3215 Commits

Author SHA1 Message Date
Stephen Smalley
a050a570db selinux: fix off-by-one in setprocattr
SELinux tries to support setting/clearing of /proc/pid/attr attributes
from the shell by ignoring terminating newlines and treating an
attribute value that begins with a NUL or newline as an attempt to
clear the attribute.  However, the test for clearing attributes has
always been wrong; it has an off-by-one error, and this could further
lead to reading past the end of the allocated buffer since commit
bb646cdb12e75d82258c2f2e7746d5952d3e321a ("proc_pid_attr_write():
switch to memdup_user()").  Fix the off-by-one error.

Even with this fix, setting and clearing /proc/pid/attr attributes
from the shell is not straightforward since the interface does not
support multiple write() calls (so shells that write the value and
newline separately will set and then immediately clear the attribute,
requiring use of echo -n to set the attribute), whereas trying to use
echo -n "" to clear the attribute causes the shell to skip the
write() call altogether since POSIX says that a zero-length write
causes no side effects. Thus, one must use echo -n to set and echo
without -n to clear, as in the following example:
$ echo -n unconfined_u:object_r:user_home_t:s0 > /proc/$$/attr/fscreate
$ cat /proc/$$/attr/fscreate
unconfined_u:object_r:user_home_t:s0
$ echo "" > /proc/$$/attr/fscreate
$ cat /proc/$$/attr/fscreate

Note the use of /proc/$$ rather than /proc/self, as otherwise
the cat command will read its own attribute value, not that of the shell.

There are no users of this facility to my knowledge; possibly we
should just get rid of it.

UPDATE: Upon further investigation it appears that a local process
with the process:setfscreate permission can cause a kernel panic as a
result of this bug.  This patch fixes CVE-2017-2618.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: added the update about CVE-2017-2618 to the commit description]
Cc: stable@vger.kernel.org # 3.5: d6ea83ec6864e
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-02-07 17:31:38 -05:00
Lans Zhang
20f482ab9e ima: allow to check MAY_APPEND
Otherwise some mask and inmask tokens with MAY_APPEND flag may not work
as expected.

Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2017-01-27 14:17:21 -05:00
Mimi Zohar
bc15ed663e ima: fix ima_d_path() possible race with rename
On failure to return a pathname from ima_d_path(), a pointer to
dname is returned, which is subsequently used in the IMA measurement
list, the IMA audit records, and other audit logging.  Saving the
pointer to dname for later use has the potential to race with rename.

Intead of returning a pointer to dname on failure, this patch returns
a pointer to a copy of the filename.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
2017-01-27 14:16:02 -05:00
James Morris
710584b9da Merge branch 'smack-for-4.11' of git://github.com/cschaufler/smack-next into next 2017-01-27 09:23:21 +11:00
Krister Johansen
4548b683b7 Introduce a sysctl that modifies the value of PROT_SOCK.
Add net.ipv4.ip_unprivileged_port_start, which is a per namespace sysctl
that denotes the first unprivileged inet port in the namespace.  To
disable all privileged ports set this to zero.  It also checks for
overlap with the local port range.  The privileged and local range may
not overlap.

The use case for this change is to allow containerized processes to bind
to priviliged ports, but prevent them from ever being allowed to modify
their container's network configuration.  The latter is accomplished by
ensuring that the network namespace is not a child of the user
namespace.  This modification was needed to allow the container manager
to disable a namespace's priviliged port restrictions without exposing
control of the network namespace to processes in the user namespace.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-24 12:10:51 -05:00
Eric W. Biederman
9227dd2a84 exec: Remove LSM_UNSAFE_PTRACE_CAP
With previous changes every location that tests for
LSM_UNSAFE_PTRACE_CAP also tests for LSM_UNSAFE_PTRACE making the
LSM_UNSAFE_PTRACE_CAP redundant, so remove it.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-01-24 12:03:08 +13:00
Eric W. Biederman
20523132ec exec: Test the ptracer's saved cred to see if the tracee can gain caps
Now that we have user namespaces and non-global capabilities verify
the tracer has capabilities in the relevant user namespace instead
of in the current_user_ns().

As the test for setting LSM_UNSAFE_PTRACE_CAP is currently
ptracer_capable(p, current_user_ns()) and the new task credentials are
in current_user_ns() this change does not have any user visible change
and simply moves the test to where it is used, making the code easier
to read.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-01-24 12:03:08 +13:00
Eric W. Biederman
70169420f5 exec: Don't reset euid and egid when the tracee has CAP_SETUID
Don't reset euid and egid when the tracee has CAP_SETUID in
it's user namespace.  I punted on relaxing this permission check
long ago but now that I have read this code closely it is clear
it is safe to test against CAP_SETUID in the user namespace.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-01-24 12:03:07 +13:00
Greg Kroah-Hartman
64e90a8acb Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()
Some usermode helper applications are defined at kernel build time, while
others can be changed at runtime.  To provide a sane way to filter these, add a
new kernel option "STATIC_USERMODEHELPER".  This option routes all
call_usermodehelper() calls through this binary, no matter what the caller
wishes to have called.

The new binary (by default set to /sbin/usermode-helper, but can be changed
through the STATIC_USERMODEHELPER_PATH option) can properly filter the
requested programs to be run by the kernel by looking at the first argument
that is passed to it.  All other options should then be passed onto the proper
program if so desired.

To disable all call_usermodehelper() calls by the kernel, set
STATIC_USERMODEHELPER_PATH to an empty string.

Thanks to Neil Brown for the idea of this feature.

Cc: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 12:59:45 +01:00
Greg Kroah-Hartman
377e7a27c0 Make static usermode helper binaries constant
There are a number of usermode helper binaries that are "hard coded" in
the kernel today, so mark them as "const" to make it harder for someone
to change where the variables point to.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Sailer <t.sailer@alumni.ethz.ch>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Alex Elder <elder@kernel.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 12:59:45 +01:00
Casey Schaufler
d69dece5f5 LSM: Add /sys/kernel/security/lsm
I am still tired of having to find indirect ways to determine
what security modules are active on a system. I have added
/sys/kernel/security/lsm, which contains a comma separated
list of the active security modules. No more groping around
in /proc/filesystems or other clever hacks.

Unchanged from previous versions except for being updated
to the latest security next branch.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-01-19 13:18:29 +11:00
John Johansen
3ccb76c5df apparmor: fix undefined reference to `aa_g_hash_policy'
The kernel build bot turned up a bad config combination when
CONFIG_SECURITY_APPARMOR is y and CONFIG_SECURITY_APPARMOR_HASH is n,
resulting in the build error
   security/built-in.o: In function `aa_unpack':
   (.text+0x841e2): undefined reference to `aa_g_hash_policy'

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 13:21:27 -08:00
John Johansen
e6bfa25deb apparmor: replace remaining BUG_ON() asserts with AA_BUG()
AA_BUG() uses WARN and won't break the kernel like BUG_ON().

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:56 -08:00
John Johansen
2c17cd3681 apparmor: fix restricted endian type warnings for policy unpack
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:55 -08:00
John Johansen
e6e8bf4188 apparmor: fix restricted endian type warnings for dfa unpack
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:54 -08:00
John Johansen
ca4bd5ae0a apparmor: add check for apparmor enabled in module parameters missing it
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:53 -08:00
John Johansen
d4669f0b03 apparmor: add per cpu work buffers to avoid allocating buffers at every hook
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:53 -08:00
Tyler Hicks
e3ea1ca59a apparmor: sysctl to enable unprivileged user ns AppArmor policy loading
If this sysctl is set to non-zero and a process with CAP_MAC_ADMIN in
the root namespace has created an AppArmor policy namespace,
unprivileged processes will be able to change to a profile in the
newly created AppArmor policy namespace and, if the profile allows
CAP_MAC_ADMIN and appropriate file permissions, will be able to load
policy in the respective policy namespace.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:52 -08:00
William Hua
e025be0f26 apparmor: support querying extended trusted helper extra data
Allow a profile to carry extra data that can be queried via userspace.
This provides a means to store extra data in a profile that a trusted
helper can extract and use from live policy.

Signed-off-by: William Hua <william.hua@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:51 -08:00
John Johansen
12eb87d50b apparmor: update cap audit to check SECURITY_CAP_NOAUDIT
apparmor should be checking the SECURITY_CAP_NOAUDIT constant. Also
in complain mode make it so apparmor can elect to log a message,
informing of the check.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:50 -08:00
John Johansen
31f75bfecd apparmor: make computing policy hashes conditional on kernel parameter
Allow turning off the computation of the policy hashes via the
apparmor.hash_policy kernel parameter.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:50 -08:00
John Johansen
aa9a39ad8f apparmor: convert change_profile to use fqname later to give better control
Moving the use of fqname to later allows learning profiles to be based
on the fqname request instead of just the hname. It also allows cleaning
up some of the name parsing and lookup by allowing the use of
the fqlookupn_profile() lib fn.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:49 -08:00
John Johansen
c3e1e584ad apparmor: fix change_hat debug output
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:48 -08:00
John Johansen
5ef50d014c apparmor: remove unused op parameter from simple_write_to_buffer()
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:48 -08:00
John Johansen
ef88a7ac55 apparmor: change aad apparmor_audit_data macro to a fn macro
The aad macro can replace aad strings when it is not intended to. Switch
to a fn macro so it is only applied when intended.

Also at the same time cleanup audit_data initialization by putting
common boiler plate behind a macro, and dropping the gfp_t parameter
which will become useless.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:47 -08:00
John Johansen
47f6e5cc73 apparmor: change op from int to const char *
Having ops be an integer that is an index into an op name table is
awkward and brittle. Every op change requires an edit for both the
op constant and a string in the table. Instead switch to using const
strings directly, eliminating the need for the table that needs to
be kept in sync.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:46 -08:00
John Johansen
55a26ebf63 apparmor: rename context abreviation cxt to the more standard ctx
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:45 -08:00
John Johansen
a20aa95fbe apparmor: fail task profile update if current_cred isn't real_cred
Trying to update the task cred while the task current cred is not the
real cred will result in an error at the cred layer. Avoid this by
failing early and delaying the update.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:45 -08:00
John Johansen
b7fd2c0340 apparmor: add per policy ns .load, .replace, .remove interface files
Having per policy ns interface files helps with containers restoring
policy.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:44 -08:00
John Johansen
12dd7171d6 apparmor: pass the subject profile into profile replace/remove
This is just setup for new ns specific .load, .replace, .remove interface
files.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:43 -08:00
John Johansen
04dc715e24 apparmor: audit policy ns specified in policy load
Verify that profiles in a load set specify the same policy ns and
audit the name of the policy ns that policy is being loaded for.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:43 -08:00
John Johansen
5ac8c355ae apparmor: allow introspecting the loaded policy pre internal transform
Store loaded policy and allow introspecting it through apparmorfs. This
has several uses from debugging, policy validation, and policy checkpoint
and restore for containers.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:42 -08:00
John Johansen
fc1c9fd10a apparmor: add ns name to the audit data for policy loads
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:41 -08:00
John Johansen
078c73c63f apparmor: add profile and ns params to aa_may_manage_policy()
Policy management will be expanded beyond traditional unconfined root.
This will require knowning the profile of the task doing the management
and the ns view.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:40 -08:00
John Johansen
fd2a80438d apparmor: add ns being viewed as a param to policy_admin_capable()
Prepare for a tighter pairing of user namespaces and apparmor policy
namespaces, by making the ns to be viewed available.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:40 -08:00
John Johansen
2bd8dbbf22 apparmor: add ns being viewed as a param to policy_view_capable()
Prepare for a tighter pairing of user namespaces and apparmor policy
namespaces, by making the ns to be viewed available and checking
that the user namespace level is the same as the policy ns level.

This strict pairing will be relaxed once true support of user namespaces
lands.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:39 -08:00
John Johansen
a6f233003b apparmor: allow specifying the profile doing the management
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:38 -08:00
John Johansen
3e3e569539 apparmor: allow introspecting the policy namespace name
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:37 -08:00
John Johansen
b79473f2de apparmor: Make aa_remove_profile() callable from a different view
This is prep work for fs operations being able to remove namespaces.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:37 -08:00
John Johansen
ee2351e4b0 apparmor: track ns level so it can be used to help in view checks
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:36 -08:00
John Johansen
a71ada3058 apparmor: add special .null file used to "close" fds at exec
Borrow the special null device file from selinux to "close" fds that
don't have sufficient permissions at exec time.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:35 -08:00
John Johansen
34c426acb7 apparmor: provide userspace flag indicating binfmt_elf_mmap change
Commit 9f834ec18def ("binfmt_elf: switch to new creds when switching to new mm")
changed when the creds are installed by the binfmt_elf handler. This
affects which creds are used to mmap the executable into the address
space. Which can have an affect on apparmor policy.

Add a flag to apparmor at
/sys/kernel/security/apparmor/features/domain/fix_binfmt_elf_mmap

to make it possible to detect this semantic change so that the userspace
tools and the regression test suite can correctly deal with the change.

BugLink: http://bugs.launchpad.net/bugs/1630069
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:35 -08:00
John Johansen
11c236b89d apparmor: add a default null dfa
Instead of testing whether a given dfa exists in every code path, have
a default null dfa that is used when loaded policy doesn't provide a
dfa.

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

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:34 -08:00
John Johansen
6604d4c1c1 apparmor: allow policydb to be used as the file dfa
Newer policy will combine the file and policydb dfas, allowing for
better optimizations. However to support older policy we need to
keep the ability to address the "file" dfa separately. So dup
the policydb as if it is the file dfa and set the appropriate start
state.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:33 -08:00
John Johansen
293a4886f9 apparmor: add get_dfa() fn
The dfa is currently setup to be shared (has the basis of refcounting)
but currently can't be because the count can't be increased.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:32 -08:00
John Johansen
474d6b7510 apparmor: prepare to support newer versions of policy
Newer policy encodes more than just version in the version tag,
so add masking to make sure the comparison remains correct.

Note: this is fully compatible with older policy as it will never set
the bits being masked out.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:32 -08:00
John Johansen
5ebfb12822 apparmor: add support for force complain flag to support learning mode
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:31 -08:00
John Johansen
abbf873403 apparmor: remove paranoid load switch
Policy should always under go a full paranoid verification.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:30 -08:00
John Johansen
181f7c9776 apparmor: name null-XXX profiles after the executable
When possible its better to name a learning profile after the missing
profile in question. This allows for both more informative names and
for profile reuse.

Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:30 -08:00
John Johansen
30b026a8d1 apparmor: pass gfp_t parameter into profile allocation
Signed-off-by: John Johansen <john.johansen@canonical.com>
2017-01-16 01:18:29 -08:00