Commit Graph

26 Commits

Author SHA1 Message Date
Linus Torvalds
79e178a57d + Features
- increase left match history buffer size to provide inproved conflict
     resolution in overlapping execution rules.
   - switch buffer allocation to use a memory pool and GFP_KERNEL
     where possible.
   - add compression of policy blobs to reduce memory usage.
 + Cleanups
   - fix spelling mistake "immutible" -> "immutable"
 + Bug fixes
   - fix unsigned len comparison in update_for_len macro
   - fix sparse warning for type-casting of current->real_cred
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Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "Features:

   - increase left match history buffer size to provide improved
     conflict resolution in overlapping execution rules.

   - switch buffer allocation to use a memory pool and GFP_KERNEL where
     possible.

   - add compression of policy blobs to reduce memory usage.

  Cleanups:

   - fix spelling mistake "immutible" -> "immutable"

  Bug fixes:

   - fix unsigned len comparison in update_for_len macro

   - fix sparse warning for type-casting of current->real_cred"

* tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: make it so work buffers can be allocated from atomic context
  apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
  apparmor: fix wrong buffer allocation in aa_new_mount
  apparmor: fix unsigned len comparison with less than zero
  apparmor: increase left match history buffer size
  apparmor: Switch to GFP_KERNEL where possible
  apparmor: Use a memory pool instead per-CPU caches
  apparmor: Force type-casting of current->real_cred
  apparmor: fix spelling mistake "immutible" -> "immutable"
  apparmor: fix blob compression when ns is forced on a policy load
  apparmor: fix missing ZLIB defines
  apparmor: fix blob compression build failure on ppc
  apparmor: Initial implementation of raw policy blob compression
2019-12-03 12:51:35 -08:00
John Johansen
136db99485 apparmor: increase left match history buffer size
There have been cases reported where a history buffer size of 8 was
not enough to resolve conflict overlaps. Increase the buffer to and
get rid of the size element which is currently just storing the
constant WB_HISTORY_SIZE.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2019-06-20 10:33:31 -07:00
Thomas Gleixner
b886d83c5b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441
Based on 1 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 as published by
  the free software foundation version 2 of the license

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 315 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:17 +02:00
Zygmunt Krynicki
5d2371e123 apparmor: fix typo "traverse"
Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@canonical.com>
Acked-by: Christian Boltz <apparmor@cboltz.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-05-03 00:50:12 -07:00
Dan Carpenter
d53c9f4d21 apparmor: Fix an error code in verify_table_headers()
We accidentally return a positive EPROTO instead of a negative -EPROTO.
Since 71 is not an error pointer, that means it eventually results in an
Oops in the caller.

Fixes: d901d6a298 ("apparmor: dfa split verification of table headers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2018-03-23 17:28:38 -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
d901d6a298 apparmor: dfa split verification of table headers
separate the different types of verification so they are logically
separate and can be reused separate of each other.

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
074c1cd798 apparmor: dfa move character match into a macro
Signed-off-by: John Johansen <john.johansen@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
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
Michal Hocko
a7c3e901a4 mm: introduce kv[mz]alloc helpers
Patch series "kvmalloc", v5.

There are many open coded kmalloc with vmalloc fallback instances in the
tree.  Most of them are not careful enough or simply do not care about
the underlying semantic of the kmalloc/page allocator which means that
a) some vmalloc fallbacks are basically unreachable because the kmalloc
part will keep retrying until it succeeds b) the page allocator can
invoke a really disruptive steps like the OOM killer to move forward
which doesn't sound appropriate when we consider that the vmalloc
fallback is available.

As it can be seen implementing kvmalloc requires quite an intimate
knowledge if the page allocator and the memory reclaim internals which
strongly suggests that a helper should be implemented in the memory
subsystem proper.

Most callers, I could find, have been converted to use the helper
instead.  This is patch 6.  There are some more relying on __GFP_REPEAT
in the networking stack which I have converted as well and Eric Dumazet
was not opposed [2] to convert them as well.

[1] http://lkml.kernel.org/r/20170130094940.13546-1-mhocko@kernel.org
[2] http://lkml.kernel.org/r/1485273626.16328.301.camel@edumazet-glaptop3.roam.corp.google.com

This patch (of 9):

Using kmalloc with the vmalloc fallback for larger allocations is a
common pattern in the kernel code.  Yet we do not have any common helper
for that and so users have invented their own helpers.  Some of them are
really creative when doing so.  Let's just add kv[mz]alloc and make sure
it is implemented properly.  This implementation makes sure to not make
a large memory pressure for > PAGE_SZE requests (__GFP_NORETRY) and also
to not warn about allocation failures.  This also rules out the OOM
killer as the vmalloc is a more approapriate fallback than a disruptive
user visible action.

This patch also changes some existing users and removes helpers which
are specific for them.  In some cases this is not possible (e.g.
ext4_kvmalloc, libcfs_kvzalloc) because those seems to be broken and
require GFP_NO{FS,IO} context which is not vmalloc compatible in general
(note that the page table allocation is GFP_KERNEL).  Those need to be
fixed separately.

While we are at it, document that __vmalloc{_node} about unsupported gfp
mask because there seems to be a lot of confusion out there.
kvmalloc_node will warn about GFP_KERNEL incompatible (which are not
superset) flags to catch new abusers.  Existing ones would have to die
slowly.

[sfr@canb.auug.org.au: f2fs fixup]
  Link: http://lkml.kernel.org/r/20170320163735.332e64b7@canb.auug.org.au
Link: http://lkml.kernel.org/r/20170306103032.2540-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>	[ext4 part]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:12 -07:00
John Johansen
e6e8bf4188 apparmor: fix restricted endian type warnings for dfa unpack
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:54 -08:00
John Johansen
11c236b89d apparmor: add a default null dfa
Instead of testing whether a given dfa exists in every code path, have
a default null dfa that is used when loaded policy doesn't provide a
dfa.

This will let us get rid of special casing and avoid dereference bugs
when special casing is missed.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:34 -08:00
John Johansen
12557dcba2 apparmor: move lib definitions into separate lib include
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 00:42:13 -08:00
Heinrich Schuchardt
f4ee2def2d apparmor: do not expose kernel stack
Do not copy uninitalized fields th.td_hilen, th.td_data.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
3197f5adf5 apparmor: don't check for vmalloc_addr if kvzalloc() failed
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
15756178c6 apparmor: add missing id bounds check on dfa verification
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
ed686308c6 apparmor: reserve and mask off the top 8 bits of the base field
The top 8 bits of the base field have never been used, in fact can't
be used, by the current 'dfa16' format.  However they will be used in the
future as flags, so mask them off when using base as an index value.

Note: the use of the top 8 bits, without masking is trapped by the verify
      checks that base entries are within the size bounds.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
2013-04-28 00:37:32 -07:00
John Johansen
8e4ff109d0 apparmor: misc cleanup of match
tidying up comments, includes and defines

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
2013-04-28 00:36:55 -07:00
John Johansen
0ca554b9fc apparmor: add kvzalloc to handle zeroing for kvmalloc
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
2013-04-28 00:36:09 -07:00
John Johansen
0fe1212d05 AppArmor: Update dfa matching routines.
Update aa_dfa_match so that it doesn't result in an input string being
walked twice (once to get its length and another time to match)

Add a single step functions
  aa_dfa_next

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
2012-03-14 06:15:24 -07:00
Randy Dunlap
d410fa4ef9 Create Documentation/security/,
move LSM-, credentials-, and keys-related files from Documentation/
  to Documentation/security/,
add Documentation/security/00-INDEX, and
update all occurrences of Documentation/<moved_file>
  to Documentation/security/<moved_file>.
2011-05-19 15:59:38 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
John Johansen
e06f75a6a2 AppArmor: dfa match engine
A basic dfa matching engine based off the dfa engine in the Dragon
Book.  It uses simple row comb compression with a check field.

This allows AppArmor to do pattern matching in linear time, and also
avoids stack issues that an nfa based engine may have.  The dfa
engine uses a byte based comparison, with all values being valid.
Any potential character encoding are handled user side when the dfa
tables are created.  By convention AppArmor uses \0 to separate two
dependent path matches since \0 is not a valid path character
(this is done in the link permission check).

The dfa tables are generated in user space and are verified at load
time to be internally consistent.

There are several future improvements planned for the dfa engine:
* The dfa engine may be converted to a hybrid nfa-dfa engine, with
  a fixed size limited stack.  This would allow for size time
  tradeoffs, by inserting limited nfa states to help control
  state explosion that can occur with dfas.
* The dfa engine may pickup the ability to do limited dynamic
  variable matching, instead of fixing all variables at policy
  load time.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:35:13 +10:00