Commit Graph

3435 Commits

Author SHA1 Message Date
Bruno E. O. Meneguele
7c9bc0983f ima: check signature enforcement against cmdline param instead of CONFIG
When the user requests MODULE_CHECK policy and its kernel is compiled
with CONFIG_MODULE_SIG_FORCE not set, all modules would not load, just
those loaded in initram time. One option the user would have would be
set a kernel cmdline param (module.sig_enforce) to true, but the IMA
module check code doesn't rely on this value, it checks just
CONFIG_MODULE_SIG_FORCE.

This patch solves this problem checking for the exported value of
module.sig_enforce cmdline param intead of CONFIG_MODULE_SIG_FORCE,
which holds the effective value (CONFIG || param).

Signed-off-by: Bruno E. O. Meneguele <brdeoliv@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Boshi Wang
ebe7c0a7be ima: fix hash algorithm initialization
The hash_setup function always sets the hash_setup_done flag, even
when the hash algorithm is invalid.  This prevents the default hash
algorithm defined as CONFIG_IMA_DEFAULT_HASH from being used.

This patch sets hash_setup_done flag only for valid hash algorithms.

Fixes: e7a2ad7eb6 "ima: enable support for larger default filedata hash
	algorithms"
Signed-off-by: Boshi Wang <wangboshi@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Matthew Garrett
0485d066d8 EVM: Only complain about a missing HMAC key once
A system can validate EVM digital signatures without requiring an HMAC
key, but every EVM validation will generate a kernel error. Change this
so we only generate an error once.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Matthew Garrett
f00d797507 EVM: Allow userspace to signal an RSA key has been loaded
EVM will only perform validation once a key has been loaded. This key
may either be a symmetric trusted key (for HMAC validation and creation)
or the public half of an asymmetric key (for digital signature
validation). The /sys/kernel/security/evm interface allows userland to
signal that a symmetric key has been loaded, but does not allow userland
to signal that an asymmetric public key has been loaded.

This patch extends the interface to permit userspace to pass a bitmask
of loaded key types. It also allows userspace to block loading of a
symmetric key in order to avoid a compromised system from being able to
load an additional key type later.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Matthew Garrett
096b854648 EVM: Include security.apparmor in EVM measurements
Apparmor will be gaining support for security.apparmor labels, and it
would be helpful to include these in EVM validation now so appropriate
signatures can be generated even before full support is merged.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: John Johansen <John.johansen@canonical.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Christoph Hellwig
a7d3d0392a integrity: use kernel_read_file_from_path() to read x509 certs
The CONFIG_IMA_LOAD_X509 and CONFIG_EVM_LOAD_X509 options permit
loading x509 signed certificates onto the trusted keyrings without
verifying the x509 certificate file's signature.

This patch replaces the call to the integrity_read_file() specific
function with the common kernel_read_file_from_path() function.
To avoid verifying the file signature, this patch defines
READING_X509_CERTFICATE.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Mimi Zohar
f3cc6b25dc ima: always measure and audit files in policy
All files matching a "measure" rule must be included in the IMA
measurement list, even when the file hash cannot be calculated.
Similarly, all files matching an "audit" rule must be audited, even when
the file hash can not be calculated.

The file data hash field contained in the IMA measurement list template
data will contain 0's instead of the actual file hash digest.

Note:
In general, adding, deleting or in anyway changing which files are
included in the IMA measurement list is not a good idea, as it might
result in not being able to unseal trusted keys sealed to a specific
TPM PCR value.  This patch not only adds file measurements that were
not previously measured, but specifies that the file hash value for
these files will be 0's.

As the IMA measurement list ordering is not consistent from one boot
to the next, it is unlikely that anyone is sealing keys based on the
IMA measurement list.  Remote attestation servers should be able to
process these new measurement records, but might complain about
these unknown records.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2017-11-08 15:16:36 -05:00
Mimi Zohar
2068626d13 ima: don't remove the securityfs policy file
The securityfs policy file is removed unless additional rules can be
appended to the IMA policy (CONFIG_IMA_WRITE_POLICY), regardless as
to whether the policy is configured so that it can be displayed.

This patch changes this behavior, removing the securityfs policy file,
only if CONFIG_IMA_READ_POLICY is also not enabled.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-11-08 15:16:36 -05:00
Casey Schaufler
d6d80cb57b Smack: Base support for overlayfs
Supply the Smack module hooks in support of overlayfs.
Ensure that the Smack label of new files gets the correct
value when a directory is transmuting. Original implementation
by Romanini Daniele, with a few tweaks added.

Signed-off-by: Romanini Daniele <daniele.romanini@aalto.fi>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-11-02 11:26:57 +11:00
Arnd Bergmann
927340926e tomoyo: fix timestamping for y2038
Tomoyo uses an open-coded version of time_to_tm() to create a timestamp
from the current time as read by get_seconds(). This will overflow and
give wrong results on 32-bit systems in 2038.

To correct this, this changes the code to use ktime_get_real_seconds()
and the generic time64_to_tm() function that are both y2038-safe.
Using the library function avoids adding an expensive 64-bit division
in this code and can benefit from any optimizations we do in common
code.

Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-21 06:21:06 +04:00
Richard Guy Briggs
dbbbe1105e capabilities: audit log other surprising conditions
The existing condition tested for process effective capabilities set by
file attributes but intended to ignore the change if the result was
unsurprisingly an effective full set in the case root is special with a
setuid root executable file and we are root.

Stated again:
- When you execute a setuid root application, it is no surprise and
  expected that it got all capabilities, so we do not want capabilities
  recorded.
        if (pE_grew && !(pE_fullset && (eff_root || real_root) && root_priveleged) )

Now make sure we cover other cases:
- If something prevented a setuid root app getting all capabilities and
  it wound up with one capability only, then it is a surprise and should
  be logged.  When it is a setuid root file, we only want capabilities
  when the process does not get full capabilities..
        root_priveleged && setuid_root && !pE_fullset

- Similarly if a non-setuid program does pick up capabilities due to
  file system based capabilities, then we want to know what capabilities
  were picked up.  When it has file system based capabilities we want
  the capabilities.
        !is_setuid && (has_fcap && pP_gained)

- If it is a non-setuid file and it gets ambient capabilities, we want
  the capabilities.
        !is_setuid && pA_gained

- These last two are combined into one due to the common first parameter.

Related: https://github.com/linux-audit/audit-kernel/issues/16

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:46 +11:00
Richard Guy Briggs
588fb2c7e2 capabilities: fix logic for effective root or real root
Now that the logic is inverted, it is much easier to see that both real
root and effective root conditions had to be met to avoid printing the
BPRM_FCAPS record with audit syscalls.  This meant that any setuid root
applications would print a full BPRM_FCAPS record when it wasn't
necessary, cluttering the event output, since the SYSCALL and PATH
records indicated the presence of the setuid bit and effective root user
id.

Require only one of effective root or real root to avoid printing the
unnecessary record.

Ref: commit 3fc689e96c ("Add audit_log_bprm_fcaps/AUDIT_BPRM_FCAPS")
See: https://github.com/linux-audit/audit-kernel/issues/16

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:45 +11:00
Richard Guy Briggs
c0d1adefe0 capabilities: invert logic for clarity
The way the logic was presented, it was awkward to read and verify.
Invert the logic using DeMorgan's Law to be more easily able to read and
understand.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:45 +11:00
Richard Guy Briggs
02ebbaf48c capabilities: remove a layer of conditional logic
Remove a layer of conditional logic to make the use of conditions
easier to read and analyse.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:45 +11:00
Richard Guy Briggs
9fbc2c7964 capabilities: move audit log decision to function
Move the audit log decision logic to its own function to isolate the
complexity in one place.

Suggested-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:44 +11:00
Richard Guy Briggs
81a6a01299 capabilities: use intuitive names for id changes
Introduce a number of inlines to make the use of the negation of
uid_eq() easier to read and analyse.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:44 +11:00
Richard Guy Briggs
9304b46c91 capabilities: use root_priveleged inline to clarify logic
Introduce inline root_privileged() to make use of SECURE_NONROOT
easier to read.

Suggested-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:44 +11:00
Richard Guy Briggs
fc7eadf768 capabilities: rename has_cap to has_fcap
Rename has_cap to has_fcap to clarify it applies to file capabilities
since the entire source file is about capabilities.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:44 +11:00
Richard Guy Briggs
4c7e715fc8 capabilities: intuitive names for cap gain status
Introduce macros cap_gained, cap_grew, cap_full to make the use of the
negation of is_subset() easier to read and analyse.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:43 +11:00
Richard Guy Briggs
db1a8922cf capabilities: factor out cap_bprm_set_creds privileged root
Factor out the case of privileged root from the function
cap_bprm_set_creds() to make the latter easier to read and analyse.

Suggested-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Okay-ished-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-10-20 15:22:43 +11:00
Linus Torvalds
a302824782 Merge branch 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull misc security layer update from James Morris:
 "This is the remaining 'general' change in the security tree for v4.14,
  following the direct merging of SELinux (+ TOMOYO), AppArmor, and
  seccomp.

  That's everything now for the security tree except IMA, which will
  follow shortly (I've been traveling for the past week with patchy
  internet)"

* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  security: fix description of values returned by cap_inode_need_killpriv
2017-09-24 11:40:41 -07:00
Stefan Berger
ab5348c9c2 security: fix description of values returned by cap_inode_need_killpriv
cap_inode_need_killpriv returns 1 if security.capability exists and
has a value and inode_killpriv() is required, 0 otherwise. Fix the
description of the return value to reflect this.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-09-23 21:15:41 -07:00
Linus Torvalds
79444df4e7 + Features
- in preparation for secid mapping add support for absolute root view
     based labels
   - add base infastructure for socket mediation
   - add mount mediation
   - add signal mediation
 
 + minor cleanups and changes
   - be defensive, ensure unconfined profiles have dfas initialized
   - add more debug asserts to apparmorfs
   - enable policy unpacking to audit different reasons for failure
   - cleanup conditional check for label in label_print
   - Redundant condition: prev_ns. in [label.c:1498]
 
 + Bug Fixes
   - fix regression in apparmorfs DAC access permissions
   - fix build failure on sparc caused by undeclared signals
   - fix sparse report of incorrect type assignment when freeing label proxies
   - fix race condition in null profile creation
   - Fix an error code in aafs_create()
   - Fix logical error in verify_header()
   - Fix shadowed local variable in unpack_trans_table()
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Merge tag 'apparmor-pr-2017-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "This is the apparmor pull request, similar to SELinux and seccomp.

  It's the same series that I was sent to James' security tree + one
  regression fix that was found after the series was sent to James and
  would have been sent for v4.14-rc2.

  Features:
  - in preparation for secid mapping add support for absolute root view
    based labels
  - add base infastructure for socket mediation
  - add mount mediation
  - add signal mediation

  minor cleanups and changes:
  - be defensive, ensure unconfined profiles have dfas initialized
  - add more debug asserts to apparmorfs
  - enable policy unpacking to audit different reasons for failure
  - cleanup conditional check for label in label_print
  - Redundant condition: prev_ns. in [label.c:1498]

  Bug Fixes:
  - fix regression in apparmorfs DAC access permissions
  - fix build failure on sparc caused by undeclared signals
  - fix sparse report of incorrect type assignment when freeing label proxies
  - fix race condition in null profile creation
  - Fix an error code in aafs_create()
  - Fix logical error in verify_header()
  - Fix shadowed local variable in unpack_trans_table()"

* tag 'apparmor-pr-2017-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: fix apparmorfs DAC access permissions
  apparmor: fix build failure on sparc caused by undeclared signals
  apparmor: fix incorrect type assignment when freeing proxies
  apparmor: ensure unconfined profiles have dfas initialized
  apparmor: fix race condition in null profile creation
  apparmor: move new_null_profile to after profile lookup fns()
  apparmor: add base infastructure for socket mediation
  apparmor: add more debug asserts to apparmorfs
  apparmor: make policy_unpack able to audit different info messages
  apparmor: add support for absolute root view based labels
  apparmor: cleanup conditional check for label in label_print
  apparmor: add mount mediation
  apparmor: add the ability to mediate signals
  apparmor: Redundant condition: prev_ns. in [label.c:1498]
  apparmor: Fix an error code in aafs_create()
  apparmor: Fix logical error in verify_header()
  apparmor: Fix shadowed local variable in unpack_trans_table()
2017-09-23 05:33:29 -10:00
John Johansen
bf81100f63 apparmor: fix apparmorfs DAC access permissions
The DAC access permissions for several apparmorfs files are wrong.

.access - needs to be writable by all tasks to perform queries
the others in the set only provide a read fn so should be read only.

With policy namespace virtualization all apparmor needs to control
the permission and visibility checks directly which means DAC
access has to be allowed for all user, group, and other.

BugLink: http://bugs.launchpad.net/bugs/1713103
Fixes: c97204baf8 ("apparmor: rename apparmor file fns and data to indicate use")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:20:01 -07:00
John Johansen
b1545dba09 apparmor: fix build failure on sparc caused by undeclared signals
In file included from security/apparmor/ipc.c:23:0:
  security/apparmor/include/sig_names.h:26:3: error: 'SIGSTKFLT' undeclared here (not in a function)
    [SIGSTKFLT] = 16, /* -, 16, - */
     ^
  security/apparmor/include/sig_names.h:26:3: error: array index in initializer not of integer type
  security/apparmor/include/sig_names.h:26:3: note: (near initialization for 'sig_map')
  security/apparmor/include/sig_names.h:51:3: error: 'SIGUNUSED' undeclared here (not in a function)
    [SIGUNUSED] = 34, /* -, 31, - */
     ^
  security/apparmor/include/sig_names.h:51:3: error: array index in initializer not of integer type
  security/apparmor/include/sig_names.h:51:3: note: (near initialization for 'sig_map')

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: c6bf1adaecaa ("apparmor: add the ability to mediate signals")
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
bc4d82fb94 apparmor: fix incorrect type assignment when freeing proxies
sparse reports

poisoning the proxy->label before freeing the struct is resulting in
a sparse build warning.
../security/apparmor/label.c:52:30: warning: incorrect type in assignment (different address spaces)
../security/apparmor/label.c:52:30:    expected struct aa_label [noderef] <asn:4>*label
../security/apparmor/label.c:52:30:    got struct aa_label *<noident>

fix with RCU_INIT_POINTER as this is one of those cases where
rcu_assign_pointer() is not needed.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
15372b97aa apparmor: ensure unconfined profiles have dfas initialized
Generally unconfined has early bailout tests and does not need the
dfas initialized, however if an early bailout test is ever missed
it will result in an oops.

Be defensive and initialize the unconfined profile to have null dfas
(no permission) so if an early bailout test is missed we fail
closed (no perms granted) instead of oopsing.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
290638a52a apparmor: fix race condition in null profile creation
There is a race when null- profile is being created between the
initial lookup/creation of the profile and lock/addition of the
profile. This could result in multiple version of a profile being
added to the list which need to be removed/replaced.

Since these are learning profile their is no affect on mediation.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
d07881d2ed apparmor: move new_null_profile to after profile lookup fns()
new_null_profile will need to use some of the profile lookup fns()
so move instead of doing forward fn declarations.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
651e28c553 apparmor: add base infastructure for socket mediation
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>
2017-09-22 13:00:58 -07:00
John Johansen
cbf2d0e1a9 apparmor: add more debug asserts to apparmorfs
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
2410aa96d6 apparmor: make policy_unpack able to audit different info messages
Switch unpack auditing to using the generic name field in the audit
struct and make it so we can start adding new info messages about
why an unpack failed.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
26b7899510 apparmor: add support for absolute root view based labels
With apparmor policy virtualization based on policy namespace View's
we don't generally want/need absolute root based views, however there
are cases like debugging and some secid based conversions where
using a root based view is important.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22 13:00:58 -07:00
John Johansen
f872af75d3 apparmor: cleanup conditional check for label in label_print
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22 13:00:57 -07:00
John Johansen
2ea3ffb778 apparmor: add mount mediation
Add basic mount mediation. That allows controlling based on basic
mount parameters. It does not include special mount parameters for
apparmor, super block labeling, or any triggers for apparmor namespace
parameter modifications on pivot root.

default userspace policy rules have the form of
  MOUNT RULE = ( MOUNT | REMOUNT | UMOUNT )

  MOUNT = [ QUALIFIERS ] 'mount' [ MOUNT CONDITIONS ] [ SOURCE FILEGLOB ]
          [ '->' MOUNTPOINT FILEGLOB ]

  REMOUNT = [ QUALIFIERS ] 'remount' [ MOUNT CONDITIONS ]
            MOUNTPOINT FILEGLOB

  UMOUNT = [ QUALIFIERS ] 'umount' [ MOUNT CONDITIONS ] MOUNTPOINT FILEGLOB

  MOUNT CONDITIONS = [ ( 'fstype' | 'vfstype' ) ( '=' | 'in' )
                       MOUNT FSTYPE EXPRESSION ]
		       [ 'options' ( '=' | 'in' ) MOUNT FLAGS EXPRESSION ]

  MOUNT FSTYPE EXPRESSION = ( MOUNT FSTYPE LIST | MOUNT EXPRESSION )

  MOUNT FSTYPE LIST = Comma separated list of valid filesystem and
                      virtual filesystem types (eg ext4, debugfs, etc)

  MOUNT FLAGS EXPRESSION = ( MOUNT FLAGS LIST | MOUNT EXPRESSION )

  MOUNT FLAGS LIST = Comma separated list of MOUNT FLAGS.

  MOUNT FLAGS = ( 'ro' | 'rw' | 'nosuid' | 'suid' | 'nodev' | 'dev' |
                  'noexec' | 'exec' | 'sync' | 'async' | 'remount' |
		  'mand' | 'nomand' | 'dirsync' | 'noatime' | 'atime' |
		  'nodiratime' | 'diratime' | 'bind' | 'rbind' | 'move' |
		  'verbose' | 'silent' | 'loud' | 'acl' | 'noacl' |
		  'unbindable' | 'runbindable' | 'private' | 'rprivate' |
		  'slave' | 'rslave' | 'shared' | 'rshared' |
		  'relatime' | 'norelatime' | 'iversion' | 'noiversion' |
		  'strictatime' | 'nouser' | 'user' )

  MOUNT EXPRESSION = ( ALPHANUMERIC | AARE ) ...

  PIVOT ROOT RULE = [ QUALIFIERS ] pivot_root [ oldroot=OLD PUT FILEGLOB ]
                    [ NEW ROOT FILEGLOB ]

  SOURCE FILEGLOB = FILEGLOB

  MOUNTPOINT FILEGLOB = FILEGLOB

eg.
  mount,
  mount /dev/foo,
  mount options=ro /dev/foo -> /mnt/,
  mount options in (ro,atime) /dev/foo -> /mnt/,
  mount options=ro options=atime,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22 13:00:57 -07:00
John Johansen
cd1dbf76b2 apparmor: add the ability to mediate signals
Add signal mediation where the signal can be mediated based on the
signal, direction, or the label or the peer/target. The signal perms
are verified on a cross check to ensure policy consistency in the case
of incremental policy load/replacement.

The optimization of skipping the cross check when policy is guaranteed
to be consistent (single compile unit) remains to be done.

policy rules have the form of
  SIGNAL_RULE = [ QUALIFIERS ] 'signal' [ SIGNAL ACCESS PERMISSIONS ]
                [ SIGNAL SET ] [ SIGNAL PEER ]

  SIGNAL ACCESS PERMISSIONS = SIGNAL ACCESS | SIGNAL ACCESS LIST

  SIGNAL ACCESS LIST = '(' Comma or space separated list of SIGNAL
                           ACCESS ')'

  SIGNAL ACCESS = ( 'r' | 'w' | 'rw' | 'read' | 'write' | 'send' |
                    'receive' )

  SIGNAL SET = 'set' '=' '(' SIGNAL LIST ')'

  SIGNAL LIST = Comma or space separated list of SIGNALS

  SIGNALS = ( 'hup' | 'int' | 'quit' | 'ill' | 'trap' | 'abrt' |
              'bus' | 'fpe' | 'kill' | 'usr1' | 'segv' | 'usr2' |
	      'pipe' | 'alrm' | 'term' | 'stkflt' | 'chld' | 'cont' |
	      'stop' | 'stp' | 'ttin' | 'ttou' | 'urg' | 'xcpu' |
	      'xfsz' | 'vtalrm' | 'prof' | 'winch' | 'io' | 'pwr' |
	      'sys' | 'emt' | 'exists' | 'rtmin+0' ... 'rtmin+32'
            )

  SIGNAL PEER = 'peer' '=' AARE

eg.
  signal,                                 # allow all signals
  signal send set=(hup, kill) peer=foo,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2017-09-22 13:00:57 -07:00
John Johansen
c5561700c9 apparmor: Redundant condition: prev_ns. in [label.c:1498]
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:57 -07:00
Dan Carpenter
5d314a81ec apparmor: Fix an error code in aafs_create()
We accidentally forgot to set the error code on this path.  It means we
return NULL instead of an error pointer.  I looked through a bunch of
callers and I don't think it really causes a big issue, but the
documentation says we're supposed to return error pointers here.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:57 -07:00
Christos Gkekas
86aea56f14 apparmor: Fix logical error in verify_header()
verify_header() is currently checking whether interface version is less
than 5 *and* greater than 7, which always evaluates to false. Instead it
should check whether it is less than 5 *or* greater than 7.

Signed-off-by: Christos Gkekas <chris.gekas@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:57 -07:00
Geert Uytterhoeven
19fe43a54f apparmor: Fix shadowed local variable in unpack_trans_table()
with W=2:

    security/apparmor/policy_unpack.c: In function ‘unpack_trans_table’:
    security/apparmor/policy_unpack.c:469: warning: declaration of ‘pos’ shadows a previous local
    security/apparmor/policy_unpack.c:451: warning: shadowed declaration is here

Rename the old "pos" to "saved_pos" to fix this.

Fixes: 5379a33120 ("apparmor: support v7 transition format compatible with label_parse")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-09-22 13:00:57 -07:00
Linus Torvalds
581bfce969 Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more set_fs removal from Al Viro:
 "Christoph's 'use kernel_read and friends rather than open-coding
  set_fs()' series"

* 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: unexport vfs_readv and vfs_writev
  fs: unexport vfs_read and vfs_write
  fs: unexport __vfs_read/__vfs_write
  lustre: switch to kernel_write
  gadget/f_mass_storage: stop messing with the address limit
  mconsole: switch to kernel_read
  btrfs: switch write_buf to kernel_write
  net/9p: switch p9_fd_read to kernel_write
  mm/nommu: switch do_mmap_private to kernel_read
  serial2002: switch serial2002_tty_write to kernel_{read/write}
  fs: make the buf argument to __kernel_write a void pointer
  fs: fix kernel_write prototype
  fs: fix kernel_read prototype
  fs: move kernel_read to fs/read_write.c
  fs: move kernel_write to fs/read_write.c
  autofs4: switch autofs4_write to __kernel_write
  ashmem: switch to ->read_iter
2017-09-14 18:13:32 -07:00
Linus Torvalds
7f85565a3f selinux/stable-4.14 PR 20170831
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Merge tag 'selinux-pr-20170831' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux

Pull selinux updates from Paul Moore:
 "A relatively quiet period for SELinux, 11 patches with only two/three
  having any substantive changes.

  These noteworthy changes include another tweak to the NNP/nosuid
  handling, per-file labeling for cgroups, and an object class fix for
  AF_UNIX/SOCK_RAW sockets; the rest of the changes are minor tweaks or
  administrative updates (Stephen's email update explains the file
  explosion in the diffstat).

  Everything passes the selinux-testsuite"

[ Also a couple of small patches from the security tree from Tetsuo
  Handa for Tomoyo and LSM cleanup. The separation of security policy
  updates wasn't all that clean - Linus ]

* tag 'selinux-pr-20170831' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: constify nf_hook_ops
  selinux: allow per-file labeling for cgroupfs
  lsm_audit: update my email address
  selinux: update my email address
  MAINTAINERS: update the NetLabel and Labeled Networking information
  selinux: use GFP_NOWAIT in the AVC kmem_caches
  selinux: Generalize support for NNP/nosuid SELinux domain transitions
  selinux: genheaders should fail if too many permissions are defined
  selinux: update the selinux info in MAINTAINERS
  credits: update Paul Moore's info
  selinux: Assign proper class to PF_UNIX/SOCK_RAW sockets
  tomoyo: Update URLs in Documentation/admin-guide/LSM/tomoyo.rst
  LSM: Remove security_task_create() hook.
2017-09-12 13:21:00 -07:00
Linus Torvalds
dd198ce714 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman:
 "Life has been busy and I have not gotten half as much done this round
  as I would have liked. I delayed it so that a minor conflict
  resolution with the mips tree could spend a little time in linux-next
  before I sent this pull request.

  This includes two long delayed user namespace changes from Kirill
  Tkhai. It also includes a very useful change from Serge Hallyn that
  allows the security capability attribute to be used inside of user
  namespaces. The practical effect of this is people can now untar
  tarballs and install rpms in user namespaces. It had been suggested to
  generalize this and encode some of the namespace information
  information in the xattr name. Upon close inspection that makes the
  things that should be hard easy and the things that should be easy
  more expensive.

  Then there is my bugfix/cleanup for signal injection that removes the
  magic encoding of the siginfo union member from the kernel internal
  si_code. The mips folks reported the case where I had used FPE_FIXME
  me is impossible so I have remove FPE_FIXME from mips, while at the
  same time including a return statement in that case to keep gcc from
  complaining about unitialized variables.

  I almost finished the work to get make copy_siginfo_to_user a trivial
  copy to user. The code is available at:

     git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git neuter-copy_siginfo_to_user-v3

  But I did not have time/energy to get the code posted and reviewed
  before the merge window opened.

  I was able to see that the security excuse for just copying fields
  that we know are initialized doesn't work in practice there are buggy
  initializations that don't initialize the proper fields in siginfo. So
  we still sometimes copy unitialized data to userspace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  Introduce v3 namespaced file capabilities
  mips/signal: In force_fcr31_sig return in the impossible case
  signal: Remove kernel interal si_code magic
  fcntl: Don't use ambiguous SIG_POLL si_codes
  prctl: Allow local CAP_SYS_ADMIN changing exe_file
  security: Use user_namespace::level to avoid redundant iterations in cap_capable()
  userns,pidns: Verify the userns for new pid namespaces
  signal/testing: Don't look for __SI_FAULT in userspace
  signal/mips: Document a conflict with SI_USER with SIGFPE
  signal/sparc: Document a conflict with SI_USER with SIGFPE
  signal/ia64: Document a conflict with SI_USER with SIGFPE
  signal/alpha: Document a conflict with SI_USER for SIGTRAP
2017-09-11 18:34:47 -07:00
Linus Torvalds
0fb02e718f audit/stable-4.14 PR 20170907
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Merge tag 'audit-pr-20170907' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit

Pull audit updates from Paul Moore:
 "A small pull request for audit this time, only four patches and only
  two with any real code changes.

  Those two changes are the removal of a pointless SELinux AVC
  initialization audit event and a fix to improve the audit timestamp
  overhead.

  The other two patches are comment cleanup and administrative updates,
  nothing very exciting.

  Everything passes our tests"

* tag 'audit-pr-20170907' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: update the function comments
  selinux: remove AVC init audit log message
  audit: update the audit info in MAINTAINERS
  audit: Reduce overhead using a coarse clock
2017-09-07 20:48:25 -07:00
Linus Torvalds
828f4257d1 This series has the ultimate goal of providing a sane stack rlimit when
running set*id processes. To do this, the bprm_secureexec LSM hook is
 collapsed into the bprm_set_creds hook so the secureexec-ness of an exec
 can be determined early enough to make decisions about rlimits and the
 resulting memory layouts. Other logic acting on the secureexec-ness of an
 exec is similarly consolidated. Capabilities needed some special handling,
 but the refactoring removed other special handling, so that was a wash.
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Merge tag 'secureexec-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull secureexec update from Kees Cook:
 "This series has the ultimate goal of providing a sane stack rlimit
  when running set*id processes.

  To do this, the bprm_secureexec LSM hook is collapsed into the
  bprm_set_creds hook so the secureexec-ness of an exec can be
  determined early enough to make decisions about rlimits and the
  resulting memory layouts. Other logic acting on the secureexec-ness of
  an exec is similarly consolidated. Capabilities needed some special
  handling, but the refactoring removed other special handling, so that
  was a wash"

* tag 'secureexec-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  exec: Consolidate pdeath_signal clearing
  exec: Use sane stack rlimit under secureexec
  exec: Consolidate dumpability logic
  smack: Remove redundant pdeath_signal clearing
  exec: Use secureexec for clearing pdeath_signal
  exec: Use secureexec for setting dumpability
  LSM: drop bprm_secureexec hook
  commoncap: Move cap_elevated calculation into bprm_set_creds
  commoncap: Refactor to remove bprm_secureexec hook
  smack: Refactor to remove bprm_secureexec hook
  selinux: Refactor to remove bprm_secureexec hook
  apparmor: Refactor to remove bprm_secureexec hook
  binfmt: Introduce secureexec flag
  exec: Correct comments about "point of no return"
  exec: Rename bprm->cred_prepared to called_set_creds
2017-09-07 20:35:29 -07:00
Richard Guy Briggs
19128341d6 selinux: remove AVC init audit log message
In the process of normalizing audit log messages, it was noticed that the AVC
initialization code registered an audit log KERNEL record that didn't fit the
standard format.  In the process of attempting to normalize it it was
determined that this record was not even necessary.  Remove it.

Ref: http://marc.info/?l=selinux&m=149614868525826&w=2
See: https://github.com/linux-audit/audit-kernel/issues/48
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Steve Grubb <sgrubb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-09-05 09:46:57 -04:00
Christoph Hellwig
e13ec939e9 fs: fix kernel_write prototype
Make the position an in/out argument like all the other read/write
helpers and and make the buf argument a void pointer.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-04 19:05:15 -04:00
Christoph Hellwig
bdd1d2d3d2 fs: fix kernel_read prototype
Use proper ssize_t and size_t types for the return value and count
argument, move the offset last and make it an in/out argument like
all other read/write helpers, and make the buf argument a void pointer
to get rid of lots of casts in the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-04 19:05:15 -04:00
Serge E. Hallyn
8db6c34f1d Introduce v3 namespaced file capabilities
Root in a non-initial user ns cannot be trusted to write a traditional
security.capability xattr.  If it were allowed to do so, then any
unprivileged user on the host could map his own uid to root in a private
namespace, write the xattr, and execute the file with privilege on the
host.

However supporting file capabilities in a user namespace is very
desirable.  Not doing so means that any programs designed to run with
limited privilege must continue to support other methods of gaining and
dropping privilege.  For instance a program installer must detect
whether file capabilities can be assigned, and assign them if so but set
setuid-root otherwise.  The program in turn must know how to drop
partial capabilities, and do so only if setuid-root.

This patch introduces v3 of the security.capability xattr.  It builds a
vfs_ns_cap_data struct by appending a uid_t rootid to struct
vfs_cap_data.  This is the absolute uid_t (that is, the uid_t in user
namespace which mounted the filesystem, usually init_user_ns) of the
root id in whose namespaces the file capabilities may take effect.

When a task asks to write a v2 security.capability xattr, if it is
privileged with respect to the userns which mounted the filesystem, then
nothing should change.  Otherwise, the kernel will transparently rewrite
the xattr as a v3 with the appropriate rootid.  This is done during the
execution of setxattr() to catch user-space-initiated capability writes.
Subsequently, any task executing the file which has the noted kuid as
its root uid, or which is in a descendent user_ns of such a user_ns,
will run the file with capabilities.

Similarly when asking to read file capabilities, a v3 capability will
be presented as v2 if it applies to the caller's namespace.

If a task writes a v3 security.capability, then it can provide a uid for
the xattr so long as the uid is valid in its own user namespace, and it
is privileged with CAP_SETFCAP over its namespace.  The kernel will
translate that rootid to an absolute uid, and write that to disk.  After
this, a task in the writer's namespace will not be able to use those
capabilities (unless rootid was 0), but a task in a namespace where the
given uid is root will.

Only a single security.capability xattr may exist at a time for a given
file.  A task may overwrite an existing xattr so long as it is
privileged over the inode.  Note this is a departure from previous
semantics, which required privilege to remove a security.capability
xattr.  This check can be re-added if deemed useful.

This allows a simple setxattr to work, allows tar/untar to work, and
allows us to tar in one namespace and untar in another while preserving
the capability, without risking leaking privilege into a parent
namespace.

Example using tar:

 $ cp /bin/sleep sleepx
 $ mkdir b1 b2
 $ lxc-usernsexec -m b:0:100000:1 -m b:1:$(id -u):1 -- chown 0:0 b1
 $ lxc-usernsexec -m b:0:100001:1 -m b:1:$(id -u):1 -- chown 0:0 b2
 $ lxc-usernsexec -m b:0:100000:1000 -- tar --xattrs-include=security.capability --xattrs -cf b1/sleepx.tar sleepx
 $ lxc-usernsexec -m b:0:100001:1000 -- tar --xattrs-include=security.capability --xattrs -C b2 -xf b1/sleepx.tar
 $ lxc-usernsexec -m b:0:100001:1000 -- getcap b2/sleepx
   b2/sleepx = cap_sys_admin+ep
 # /opt/ltp/testcases/bin/getv3xattr b2/sleepx
   v3 xattr, rootid is 100001

A patch to linux-test-project adding a new set of tests for this
functionality is in the nsfscaps branch at github.com/hallyn/ltp

Changelog:
   Nov 02 2016: fix invalid check at refuse_fcap_overwrite()
   Nov 07 2016: convert rootid from and to fs user_ns
   (From ebiederm: mar 28 2017)
     commoncap.c: fix typos - s/v4/v3
     get_vfs_caps_from_disk: clarify the fs_ns root access check
     nsfscaps: change the code split for cap_inode_setxattr()
   Apr 09 2017:
       don't return v3 cap for caps owned by current root.
      return a v2 cap for a true v2 cap in non-init ns
   Apr 18 2017:
      . Change the flow of fscap writing to support s_user_ns writing.
      . Remove refuse_fcap_overwrite().  The value of the previous
        xattr doesn't matter.
   Apr 24 2017:
      . incorporate Eric's incremental diff
      . move cap_convert_nscap to setxattr and simplify its usage
   May 8, 2017:
      . fix leaking dentry refcount in cap_inode_getsecurity

Signed-off-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2017-09-01 14:57:15 -05:00
Arvind Yadav
0c3014f22d selinux: constify nf_hook_ops
nf_hook_ops are not supposed to change at runtime. nf_register_net_hooks
and nf_unregister_net_hooks are working with const nf_hook_ops.
So mark the non-const nf_hook_ops structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-08-28 17:33:19 -04:00