Commit Graph

3367 Commits

Author SHA1 Message Date
John Johansen b2d09ae449 apparmor: move ptrace checks to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:41 -07:00
John Johansen ca916e8e2d apparmor: add cross check permission helper macros
The cross check permission helper macros will help simplify code
that does cross task permission checks like ptrace.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:41 -07:00
John Johansen 86b92cb782 apparmor: move resource checks to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:40 -07:00
John Johansen c70c86c421 apparmor: move capability checks to using labels
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:40 -07:00
John Johansen 317d9a054e apparmor: update query interface to support label queries
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:39 -07:00
John Johansen 76a1d263ab apparmor: switch getprocattr to using label_print fns()
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:39 -07:00
John Johansen 637f688dc3 apparmor: switch from profiles to using labels on contexts
Begin the actual switch to using domain labels by storing them on
the context and converting the label to a singular profile where
possible.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:38 -07:00
John Johansen f1bd904175 apparmor: add the base fns() for domain labels
Begin moving apparmor to using broader domain labels, that will allow
run time computation of domain type splitting via "stacking" of
profiles into a domain label vec.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:38 -07:00
John Johansen 192ca6b55a apparmor: revalidate files during exec
Instead of running file revalidation lazily when read/write are called
copy selinux and revalidate the file table on exec. This avoids
extra mediation overhead in read/write and also prevents file handles
being passed through to a grand child unchecked.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:37 -07:00
John Johansen 2835a13bbd apparmor: cleanup rename XXX_file_context() to XXX_file_ctx()
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:37 -07:00
John Johansen df8073c67f apparmor: convert aa_change_XXX bool parameters to flags
Instead of passing multiple booleans consolidate on a single flags
field.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:36 -07:00
John Johansen dca91402e9 apparmor: cleanup remove unused and not fully implemented profile rename
Remove the partially implemented code, until this can be properly
implemented.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:36 -07:00
John Johansen 435222bc1b apparmor: refactor updating profiles to the newest parent
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:35 -07:00
John Johansen a1bd627b46 apparmor: share profile name on replacement
The profile names are the same, leverage this.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:35 -07:00
John Johansen cf797c0e5e apparmor: convert to profile block critical sections
There are still a few places where profile replacement fails to update
and a stale profile is used for mediation. Fix this by moving to
accessing the current label through a critical section that will
always ensure mediation is using the current label regardless of
whether the tasks cred has been updated or not.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:34 -07:00
John Johansen fe864821d5 apparmor: move bprm_committing_creds/committed_creds to lsm.c
There is no reason to have the small stubs that don't use domain
private functions in domain.c, instead move them to lsm.c and make
them static.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:34 -07:00
John Johansen d9f02d9c23 apparmor: fix display of ns name
The ns name being displayed should go through an ns view lookup.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:33 -07:00
John Johansen 5262ef60b1 apparmor: fix apparmor_query data
The data being queried isn't always the current profile and a lookup
relative to the current profile should be done.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:33 -07:00
John Johansen 60285eb3e7 apparmor: fix policy load/remove semantics
The namespace being passed into the replace/remove profiles fns() is
not the view, but the namespace specified by the inode from the
file hook (if present) or the loading tasks ns, if accessing the
top level virtualized load/replace file interface.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:32 -07:00
John Johansen 3664268f19 apparmor: add namespace lookup fns()
Currently lookups are restricted to a single ns component in the
path. However when namespaces are allowed to have separate views, and
scopes this will not be sufficient, as it will be possible to have
a multiple component ns path in scope.

Add some ns lookup fns() to allow this and use them.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:32 -07:00
John Johansen ae3b316536 apparmor: cleanup __find_child()
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:31 -07:00
John Johansen 39d84824ea apparmor: provide information about path buffer size at boot
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:31 -07:00
John Johansen 4f3b3f2d79 apparmor: add profile permission query ability
Allow userspace to query a profile about permissions, through the
transaction interface that is already used to allow userspace to
query about key,value data.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:30 -07:00
John Johansen 2d679f3cb0 apparmor: switch from file_perms to aa_perms
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:30 -07:00
John Johansen aa9aeea8d4 apparmor: add gerneric permissions struct and support fns
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:30 -07:00
John Johansen b5b2557c0a apparmor: add fn to test if profile supports a given mediation class
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:29 -07:00
John Johansen 1dea3b41e8 apparmor: speed up transactional queries
The simple_transaction interface is slow. It requires 4 syscalls
(open, write, read, close) per query and shares a single lock for each
queries.

So replace its use with a compatible in multi_transaction interface.
It allows for a faster 2 syscall pattern per query. After an initial
open, an arbitrary number of writes and reads can be issued. Each
write will reset the query with new data that can be read. Reads do
not clear the data, and can be issued multiple times, and used with
seek, until a new write is performed which will reset the data
available and the seek position.

Note: this keeps the single lock design, if needed moving to a per
file lock will have to come later.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:29 -07:00
John Johansen a83bd86e83 apparmor: add label data availability to the feature set
gsettings mediation needs to be able to determine if apparmor supports
label data queries. A label data query can be done to test for support
but its failure is indistinguishable from other failures, making it an
unreliable indicator.

Fix by making support of label data queries available as a flag in the
apparmorfs features dir tree.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:28 -07:00
John Johansen 4ae47f3335 apparmor: add mkdir/rmdir interface to manage policy namespaces
When setting up namespaces for containers its easier for them to use
an fs interface to create the namespace for the containers
policy. Allow mkdir/rmdir under the policy/namespaces/ dir to be used
to create and remove namespaces.

BugLink: http://bugs.launchpad.net/bugs/1611078

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:27 -07:00
John Johansen d9bf2c268b apparmor: add policy revision file interface
Add a policy revision file to find the current revision of a ns's policy.
There is a revision file per ns, as well as a virtualized global revision
file in the base apparmor fs directory. The global revision file when
opened will provide the revision of the opening task namespace.

The revision file can be waited on via select/poll to detect apparmor
policy changes from the last read revision of the opened file. This
means that the revision file must be read after the select/poll other
wise update data will remain ready for reading.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:27 -07:00
John Johansen 18e99f191a apparmor: provide finer control over policy management
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-10 17:11:20 -07:00
Scott Mayhew 0b4d3452b8 security/selinux: allow security_sb_clone_mnt_opts to enable/disable native labeling behavior
When an NFSv4 client performs a mount operation, it first mounts the
NFSv4 root and then does path walk to the exported path and performs a
submount on that, cloning the security mount options from the root's
superblock to the submount's superblock in the process.

Unless the NFS server has an explicit fsid=0 export with the
"security_label" option, the NFSv4 root superblock will not have
SBLABEL_MNT set, and neither will the submount superblock after cloning
the security mount options.  As a result, setxattr's of security labels
over NFSv4.2 will fail.  In a similar fashion, NFSv4.2 mounts mounted
with the context= mount option will not show the correct labels because
the nfs_server->caps flags of the cloned superblock will still have
NFS_CAP_SECURITY_LABEL set.

Allowing the NFSv4 client to enable or disable SECURITY_LSM_NATIVE_LABELS
behavior will ensure that the SBLABEL_MNT flag has the correct value
when the client traverses from an exported path without the
"security_label" option to one with the "security_label" option and
vice versa.  Similarly, checking to see if SECURITY_LSM_NATIVE_LABELS is
set upon return from security_sb_clone_mnt_opts() and clearing
NFS_CAP_SECURITY_LABEL if necessary will allow the correct labels to
be displayed for NFSv4.2 mounts mounted with the context= mount option.

Resolves: https://github.com/SELinuxProject/selinux-kernel/issues/35

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov>
Tested-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-06-09 16:17:47 -04:00
Junil Lee b4958c892e selinux: use kmem_cache for ebitmap
The allocated size for each ebitmap_node is 192byte by kzalloc().
Then, ebitmap_node size is fixed, so it's possible to use only 144byte
for each object by kmem_cache_zalloc().
It can reduce some dynamic allocation size.

Signed-off-by: Junil Lee <junil0814.lee@lge.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-06-09 16:13:50 -04:00
John Johansen e53cfe6c7c apparmor: rework perm mapping to a slightly broader set
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-09 05:59:22 -07:00
Mark Rutland 92347cfd62 KEYS: fix refcount_inc() on zero
If a key's refcount is dropped to zero between key_lookup() peeking at
the refcount and subsequently attempting to increment it, refcount_inc()
will see a zero refcount.  Here, refcount_inc() will WARN_ONCE(), and
will *not* increment the refcount, which will remain zero.

Once key_lookup() drops key_serial_lock, it is possible for the key to
be freed behind our back.

This patch uses refcount_inc_not_zero() to perform the peek and increment
atomically.

Fixes: fff292914d ("security, keys: convert key.usage from atomic_t to refcount_t")
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: David Windsor <dwindsor@gmail.com>
Cc: Elena Reshetova <elena.reshetova@intel.com>
Cc: Hans Liljestrand <ishkamiel@gmail.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:50 +10:00
Mat Martineau 7cbe0932c2 KEYS: Convert KEYCTL_DH_COMPUTE to use the crypto KPP API
The initial Diffie-Hellman computation made direct use of the MPI
library because the crypto module did not support DH at the time. Now
that KPP is implemented, KEYCTL_DH_COMPUTE should use it to get rid of
duplicate code and leverage possible hardware acceleration.

This fixes an issue whereby the input to the KDF computation would
include additional uninitialized memory when the result of the
Diffie-Hellman computation was shorter than the input prime number.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:50 +10:00
Eric Biggers 0ddd9f1a6b KEYS: DH: ensure the KDF counter is properly aligned
Accessing a 'u8[4]' through a '__be32 *' violates alignment rules.  Just
make the counter a __be32 instead.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:49 +10:00
Eric Biggers 281590b422 KEYS: DH: don't feed uninitialized "otherinfo" into KDF
If userspace called KEYCTL_DH_COMPUTE with kdf_params containing NULL
otherinfo but nonzero otherinfolen, the kernel would allocate a buffer
for the otherinfo, then feed it into the KDF without initializing it.
Fix this by always doing the copy from userspace (which will fail with
EFAULT in this scenario).

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:49 +10:00
Eric Biggers bbe240454d KEYS: DH: forbid using digest_null as the KDF hash
Requesting "digest_null" in the keyctl_kdf_params caused an infinite
loop in kdf_ctr() because the "null" hash has a digest size of 0.  Fix
it by rejecting hash algorithms with a digest size of 0.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:49 +10:00
Eric Biggers 0620fddb56 KEYS: sanitize key structs before freeing
While a 'struct key' itself normally does not contain sensitive
information, Documentation/security/keys.txt actually encourages this:

     "Having a payload is not required; and the payload can, in fact,
     just be a value stored in the struct key itself."

In case someone has taken this advice, or will take this advice in the
future, zero the key structure before freeing it.  We might as well, and
as a bonus this could make it a bit more difficult for an adversary to
determine which keys have recently been in use.

This is safe because the key_jar cache does not use a constructor.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:48 +10:00
Eric Biggers ee618b4619 KEYS: trusted: sanitize all key material
As the previous patch did for encrypted-keys, zero sensitive any
potentially sensitive data related to the "trusted" key type before it
is freed.  Notably, we were not zeroing the tpm_buf structures in which
the actual key is stored for TPM seal and unseal, nor were we zeroing
the trusted_key_payload in certain error paths.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Safford <safford@us.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:48 +10:00
Eric Biggers a9dd74b252 KEYS: encrypted: sanitize all key material
For keys of type "encrypted", consistently zero sensitive key material
before freeing it.  This was already being done for the decrypted
payloads of encrypted keys, but not for the master key and the keys
derived from the master key.

Out of an abundance of caution and because it is trivial to do so, also
zero buffers containing the key payload in encrypted form, although
depending on how the encrypted-keys feature is used such information
does not necessarily need to be kept secret.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: David Safford <safford@us.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:48 +10:00
Eric Biggers 6966c74932 KEYS: user_defined: sanitize key payloads
Zero the payloads of user and logon keys before freeing them.  This
prevents sensitive key material from being kept around in the slab
caches after a key is released.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:48 +10:00
Eric Biggers 57070c850a KEYS: sanitize add_key() and keyctl() key payloads
Before returning from add_key() or one of the keyctl() commands that
takes in a key payload, zero the temporary buffer that was allocated to
hold the key payload copied from userspace.  This may contain sensitive
key material that should not be kept around in the slab caches.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:48 +10:00
Eric Biggers 63a0b0509e KEYS: fix freeing uninitialized memory in key_update()
key_update() freed the key_preparsed_payload even if it was not
initialized first.  This would cause a crash if userspace called
keyctl_update() on a key with type like "asymmetric" that has a
->preparse() method but not an ->update() method.  Possibly it could
even be triggered for other key types by racing with keyctl_setperm() to
make the KEY_NEED_WRITE check fail (the permission was already checked,
so normally it wouldn't fail there).

Reproducer with key type "asymmetric", given a valid cert.der:

keyctl new_session
keyid=$(keyctl padd asymmetric desc @s < cert.der)
keyctl setperm $keyid 0x3f000000
keyctl update $keyid data

[  150.686666] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
[  150.687601] IP: asymmetric_key_free_kids+0x12/0x30
[  150.688139] PGD 38a3d067
[  150.688141] PUD 3b3de067
[  150.688447] PMD 0
[  150.688745]
[  150.689160] Oops: 0000 [#1] SMP
[  150.689455] Modules linked in:
[  150.689769] CPU: 1 PID: 2478 Comm: keyctl Not tainted 4.11.0-rc4-xfstests-00187-ga9f6b6b8cd2f #742
[  150.690916] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
[  150.692199] task: ffff88003b30c480 task.stack: ffffc90000350000
[  150.692952] RIP: 0010:asymmetric_key_free_kids+0x12/0x30
[  150.693556] RSP: 0018:ffffc90000353e58 EFLAGS: 00010202
[  150.694142] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000004
[  150.694845] RDX: ffffffff81ee3920 RSI: ffff88003d4b0700 RDI: 0000000000000001
[  150.697569] RBP: ffffc90000353e60 R08: ffff88003d5d2140 R09: 0000000000000000
[  150.702483] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
[  150.707393] R13: 0000000000000004 R14: ffff880038a4d2d8 R15: 000000000040411f
[  150.709720] FS:  00007fcbcee35700(0000) GS:ffff88003fd00000(0000) knlGS:0000000000000000
[  150.711504] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  150.712733] CR2: 0000000000000001 CR3: 0000000039eab000 CR4: 00000000003406e0
[  150.714487] Call Trace:
[  150.714975]  asymmetric_key_free_preparse+0x2f/0x40
[  150.715907]  key_update+0xf7/0x140
[  150.716560]  ? key_default_cmp+0x20/0x20
[  150.717319]  keyctl_update_key+0xb0/0xe0
[  150.718066]  SyS_keyctl+0x109/0x130
[  150.718663]  entry_SYSCALL_64_fastpath+0x1f/0xc2
[  150.719440] RIP: 0033:0x7fcbce75ff19
[  150.719926] RSP: 002b:00007ffd5d167088 EFLAGS: 00000206 ORIG_RAX: 00000000000000fa
[  150.720918] RAX: ffffffffffffffda RBX: 0000000000404d80 RCX: 00007fcbce75ff19
[  150.721874] RDX: 00007ffd5d16785e RSI: 000000002866cd36 RDI: 0000000000000002
[  150.722827] RBP: 0000000000000006 R08: 000000002866cd36 R09: 00007ffd5d16785e
[  150.723781] R10: 0000000000000004 R11: 0000000000000206 R12: 0000000000404d80
[  150.724650] R13: 00007ffd5d16784d R14: 00007ffd5d167238 R15: 000000000040411f
[  150.725447] Code: 83 c4 08 31 c0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 85 ff 74 23 55 48 89 e5 53 48 89 fb <48> 8b 3f e8 06 21 c5 ff 48 8b 7b 08 e8 fd 20 c5 ff 48 89 df e8
[  150.727489] RIP: asymmetric_key_free_kids+0x12/0x30 RSP: ffffc90000353e58
[  150.728117] CR2: 0000000000000001
[  150.728430] ---[ end trace f7f8fe1da2d5ae8d ]---

Fixes: 4d8c0250b8 ("KEYS: Call ->free_preparse() even after ->preparse() returns an error")
Cc: stable@vger.kernel.org # 3.17+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers 5649645d72 KEYS: fix dereferencing NULL payload with nonzero length
sys_add_key() and the KEYCTL_UPDATE operation of sys_keyctl() allowed a
NULL payload with nonzero length to be passed to the key type's
->preparse(), ->instantiate(), and/or ->update() methods.  Various key
types including asymmetric, cifs.idmap, cifs.spnego, and pkcs7_test did
not handle this case, allowing an unprivileged user to trivially cause a
NULL pointer dereference (kernel oops) if one of these key types was
present.  Fix it by doing the copy_from_user() when 'plen' is nonzero
rather than when '_payload' is non-NULL, causing the syscall to fail
with EFAULT as expected when an invalid buffer is specified.

Cc: stable@vger.kernel.org # 2.6.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers 0f534e4a13 KEYS: encrypted: use constant-time HMAC comparison
MACs should, in general, be compared using crypto_memneq() to prevent
timing attacks.

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers 64d107d3ac KEYS: encrypted: fix race causing incorrect HMAC calculations
The encrypted-keys module was using a single global HMAC transform,
which could be rekeyed by multiple threads concurrently operating on
different keys, causing incorrect HMAC values to be calculated.  Fix
this by allocating a new HMAC transform whenever we need to calculate a
HMAC.  Also simplify things a bit by allocating the shash_desc's using
SHASH_DESC_ON_STACK() for both the HMAC and unkeyed hashes.

The following script reproduces the bug:

    keyctl new_session
    keyctl add user master "abcdefghijklmnop" @s
    for i in $(seq 2); do
        (
            set -e
            for j in $(seq 1000); do
                keyid=$(keyctl add encrypted desc$i "new user:master 25" @s)
                datablob="$(keyctl pipe $keyid)"
                keyctl unlink $keyid > /dev/null
                keyid=$(keyctl add encrypted desc$i "load $datablob" @s)
                keyctl unlink $keyid > /dev/null
            done
        ) &
    done

Output with bug:

    [  439.691094] encrypted_key: bad hmac (-22)
    add_key: Invalid argument
    add_key: Invalid argument

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:47 +10:00
Eric Biggers 794b4bc292 KEYS: encrypted: fix buffer overread in valid_master_desc()
With the 'encrypted' key type it was possible for userspace to provide a
data blob ending with a master key description shorter than expected,
e.g. 'keyctl add encrypted desc "new x" @s'.  When validating such a
master key description, validate_master_desc() could read beyond the end
of the buffer.  Fix this by using strncmp() instead of memcmp().  [Also
clean up the code to deduplicate some logic.]

Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Eric Biggers e9ff56ac35 KEYS: encrypted: avoid encrypting/decrypting stack buffers
Since v4.9, the crypto API cannot (normally) be used to encrypt/decrypt
stack buffers because the stack may be virtually mapped.  Fix this for
the padding buffers in encrypted-keys by using ZERO_PAGE for the
encryption padding and by allocating a temporary heap buffer for the
decryption padding.

Tested with CONFIG_DEBUG_SG=y:
	keyctl new_session
	keyctl add user master "abcdefghijklmnop" @s
	keyid=$(keyctl add encrypted desc "new user:master 25" @s)
	datablob="$(keyctl pipe $keyid)"
	keyctl unlink $keyid
	keyid=$(keyctl add encrypted desc "load $datablob" @s)
	datablob2="$(keyctl pipe $keyid)"
	[ "$datablob" = "$datablob2" ] && echo "Success!"

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Eric Biggers d636bd9f12 KEYS: put keyring if install_session_keyring_to_cred() fails
In join_session_keyring(), if install_session_keyring_to_cred() were to
fail, we would leak the keyring reference, just like in the bug fixed by
commit 23567fd052 ("KEYS: Fix keyring ref leak in
join_session_keyring()").  Fortunately this cannot happen currently, but
we really should be more careful.  Do this by adding and using a new
error label at which the keyring reference is dropped.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Markus Elfring 41f1c53e0d KEYS: Delete an error message for a failed memory allocation in get_derived_key()
Omit an extra message for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdf
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:46 +10:00
Davidlohr Bueso 381f20fceb security: use READ_ONCE instead of deprecated ACCESS_ONCE
With the new standardized functions, we can replace all ACCESS_ONCE()
calls across relevant security/keyrings/.

ACCESS_ONCE() does not work reliably on non-scalar types. For example
gcc 4.6 and 4.7 might remove the volatile tag for such accesses during
the SRA (scalar replacement of aggregates) step:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145

Update the new calls regardless of if it is a scalar type, this is
cleaner than having three alternatives.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:45 +10:00
Bilal Amarni 47b2c3fff4 security/keys: add CONFIG_KEYS_COMPAT to Kconfig
CONFIG_KEYS_COMPAT is defined in arch-specific Kconfigs and is missing for
several 64-bit architectures : mips, parisc, tile.

At the moment and for those architectures, calling in 32-bit userspace the
keyctl syscall would return an ENOSYS error.

This patch moves the CONFIG_KEYS_COMPAT option to security/keys/Kconfig, to
make sure the compatibility wrapper is registered by default for any 64-bit
architecture as long as it is configured with CONFIG_COMPAT.

[DH: Modified to remove arm64 compat enablement also as requested by Eric
 Biggers]

Signed-off-by: Bilal Amarni <bilal.amarni@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
cc: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:45 +10:00
John Johansen fc7e0b26b8 apparmor: move permissions into their own file to be more easily shared
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 12:51:53 -07:00
John Johansen c961ee5f21 apparmor: convert from securityfs to apparmorfs for policy ns files
Virtualize the apparmor policy/ directory so that the current
namespace affects what part of policy is seen. To do this convert to
using apparmorfs for policy namespace files and setup a magic symlink
in the securityfs apparmor dir to access those files.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:52 -07:00
John Johansen 98407f0a0d apparmor: allow specifying an already created dir to create ns entries in
Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:52 -07:00
John Johansen c97204baf8 apparmor: rename apparmor file fns and data to indicate use
prefixes are used for fns/data that are not static to apparmorfs.c
with the prefixes being
  aafs   - special magic apparmorfs for policy namespace data
  aa_sfs - for fns/data that go into securityfs
  aa_fs  - for fns/data that may be used in the either of aafs or
           securityfs

Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:52 -07:00
John Johansen a481f4d917 apparmor: add custom apparmorfs that will be used by policy namespace files
AppArmor policy needs to be able to be resolved based on the policy
namespace a task is confined by. Add a base apparmorfs filesystem that
(like nsfs) will exist as a kern mount and be accessed via jump_link
through a securityfs file.

Setup the base apparmorfs fns and data, but don't use it yet.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:51 -07:00
John Johansen 64c8697045 apparmor: use macro template to simplify namespace seq_files
Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:51 -07:00
John Johansen 52b97de322 apparmor: use macro template to simplify profile seq_files
Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:50 -07:00
John Johansen 5d5182cae4 apparmor: move to per loaddata files, instead of replicating in profiles
The loaddata sets cover more than just a single profile and should
be tracked at the ns level. Move the load data files under the namespace
and reference the files from the profiles via a symlink.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:49 -07:00
John Johansen 6623ec7c4d securityfs: add the ability to support symlinks
Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
2017-06-08 12:51:43 -07:00
John Johansen 4227c333f6 apparmor: Move path lookup to using preallocated buffers
Dynamically allocating buffers is problematic and is an extra layer
that is a potntial point of failure and can slow down mediation.
Change path lookup to use the preallocated per cpu buffers.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:29:34 -07:00
John Johansen 72c8a76864 apparmor: allow profiles to provide info to disconnected paths
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:29:34 -07:00
John Johansen b91deb9db1 apparmor: make internal lib fn skipn_spaces available to the rest of apparmor
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:29:33 -07:00
John Johansen af7caa8f8d apparmor: move file context into file.h
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:29:33 -07:00
Thomas Schneider 651e54953b security/apparmor: Use POSIX-compatible "printf '%s'"
When using a strictly POSIX-compliant shell, "-n #define ..." gets
written into the file.  Use "printf '%s'" to avoid this.

Signed-off-by: Thomas Schneider <qsx@qsx.re>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:29:27 -07:00
Dan Carpenter ffac1de6cf apparmor: Fix error cod in __aa_fs_profile_mkdir()
We can either return PTR_ERR(NULL) or a PTR_ERR(a valid pointer) here.
Returning NULL is probably not good, but since this happens at boot
then we are probably already toasted if we were to hit this bug in real
life.  In other words, it seems like a very low severity bug to me.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:21:05 -07:00
Markus Elfring 47dbd1cdbb apparmorfs: Use seq_putc() in two functions
Two single characters (line breaks) should be put into a sequence.
Thus use the corresponding function "seq_putc".

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:21:02 -07:00
Markus Elfring 0ff3d97f76 apparmorfs: Combine two function calls into one in aa_fs_seq_raw_abi_show()
A bit of data was put into a sequence by two separate function calls.
Print the same data by a single function call instead.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-06-08 11:20:58 -07:00
Christoph Hellwig 85787090a2 fs: switch ->s_uuid to uuid_t
For some file systems we still memcpy into it, but in various places this
already allows us to use the proper uuid helpers.  More to come..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com> (Changes to IMA/EVM)
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2017-06-05 16:59:12 +02:00
Christoph Hellwig 787d8c530a ima/policy: switch to use uuid_t
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2017-06-05 16:59:11 +02:00
Christoph Hellwig 1dd771eb0b block: remove blk_part_pack_uuid
This helper was only used by IMA of all things, which would get spurious
errors if CONFIG_BLOCK is disabled.  Just opencode the call there.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2017-06-05 16:59:10 +02:00
Florian Westphal 8e71bf75ef selinux: use pernet operations for hook registration
It will allow us to remove the old netfilter hook api in the near future.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-06-02 10:27:46 -04:00
Casey Schaufler f28e783ff6 Smack: Use cap_capable in privilege check
Use cap_capable() rather than capable() in the Smack privilege
check as the former does not invoke other security module
privilege check, while the later does. This becomes important
when stacking. It may be a problem even with minor modules.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2017-06-01 09:27:21 -07:00
Casey Schaufler 51d59af26f Smack: Safer check for a socket in file_receive
The check of S_ISSOCK() in smack_file_receive() is not
appropriate if the passed descriptor is a socket.

Reported-by: Stephen Smalley <sds@tyco.nsa.gov>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2017-06-01 09:27:12 -07:00
Florian Westphal e661a58279 smack: use pernet operations for hook registration
It will allow us to remove the old netfilter hook api in the near future.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2017-06-01 09:26:43 -07:00
Al Viro 0b884d25f5 sel_write_validatetrans(): don't open-code memdup_user_nul()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-05-25 23:28:36 -04:00
Daniel Jurgens 409dcf3153 selinux: Add a cache for quicker retreival of PKey SIDs
It is likely that the SID for the same PKey will be requested many
times. To reduce the time to modify QPs and process MADs use a cache to
store PKey SIDs.

This code is heavily based on the "netif" and "netport" concept
originally developed by James Morris <jmorris@redhat.com> and Paul Moore
<paul@paul-moore.com> (see security/selinux/netif.c and
security/selinux/netport.c for more information)

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:28:12 -04:00
Daniel Jurgens ab861dfca1 selinux: Add IB Port SMP access vector
Add a type for Infiniband ports and an access vector for subnet
management packets. Implement the ib_port_smp hook to check that the
caller has permission to send and receive SMPs on the end port specified
by the device name and port. Add interface to query the SID for a IB
port, which walks the IB_PORT ocontexts to find an entry for the
given name and port.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:28:02 -04:00
Daniel Jurgens cfc4d882d4 selinux: Implement Infiniband PKey "Access" access vector
Add a type and access vector for PKeys. Implement the ib_pkey_access
hook to check that the caller has permission to access the PKey on the
given subnet prefix. Add an interface to get the PKey SID. Walk the PKey
ocontexts to find an entry for the given subnet prefix and pkey.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:27:50 -04:00
Daniel Jurgens 3a976fa676 selinux: Allocate and free infiniband security hooks
Implement and attach hooks to allocate and free Infiniband object
security structures.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:27:41 -04:00
Daniel Jurgens a806f7a161 selinux: Create policydb version for Infiniband support
Support for Infiniband requires the addition of two new object contexts,
one for infiniband PKeys and another IB Ports. Added handlers to read
and write the new ocontext types when reading or writing a binary policy
representation.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: Eli Cohen <eli@mellanox.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:27:32 -04:00
Daniel Jurgens 47a2b338fe IB/core: Enforce security on management datagrams
Allocate and free a security context when creating and destroying a MAD
agent.  This context is used for controlling access to PKeys and sending
and receiving SMPs.

When sending or receiving a MAD check that the agent has permission to
access the PKey for the Subnet Prefix of the port.

During MAD and snoop agent registration for SMI QPs check that the
calling process has permission to access the manage the subnet  and
register a callback with the LSM to be notified of policy changes. When
notificaiton of a policy change occurs recheck permission and set a flag
indicating sending and receiving SMPs is allowed.

When sending and receiving MADs check that the agent has access to the
SMI if it's on an SMI QP.  Because security policy can change it's
possible permission was allowed when creating the agent, but no longer
is.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Acked-by: Doug Ledford <dledford@redhat.com>
[PM: remove the LSM hook init code]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:27:21 -04:00
Daniel Jurgens 8f408ab64b selinux lsm IB/core: Implement LSM notification system
Add a generic notificaiton mechanism in the LSM. Interested consumers
can register a callback with the LSM and security modules can produce
events.

Because access to Infiniband QPs are enforced in the setup phase of a
connection security should be enforced again if the policy changes.
Register infiniband devices for policy change notification and check all
QPs on that device when the notification is received.

Add a call to the notification mechanism from SELinux when the AVC
cache changes or setenforce is cleared.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:27:11 -04:00
Daniel Jurgens d291f1a652 IB/core: Enforce PKey security on QPs
Add new LSM hooks to allocate and free security contexts and check for
permission to access a PKey.

Allocate and free a security context when creating and destroying a QP.
This context is used for controlling access to PKeys.

When a request is made to modify a QP that changes the port, PKey index,
or alternate path, check that the QP has permission for the PKey in the
PKey table index on the subnet prefix of the port. If the QP is shared
make sure all handles to the QP also have access.

Store which port and PKey index a QP is using. After the reset to init
transition the user can modify the port, PKey index and alternate path
independently. So port and PKey settings changes can be a merge of the
previous settings and the new ones.

In order to maintain access control if there are PKey table or subnet
prefix change keep a list of all QPs are using each PKey index on
each port. If a change occurs all QPs using that device and port must
have access enforced for the new cache settings.

These changes add a transaction to the QP modify process. Association
with the old port and PKey index must be maintained if the modify fails,
and must be removed if it succeeds. Association with the new port and
PKey index must be established prior to the modify and removed if the
modify fails.

1. When a QP is modified to a particular Port, PKey index or alternate
   path insert that QP into the appropriate lists.

2. Check permission to access the new settings.

3. If step 2 grants access attempt to modify the QP.

4a. If steps 2 and 3 succeed remove any prior associations.

4b. If ether fails remove the new setting associations.

If a PKey table or subnet prefix changes walk the list of QPs and
check that they have permission. If not send the QP to the error state
and raise a fatal error event. If it's a shared QP make sure all the
QPs that share the real_qp have permission as well. If the QP that
owns a security structure is denied access the security structure is
marked as such and the QP is added to an error_list. Once the moving
the QP to error is complete the security structure mark is cleared.

Maintaining the lists correctly turns QP destroy into a transaction.
The hardware driver for the device frees the ib_qp structure, so while
the destroy is in progress the ib_qp pointer in the ib_qp_security
struct is undefined. When the destroy process begins the ib_qp_security
structure is marked as destroying. This prevents any action from being
taken on the QP pointer. After the QP is destroyed successfully it
could still listed on an error_list wait for it to be processed by that
flow before cleaning up the structure.

If the destroy fails the QPs port and PKey settings are reinserted into
the appropriate lists, the destroying flag is cleared, and access control
is enforced, in case there were any cache changes during the destroy
flow.

To keep the security changes isolated a new file is used to hold security
related functionality.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Acked-by: Doug Ledford <dledford@redhat.com>
[PM: merge fixup in ib_verbs.h and uverbs_cmd.c]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 12:26:59 -04:00
Matthias Kaehlcke 270e857314 selinux: Remove redundant check for unknown labeling behavior
The check is already performed in ocontext_read() when the policy is
loaded. Removing the array also fixes the following warning when
building with clang:

security/selinux/hooks.c:338:20: error: variable 'labeling_behaviors'
    is not needed and will not be emitted
    [-Werror,-Wunneeded-internal-declaration]

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:24:06 -04:00
Stephen Smalley 4dc2fce342 selinux: log policy capability state when a policy is loaded
Log the state of SELinux policy capabilities when a policy is loaded.
For each policy capability known to the kernel, log the policy capability
name and the value set in the policy.  For policy capabilities that are
set in the loaded policy but unknown to the kernel, log the policy
capability index, since this is the only information presently available
in the policy.

Sample output with a policy created with a new capability defined
that is not known to the kernel:
SELinux:  policy capability network_peer_controls=1
SELinux:  policy capability open_perms=1
SELinux:  policy capability extended_socket_class=1
SELinux:  policy capability always_check_network=0
SELinux:  policy capability cgroup_seclabel=0
SELinux:  unknown policy capability 5

Resolves: https://github.com/SELinuxProject/selinux-kernel/issues/32

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:23:50 -04:00
Stephen Smalley ccb544781d selinux: do not check open permission on sockets
open permission is currently only defined for files in the kernel
(COMMON_FILE_PERMS rather than COMMON_FILE_SOCK_PERMS). Construction of
an artificial test case that tries to open a socket via /proc/pid/fd will
generate a recvfrom avc denial because recvfrom and open happen to map to
the same permission bit in socket vs file classes.

open of a socket via /proc/pid/fd is not supported by the kernel regardless
and will ultimately return ENXIO. But we hit the permission check first and
can thus produce these odd/misleading denials.  Omit the open check when
operating on a socket.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:23:42 -04:00
Stephen Smalley 3ba4bf5f1e selinux: add a map permission check for mmap
Add a map permission check on mmap so that we can distinguish memory mapped
access (since it has different implications for revocation). When a file
is opened and then read or written via syscalls like read(2)/write(2),
we revalidate access on each read/write operation via
selinux_file_permission() and therefore can revoke access if the
process context, the file context, or the policy changes in such a
manner that access is no longer allowed. When a file is opened and then
memory mapped via mmap(2) and then subsequently read or written directly
in memory, we presently have no way to revalidate or revoke access.
The purpose of a separate map permission check on mmap(2) is to permit
policy to prohibit memory mapping of specific files for which we need
to ensure that every access is revalidated, particularly useful for
scenarios where we expect the file to be relabeled at runtime in order
to reflect state changes (e.g. cross-domain solution, assured pipeline
without data copying).

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:23:39 -04:00
Stephen Smalley db59000ab7 selinux: only invoke capabilities and selinux for CAP_MAC_ADMIN checks
SELinux uses CAP_MAC_ADMIN to control the ability to get or set a raw,
uninterpreted security context unknown to the currently loaded security
policy. When performing these checks, we only want to perform a base
capabilities check and a SELinux permission check.  If any other
modules that implement a capable hook are stacked with SELinux, we do
not want to require them to also have to authorize CAP_MAC_ADMIN,
since it may have different implications for their security model.
Rework the CAP_MAC_ADMIN checks within SELinux to only invoke the
capabilities module and the SELinux permission checking.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:23:22 -04:00
Markus Elfring 46be14d2b6 selinux: Return an error code only as a constant in sidtab_insert()
* Return an error code without storing it in an intermediate variable.

* Delete the local variable "rc" and the jump label "out" which became
  unnecessary with this refactoring.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:23:17 -04:00
Markus Elfring 62934ffb9e selinux: Return directly after a failed memory allocation in policydb_index()
Replace five goto statements (and previous variable assignments) by
direct returns after a memory allocation failure in this function.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:23:12 -04:00
Tetsuo Handa a79be23860 selinux: Use task_alloc hook rather than task_create hook
This patch is a preparation for getting rid of task_create hook because
task_alloc hook which can do what task_create hook can do was revived.

Creating a new thread is unlikely prohibited by security policy, for
fork()/execve()/exit() is fundamental of how processes are managed in
Unix. If a program is known to create a new thread, it is likely that
permission to create a new thread is given to that program. Therefore,
a situation where security_task_create() returns an error is likely that
the program was exploited and lost control. Even if SELinux failed to
check permission to create a thread at security_task_create(), SELinux
can later check it at security_task_alloc(). Since the new thread is not
yet visible from the rest of the system, nobody can do bad things using
the new thread. What we waste will be limited to some initialization
steps such as dup_task_struct(), copy_creds() and audit_alloc() in
copy_process(). We can tolerate these overhead for unlikely situation.

Therefore, this patch changes SELinux to use task_alloc hook rather than
task_create hook so that we can remove task_create hook.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23 10:23:02 -04:00
James Morris d68c51e0b3 Sync to mainline for security submaintainers to work against 2017-05-22 16:32:40 +10:00
Kees Cook 5395d312df doc: ReSTify keys-trusted-encrypted.txt
Adjusts for ReST markup and moves under keys security devel index.

Cc: David Howells <dhowells@redhat.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:56 -06:00
Kees Cook 3db38ed768 doc: ReSTify keys-request-key.txt
Adjusts for ReST markup and moves under keys security devel index.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:51 -06:00
Kees Cook 90bb766440 doc: ReSTify Yama.txt
Adjusts for ReST markup and moves under LSM admin guide.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:04 -06:00
Kees Cook 26fccd9ed2 doc: ReSTify apparmor.txt
Adjusts for ReST markup and moves under LSM admin guide.

Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:32:38 -06:00