Commit Graph

2908 Commits

Author SHA1 Message Date
Arnd Bergmann
7616ac70d1 apparmor: fix SECURITY_APPARMOR_HASH_DEFAULT parameter handling
The newly added Kconfig option could never work and just causes a build error
when disabled:

security/apparmor/lsm.c:675:25: error: 'CONFIG_SECURITY_APPARMOR_HASH_DEFAULT' undeclared here (not in a function)
 bool aa_g_hash_policy = CONFIG_SECURITY_APPARMOR_HASH_DEFAULT;

The problem is that the macro undefined in this case, and we need to use the IS_ENABLED()
helper to turn it into a boolean constant.

Another minor problem with the original patch is that the option is even offered
in sysfs when SECURITY_APPARMOR_HASH is not enabled, so this also hides the option
in that case.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 6059f71f1e ("apparmor: add parameter to control whether policy hashing is used")
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-07-27 17:39:26 +10:00
John Johansen
d4d03f74a7 apparmor: fix arg_size computation for when setprocattr is null terminated
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12 08:43:10 -07:00
Vegard Nossum
e89b808132 apparmor: fix oops, validate buffer size in apparmor_setprocattr()
When proc_pid_attr_write() was changed to use memdup_user apparmor's
(interface violating) assumption that the setprocattr buffer was always
a single page was violated.

The size test is not strictly speaking needed as proc_pid_attr_write()
will reject anything larger, but for the sake of robustness we can keep
it in.

SMACK and SELinux look safe to me, but somebody else should probably
have a look just in case.

Based on original patch from Vegard Nossum <vegard.nossum@oracle.com>
modified for the case that apparmor provides null termination.

Fixes: bb646cdb12
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: stable@kernel.org
Signed-off-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-07-12 08:43:10 -07:00
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
58acf9d911 apparmor: fix module parameters can be changed after policy is locked
the policy_lock parameter is a one way switch that prevents policy
from being further modified. Unfortunately some of the module parameters
can effectively modify policy by turning off enforcement.

split policy_admin_capable into a view check and a full admin check,
and update the admin check to test the policy_lock parameter.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
5f20fdfed1 apparmor: fix oops in profile_unpack() when policy_db is not present
BugLink: http://bugs.launchpad.net/bugs/1592547

If unpack_dfa() returns NULL due to the dfa not being present,
profile_unpack() is not checking if the dfa is not present (NULL).

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
Jeff Mahoney
ff118479a7 apparmor: allow SYS_CAP_RESOURCE to be sufficient to prlimit another task
While using AppArmor, SYS_CAP_RESOURCE is insufficient to call prlimit
on another task. The only other example of a AppArmor mediating access to
another, already running, task (ignoring fork+exec) is ptrace.

The AppArmor model for ptrace is that one of the following must be true:
1) The tracer is unconfined
2) The tracer is in complain mode
3) The tracer and tracee are confined by the same profile
4) The tracer is confined but has SYS_CAP_PTRACE

1), 2, and 3) are already true for setrlimit.

We can match the ptrace model just by allowing CAP_SYS_RESOURCE.

We still test the values of the rlimit since it can always be overridden
using a value that means unlimited for a particular resource.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12 08:43:10 -07:00
Geliang Tang
38dbd7d8be apparmor: use list_next_entry instead of list_entry_next
list_next_entry has been defined in list.h, so I replace list_entry_next
with it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
de7c4cc947 apparmor: fix refcount race when finding a child profile
When finding a child profile via an rcu critical section, the profile
may be put and scheduled for deletion after the child is found but
before its refcount is incremented.

Protect against this by repeating the lookup if the profiles refcount
is 0 and is one its way to deletion.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
0b938a2e2c apparmor: fix ref count leak when profile sha1 hash is read
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
23ca7b640b apparmor: check that xindex is in trans_table bounds
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
f7da2de011 apparmor: ensure the target profile name is always audited
The target profile name was not being correctly audited in a few
cases because the target variable was not being set and gotos
passed the code to set it at apply:

Since it is always based on new_profile just drop the target var
and conditionally report based on new_profile.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
7ee6da25dc apparmor: fix audit full profile hname on successful load
Currently logging of a successful profile load only logs the basename
of the profile. This can result in confusion when a child profile has
the same name as the another profile in the set. Logging the hname
will ensure there is no confusion.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
bf15cf0c64 apparmor: fix log failures for all profiles in a set
currently only the profile that is causing the failure is logged. This
makes it more confusing than necessary about which profiles loaded
and which didn't. So make sure to log success and failure messages for
all profiles in the set being loaded.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
f351841f8d apparmor: fix put() parent ref after updating the active ref
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
6059f71f1e apparmor: add parameter to control whether policy hashing is used
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
bd35db8b8c apparmor: internal paths should be treated as disconnected
Internal mounts are not mounted anywhere and as such should be treated
as disconnected paths.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
f2e561d190 apparmor: fix disconnected bind mnts reconnection
Bind mounts can fail to be properly reconnected when PATH_CONNECT is
specified. Ensure that when PATH_CONNECT is specified the path has
a root.

BugLink: http://bugs.launchpad.net/bugs/1319984

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
d671e89020 apparmor: fix update the mtime of the profile file on replacement
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
9049a79221 apparmor: exec should not be returning ENOENT when it denies
The current behavior is confusing as it causes exec failures to report
the executable is missing instead of identifying that apparmor
caused the failure.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
b6b1b81b3a apparmor: fix uninitialized lsm_audit member
BugLink: http://bugs.launchpad.net/bugs/1268727

The task field in the lsm_audit struct needs to be initialized if
a change_hat fails, otherwise the following oops will occur

BUG: unable to handle kernel paging request at 0000002fbead7d08
IP: [<ffffffff8171153e>] _raw_spin_lock+0xe/0x50
PGD 1e3f35067 PUD 0
Oops: 0002 [#1] SMP
Modules linked in: pppox crc_ccitt p8023 p8022 psnap llc ax25 btrfs raid6_pq xor xfs libcrc32c dm_multipath scsi_dh kvm_amd dcdbas kvm microcode amd64_edac_mod joydev edac_core psmouse edac_mce_amd serio_raw k10temp sp5100_tco i2c_piix4 ipmi_si ipmi_msghandler acpi_power_meter mac_hid lp parport hid_generic usbhid hid pata_acpi mpt2sas ahci raid_class pata_atiixp bnx2 libahci scsi_transport_sas [last unloaded: tipc]
CPU: 2 PID: 699 Comm: changehat_twice Tainted: GF          O 3.13.0-7-generic #25-Ubuntu
Hardware name: Dell Inc. PowerEdge R415/08WNM9, BIOS 1.8.6 12/06/2011
task: ffff8802135c6000 ti: ffff880212986000 task.ti: ffff880212986000
RIP: 0010:[<ffffffff8171153e>]  [<ffffffff8171153e>] _raw_spin_lock+0xe/0x50
RSP: 0018:ffff880212987b68  EFLAGS: 00010006
RAX: 0000000000020000 RBX: 0000002fbead7500 RCX: 0000000000000000
RDX: 0000000000000292 RSI: ffff880212987ba8 RDI: 0000002fbead7d08
RBP: ffff880212987b68 R08: 0000000000000246 R09: ffff880216e572a0
R10: ffffffff815fd677 R11: ffffea0008469580 R12: ffffffff8130966f
R13: ffff880212987ba8 R14: 0000002fbead7d08 R15: ffff8800d8c6b830
FS:  00002b5e6c84e7c0(0000) GS:ffff880216e40000(0000) knlGS:0000000055731700
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000002fbead7d08 CR3: 000000021270f000 CR4: 00000000000006e0
Stack:
 ffff880212987b98 ffffffff81075f17 ffffffff8130966f 0000000000000009
 0000000000000000 0000000000000000 ffff880212987bd0 ffffffff81075f7c
 0000000000000292 ffff880212987c08 ffff8800d8c6b800 0000000000000026
Call Trace:
 [<ffffffff81075f17>] __lock_task_sighand+0x47/0x80
 [<ffffffff8130966f>] ? apparmor_cred_prepare+0x2f/0x50
 [<ffffffff81075f7c>] do_send_sig_info+0x2c/0x80
 [<ffffffff81075fee>] send_sig_info+0x1e/0x30
 [<ffffffff8130242d>] aa_audit+0x13d/0x190
 [<ffffffff8130c1dc>] aa_audit_file+0xbc/0x130
 [<ffffffff8130966f>] ? apparmor_cred_prepare+0x2f/0x50
 [<ffffffff81304cc2>] aa_change_hat+0x202/0x530
 [<ffffffff81308fc6>] aa_setprocattr_changehat+0x116/0x1d0
 [<ffffffff8130a11d>] apparmor_setprocattr+0x25d/0x300
 [<ffffffff812cee56>] security_setprocattr+0x16/0x20
 [<ffffffff8121fc87>] proc_pid_attr_write+0x107/0x130
 [<ffffffff811b7604>] vfs_write+0xb4/0x1f0
 [<ffffffff811b8039>] SyS_write+0x49/0xa0
 [<ffffffff8171a1bf>] tracesys+0xe1/0xe6

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
ec34fa24a9 apparmor: fix replacement bug that adds new child to old parent
When set atomic replacement is used and the parent is updated before the
child, and the child did not exist in the old parent so there is no
direct replacement then the new child is incorrectly added to the old
parent. This results in the new parent not having the child(ren) that
it should and the old parent when being destroyed asserting the
following error.

AppArmor: policy_destroy: internal error, policy '<profile/name>' still
contains profiles

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
John Johansen
dcda617a0c apparmor: fix refcount bug in profile replacement
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2016-07-12 08:43:10 -07:00
James Morris
e1e5fa9616 Merge tag 'keys-misc-20160708' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into next 2016-07-09 12:49:00 +10:00
James Morris
c632809953 Merge branch 'smack-for-4.8' of https://github.com/cschaufler/smack-next into next 2016-07-08 10:41:15 +10:00
James Morris
d011a4d861 Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/selinux into next 2016-07-07 10:15:34 +10:00
Eric Richter
544e1cea03 ima: extend the measurement entry specific pcr
Extend the PCR supplied as a parameter, instead of assuming that the
measurement entry uses the default configured PCR.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:22 -04:00
Eric Richter
a422638d49 ima: change integrity cache to store measured pcr
IMA avoids re-measuring files by storing the current state as a flag in
the integrity cache. It will then skip adding a new measurement log entry
if the cache reports the file as already measured.

If a policy measures an already measured file to a new PCR, the measurement
will not be added to the list. This patch implements a new bitfield for
specifying which PCR the file was measured into, rather than if it was
measured.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:22 -04:00
Eric Richter
67696f6d79 ima: redefine duplicate template entries
Template entry duplicates are prevented from being added to the
measurement list by checking a hash table that contains the template
entry digests. However, the PCR value is not included in this comparison,
so duplicate template entry digests with differing PCRs may be dropped.

This patch redefines duplicate template entries as template entries with
the same digest and same PCR values.

Reported-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:21 -04:00
Eric Richter
5f6f027b50 ima: change ima_measurements_show() to display the entry specific pcr
IMA assumes that the same default Kconfig PCR is extended for each
entry. This patch replaces the default configured PCR with the policy
defined PCR.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:21 -04:00
Eric Richter
14b1da85bb ima: include pcr for each measurement log entry
The IMA measurement list entries include the Kconfig defined PCR value.
This patch defines a new ima_template_entry field for including the PCR
as specified in the policy rule.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:21 -04:00
Eric Richter
725de7fabb ima: extend ima_get_action() to return the policy pcr
Different policy rules may extend different PCRs. This patch retrieves
the specific PCR for the matched rule.  Subsequent patches will include
the rule specific PCR in the measurement list and extend the appropriate
PCR.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:20 -04:00
Eric Richter
0260643ce8 ima: add policy support for extending different pcrs
This patch defines a new IMA measurement policy rule option "pcr=",
which allows extending different PCRs on a per rule basis. For example,
the system independent files could extend the default IMA Kconfig
specified PCR, while the system dependent files could extend a different
PCR.

The following is an example of this usage with an SELinux policy; the
rule would extend PCR 11 with system configuration files:

  measure func=FILE_CHECK mask=MAY_READ obj_type=system_conf_t pcr=11

Changelog v3:
- FIELD_SIZEOF returns bytes, not bits. Fixed INVALID_PCR

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:20 -04:00
Eric Richter
96d450bbec integrity: add measured_pcrs field to integrity cache
To keep track of which measurements have been extended to which PCRs, this
patch defines a new integrity_iint_cache field named measured_pcrs. This
field is a bitmask of the PCRs measured. Each bit corresponds to a PCR
index. For example, bit 10 corresponds to PCR 10.

Signed-off-by: Eric Richter <erichte@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-06-30 01:14:19 -04:00
Huw Davies
4fee5242bf calipso: Add a label cache.
This works in exactly the same way as the CIPSO label cache.
The idea is to allow the lsm to cache the result of a secattr
lookup so that it doesn't need to perform the lookup for
every skbuff.

It introduces two sysctl controls:
 calipso_cache_enable - enables/disables the cache.
 calipso_cache_bucket_size - sets the size of a cache bucket.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 15:06:17 -04:00
Huw Davies
a04e71f631 netlabel: Pass a family parameter to netlbl_skbuff_err().
This makes it possible to route the error to the appropriate
labelling engine.  CALIPSO is far less verbose than CIPSO
when encountering a bogus packet, so there is no need for a
CALIPSO error handler.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 15:06:16 -04:00
Huw Davies
2917f57b6b calipso: Allow the lsm to label the skbuff directly.
In some cases, the lsm needs to add the label to the skbuff directly.
A NF_INET_LOCAL_OUT IPv6 hook is added to selinux to match the IPv4
behaviour.  This allows selinux to label the skbuffs that it requires.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 15:06:15 -04:00
Huw Davies
e1adea9270 calipso: Allow request sockets to be relabelled by the lsm.
Request sockets need to have a label that takes into account the
incoming connection as well as their parent's label.  This is used
for the outgoing SYN-ACK and for their child full-socket.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 15:05:29 -04:00
Huw Davies
1f440c99d3 netlabel: Prevent setsockopt() from changing the hop-by-hop option.
If a socket has a netlabel in place then don't let setsockopt() alter
the socket's IPv6 hop-by-hop option.  This is in the same spirit as
the existing check for IPv4.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 15:05:27 -04:00
Huw Davies
ceba1832b1 calipso: Set the calipso socket label to match the secattr.
CALIPSO is a hop-by-hop IPv6 option.  A lot of this patch is based on
the equivalent CISPO code.  The main difference is due to manipulating
the options in the hop-by-hop header.

Signed-off-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-27 15:02:51 -04:00
Heinrich Schuchardt
309c5fad5d selinux: fix type mismatch
avc_cache_threshold is of type unsigned int.  Do not use a signed
new_value in sscanf(page, "%u", &new_value).

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
[PM: subject prefix fix, description cleanup]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-15 16:20:28 -04:00
David Howells
965475acca KEYS: Strip trailing spaces
Strip some trailing spaces.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-06-14 10:29:44 +01:00
Paul Moore
8bebe88c09 selinux: import NetLabel category bitmaps correctly
The existing ebitmap_netlbl_import() code didn't correctly handle the
case where the ebitmap_node was not aligned/sized to a power of two,
this patch fixes this (on x86_64 ebitmap_node contains six bitmaps
making a range of 0..383).

Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-06-09 10:40:37 -04:00
Rafal Krypa
18d872f77c Smack: ignore null signal in smack_task_kill
Kill with signal number 0 is commonly used for checking PID existence.
Smack treated such cases like any other kills, although no signal is
actually delivered when sig == 0.

Checking permissions when sig == 0 didn't prevent an unprivileged caller
from learning whether PID exists or not. When it existed, kernel returned
EPERM, when it didn't - ESRCH. The only effect of policy check in such
case is noise in audit logs.

This change lets Smack silently ignore kill() invocations with sig == 0.

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2016-06-08 13:52:31 -07:00
Mike Danese
40d273782f security: tomoyo: simplify the gc kthread creation
The code is doing the equivalent of the kthread_run macro.

Signed-off-by: Mike Danese <mikedanese@google.com>
Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-06-06 20:23:55 +10:00
Casey Schaufler
2885c1e3e0 LSM: Fix for security_inode_getsecurity and -EOPNOTSUPP
Serge Hallyn pointed out that the current implementation of
security_inode_getsecurity() works if there is only one hook
provided for it, but will fail if there is more than one and
the attribute requested isn't supplied by the first module.
This isn't a problem today, since only SELinux and Smack
provide this hook and there is (currently) no way to enable
both of those modules at the same time. Serge, however, wants
to introduce a capability attribute and an inode_getsecurity
hook in the capability security module to handle it. This
addresses that upcoming problem, will be required for "extreme
stacking" and is just a better implementation.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-06-06 19:59:18 +10:00
Stephan Mueller
4693fc734d KEYS: Add placeholder for KDF usage with DH
The values computed during Diffie-Hellman key exchange are often used
in combination with key derivation functions to create cryptographic
keys.  Add a placeholder for a later implementation to configure a
key derivation function that will transform the Diffie-Hellman
result returned by the KEYCTL_DH_COMPUTE command.

[This patch was stripped down from a patch produced by Mat Martineau that
 had a bug in the compat code - so for the moment Stephan's patch simply
 requires that the placeholder argument must be NULL]

Original-signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-06-03 16:14:34 +10:00
Stephen Smalley
7ea59202db selinux: Only apply bounds checking to source types
The current bounds checking of both source and target types
requires allowing any domain that has access to the child
domain to also have the same permissions to the parent, which
is undesirable.  Drop the target bounds checking.

KaiGai Kohei originally removed all use of target bounds in
commit 7d52a155e3 ("selinux: remove dead code in
type_attribute_bounds_av()") but this was reverted in
commit 2ae3ba3938 ("selinux: libsepol: remove dead code in
check_avtab_hierarchy_callback()") because it would have
required explicitly allowing the parent any permissions
to the child that the child is allowed to itself.

This change in contrast retains the logic for the case where both
source and target types are bounded, thereby allowing access
if the parent of the source is allowed the corresponding
permissions to the parent of the target.  Further, this change
reworks the logic such that we only perform a single computation
for each case and there is no ambiguity as to how to resolve
a bounds violation.

Under the new logic, if the source type and target types are both
bounded, then the parent of the source type must be allowed the same
permissions to the parent of the target type.  If only the source
type is bounded, then the parent of the source type must be allowed
the same permissions to the target type.

Examples of the new logic and comparisons with the old logic:
1. If we have:
	typebounds A B;
then:
	allow B self:process <permissions>;
will satisfy the bounds constraint iff:
	allow A self:process <permissions>;
is also allowed in policy.

Under the old logic, the allow rule on B satisfies the
bounds constraint if any of the following three are allowed:
	allow A B:process <permissions>; or
	allow B A:process <permissions>; or
	allow A self:process <permissions>;
However, either of the first two ultimately require the third to
satisfy the bounds constraint under the old logic, and therefore
this degenerates to the same result (but is more efficient - we only
need to perform one compute_av call).

2. If we have:
	typebounds A B;
	typebounds A_exec B_exec;
then:
	allow B B_exec:file <permissions>;
will satisfy the bounds constraint iff:
	allow A A_exec:file <permissions>;
is also allowed in policy.

This is essentially the same as #1; it is merely included as
an example of dealing with object types related to a bounded domain
in a manner that satisfies the bounds relationship.  Note that
this approach is preferable to leaving B_exec unbounded and having:
	allow A B_exec:file <permissions>;
in policy because that would allow B's entrypoints to be used to
enter A.  Similarly for _tmp or other related types.

3. If we have:
	typebounds A B;
and an unbounded type T, then:
	allow B T:file <permissions>;
will satisfy the bounds constraint iff:
	allow A T:file <permissions>;
is allowed in policy.

The old logic would have been identical for this example.

4. If we have:
	typebounds A B;
and an unbounded domain D, then:
	allow D B:unix_stream_socket <permissions>;
is not subject to any bounds constraints under the new logic
because D is not bounded.  This is desirable so that we can
allow a domain to e.g. connectto a child domain without having
to allow it to do the same to its parent.

The old logic would have required:
	allow D A:unix_stream_socket <permissions>;
to also be allowed in policy.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: re-wrapped description to appease checkpatch.pl]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-05-31 12:01:59 -04:00