEAR		Can clear this keyring


The KEYCTL_SETPERM function is then deprecated.

The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.

The KEYCTL_INVALIDATE function then requires INVAL.

The KEYCTL_REVOKE function then requires REVOKE.

The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.

The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.


======================
BACKWARD COMPATIBILITY
======================

To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.

It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.

SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY.  WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR.  JOIN is turned
on if a keyring is being altered.

The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.

It will make the following mappings:

 (1) INVAL, JOIN -> SEARCH

 (2) SET_SECURITY -> SETATTR

 (3) REVOKE -> WRITE if SETATTR isn't already set

 (4) CLEAR -> WRITE

Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.


=======
TESTING
=======

This passes the keyutils testsuite for all but a couple of tests:

 (1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
     returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
     if the type doesn't have ->read().  You still can't actually read the
     key.

 (2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
     work as Other has been replaced with Everyone in the ACL.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-27 23:03:07 +01:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Janne Karhunen
42df744c41 LSM: switch to blocking policy update notifiers
Atomic policy updaters are not very useful as they cannot
usually perform the policy updates on their own. Since it
seems that there is no strict need for the atomicity,
switch to the blocking variant. While doing so, rename
the functions accordingly.

Signed-off-by: Janne Karhunen <janne.karhunen@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-06-14 09:02:42 -04:00
Ondrej Mosnacek
464c258aa4 selinux: fix empty write to keycreate file
When sid == 0 (we are resetting keycreate_sid to the default value), we
should skip the KEY__CREATE check.

Before this patch, doing a zero-sized write to /proc/self/keycreate
would check if the current task can create unlabeled keys (which would
usually fail with -EACCESS and generate an AVC). Now it skips the check
and correctly sets the task's keycreate_sid to 0.

Bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1719067

Tested using the reproducer from the report above.

Fixes: 4eb582cf1f ("[PATCH] keys: add a way to store the appropriate context for newly-created keys")
Reported-by: Kir Kolyshkin <kir@sacred.ru>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-06-12 16:04:05 -04:00
Gen Zhang
fec6375320 selinux: fix a missing-check bug in selinux_sb_eat_lsm_opts()
In selinux_sb_eat_lsm_opts(), 'arg' is allocated by kmemdup_nul(). It
returns NULL when fails. So 'arg' should be checked. And 'mnt_opts'
should be freed when error.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Fixes: 99dbbb593f ("selinux: rewrite selinux_sb_eat_lsm_opts()")
Cc: <stable@vger.kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-06-12 12:27:26 -04:00
Gen Zhang
e2e0e09758 selinux: fix a missing-check bug in selinux_add_mnt_opt( )
In selinux_add_mnt_opt(), 'val' is allocated by kmemdup_nul(). It returns
NULL when fails. So 'val' should be checked. And 'mnt_opts' should be
freed when error.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Fixes: 757cbe597f ("LSM: new method: ->sb_add_mnt_opt()")
Cc: <stable@vger.kernel.org>
[PM: fixed some indenting problems]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-06-12 11:39:38 -04:00
Paolo Abeni
05174c95b8 selinux: do not report error on connect(AF_UNSPEC)
calling connect(AF_UNSPEC) on an already connected TCP socket is an
established way to disconnect() such socket. After commit 68741a8ada
("selinux: Fix ltp test connect-syscall failure") it no longer works
and, in the above scenario connect() fails with EAFNOSUPPORT.

Fix the above explicitly early checking for AF_UNSPEC family, and
returning success in that case.

Reported-by: Tom Deseyn <tdeseyn@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 68741a8ada ("selinux: Fix ltp test connect-syscall failure")
Suggested-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-05-20 21:46:02 -04:00
Paolo Abeni
e711ab936a Revert "selinux: do not report error on connect(AF_UNSPEC)"
This reverts commit c7e0d6cca8.

It was agreed a slightly different fix via the selinux tree.

v1 -> v2:
 - use the correct reverted commit hash

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-10 09:34:31 -07:00
Paolo Abeni
c7e0d6cca8 selinux: do not report error on connect(AF_UNSPEC)
calling connect(AF_UNSPEC) on an already connected TCP socket is an
established way to disconnect() such socket. After commit 68741a8ada
("selinux: Fix ltp test connect-syscall failure") it no longer works
and, in the above scenario connect() fails with EAFNOSUPPORT.

Fix the above falling back to the generic/old code when the address family
is not AF_INET{4,6}, but leave the SCTP code path untouched, as it has
specific constraints.

Fixes: 68741a8ada ("selinux: Fix ltp test connect-syscall failure")
Reported-by: Tom Deseyn <tdeseyn@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-08 09:45:38 -07:00
Tetsuo Handa
c750e6929d selinux: Check address length before reading address family
KMSAN will complain if valid address length passed to bind()/connect() is
shorter than sizeof("struct sockaddr"->sa_family) bytes.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-04-15 12:42:06 -04:00
Ondrej Mosnacek
1537ad15c9 kernfs: fix xattr name handling in LSM helpers
The implementation of kernfs_security_xattr_*() helpers reuses the
kernfs_node_xattr_*() functions, which take the suffix of the xattr name
and extract full xattr name from it using xattr_full_name(). However,
this function relies on the fact that the suffix passed to xattr
handlers from VFS is always constructed from the full name by just
incerementing the pointer. This doesn't necessarily hold for the callers
of kernfs_security_xattr_*(), so their usage will easily lead to
out-of-bounds access.

Fix this by moving the xattr name reconstruction to the VFS xattr
handlers and replacing the kernfs_security_xattr_*() helpers with more
general kernfs_xattr_*() helpers that take full xattr name and allow
accessing all kernfs node's xattrs.

Reported-by: kernel test robot <rong.a.chen@intel.com>
Fixes: b230d5aba2 ("LSM: add new hook for kernfs node initialization")
Fixes: ec882da5cd ("selinux: implement the kernfs_init_security hook")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-04-04 09:00:27 -04:00
YueHaibing
c72c4cde80 selinux: Make selinux_kernfs_init_security static
Fix sparse warning:

security/selinux/hooks.c:3389:5: warning:
 symbol 'selinux_kernfs_init_security' was not declared. Should it be static?

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-22 15:59:30 -04:00
Ondrej Mosnacek
ec882da5cd selinux: implement the kernfs_init_security hook
The hook applies the same logic as selinux_determine_inode_label(), with
the exception of the super_block handling, which will be enforced on the
actual inodes later by other hooks.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
[PM: minor merge fixes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 22:07:45 -04:00
Ondrej Mosnacek
b754026bd9 selinux: try security xattr after genfs for kernfs filesystems
Since kernfs supports the security xattr handlers, we can simply use
these to determine the inode's context, dropping the need to update it
from kernfs explicitly using a security_inode_notifysecctx() call.

We achieve this by setting a new sbsec flag SE_SBGENFS_XATTR to all
mounts that are known to use kernfs under the hood and then fetching the
xattrs after determining the fallback genfs sid in
inode_doinit_with_dentry() when this flag is set.

This will allow implementing full security xattr support in kernfs and
removing the ...notifysecctx() call in a subsequent patch.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: more manual merge fixups]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20 21:53:04 -04:00
Linus Torvalds
fa3d493f7a selinux/stable-5.1 PR 20190312
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Merge tag 'selinux-pr-20190312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux fixes from Paul Moore:
 "Two small fixes for SELinux in v5.1: one adds a buffer length check to
  the SELinux SCTP code, the other ensures that the SELinux labeling for
  a NFS mount is not disabled if the filesystem is mounted twice"

* tag 'selinux-pr-20190312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock
  selinux: add the missing walk_size + len check in selinux_sctp_bind_connect
2019-03-13 11:10:42 -07:00
Linus Torvalds
7b47a9e7c8 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount infrastructure updates from Al Viro:
 "The rest of core infrastructure; no new syscalls in that pile, but the
  old parts are switched to new infrastructure. At that point
  conversions of individual filesystems can happen independently; some
  are done here (afs, cgroup, procfs, etc.), there's also a large series
  outside of that pile dealing with NFS (quite a bit of option-parsing
  stuff is getting used there - it's one of the most convoluted
  filesystems in terms of mount-related logics), but NFS bits are the
  next cycle fodder.

  It got seriously simplified since the last cycle; documentation is
  probably the weakest bit at the moment - I considered dropping the
  commit introducing Documentation/filesystems/mount_api.txt (cutting
  the size increase by quarter ;-), but decided that it would be better
  to fix it up after -rc1 instead.

  That pile allows to do followup work in independent branches, which
  should make life much easier for the next cycle. fs/super.c size
  increase is unpleasant; there's a followup series that allows to
  shrink it considerably, but I decided to leave that until the next
  cycle"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
  afs: Use fs_context to pass parameters over automount
  afs: Add fs_context support
  vfs: Add some logging to the core users of the fs_context log
  vfs: Implement logging through fs_context
  vfs: Provide documentation for new mount API
  vfs: Remove kern_mount_data()
  hugetlbfs: Convert to fs_context
  cpuset: Use fs_context
  kernfs, sysfs, cgroup, intel_rdt: Support fs_context
  cgroup: store a reference to cgroup_ns into cgroup_fs_context
  cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper
  cgroup_do_mount(): massage calling conventions
  cgroup: stash cgroup_root reference into cgroup_fs_context
  cgroup2: switch to option-by-option parsing
  cgroup1: switch to option-by-option parsing
  cgroup: take options parsing into ->parse_monolithic()
  cgroup: fold cgroup1_mount() into cgroup1_get_tree()
  cgroup: start switching to fs_context
  ipc: Convert mqueue fs to fs_context
  proc: Add fs_context support to procfs
  ...
2019-03-12 14:08:19 -07:00
J. Bruce Fields
3815a245b5 security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock
In the case when we're reusing a superblock, selinux_sb_clone_mnt_opts()
fails to set set_kern_flags, with the result that
nfs_clone_sb_security() incorrectly clears NFS_CAP_SECURITY_LABEL.

The result is that if you mount the same NFS filesystem twice, NFS
security labels are turned off, even if they would work fine if you
mounted the filesystem only once.

("fixes" may be not exactly the right tag, it may be more like
"fixed-other-cases-but-missed-this-one".)

Cc: Scott Mayhew <smayhew@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0b4d3452b8 "security/selinux: allow security_sb_clone_mnt_opts..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-11 16:13:17 -04:00
Xin Long
292c997a19 selinux: add the missing walk_size + len check in selinux_sctp_bind_connect
As does in __sctp_connect(), when checking addrs in a while loop, after
get the addr len according to sa_family, it's necessary to do the check
walk_size + af->sockaddr_len > addrs_size to make sure it won't access
an out-of-bounds addr.

The same thing is needed in selinux_sctp_bind_connect(), otherwise an
out-of-bounds issue can be triggered:

  [14548.772313] BUG: KASAN: slab-out-of-bounds in selinux_sctp_bind_connect+0x1aa/0x1f0
  [14548.927083] Call Trace:
  [14548.938072]  dump_stack+0x9a/0xe9
  [14548.953015]  print_address_description+0x65/0x22e
  [14548.996524]  kasan_report.cold.6+0x92/0x1a6
  [14549.015335]  selinux_sctp_bind_connect+0x1aa/0x1f0
  [14549.036947]  security_sctp_bind_connect+0x58/0x90
  [14549.058142]  __sctp_setsockopt_connectx+0x5a/0x150 [sctp]
  [14549.081650]  sctp_setsockopt.part.24+0x1322/0x3ce0 [sctp]

Cc: stable@vger.kernel.org
Fixes: d452930fd3 ("selinux: Add SCTP support")
Reported-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-11 16:00:44 -04:00
Linus Torvalds
1a29e85750 A fairly routine cycle for docs - lots of typo fixes, some new documents,
and more translations.  There's also some LICENSES adjustments from
 Thomas.
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Merge tag 'docs-5.1' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "A fairly routine cycle for docs - lots of typo fixes, some new
  documents, and more translations. There's also some LICENSES
  adjustments from Thomas"

* tag 'docs-5.1' of git://git.lwn.net/linux: (74 commits)
  docs: Bring some order to filesystem documentation
  Documentation/locking/lockdep: Drop last two chars of sample states
  doc: rcu: Suspicious RCU usage is a warning
  docs: driver-api: iio: fix errors in documentation
  Documentation/process/howto: Update for 4.x -> 5.x versioning
  docs: Explicitly state that the 'Fixes:' tag shouldn't split lines
  doc: security: Add kern-doc for lsm_hooks.h
  doc: sctp: Merge and clean up rst files
  Docs: Correct /proc/stat path
  scripts/spdxcheck.py: fix C++ comment style detection
  doc: fix typos in license-rules.rst
  Documentation: fix admin-guide/README.rst minimum gcc version requirement
  doc: process: complete removal of info about -git patches
  doc: translations: sync translations 'remove info about -git patches'
  perf-security: wrap paragraphs on 72 columns
  perf-security: elaborate on perf_events/Perf privileged users
  perf-security: document collected perf_events/Perf data categories
  perf-security: document perf_events/Perf resource control
  sysfs.txt: add note on available attribute macros
  docs: kernel-doc: typo "if ... if" -> "if ... is"
  ...
2019-03-09 09:56:17 -08:00
Linus Torvalds
3ac96c30cc selinux/stable-5.1 PR 20190305
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Merge tag 'selinux-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull SELinux updates from Paul Moore:
 "Nine SELinux patches for v5.1, all bug fixes.

  As far as I'm concerned, nothing really jumps out as risky or special
  to me, but each commit has a decent description so you can judge for
  yourself. As usual, everything passes the selinux-testsuite; please
  merge for v5.1"

* tag 'selinux-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: fix avc audit messages
  selinux: replace BUG_ONs with WARN_ONs in avc.c
  selinux: log invalid contexts in AVCs
  selinux: replace some BUG_ON()s with a WARN_ON()
  selinux: inline some AVC functions used only once
  selinux: do not override context on context mounts
  selinux: never allow relabeling on context mounts
  selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link
  selinux: avoid silent denials in permissive mode under RCU walk
2019-03-07 12:12:45 -08:00
Al Viro
0b52075ee6 introduce cloning of fs_context
new primitive: vfs_dup_fs_context().  Comes with fs_context
method (->dup()) for copying the filesystem-specific parts
of fs_context, along with LSM one (->fs_context_dup()) for
doing the same to LSM parts.

[needs better commit message, and change of Author:, anyway]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:27 -05:00
David Howells
442155c1bd selinux: Implement the new mount API LSM hooks
Implement the new mount API LSM hooks for SELinux.  At some point the old
hooks will need to be removed.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Paul Moore <paul@paul-moore.com>
cc: Stephen Smalley <sds@tycho.nsa.gov>
cc: selinux@tycho.nsa.gov
cc: linux-security-module@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:24 -05:00
Kees Cook
d61330c689 doc: sctp: Merge and clean up rst files
The SCTP sections were ending up at the top-level table of contents
under the security section when they should have be sections with the
SCTP chapters. In addition to correcting the section and subsection
headings, this merges the SCTP documents into a single file to organize
the chapters more clearly, internally linkifies them, and adds the
missing SPDX header.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-02-22 08:51:40 -07:00
Tetsuo Handa
1cfb2a512e LSM: Make lsm_early_cred() and lsm_early_task() local functions.
Since current->cred == current->real_cred when ordered_lsm_init()
is called, and lsm_early_cred()/lsm_early_task() need to be called
between the amount of required bytes is determined and module specific
initialization function is called, we can move these calls from
individual modules to ordered_lsm_init().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-18 11:44:02 -08:00
Ondrej Mosnacek
53e0c2aa9a selinux: do not override context on context mounts
Ignore all selinux_inode_notifysecctx() calls on mounts with SBLABEL_MNT
flag unset. This is achived by returning -EOPNOTSUPP for this case in
selinux_inode_setsecurtity() (because that function should not be called
in such case anyway) and translating this error to 0 in
selinux_inode_notifysecctx().

This fixes behavior of kernfs-based filesystems when mounted with the
'context=' option. Before this patch, if a node's context had been
explicitly set to a non-default value and later the filesystem has been
remounted with the 'context=' option, then this node would show up as
having the manually-set context and not the mount-specified one.

Steps to reproduce:
    # mount -t cgroup2 cgroup2 /sys/fs/cgroup/unified
    # chcon unconfined_u:object_r:user_home_t:s0 /sys/fs/cgroup/unified/cgroup.stat
    # ls -lZ /sys/fs/cgroup/unified
    total 0
    -r--r--r--. 1 root root system_u:object_r:cgroup_t:s0        0 Dec 13 10:41 cgroup.controllers
    -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0        0 Dec 13 10:41 cgroup.max.depth
    -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0        0 Dec 13 10:41 cgroup.max.descendants
    -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0        0 Dec 13 10:41 cgroup.procs
    -r--r--r--. 1 root root unconfined_u:object_r:user_home_t:s0 0 Dec 13 10:41 cgroup.stat
    -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0        0 Dec 13 10:41 cgroup.subtree_control
    -rw-r--r--. 1 root root system_u:object_r:cgroup_t:s0        0 Dec 13 10:41 cgroup.threads
    # umount /sys/fs/cgroup/unified
    # mount -o context=system_u:object_r:tmpfs_t:s0 -t cgroup2 cgroup2 /sys/fs/cgroup/unified

Result before:
    # ls -lZ /sys/fs/cgroup/unified
    total 0
    -r--r--r--. 1 root root system_u:object_r:tmpfs_t:s0         0 Dec 13 10:41 cgroup.controllers
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0         0 Dec 13 10:41 cgroup.max.depth
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0         0 Dec 13 10:41 cgroup.max.descendants
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0         0 Dec 13 10:41 cgroup.procs
    -r--r--r--. 1 root root unconfined_u:object_r:user_home_t:s0 0 Dec 13 10:41 cgroup.stat
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0         0 Dec 13 10:41 cgroup.subtree_control
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0         0 Dec 13 10:41 cgroup.threads

Result after:
    # ls -lZ /sys/fs/cgroup/unified
    total 0
    -r--r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.controllers
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.max.depth
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.max.descendants
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.procs
    -r--r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.stat
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.subtree_control
    -rw-r--r--. 1 root root system_u:object_r:tmpfs_t:s0 0 Dec 13 10:41 cgroup.threads

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10 21:24:43 -05:00
Ondrej Mosnacek
a83d6ddaeb selinux: never allow relabeling on context mounts
In the SECURITY_FS_USE_MNTPOINT case we never want to allow relabeling
files/directories, so we should never set the SBLABEL_MNT flag. The
'special handling' in selinux_is_sblabel_mnt() is only intended for when
the behavior is set to SECURITY_FS_USE_GENFS.

While there, make the logic in selinux_is_sblabel_mnt() more explicit
and add a BUILD_BUG_ON() to make sure that introducing a new
SECURITY_FS_USE_* forces a review of the logic.

Fixes: d5f3a5f6e7 ("selinux: add security in-core xattr support for pstore and debugfs")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10 21:23:39 -05:00
Stephen Smalley
e46e01eebb selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link
commit bda0be7ad9 ("security: make inode_follow_link RCU-walk aware")
switched selinux_inode_follow_link() to use avc_has_perm_flags() and
pass down the MAY_NOT_BLOCK flag if called during RCU walk.  However,
the only test of MAY_NOT_BLOCK occurs during slow_avc_audit()
and only if passing an inode as audit data (LSM_AUDIT_DATA_INODE).  Since
selinux_inode_follow_link() passes a dentry directly, passing MAY_NOT_BLOCK
here serves no purpose.  Switch selinux_inode_follow_link() to use
avc_has_perm() and drop avc_has_perm_flags() since there are no other
users.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10 20:34:37 -05:00
Stephen Smalley
3a28cff3bd selinux: avoid silent denials in permissive mode under RCU walk
commit 0dc1ba24f7 ("SELINUX: Make selinux cache VFS RCU walks safe")
results in no audit messages at all if in permissive mode because the
cache is updated during the rcu walk and thus no denial occurs on
the subsequent ref walk.  Fix this by not updating the cache when
performing a non-blocking permission check.  This only affects search
and symlink read checks during rcu walk.

Fixes: 0dc1ba24f7 ("SELINUX: Make selinux cache VFS RCU walks safe")
Reported-by: BMK <bmktuwien@gmail.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-10 20:32:53 -05:00
Micah Morton
c1a85a00ea LSM: generalize flag passing to security_capable
This patch provides a general mechanism for passing flags to the
security_capable LSM hook. It replaces the specific 'audit' flag that is
used to tell security_capable whether it should log an audit message for
the given capability check. The reason for generalizing this flag
passing is so we can add an additional flag that signifies whether
security_capable is being called by a setid syscall (which is needed by
the proposed SafeSetID LSM).

Signed-off-by: Micah Morton <mortonm@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-10 14:16:06 -08:00
Casey Schaufler
ecd5f82e05 LSM: Infrastructure management of the ipc security blob
Move management of the kern_ipc_perm->security and
msg_msg->security blobs 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.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:45 -08:00
Casey Schaufler
7c6538280a SELinux: Abstract use of ipc security blobs
Don't use the ipc->security pointer directly.
Don't use the msg_msg->security pointer directly.
Provide helper functions that provides the security blob pointers.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:45 -08:00
Casey Schaufler
afb1cbe374 LSM: Infrastructure management of the inode security
Move management of the inode->i_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.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:45 -08:00
Casey Schaufler
80788c2291 SELinux: Abstract use of inode security blob
Don't use the inode->i_security pointer directly.
Provide a helper function that provides the security blob pointer.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:44 -08:00
Casey Schaufler
33bf60cabc LSM: Infrastructure management of the file security
Move management of the file->f_security blob out of the
individual security modules and into the infrastructure.
The modules no longer allocate or free the data, instead
they tell the infrastructure how much space they require.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:44 -08:00
Casey Schaufler
bb6c6b02cc SELinux: Abstract use of file security blob
Don't use the file->f_security pointer directly.
Provide a helper function that provides the security blob pointer.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:44 -08:00
Casey Schaufler
bbd3662a83 Infrastructure management of the cred security blob
Move management of the cred security blob out of the
security modules and into the security infrastructre.
Instead of allocating and freeing space the security
modules tell the infrastructure how much space they
require.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:44 -08:00
Casey Schaufler
3d25252948 SELinux: Remove unused selinux_is_enabled
There are no longer users of selinux_is_enabled().
Remove it. As selinux_is_enabled() is the only reason
for include/linux/selinux.h remove that as well.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:44 -08:00
Casey Schaufler
98c8865136 SELinux: Remove cred security blob poisoning
The SELinux specific credential poisioning only makes sense
if SELinux is managing the credentials. As the intent of this
patch set is to move the blob management out of the modules
and into the infrastructure, the SELinux specific code has
to go. The poisioning could be introduced into the infrastructure
at some later date.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:44 -08:00
Casey Schaufler
0c6cfa622c SELinux: Abstract use of cred security blob
Don't use the cred->security pointer directly.
Provide a helper function that provides the security blob pointer.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:44 -08:00
Kees Cook
be6ec88f41 selinux: Remove SECURITY_SELINUX_BOOTPARAM_VALUE
In preparation for removing CONFIG_DEFAULT_SECURITY, this removes the
soon-to-be redundant SECURITY_SELINUX_BOOTPARAM_VALUE. Since explicit
ordering via CONFIG_LSM or "lsm=" will define whether an LSM is enabled or
not, this CONFIG will become effectively ignored, so remove it. However,
in order to stay backward-compatible with "security=selinux", the enable
variable defaults to true.

Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08 13:18:43 -08:00
Kees Cook
14bd99c821 LSM: Separate idea of "major" LSM from "exclusive" LSM
In order to both support old "security=" Legacy Major LSM selection, and
handling real exclusivity, this creates LSM_FLAG_EXCLUSIVE and updates
the selection logic to handle them.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08 13:18:43 -08:00
Kees Cook
f4941d75b9 LSM: Lift LSM selection out of individual LSMs
As a prerequisite to adjusting LSM selection logic in the future, this
moves the selection logic up out of the individual major LSMs, making
their init functions only run when actually enabled. This considers all
LSMs enabled by default unless they specified an external "enable"
variable.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
2019-01-08 13:18:42 -08:00
Kees Cook
c5459b829b LSM: Plumb visibility into optional "enabled" state
In preparation for lifting the "is this LSM enabled?" logic out of the
individual LSMs, pass in any special enabled state tracking (as needed
for SELinux, AppArmor, and LoadPin). This should be an "int" to include
handling any future cases where "enabled" is exposed via sysctl which
has no "bool" type.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
2019-01-08 13:18:42 -08:00