Commit Graph

182 Commits

Author SHA1 Message Date
John Johansen
a4c3f89c9b apparmor: fixup secid map conversion to using IDR
The IDR conversion did not handle an error case for when allocating a
mapping fails, and it did not ensure that mappings did not allocate or
use a 0 value, which is used as an invalid secid. Which is used when a
mapping fails.

Fixes: 3ae7eb49a2be ("apparmor: Use an IDR to allocate apparmor secids")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-06-07 01:50:49 -07:00
Matthew Garrett
e79c26d040 apparmor: Add support for audit rule filtering
This patch adds support to Apparmor for integrating with audit rule
filtering. Right now it only handles SUBJ_ROLE, interpreting it as a
single component of a label. This is sufficient to get Apparmor working
with IMA's appraisal rules without any modifications on the IMA side.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-06-07 01:50:47 -07:00
John Johansen
38125c2c2b apparmor: improve get_buffers macro by using get_cpu_ptr
Refactor get_buffers so the cpu_ptr can be obtained in the outer
layer, instead of inside the macro.

This also enables us to cleanup the code and use get_cpu_ptr,
to handle the preempt_disable()

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2018-06-07 01:49:21 -07:00
John Johansen
c092921219 apparmor: add support for mapping secids and using secctxes
Use a radix tree to provide a map between the secid and the label,
and along with it a basic ability to provide secctx conversion.

Shared/cached secctx will be added later.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-05-02 00:48:55 -07:00
Linus Torvalds
80a17a5f50 Merge tag 'apparmor-pr-2018-04-10' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
 "Features:
  - add base infrastructure for socket mediation. ABI bump and
    additional checks to ensure only v8 compliant policy uses socket af
    mediation.
  - improve and cleanup dfa verification
  - improve profile attachment logic
     - improve overlapping expression handling
     - add the xattr matching to the attachment logic
  - improve signal mediation handling with stacked labels
  - improve handling of no_new_privs in a label stack

  Cleanups and changes:
  - use dfa to parse string split
  - bounded version of label_parse
  - proper line wrap nulldfa.in
  - split context out into task and cred naming to better match usage
  - simplify code in aafs

  Bug fixes:
  - fix display of .ns_name for containers
  - fix resource audit messages when auditing peer
  - fix logging of the existence test for signals
  - fix resource audit messages when auditing peer
  - fix display of .ns_name for containers
  - fix an error code in verify_table_headers()
  - fix memory leak on buffer on error exit path
  - fix error returns checks by making size a ssize_t"

* tag 'apparmor-pr-2018-04-10' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor: (36 commits)
  apparmor: fix memory leak on buffer on error exit path
  apparmor: fix dangling symlinks to policy rawdata after replacement
  apparmor: Fix an error code in verify_table_headers()
  apparmor: fix error returns checks by making size a ssize_t
  apparmor: update MAINTAINERS file git and wiki locations
  apparmor: remove POLICY_MEDIATES_SAFE
  apparmor: add base infastructure for socket mediation
  apparmor: improve overlapping domain attachment resolution
  apparmor: convert attaching profiles via xattrs to use dfa matching
  apparmor: Add support for attaching profiles via xattr, presence and value
  apparmor: cleanup: simplify code to get ns symlink name
  apparmor: cleanup create_aafs() error path
  apparmor: dfa split verification of table headers
  apparmor: dfa add support for state differential encoding
  apparmor: dfa move character match into a macro
  apparmor: update domain transitions that are subsets of confinement at nnp
  apparmor: move context.h to cred.h
  apparmor: move task related defines and fns to task.X files
  apparmor: cleanup, drop unused fn __aa_task_is_confined()
  apparmor: cleanup fixup description of aa_replace_profiles
  ...
2018-04-13 15:38:53 -07:00
Alexei Starovoitov
cf14f27f82 macro: introduce COUNT_ARGS() macro
move COUNT_ARGS() macro from apparmor to generic header and extend it
to count till twelve.

COUNT() was an alternative name for this logic, but it's used for
different purpose in many other places.

Similarly for CONCATENATE() macro.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-03-28 22:55:19 +02:00
John Johansen
b9590ad4c4 apparmor: remove POLICY_MEDIATES_SAFE
The unpack code now makes sure every profile has a dfa so the safe
version of POLICY_MEDIATES is no longer needed.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-03-13 17:25:49 -07:00
John Johansen
56974a6fcf apparmor: add base infastructure for socket mediation
version 2 - Force an abi break. Network mediation will only be
            available in v8 abi complaint policy.

Provide a basic mediation of sockets. This is not a full net mediation
but just whether a spcific family of socket can be used by an
application, along with setting up some basic infrastructure for
network mediation to follow.

the user space rule hav the basic form of
  NETWORK RULE = [ QUALIFIERS ] 'network' [ DOMAIN ]
                 [ TYPE | PROTOCOL ]

  DOMAIN = ( 'inet' | 'ax25' | 'ipx' | 'appletalk' | 'netrom' |
             'bridge' | 'atmpvc' | 'x25' | 'inet6' | 'rose' |
	     'netbeui' | 'security' | 'key' | 'packet' | 'ash' |
	     'econet' | 'atmsvc' | 'sna' | 'irda' | 'pppox' |
	     'wanpipe' | 'bluetooth' | 'netlink' | 'unix' | 'rds' |
	     'llc' | 'can' | 'tipc' | 'iucv' | 'rxrpc' | 'isdn' |
	     'phonet' | 'ieee802154' | 'caif' | 'alg' | 'nfc' |
	     'vsock' | 'mpls' | 'ib' | 'kcm' ) ','

  TYPE = ( 'stream' | 'dgram' | 'seqpacket' |  'rdm' | 'raw' |
           'packet' )

  PROTOCOL = ( 'tcp' | 'udp' | 'icmp' )

eg.
  network,
  network inet,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2018-03-13 17:25:48 -07:00
John Johansen
21f6066105 apparmor: improve overlapping domain attachment resolution
Overlapping domain attachments using the current longest left exact
match fail in some simple cases, and with the fix to ensure consistent
behavior by failing unresolvable attachments it becomes important to
do a better job.

eg. under the current match the following are unresolvable where
the alternation is clearly a better match under the most specific
left match rule.
  /**
  /{bin/,}usr/

Use a counting match that detects when a loop in the state machine is
enter, and return the match count to provide a better specific left
match resolution.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:02 -08:00
John Johansen
73f488cd90 apparmor: convert attaching profiles via xattrs to use dfa matching
This converts profile attachment based on xattrs to a fixed extended
conditional using dfa matching.

This has a couple of advantages
- pattern matching can be used for the xattr match

- xattrs can be optional for an attachment or marked as required

- the xattr attachment conditional will be able to be combined with
  other extended conditionals when the flexible extended conditional
  work lands.

The xattr fixed extended conditional is appended to the xmatch
conditional. If an xattr attachment is specified the profile xmatch
will be generated regardless of whether there is a pattern match on
the executable name.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2018-02-09 11:30:02 -08:00
Matthew Garrett
8e51f9087f apparmor: Add support for attaching profiles via xattr, presence and value
Make it possible to tie Apparmor profiles to the presence of one or more
extended attributes, and optionally their values. An example usecase for
this is to automatically transition to a more privileged Apparmor profile
if an executable has a valid IMA signature, which can then be appraised
by the IMA subsystem.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:02 -08:00
John Johansen
031dcc8f4e apparmor: dfa add support for state differential encoding
State differential encoding can provide better compression for
apparmor policy, without having significant impact on match time.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
9fcf78cca1 apparmor: update domain transitions that are subsets of confinement at nnp
Domain transition so far have been largely blocked by no new privs,
unless the transition has been provably a subset of the previous
confinement. There was a couple problems with the previous
implementations,

- transitions that weren't explicitly a stack but resulted in a subset
  of confinement were disallowed

- confinement subsets were only calculated from the previous
  confinement instead of the confinement being enforced at the time of
  no new privs, so transitions would have to get progressively
  tighter.

Fix this by detecting and storing a reference to the task's
confinement at the "time" no new privs is set. This reference is then
used to determine whether a transition is a subsystem of the
confinement at the time no new privs was set.

Unfortunately the implementation is less than ideal in that we have to
detect no new privs after the fact when a task attempts a domain
transition. This is adequate for the currently but will not work in a
stacking situation where no new privs could be conceivably be set in
both the "host" and in the container.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
d8889d49e4 apparmor: move context.h to cred.h
Now that file contexts have been moved into file, and task context
fns() and data have been split from the context, only the cred context
remains in context.h so rename to cred.h to better reflect what it
deals with.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
de62de59c2 apparmor: move task related defines and fns to task.X files
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
d065f2f565 apparmor: cleanup, drop unused fn __aa_task_is_confined()
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
d9087c49d4 apparmor: drop cred_ctx and reference the label directly
With the task domain change information now stored in the task->security
context, the cred->security context only stores the label. We can get
rid of the cred_ctx and directly reference the label, removing a layer
of indirection, and unneeded extra allocations.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
3b529a7600 apparmor: move task domain change info to task security
The task domain change info is task specific and its and abuse of
the cred to store the information in there. Now that a task->security
field exists store it in the proper place.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
4d2f8ba3e3 apparmor: rename task_ctx to the more accurate cred_ctx
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
3acfd5f54c apparmor: audit unknown signal numbers
Allow apparmor to audit the number of a signal that it does not
provide a mapping for and is currently being reported only as
unknown.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
95652cac83 apparmor: provide a bounded version of label_parse
some label/context sources might not be guaranteed to be null terminiated
provide a size bounded version of label parse to deal with these.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
6e0654d20e apparmor: use the dfa to do label parse string splitting
The current split scheme is actually wrong in that it splits
  ///&

where that is invalid and should fail. Use the dfa to do a proper
bounded split without having to worry about getting the string
processing right in code.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
cf65fabc2a apparmor: add first substr match to dfa
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2018-02-09 11:30:01 -08:00
John Johansen
a6a52579e5 apparmor: split load data into management struct and data blob
Splitting the management struct from the actual data blob will allow
us in the future to do some sharing and other data reduction
techniques like replacing the the raw data with compressed data.

Prepare for this by separating the management struct from the data
blob.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:00 -08:00
John Johansen
98cf5bbff4 apparmor: fix logging of the existence test for signals
The existence test is not being properly logged as the signal mapping
maps it to the last entry in the named signal table. This is done
to help catch bugs by making the 0 mapped signal value invalid so
that we can catch the signal value not being filled in.

When fixing the off-by-one comparision logic the reporting of the
existence test was broken, because the logic behind the mapped named
table was hidden. Fix this by adding a define for the name lookup
and using it.

Cc: Stable <stable@vger.kernel.org>
Fixes: f7dc4c9a85 ("apparmor: fix off-by-one comparison on MAXMAPPED_SIG")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-02-09 11:30:00 -08:00