Linus found that the gigantic size of the common audit data caused a big
perf hit on something as simple as running stat() in a loop. This patch
requires LSMs to declare the LSM specific portion separately rather than
doing it in a union. Thus each LSM can be responsible for shrinking their
portion and don't have to pay a penalty just because other LSMs have a
bigger space requirement.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Move the path name lookup failure messages into the main path name lookup
routine, as the information is useful in more than just aa_path_perm.
Also rename aa_get_name to aa_path_name as it is not getting a reference
counted object with a corresponding put fn.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
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>
If the xindex value stored in the accept tables is 0, the extraction of
that value will result in an underflow (0 - 4).
In properly compiled policy this should not happen for file rules but
it may be possible for other rule types in the future.
To exploit this underflow a user would have to be able to load a corrupt
policy, which requires CAP_MAC_ADMIN, overwrite system policy in kernel
memory or know of a compiler error resulting in the flaw being present
for loaded policy (no such flaw is known at this time).
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
The audit permission flag, that specifies an audit message should be
provided when an operation is allowed, was being ignored in some cases.
This is because the auto audit mode (which determines the audit mode from
system flags) was incorrectly assigned the same value as audit mode. The
shared value would result in messages that should be audited going through
a second evaluation as to whether they should be audited based on the
auto audit, resulting in some messages being dropped.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
Since the parser needs to know which rlimits are known to the kernel,
export the list via a mask file in the "rlimit" subdirectory in the
securityfs "features" directory.
Signed-off-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Create the "file" directory in the securityfs for tracking features
related to files.
Signed-off-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
This adds the "features" subdirectory to the AppArmor securityfs
to display boolean features flags and the known capability mask.
Signed-off-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Use a file tree structure to represent the AppArmor securityfs.
Signed-off-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
module_param(bool) used to counter-intuitively take an int. In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.
It's time to remove the int/unsigned int option. For this version
it'll simply give a warning, but it'll break next kernel version.
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove kobject.h from files which don't need it, notably,
sched.h and fs.h.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove path.h from sched.h and other files.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.6.36 introduced the abilitiy to specify the task that is having its
rlimits set. Update mediation to ensure that confined tasks can only
set their own group_leader as expected by current policy.
Add TODO note about extending policy to support setting other tasks
rlimits.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
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>
AppArmor policy is loaded in a platform independent flattened binary
stream. Verify and unpack the data converting it to the internal
format needed for enforcement.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
ipc:
AppArmor ipc is currently limited to mediation done by file mediation
and basic ptrace tests. Improved mediation is a wip.
rlimits:
AppArmor provides basic abilities to set and control rlimits at
a per profile level. Only resources specified in a profile are controled
or set. AppArmor rules set the hard limit to a value <= to the current
hard limit (ie. they can not currently raise hard limits), and if
necessary will lower the soft limit to the new hard limit value.
AppArmor does not track resource limits to reset them when a profile
is left so that children processes inherit the limits set by the
parent even if they are not confined by the same profile.
Capabilities: AppArmor provides a per profile mask of capabilities,
that will further restrict.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor routines for controling domain transitions, which can occur at
exec or through self directed change_profile/change_hat calls.
Unconfined tasks are checked at exec against the profiles in the confining
profile namespace to determine if a profile should be attached to the task.
Confined tasks execs are controlled by the profile which provides rules
determining which execs are allowed and if so which profiles should be
transitioned to.
Self directed domain transitions allow a task to request transition
to a given profile. If the transition is allowed then the profile will
be applied, either immeditately or at exec time depending on the request.
Immeditate self directed transitions have several security limitations
but have uses in setting up stub transition profiles and other limited
cases.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
AppArmor does files enforcement via pathname matching. Matching is done
at file open using a dfa match engine. Permission is against the final
file object not parent directories, ie. the traversal of directories
as part of the file match is implicitly allowed. In the case of nonexistant
files (creation) permissions are checked against the target file not the
directory. eg. In case of creating the file /dir/new, permissions are
checked against the match /dir/new not against /dir/.
The permissions for matches are currently stored in the dfa accept table,
but this will change to allow for dfa reuse and also to allow for sharing
of wider accept states.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
The /proc/<pid>/attr/* interface is used for process introspection and
commands. While the apparmorfs interface is used for global introspection
and loading and removing policy.
The interface currently only contains the files necessary for loading
policy, and will be extended in the future to include sysfs style
single per file introspection inteface.
The old AppArmor 2.4 interface files have been removed into a compatibility
patch, that distros can use to maintain backwards compatibility.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
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>
AppArmor contexts attach profiles and state to tasks, files, etc. when
a direct profile reference is not sufficient.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Update lsm_audit for AppArmor specific data, and add the core routines for
AppArmor uses for auditing.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
Miscellaneous functions and defines needed by AppArmor, including
the base path resolution routines.
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
