Commit Graph

15 Commits

Author SHA1 Message Date
John Johansen 4cd4fc7703 apparmor: fix suspicious RCU usage warning in policy.c/policy.h
The recent 3.12 pull request for apparmor was missing a couple rcu _protected
access modifiers. Resulting in the follow suspicious RCU usage

 [   29.804534] [ INFO: suspicious RCU usage. ]
 [   29.804539] 3.11.0+ #5 Not tainted
 [   29.804541] -------------------------------
 [   29.804545] security/apparmor/include/policy.h:363 suspicious rcu_dereference_check() usage!
 [   29.804548]
 [   29.804548] other info that might help us debug this:
 [   29.804548]
 [   29.804553]
 [   29.804553] rcu_scheduler_active = 1, debug_locks = 1
 [   29.804558] 2 locks held by apparmor_parser/1268:
 [   29.804560]  #0:  (sb_writers#9){.+.+.+}, at: [<ffffffff81120a4c>] file_start_write+0x27/0x29
 [   29.804576]  #1:  (&ns->lock){+.+.+.}, at: [<ffffffff811f5d88>] aa_replace_profiles+0x166/0x57c
 [   29.804589]
 [   29.804589] stack backtrace:
 [   29.804595] CPU: 0 PID: 1268 Comm: apparmor_parser Not tainted 3.11.0+ #5
 [   29.804599] Hardware name: ASUSTeK Computer Inc.         UL50VT          /UL50VT    , BIOS 217     03/01/2010
 [   29.804602]  0000000000000000 ffff8800b95a1d90 ffffffff8144eb9b ffff8800b94db540
 [   29.804611]  ffff8800b95a1dc0 ffffffff81087439 ffff880138cc3a18 ffff880138cc3a18
 [   29.804619]  ffff8800b9464a90 ffff880138cc3a38 ffff8800b95a1df0 ffffffff811f5084
 [   29.804628] Call Trace:
 [   29.804636]  [<ffffffff8144eb9b>] dump_stack+0x4e/0x82
 [   29.804642]  [<ffffffff81087439>] lockdep_rcu_suspicious+0xfc/0x105
 [   29.804649]  [<ffffffff811f5084>] __aa_update_replacedby+0x53/0x7f
 [   29.804655]  [<ffffffff811f5408>] __replace_profile+0x11f/0x1ed
 [   29.804661]  [<ffffffff811f6032>] aa_replace_profiles+0x410/0x57c
 [   29.804668]  [<ffffffff811f16d4>] profile_replace+0x35/0x4c
 [   29.804674]  [<ffffffff81120fa3>] vfs_write+0xad/0x113
 [   29.804680]  [<ffffffff81121609>] SyS_write+0x44/0x7a
 [   29.804687]  [<ffffffff8145bfd2>] system_call_fastpath+0x16/0x1b
 [   29.804691]
 [   29.804694] ===============================
 [   29.804697] [ INFO: suspicious RCU usage. ]
 [   29.804700] 3.11.0+ #5 Not tainted
 [   29.804703] -------------------------------
 [   29.804706] security/apparmor/policy.c:566 suspicious rcu_dereference_check() usage!
 [   29.804709]
 [   29.804709] other info that might help us debug this:
 [   29.804709]
 [   29.804714]
 [   29.804714] rcu_scheduler_active = 1, debug_locks = 1
 [   29.804718] 2 locks held by apparmor_parser/1268:
 [   29.804721]  #0:  (sb_writers#9){.+.+.+}, at: [<ffffffff81120a4c>] file_start_write+0x27/0x29
 [   29.804733]  #1:  (&ns->lock){+.+.+.}, at: [<ffffffff811f5d88>] aa_replace_profiles+0x166/0x57c
 [   29.804744]
 [   29.804744] stack backtrace:
 [   29.804750] CPU: 0 PID: 1268 Comm: apparmor_parser Not tainted 3.11.0+ #5
 [   29.804753] Hardware name: ASUSTeK Computer Inc.         UL50VT          /UL50VT    , BIOS 217     03/01/2010
 [   29.804756]  0000000000000000 ffff8800b95a1d80 ffffffff8144eb9b ffff8800b94db540
 [   29.804764]  ffff8800b95a1db0 ffffffff81087439 ffff8800b95b02b0 0000000000000000
 [   29.804772]  ffff8800b9efba08 ffff880138cc3a38 ffff8800b95a1dd0 ffffffff811f4f94
 [   29.804779] Call Trace:
 [   29.804786]  [<ffffffff8144eb9b>] dump_stack+0x4e/0x82
 [   29.804791]  [<ffffffff81087439>] lockdep_rcu_suspicious+0xfc/0x105
 [   29.804798]  [<ffffffff811f4f94>] aa_free_replacedby_kref+0x4d/0x62
 [   29.804804]  [<ffffffff811f4f47>] ? aa_put_namespace+0x17/0x17
 [   29.804810]  [<ffffffff811f4f0b>] kref_put+0x36/0x40
 [   29.804816]  [<ffffffff811f5423>] __replace_profile+0x13a/0x1ed
 [   29.804822]  [<ffffffff811f6032>] aa_replace_profiles+0x410/0x57c
 [   29.804829]  [<ffffffff811f16d4>] profile_replace+0x35/0x4c
 [   29.804835]  [<ffffffff81120fa3>] vfs_write+0xad/0x113
 [   29.804840]  [<ffffffff81121609>] SyS_write+0x44/0x7a
 [   29.804847]  [<ffffffff8145bfd2>] system_call_fastpath+0x16/0x1b

Reported-by: miles.lane@gmail.com
CC: paulmck@linux.vnet.ibm.com
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2013-09-30 09:54:01 +10:00
John Johansen f8eb8a1324 apparmor: add the ability to report a sha1 hash of loaded policy
Provide userspace the ability to introspect a sha1 hash value for each
profile currently loaded.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-08-14 11:42:08 -07:00
John Johansen 556d0be74b apparmor: add an optional profile attachment string for profiles
Add the ability to take in and report a human readable profile attachment
string for profiles so that attachment specifications can be easily
inspected.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-08-14 11:42:07 -07:00
John Johansen 0d259f043f apparmor: add interface files for profiles and namespaces
Add basic interface files to access namespace and profile information.
The interface files are created when a profile is loaded and removed
when the profile or namespace is removed.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-08-14 11:42:07 -07:00
John Johansen 038165070a apparmor: allow setting any profile into the unconfined state
Allow emulating the default profile behavior from boot, by allowing
loading of a profile in the unconfined state into a new NS.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-08-14 11:42:07 -07:00
John Johansen 8651e1d657 apparmor: make free_profile available outside of policy.c
Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen 742058b0f3 apparmor: rework namespace free path
namespaces now completely use the unconfined profile to track the
refcount and rcu freeing cycle. So rework the code to simplify (track
everything through the profile path right up to the end), and move the
rcu_head from policy base to profile as the namespace no longer needs
it.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen fa2ac468db apparmor: update how unconfined is handled
ns->unconfined is being used read side without locking, nor rcu but is
being updated when a namespace is removed. This works for the root ns
which is never removed but has a race window and can cause failures when
children namespaces are removed.

Also ns and ns->unconfined have a circular refcounting dependency that
is problematic and must be broken. Currently this is done incorrectly
when the namespace is destroyed.

Fix this by forward referencing unconfined via the replacedby infrastructure
instead of directly updating the ns->unconfined pointer.

Remove the circular refcount dependency by making the ns and its unconfined
profile share the same refcount.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen 77b071b340 apparmor: change how profile replacement update is done
remove the use of replaced by chaining and move to profile invalidation
and lookup to handle task replacement.

Replacement chaining can result in large chains of profiles being pinned
in memory when one profile in the chain is use. With implicit labeling
this will be even more of a problem, so move to a direct lookup method.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen 01e2b670aa apparmor: convert profile lists to RCU based locking
Signed-off-by: John Johansen <john.johansen@canonical.com>
2013-08-14 11:42:06 -07:00
John Johansen a4987857d2 apparmor: remove sid from profiles
The sid is not going to be a direct property of a profile anymore, instead
it will be directly related to the label, and the profile will pickup
a label back reference.

For null-profiles replace the use of sid with a per namespace unique
id.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
2013-04-28 00:37:13 -07:00
John Johansen 50c5ecd5d8 apparmor: refactor profile mode macros
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <sbeattie@ubuntu.com>
2013-04-28 00:35:29 -07:00
Jan Engelhardt 2d4cee7e3a AppArmor: add const qualifiers to string arrays
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2012-03-14 19:09:13 -07:00
John Johansen ad5ff3db53 AppArmor: Add ability to load extended policy
Add the base support for the new policy extensions. This does not bring
any additional functionality, or change current semantics.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
2012-03-14 19:09:03 -07:00
John Johansen c88d4c7b04 AppArmor: core policy routines
The basic routines and defines for AppArmor policy.  AppArmor policy
is defined by a few basic components.
      profiles - the basic unit of confinement contain all the information
                 to enforce policy on a task

                 Profiles tend to be named after an executable that they
                 will attach to but this is not required.
      namespaces - a container for a set of profiles that will be used
                 during attachment and transitions between profiles.
      sids - which provide a unique id for each profile

Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:38:37 +10:00