Commit Graph

1771 Commits

Author SHA1 Message Date
Eric Paris
899838b25f SELinux: unify the selinux_audit_data and selinux_late_audit_data
We no longer need the distinction.  We only need data after we decide to do an
audit.  So turn the "late" audit data into just "data" and remove what we
currently have as "data".

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:06 -04:00
Eric Paris
1d34929271 SELinux: remove auditdeny from selinux_audit_data
It's just takin' up space.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:05 -04:00
Eric Paris
50c205f5e5 LSM: do not initialize common_audit_data to 0
It isn't needed.  If you don't set the type of the data associated with
that type it is a pretty obvious programming bug.  So why waste the cycles?

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:04 -04:00
Eric Paris
07f62eb66c LSM: BUILD_BUG_ON if the common_audit_data union ever grows
We did a lot of work to shrink the common_audit_data.  Add a BUILD_BUG_ON
so future programers (let's be honest, probably me) won't do something
foolish like make it large again!

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:03 -04:00
Eric Paris
b466066f9b LSM: remove the task field from common_audit_data
There are no legitimate users.  Always use current and get back some stack
space for the common_audit_data.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:03 -04:00
Eric Paris
0972c74ecb apparmor: move task from common_audit_data to apparmor_audit_data
apparmor is the only LSM that uses the common_audit_data tsk field.
Instead of making all LSMs pay for the stack space move the aa usage into
the apparmor_audit_data.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:02 -04:00
Eric Paris
bd5e50f9c1 LSM: remove the COMMON_AUDIT_DATA_INIT type expansion
Just open code it so grep on the source code works better.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:01 -04:00
Eric Paris
d4cf970d07 SELinux: move common_audit_data to a noinline slow path function
selinux_inode_has_perm is a hot path.  Instead of declaring the
common_audit_data on the stack move it to a noinline function only used in
the rare case we need to send an audit message.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:00 -04:00
Eric Paris
602a8dd6ea SELinux: remove inode_has_perm_noadp
Both callers could better be using file_has_perm() to get better audit
results.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:00 -04:00
Eric Paris
2e33405785 SELinux: delay initialization of audit data in selinux_inode_permission
We pay a rather large overhead initializing the common_audit_data.
Since we only need this information if we actually emit an audit
message there is little need to set it up in the hot path.  This patch
splits the functionality of avc_has_perm() into avc_has_perm_noaudit(),
avc_audit_required() and slow_avc_audit().  But we take care of setting
up to audit between required() and the actual audit call.  Thus saving
measurable time in a hot path.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:59 -04:00
Eric Paris
154c50ca4e SELinux: if sel_make_bools errors don't leave inconsistent state
We reset the bool names and values array to NULL, but do not reset the
number of entries in these arrays to 0.  If we error out and then get back
into this function we will walk these NULL pointers based on the belief
that they are non-zero length.

Signed-off-by: Eric Paris <eparis@redhat.com>
cc: stable@kernel.org
2012-04-09 12:22:58 -04:00
Eric Paris
92ae9e82d9 SELinux: remove needless sel_div function
I'm not really sure what the idea behind the sel_div function is, but it's
useless.  Since a and b are both unsigned, it's impossible for a % b < 0.
That means that part of the function never does anything.  Thus it's just a
normal /.  Just do that instead.  I don't even understand what that operation
was supposed to mean in the signed case however....

If it was signed:
sel_div(-2, 4) == ((-2 / 4) - ((-2 % 4) < 0))
		  ((0)      - ((-2)     < 0))
		  ((0)      - (1))
		  (-1)

What actually happens:
sel_div(-2, 4) == ((18446744073709551614 / 4) - ((18446744073709551614 % 4) < 0))
		  ((4611686018427387903)      - ((2 < 0))
		  (4611686018427387903        - 0)
		  ((unsigned int)4611686018427387903)
		  (4294967295)

Neither makes a whole ton of sense to me.  So I'm getting rid of the
function entirely.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:57 -04:00
Eric Paris
bb7081ab93 SELinux: possible NULL deref in context_struct_to_string
It's possible that the caller passed a NULL for scontext.  However if this
is a defered mapping we might still attempt to call *scontext=kstrdup().
This is bad.  Instead just return the len.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:56 -04:00
Eric Paris
d6ea83ec68 SELinux: audit failed attempts to set invalid labels
We know that some yum operation is causing CAP_MAC_ADMIN failures.  This
implies that an RPM is laying down (or attempting to lay down) a file with
an invalid label.  The problem is that we don't have any information to
track down the cause.  This patch will cause such a failure to report the
failed label in an SELINUX_ERR audit message.  This is similar to the
SELINUX_ERR reports on invalid transitions and things like that.  It should
help run down problems on what is trying to set invalid labels in the
future.

Resulting records look something like:
type=AVC msg=audit(1319659241.138:71): avc:  denied  { mac_admin } for pid=2594 comm="chcon" capability=33 scontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tcontext=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 tclass=capability2
type=SELINUX_ERR msg=audit(1319659241.138:71): op=setxattr invalid_context=unconfined_u:object_r:hello:s0
type=SYSCALL msg=audit(1319659241.138:71): arch=c000003e syscall=188 success=no exit=-22 a0=a2c0e0 a1=390341b79b a2=a2d620 a3=1f items=1 ppid=2519 pid=2594 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts0 ses=1 comm="chcon" exe="/usr/bin/chcon" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=CWD msg=audit(1319659241.138:71):  cwd="/root" type=PATH msg=audit(1319659241.138:71): item=0 name="test" inode=785879 dev=fc:03 mode=0100644 ouid=0 ogid=0 rdev=00:00 obj=unconfined_u:object_r:admin_home_t:s0

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:56 -04:00
Eric Paris
83d498569e SELinux: rename dentry_open to file_open
dentry_open takes a file, rename it to file_open

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:50 -04:00
Eric Paris
95dbf73931 SELinux: check OPEN on truncate calls
In RH BZ 578841 we realized that the SELinux sandbox program was allowed to
truncate files outside of the sandbox.  The reason is because sandbox
confinement is determined almost entirely by the 'open' permission.  The idea
was that if the sandbox was unable to open() files it would be unable to do
harm to those files.  This turns out to be false in light of syscalls like
truncate() and chmod() which don't require a previous open() call.  I looked
at the syscalls that did not have an associated 'open' check and found that
truncate(), did not have a seperate permission and even if it did have a
separate permission such a permission owuld be inadequate for use by
sandbox (since it owuld have to be granted so liberally as to be useless).
This patch checks the OPEN permission on truncate.  I think a better solution
for sandbox is a whole new permission, but at least this fixes what we have
today.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:49 -04:00
Eric Paris
eed7795d0a SELinux: add default_type statements
Because Fedora shipped userspace based on my development tree we now
have policy version 27 in the wild defining only default user, role, and
range.  Thus to add default_type we need a policy.28.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:48 -04:00
Eric Paris
aa893269de SELinux: allow default source/target selectors for user/role/range
When new objects are created we have great and flexible rules to
determine the type of the new object.  We aren't quite as flexible or
mature when it comes to determining the user, role, and range.  This
patch adds a new ability to specify the place a new objects user, role,
and range should come from.  For users and roles it can come from either
the source or the target of the operation.  aka for files the user can
either come from the source (the running process and todays default) or
it can come from the target (aka the parent directory of the new file)

examples always are done with
directory context: system_u:object_r:mnt_t:s0-s0:c0.c512
process context: unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

[no rule]
	unconfined_u:object_r:mnt_t:s0   test_none
[default user source]
	unconfined_u:object_r:mnt_t:s0   test_user_source
[default user target]
	system_u:object_r:mnt_t:s0       test_user_target
[default role source]
	unconfined_u:unconfined_r:mnt_t:s0 test_role_source
[default role target]
	unconfined_u:object_r:mnt_t:s0   test_role_target
[default range source low]
	unconfined_u:object_r:mnt_t:s0 test_range_source_low
[default range source high]
	unconfined_u:object_r:mnt_t:s0:c0.c1023 test_range_source_high
[default range source low-high]
	unconfined_u:object_r:mnt_t:s0-s0:c0.c1023 test_range_source_low-high
[default range target low]
	unconfined_u:object_r:mnt_t:s0 test_range_target_low
[default range target high]
	unconfined_u:object_r:mnt_t:s0:c0.c512 test_range_target_high
[default range target low-high]
	unconfined_u:object_r:mnt_t:s0-s0:c0.c512 test_range_target_low-high

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:47 -04:00
Eric Paris
72e8c8593f SELinux: loosen DAC perms on reading policy
There is no reason the DAC perms on reading the policy file need to be root
only.  There are selinux checks which should control this access.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:36 -04:00
Eric Paris
47a93a5bcb SELinux: allow seek operations on the file exposing policy
sesearch uses:
lseek(3, 0, SEEK_SET)                   = -1 ESPIPE (Illegal seek)

Make that work.

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:30 -04:00
Eric W. Biederman
aeb3ae9da9 userns: Add an explicit reference to the parent user namespace
I am about to remove the struct user_namespace reference from struct user_struct.
So keep an explicit track of the parent user namespace.

Take advantage of this new reference and replace instances of user_ns->creator->user_ns
with user_ns->parent.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07 16:55:52 -07:00
Eric W. Biederman
0093ccb68f cred: Refcount the user_ns pointed to by the cred.
struct user_struct will shortly loose it's user_ns reference
so make the cred user_ns reference a proper reference complete
with reference counting.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07 16:55:52 -07:00
Eric W. Biederman
c4a4d60379 userns: Use cred->user_ns instead of cred->user->user_ns
Optimize performance and prepare for the removal of the user_ns reference
from user_struct.  Remove the slow long walk through cred->user->user_ns and
instead go straight to cred->user_ns.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-04-07 16:55:51 -07:00
Linus Torvalds
b61c37f579 lsm_audit: don't specify the audit pre/post callbacks in 'struct common_audit_data'
It just bloats the audit data structure for no good reason, since the
only time those fields are filled are just before calling the
common_lsm_audit() function, which is also the only user of those
fields.

So just make them be the arguments to common_lsm_audit(), rather than
bloating that structure that is passed around everywhere, and is
initialized in hot paths.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03 09:49:59 -07:00
Eric Paris
3f0882c482 SELinux: do not allocate stack space for AVC data unless needed
Instead of declaring the entire selinux_audit_data on the stack when we
start an operation on declare it on the stack if we are going to use it.
We know it's usefulness at the end of the security decision and can declare
it there.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03 09:49:41 -07:00