Commit graph

759 commits

Author SHA1 Message Date
David Howells
34574dd10b keys: Handle there being no fallback destination keyring for request_key()
When request_key() is called, without there being any standard process
keyrings on which to fall back if a destination keyring is not specified, an
oops is liable to occur when construct_alloc_key() calls down_write() on
dest_keyring's semaphore.

Due to function inlining this may be seen as an oops in down_write() as called
from request_key_and_link().

This situation crops up during boot, where request_key() is called from within
the kernel (such as in CIFS mounts) where nobody is actually logged in, and so
PAM has not had a chance to create a session keyring and user keyrings to act
as the fallback.

To fix this, make construct_alloc_key() not attempt to cache a key if there is
no fallback key if no destination keyring is given specifically.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-09 10:41:19 -07:00
Serge E. Hallyn
5bf37ec3e0 cap_prctl: don't set error to 0 at 'no_change'
One-liner: capsh --print is broken without this patch.

In certain cases, cap_prctl returns error > 0 for success.  However,
the 'no_change' label was always setting error to 0.  As a result,
for example, 'prctl(CAP_BSET_READ, N)' would always return 0.
It should return 1 if a process has N in its bounding set (as
by default it does).

I'm keeping the no_change label even though it's now functionally
the same as 'error'.

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-04-09 09:12:03 +10:00
Tetsuo Handa
a0558fc349 tomoyo: remove "undelete domain" command.
Since TOMOYO's policy management tools does not use the "undelete domain"
command, we decided to remove that command.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-04-07 16:08:56 +10:00
David Howells
800a964787 CacheFiles: Export things for CacheFiles
Export a number of functions for CacheFiles's use.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:40 +01:00
Linus Torvalds
8fe74cf053 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  Remove two unneeded exports and make two symbols static in fs/mpage.c
  Cleanup after commit 585d3bc06f
  Trim includes of fdtable.h
  Don't crap into descriptor table in binfmt_som
  Trim includes in binfmt_elf
  Don't mess with descriptor table in load_elf_binary()
  Get rid of indirect include of fs_struct.h
  New helper - current_umask()
  check_unsafe_exec() doesn't care about signal handlers sharing
  New locking/refcounting for fs_struct
  Take fs_struct handling to new file (fs/fs_struct.c)
  Get rid of bumping fs_struct refcount in pivot_root(2)
  Kill unsharing fs_struct in __set_personality()
2009-04-02 21:09:10 -07:00
Li Zefan
b4046f00ee devcgroup: avoid using cgroup_lock
There is nothing special that has to be protected by cgroup_lock,
so introduce devcgroup_mtuex for it's own use.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-02 19:04:55 -07:00
Al Viro
5ad4e53bd5 Get rid of indirect include of fs_struct.h
Don't pull it in sched.h; very few files actually need it and those
can include directly.  sched.h itself only needs forward declaration
of struct fs_struct;

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-03-31 23:00:27 -04:00
Etienne Basset
4303154e86 smack: Add a new '-CIPSO' option to the network address label configuration
This patch adds a new special option '-CIPSO' to the Smack subsystem. When used
in the netlabel list, it means "use CIPSO networking". A use case is when your
local network speaks CIPSO and you want also to connect to the unlabeled
Internet. This patch also add some documentation describing that. The patch
also corrects an oops when setting a '' SMACK64 xattr to a file.

Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28 15:01:37 +11:00
Paul Moore
07feee8f81 netlabel: Cleanup the Smack/NetLabel code to fix incoming TCP connections
This patch cleans up a lot of the Smack network access control code.  The
largest changes are to fix the labeling of incoming TCP connections in a
manner similar to the recent SELinux changes which use the
security_inet_conn_request() hook to label the request_sock and let the label
move to the child socket via the normal network stack mechanisms.  In addition
to the incoming TCP connection fixes this patch also removes the smk_labled
field from the socket_smack struct as the minor optimization advantage was
outweighed by the difficulty in maintaining it's proper state.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28 15:01:37 +11:00
Paul Moore
8651d5c0b1 lsm: Remove the socket_post_accept() hook
The socket_post_accept() hook is not currently used by any in-tree modules
and its existence continues to cause problems by confusing people about
what can be safely accomplished using this hook.  If a legitimate need for
this hook arises in the future it can always be reintroduced.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28 15:01:37 +11:00
Paul Moore
58bfbb51ff selinux: Remove the "compat_net" compatibility code
The SELinux "compat_net" is marked as deprecated, the time has come to
finally remove it from the kernel.  Further code simplifications are
likely in the future, but this patch was intended to be a simple,
straight-up removal of the compat_net code.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28 15:01:37 +11:00
Paul Moore
389fb800ac netlabel: Label incoming TCP connections correctly in SELinux
The current NetLabel/SELinux behavior for incoming TCP connections works but
only through a series of happy coincidences that rely on the limited nature of
standard CIPSO (only able to convey MLS attributes) and the write equality
imposed by the SELinux MLS constraints.  The problem is that network sockets
created as the result of an incoming TCP connection were not on-the-wire
labeled based on the security attributes of the parent socket but rather based
on the wire label of the remote peer.  The issue had to do with how IP options
were managed as part of the network stack and where the LSM hooks were in
relation to the code which set the IP options on these newly created child
sockets.  While NetLabel/SELinux did correctly set the socket's on-the-wire
label it was promptly cleared by the network stack and reset based on the IP
options of the remote peer.

This patch, in conjunction with a prior patch that adjusted the LSM hook
locations, works to set the correct on-the-wire label format for new incoming
connections through the security_inet_conn_request() hook.  Besides the
correct behavior there are many advantages to this change, the most significant
is that all of the NetLabel socket labeling code in SELinux now lives in hooks
which can return error codes to the core stack which allows us to finally get
ride of the selinux_netlbl_inode_permission() logic which greatly simplfies
the NetLabel/SELinux glue code.  In the process of developing this patch I
also ran into a small handful of AF_INET6 cleanliness issues that have been
fixed which should make the code safer and easier to extend in the future.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-28 15:01:36 +11:00
Tetsuo Handa
a106cbfd1f TOMOYO: Fix a typo.
Fix a typo.

Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-27 19:03:44 +11:00
Etienne Basset
7198e2eeb4 smack: convert smack to standard linux lists
the following patch (on top of 2.6.29) converts Smack lists to standard linux lists
Please review and consider for inclusion in 2.6.30-rc

regards,
Etienne

Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2009-03-26 09:17:04 +11:00
James Morris
703a3cd728 Merge branch 'master' into next 2009-03-24 10:52:46 +11:00
Eric Paris
df7f54c012 SELinux: inode_doinit_with_dentry drop no dentry printk
Drop the printk message when an inode is found without an associated
dentry.  This should only happen when userspace can't be accessing those
inodes and those labels will get set correctly on the next d_instantiate.
Thus there is no reason to send this message.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-10 08:40:02 +11:00
Eric Paris
dd34b5d75a SELinux: new permission between tty audit and audit socket
New selinux permission to separate the ability to turn on tty auditing from
the ability to set audit rules.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-06 08:50:21 +11:00
Eric Paris
6a25b27d60 SELinux: open perm for sock files
When I did open permissions I didn't think any sockets would have an open.
Turns out AF_UNIX sockets can have an open when they are bound to the
filesystem namespace.  This patch adds a new SOCK_FILE__OPEN permission.
It's safe to add this as the open perms are already predicated on
capabilities and capabilities means we have unknown perm handling so
systems should be as backwards compatible as the policy wants them to
be.

https://bugzilla.redhat.com/show_bug.cgi?id=475224

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-06 08:50:18 +11:00
etienne
211a40c087 smack: fixes for unlabeled host support
The following patch (against 2.6.29rc5) fixes a few issues in the
smack/netlabel "unlabeled host support" functionnality that was added in
2.6.29rc.  It should go in before -final.

1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label),
preventing 'tagged' tasks to access Internet (many systems drop packets with
IP options)

2) netmasks were not handled correctly, they were stored in a way _not
equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24,
/32 masks but not other masks)

3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not
done), so there could have been different list entries for the same IP
prefix; if those entries had different labels, well ...

4) they were not sorted

1) 2) 3) are bugs, 4) is a more cosmetic issue.
The patch :

-creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr,
-sorted by netmask length

-use the new sorted nature of  smack_netlbladdrs list to simplify
 smack_host_label : the first match _will_ be the more specific

-corrects endianness issues in smk_write_netlbladdr &  netlbladdr_seq_show

Signed-off-by: <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-05 08:36:34 +11:00
etienne
113a0e4590 smack: fixes for unlabeled host support
The following patch (against 2.6.29rc5) fixes a few issues in the
smack/netlabel "unlabeled host support" functionnality that was added in
2.6.29rc.  It should go in before -final.

1) smack_host_label disregard a "0.0.0.0/0 @" rule (or other label),
preventing 'tagged' tasks to access Internet (many systems drop packets with
IP options)

2) netmasks were not handled correctly, they were stored in a way _not
equivalent_ to conversion to be32 (it was equivalent for /0, /8, /16, /24,
/32 masks but not other masks)

3) smack_netlbladdr prefixes (IP/mask) were not consistent (mask&IP was not
done), so there could have been different list entries for the same IP
prefix; if those entries had different labels, well ...

4) they were not sorted

1) 2) 3) are bugs, 4) is a more cosmetic issue.
The patch :

-creates a new helper smk_netlbladdr_insert to insert a smk_netlbladdr,
-sorted by netmask length

-use the new sorted nature of  smack_netlbladdrs list to simplify
 smack_host_label : the first match _will_ be the more specific

-corrects endianness issues in smk_write_netlbladdr &  netlbladdr_seq_show

Signed-off-by: <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-05 08:30:01 +11:00
Paul Moore
d7f59dc464 selinux: Fix a panic in selinux_netlbl_inode_permission()
Rick McNeal from LSI identified a panic in selinux_netlbl_inode_permission()
caused by a certain sequence of SUNRPC operations.  The problem appears to be
due to the lack of NULL pointer checking in the function; this patch adds the
pointer checks so the function will exit safely in the cases where the socket
is not completely initialized.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-03-02 09:30:04 +11:00
Serge E. Hallyn
454804ab03 keys: make procfiles per-user-namespace
Restrict the /proc/keys and /proc/key-users output to keys
belonging to the same user namespace as the reading task.

We may want to make this more complicated - so that any
keys in a user-namespace which is belongs to the reading
task are also shown.  But let's see if anyone wants that
first.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-27 12:35:15 +11:00
Serge E. Hallyn
2ea190d0a0 keys: skip keys from another user namespace
When listing keys, do not return keys belonging to the
same uid in another user namespace.  Otherwise uid 500
in another user namespace will return keyrings called
uid.500 for another user namespace.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-27 12:35:12 +11:00
Serge E. Hallyn
8ff3bc3138 keys: consider user namespace in key_permission
If a key is owned by another user namespace, then treat the
key as though it is owned by both another uid and gid.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-27 12:35:09 +11:00
Serge E. Hallyn
1d1e97562e keys: distinguish per-uid keys in different namespaces
per-uid keys were looked by uid only.  Use the user namespace
to distinguish the same uid in different namespaces.

This does not address key_permission.  So a task can for instance
try to join a keyring owned by the same uid in another namespace.
That will be handled by a separate patch.

Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-27 12:35:06 +11:00
Paul Moore
09c50b4a52 selinux: Fix the NetLabel glue code for setsockopt()
At some point we (okay, I) managed to break the ability for users to use the
setsockopt() syscall to set IPv4 options when NetLabel was not active on the
socket in question.  The problem was noticed by someone trying to use the
"-R" (record route) option of ping:

 # ping -R 10.0.0.1
 ping: record route: No message of desired type

The solution is relatively simple, we catch the unlabeled socket case and
clear the error code, allowing the operation to succeed.  Please note that we
still deny users the ability to override IPv4 options on socket's which have
NetLabel labeling active; this is done to ensure the labeling remains intact.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-23 10:05:55 +11:00
Mimi Zohar
be38e0fd5f integrity: ima iint radix_tree_lookup locking fix
Based on Andrew Morton's comments:
- add missing locks around radix_tree_lookup in ima_iint_insert()

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-23 09:54:53 +11:00
Tetsuo Handa
1581e7ddbd TOMOYO: Do not call tomoyo_realpath_init unless registered.
tomoyo_realpath_init() is unconditionally called by security_initcall().
But nobody will use realpath related functions if TOMOYO is not registered.

So, let tomoyo_init() call tomoyo_realpath_init().

This patch saves 4KB of memory allocation if TOMOYO is not registered.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-23 09:45:05 +11:00
Mimi Zohar
0da0a420bb integrity: ima scatterlist bug fix
Based on Alexander Beregalov's post http://lkml.org/lkml/2009/2/19/198

- replaced sg_set_buf() with sg_init_one()

 kernel BUG at include/linux/scatterlist.h:65!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 last sysfs file:
 CPU 2
 Modules linked in:
 Pid: 1, comm: swapper Not tainted 2.6.29-rc5-next-20090219 #5 PowerEdge 1950
 RIP: 0010:[<ffffffff8045ec70>]  [<ffffffff8045ec70>] ima_calc_hash+0xc0/0x160
 RSP: 0018:ffff88007f46bc40  EFLAGS: 00010286
 RAX: ffffe200032c45e8 RBX: 00000000fffffff4 RCX: 0000000087654321
 RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff88007cf71048
 RBP: ffff88007f46bcd0 R08: 0000000000000000 R09: 0000000000000163
 R10: ffff88007f4707a8 R11: 0000000000000000 R12: ffff88007cf71048
 R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000009d98
 FS:  0000000000000000(0000) GS:ffff8800051ac000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
 CR2: 0000000000000000 CR3: 0000000000201000 CR4: 00000000000006e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Tested-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-21 00:29:59 +11:00
Randy Dunlap
251a2a958b smack: fix lots of kernel-doc notation
Fix/add kernel-doc notation and fix typos in security/smack/.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-19 15:51:10 +11:00
Tetsuo Handa
e5a3b95f58 TOMOYO: Don't create securityfs entries unless registered.
TOMOYO should not create /sys/kernel/security/tomoyo/ interface unless
TOMOYO is registered.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-16 09:01:48 +11:00
Tetsuo Handa
33043cbb9f TOMOYO: Fix exception policy read failure.
Due to wrong initialization, "cat /sys/kernel/security/tomoyo/exception_policy"
returned nothing.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 12:33:30 +11:00
Eric Paris
26036651c5 SELinux: convert the avc cache hash list to an hlist
We do not need O(1) access to the tail of the avc cache lists and so we are
wasting lots of space using struct list_head instead of struct hlist_head.
This patch converts the avc cache to use hlists in which there is a single
pointer from the head which saves us about 4k of global memory.

Resulted in about a 1.5% decrease in time spent in avc_has_perm_noaudit based
on oprofile sampling of tbench.  Although likely within the noise....

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:23:48 +11:00
Eric Paris
edf3d1aecd SELinux: code readability with avc_cache
The code making use of struct avc_cache was not easy to read thanks to liberal
use of &avc_cache.{slots_lock,slots}[hvalue] throughout.  This patch simply
creates local pointers and uses those instead of the long global names.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:23:45 +11:00
Eric Paris
f1c6381a6e SELinux: remove unused av.decided field
It appears there was an intention to have the security server only decide
certain permissions and leave other for later as some sort of a portential
performance win.  We are currently always deciding all 32 bits of
permissions and this is a useless couple of branches and wasted space.
This patch completely drops the av.decided concept.

This in a 17% reduction in the time spent in avc_has_perm_noaudit
based on oprofile sampling of a tbench benchmark.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:23:08 +11:00
Eric Paris
21193dcd1f SELinux: more careful use of avd in avc_has_perm_noaudit
we are often needlessly jumping through hoops when it comes to avd
entries in avc_has_perm_noaudit and we have extra initialization and memcpy
which are just wasting performance.  Try to clean the function up a bit.

This patch resulted in a 13% drop in time spent in avc_has_perm_noaudit in my
oprofile sampling of a tbench benchmark.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:23:04 +11:00
Eric Paris
906d27d9d2 SELinux: remove the unused ae.used
Currently SELinux code has an atomic which was intended to track how many
times an avc entry was used and to evict entries when they haven't been
used recently.  Instead we never let this atomic get above 1 and evict when
it is first checked for eviction since it hits zero.  This is a total waste
of time so I'm completely dropping ae.used.

This change resulted in about a 3% faster avc_has_perm_noaudit when running
oprofile against a tbench benchmark.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed by: Paul Moore <paul.moore@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:22:37 +11:00
Eric Paris
a5dda68332 SELinux: check seqno when updating an avc_node
The avc update node callbacks do not check the seqno of the caller with the
seqno of the node found.  It is possible that a policy change could happen
(although almost impossibly unlikely) in which a permissive or
permissive_domain decision is not valid for the entry found.  Simply pass
and check that the seqno of the caller and the seqno of the node found
match.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:22:34 +11:00
Eric Paris
4cb912f1d1 SELinux: NULL terminate al contexts from disk
When a context is pulled in from disk we don't know that it is null
terminated.  This patch forecebly null terminates contexts when we pull
them from disk.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:22:30 +11:00
Eric Paris
4ba0a8ad63 SELinux: better printk when file with invalid label found
Currently when an inode is read into the kernel with an invalid label
string (can often happen with removable media) we output a string like:

SELinux: inode_doinit_with_dentry:  context_to_sid([SOME INVALID LABEL])
returned -22 dor dev=[blah] ino=[blah]

Which is all but incomprehensible to all but a couple of us.  Instead, on
EINVAL only, I plan to output a much more user friendly string and I plan to
ratelimit the printk since many of these could be generated very rapidly.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:22:27 +11:00
Eric Paris
200ac532a4 SELinux: call capabilities code directory
For cleanliness and efficiency remove all calls to secondary-> and instead
call capabilities code directly.  capabilities are the only module that
selinux stacks with and so the code should not indicate that other stacking
might be possible.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14 09:22:24 +11:00
Randy Dunlap
b53fab9d48 ima: fix build error
IMA_LSM_RULES requires AUDIT.  This is automatic if SECURITY_SELINUX=y
but not when SECURITY_SMACK=y (and SECURITY_SELINUX=n), so make the
dependency explicit.  This fixes the following build error:

security/integrity/ima/ima_policy.c:111:error: implicit declaration of function 'security_audit_rule_match'
security/integrity/ima/ima_policy.c:230:error: implicit declaration of function 'security_audit_rule_init'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-13 09:27:56 +11:00
Tetsuo Handa
35d50e60e8 tomoyo: fix sparse warning
Fix sparse warning.

$ make C=2 SUBDIRS=security/tomoyo CF="-D__cold__="
 CHECK   security/tomoyo/common.c
 CHECK   security/tomoyo/realpath.c
 CHECK   security/tomoyo/tomoyo.c
security/tomoyo/tomoyo.c:110:8: warning: symbol 'buf' shadows an earlier one
security/tomoyo/tomoyo.c💯7: originally declared here

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 20:21:10 +11:00
James Morris
42d5aaa2d8 security: change link order of LSMs so security=tomoyo works
LSMs need to be linked before root_plug to ensure the security=
boot parameter works with them.  Do this for Tomoyo.

(root_plug probably needs to be taken out and shot at some point,
too).

Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 16:29:04 +11:00
Kentaro Takeda
00d7d6f840 Kconfig and Makefile
TOMOYO uses LSM hooks for pathname based access control and securityfs support.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 15:19:00 +11:00
Kentaro Takeda
f743324377 LSM adapter functions.
DAC's permissions and TOMOYO's permissions are not one-to-one mapping.

Regarding DAC, there are "read", "write", "execute" permissions.
Regarding TOMOYO, there are "allow_read", "allow_write", "allow_read/write",
"allow_execute", "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir",
"allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar",
"allow_truncate", "allow_symlink", "allow_rewrite", "allow_link",
"allow_rename" permissions.

+----------------------------------+----------------------------------+
| requested operation              | required TOMOYO's permission     |
+----------------------------------+----------------------------------+
| sys_open(O_RDONLY)               | allow_read                       |
+----------------------------------+----------------------------------+
| sys_open(O_WRONLY)               | allow_write                      |
+----------------------------------+----------------------------------+
| sys_open(O_RDWR)                 | allow_read/write                 |
+----------------------------------+----------------------------------+
| open_exec() from do_execve()     | allow_execute                    |
+----------------------------------+----------------------------------+
| open_exec() from !do_execve()    | allow_read                       |
+----------------------------------+----------------------------------+
| sys_read()                       | (none)                           |
+----------------------------------+----------------------------------+
| sys_write()                      | (none)                           |
+----------------------------------+----------------------------------+
| sys_mmap()                       | (none)                           |
+----------------------------------+----------------------------------+
| sys_uselib()                     | allow_read                       |
+----------------------------------+----------------------------------+
| sys_open(O_CREAT)                | allow_create                     |
+----------------------------------+----------------------------------+
| sys_open(O_TRUNC)                | allow_truncate                   |
+----------------------------------+----------------------------------+
| sys_truncate()                   | allow_truncate                   |
+----------------------------------+----------------------------------+
| sys_ftruncate()                  | allow_truncate                   |
+----------------------------------+----------------------------------+
| sys_open() without O_APPEND      | allow_rewrite                    |
+----------------------------------+----------------------------------+
| setfl() without O_APPEND         | allow_rewrite                    |
+----------------------------------+----------------------------------+
| sys_sysctl() for writing         | allow_write                      |
+----------------------------------+----------------------------------+
| sys_sysctl() for reading         | allow_read                       |
+----------------------------------+----------------------------------+
| sys_unlink()                     | allow_unlink                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFREG)               | allow_create                     |
+----------------------------------+----------------------------------+
| sys_mknod(0)                     | allow_create                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFIFO)               | allow_mkfifo                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFSOCK)              | allow_mksock                     |
+----------------------------------+----------------------------------+
| sys_bind(AF_UNIX)                | allow_mksock                     |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFBLK)               | allow_mkblock                    |
+----------------------------------+----------------------------------+
| sys_mknod(S_IFCHR)               | allow_mkchar                     |
+----------------------------------+----------------------------------+
| sys_symlink()                    | allow_symlink                    |
+----------------------------------+----------------------------------+
| sys_mkdir()                      | allow_mkdir                      |
+----------------------------------+----------------------------------+
| sys_rmdir()                      | allow_rmdir                      |
+----------------------------------+----------------------------------+
| sys_link()                       | allow_link                       |
+----------------------------------+----------------------------------+
| sys_rename()                     | allow_rename                     |
+----------------------------------+----------------------------------+

TOMOYO requires "allow_execute" permission of a pathname passed to do_execve()
but does not require "allow_read" permission of that pathname.
Let's consider 3 patterns (statically linked, dynamically linked,
shell script). This description is to some degree simplified.

  $ cat hello.c
  #include <stdio.h>
  int main() {
          printf("Hello\n");
          return 0;
  }
  $ cat hello.sh
  #! /bin/sh
  echo "Hello"
  $ gcc -static -o hello-static hello.c
  $ gcc -o hello-dynamic hello.c
  $ chmod 755 hello.sh

Case 1 -- Executing hello-static from bash.

  (1) The bash process calls fork() and the child process requests
      do_execve("hello-static").

  (2) The kernel checks "allow_execute hello-static" from "bash" domain.

  (3) The kernel calculates "bash hello-static" as the domain to transit to.

  (4) The kernel overwrites the child process by "hello-static".

  (5) The child process transits to "bash hello-static" domain.

  (6) The "hello-static" starts and finishes.

Case 2 -- Executing hello-dynamic from bash.

  (1) The bash process calls fork() and the child process requests
      do_execve("hello-dynamic").

  (2) The kernel checks "allow_execute hello-dynamic" from "bash" domain.

  (3) The kernel calculates "bash hello-dynamic" as the domain to transit to.

  (4) The kernel checks "allow_read ld-linux.so" from "bash hello-dynamic"
      domain. I think permission to access ld-linux.so should be charged
      hello-dynamic program, for "hello-dynamic needs ld-linux.so" is not
      a fault of bash program.

  (5) The kernel overwrites the child process by "hello-dynamic".

  (6) The child process transits to "bash hello-dynamic" domain.

  (7) The "hello-dynamic" starts and finishes.

Case 3 -- Executing hello.sh from bash.

  (1) The bash process calls fork() and the child process requests
      do_execve("hello.sh").

  (2) The kernel checks "allow_execute hello.sh" from "bash" domain.

  (3) The kernel calculates "bash hello.sh" as the domain to transit to.

  (4) The kernel checks "allow_read /bin/sh" from "bash hello.sh" domain.
      I think permission to access /bin/sh should be charged hello.sh program,
      for "hello.sh needs /bin/sh" is not a fault of bash program.

  (5) The kernel overwrites the child process by "/bin/sh".

  (6) The child process transits to "bash hello.sh" domain.

  (7) The "/bin/sh" requests open("hello.sh").

  (8) The kernel checks "allow_read hello.sh" from  "bash hello.sh" domain.

  (9) The "/bin/sh" starts and finishes.

Whether a file is interpreted as a program or not depends on an application.
The kernel cannot know whether the file is interpreted as a program or not.
Thus, TOMOYO treats "hello-static" "hello-dynamic" "ld-linux.so" "hello.sh"
"/bin/sh" equally as merely files; no distinction between executable and
non-executable. Therefore, TOMOYO doesn't check DAC's execute permission.
TOMOYO checks "allow_read" permission instead.

Calling do_execve() is a bold gesture that an old program's instance (i.e.
current process) is ready to be overwritten by a new program and is ready to
transfer control to the new program. To split purview of programs, TOMOYO
requires "allow_execute" permission of the new program against the old
program's instance and performs domain transition. If do_execve() succeeds,
the old program is no longer responsible against the consequence of the new
program's behavior. Only the new program is responsible for all consequences.

But TOMOYO doesn't require "allow_read" permission of the new program.
If TOMOYO requires "allow_read" permission of the new program, TOMOYO will
allow an attacker (who hijacked the old program's instance) to open the new
program and steal data from the new program. Requiring "allow_read" permission
will widen purview of the old program.

Not requiring "allow_read" permission of the new program against the old
program's instance is my design for reducing purview of the old program.
To be able to know whether the current process is in do_execve() or not,
I want to add in_execve flag to "task_struct".

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 15:15:05 +11:00
Kentaro Takeda
26a2a1c9eb Domain transition handler.
This file controls domain creation/deletion/transition.

Every process belongs to a domain in TOMOYO Linux.
Domain transition occurs when execve(2) is called
and the domain is expressed as 'process invocation history',
such as '<kernel> /sbin/init /etc/init.d/rc'.
Domain information is stored in current->cred->security field.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 15:15:05 +11:00
Kentaro Takeda
b69a54ee58 File operation restriction part.
This file controls file related operations of TOMOYO Linux.

tomoyo/tomoyo.c calls the following six functions in this file.
Each function handles the following access types.

 * tomoyo_check_file_perm
sysctl()'s "read" and "write".

 * tomoyo_check_exec_perm
"execute".

 * tomoyo_check_open_permission
open(2) for "read" and "write".

 * tomoyo_check_1path_perm
"create", "unlink", "mkdir", "rmdir", "mkfifo",
"mksock", "mkblock", "mkchar", "truncate" and "symlink".

 * tomoyo_check_2path_perm
"rename" and "unlink".

 * tomoyo_check_rewrite_permission
"rewrite".
("rewrite" are operations which may lose already recorded data of a file,
i.e. open(!O_APPEND) || open(O_TRUNC) || truncate() || ftruncate())

The functions which actually checks ACLs are the following three functions.
Each function handles the following access types.
ACL directive is expressed by "allow_<access type>".

 * tomoyo_check_file_acl
Open() operation and execve() operation.
("read", "write", "read/write" and "execute")

 * tomoyo_check_single_write_acl
Directory modification operations with 1 pathname.
("create", "unlink", "mkdir", "rmdir", "mkfifo", "mksock",
 "mkblock", "mkchar", "truncate", "symlink" and "rewrite")

 * tomoyo_check_double_write_acl
Directory modification operations with 2 pathname.
("link" and "rename")

Also, this file contains handlers of some utility directives
for file related operations.

 * "allow_read":   specifies globally (for all domains) readable files.
 * "path_group":   specifies pathname macro.
 * "deny_rewrite": restricts rewrite operation.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 15:15:05 +11:00
Kentaro Takeda
9590837b89 Common functions for TOMOYO Linux.
This file contains common functions (e.g. policy I/O, pattern matching).

-------------------- About pattern matching --------------------

Since TOMOYO Linux is a name based access control, TOMOYO Linux seriously
considers "safe" string representation.

TOMOYO Linux's string manipulation functions make reviewers feel crazy,
but there are reasons why TOMOYO Linux needs its own string manipulation
functions.

----- Part 1 : preconditions -----

People definitely want to use wild card.

  To support pattern matching, we have to support wild card characters.

  In a typical Linux system, filenames are likely consists of only alphabets,
  numbers, and some characters (e.g. + - ~ . / ).
  But theoretically, the Linux kernel accepts all characters but NUL character
  (which is used as a terminator of a string).

    Some Linux systems can have filenames which contain * ? ** etc.

Therefore, we have to somehow modify string so that we can distinguish
wild card characters and normal characters.

  It might be possible for some application's configuration files to restrict
  acceptable characters.
  It is impossible for kernel to restrict acceptable characters.

    We can't accept approaches which will cause troubles for applications.

----- Part 2 : commonly used approaches -----

Text formatted strings separated by space character (0x20) and new line
character (0x0A) is more preferable for users over array of NUL-terminated
string.

  Thus, people use text formatted configuration files separated by space
  character and new line.

We sometimes need to handle non-printable characters.

  Thus, people use \ character (0x5C) as escape character and represent
  non-printable characters using octal or hexadecimal format.

At this point, we remind (at least) 3 approaches.

  (1) Shell glob style expression
  (2) POSIX regular expression (UNIX style regular expression)
  (3) Maverick wild card expression

On the surface, (1) and (2) sound good choices. But they have a big pitfall.
All meta-characters in (1) and (2) are legal characters for representing
a pathname, and users easily write incorrect expression. What is worse, users
unlikely notice incorrect expressions because characters used for regular
pathnames unlikely contain meta-characters. This incorrect use of
meta-characters in pathname representation reveals vulnerability
(e.g. unexpected results) only when irregular pathname is specified.

The authors of TOMOYO Linux think that approaches which adds some character
for interpreting meta-characters as normal characters (i.e. (1) and (2)) are
not suitable for security use.

Therefore, the authors of TOMOYO Linux propose (3).

----- Part 3: consideration points -----

We need to solve encoding problem.

  A single character can be represented in several ways using encodings.

    For Japanese language, there are "ShiftJIS", "ISO-2022-JP", "EUC-JP",
    "UTF-8" and more.

  Some languages (e.g. Japanese language) supports multi-byte characters
  (where a single character is represented using several bytes).

    Some multi-byte characters may match the escape character.

    For Japanese language, some characters in "ShiftJIS" encoding match
    \ character, and bothering Web's CGI developers.

  It is important that the kernel string is not bothered by encoding problem.

    Linus said, "I really would expect that kernel strings don't have
    an encoding. They're just C strings: a NUL-terminated stream of bytes."
    http://lkml.org/lkml/2007/11/6/142

    Yes. The kernel strings are just C strings.
    We are talking about how to store and carry "kernel strings" safely.

  If we store "kernel string" into policy file as-is, the "kernel string" will
  be interpreted differently depending on application's encoding settings.
  One application may interpret "kernel string" as "UTF-8",
  another application may interpret "kernel string" as "ShiftJIS".

    Therefore, we propose to represent strings using ASCII encoding.
    In this way, we are no longer bothered by encoding problems.

We need to avoid information loss caused by display.

  It is difficult to input and display non-printable characters, but we have to
  be able to handle such characters because the kernel string is a C string.

  If we use only ASCII printable characters (from 0x21 to 0x7E) and space
  character (0x20) and new line character (0x0A), it is easy to input from
  keyboard and display on all terminals which is running Linux.

  Therefore, we propose to represent strings using only characters which value
  is one of "from 0x21 to 0x7E", "0x20", "0x0A".

We need to consider ease of splitting strings from a line.

  If we use an approach which uses "\ " for representing a space character
  within a string, we have to count the string from the beginning to check
  whether this space character is accompanied with \ character or not.
  As a result, we cannot monotonically split a line using space character.

  If we use an approach which uses "\040" for representing a space character
  within a string, we can monotonically split a line using space character.

  If we use an approach which uses NUL character as a delimiter, we cannot
  use string manipulation functions for splitting strings from a line.

  Therefore, we propose that we represent space character as "\040".

We need to avoid wrong designations (incorrect use of special characters).

  Not all users can understand and utilize POSIX's regular expressions
  correctly and perfectly.

  If a character acts as a wild card by default, the user will get unexpected
  result if that user didn't know the meaning of that character.

    Therefore, we propose that all characters but \ character act as
    a normal character and let the user add \ character to make a character
    act as a wild card.

    In this way, users needn't to know all wild card characters beforehand.
    They can learn when they encountered an unseen wild card character
    for their first time.

----- Part 4: supported wild card expressions -----

At this point, we have wild card expressions listed below.

  +-----------+--------------------------------------------------------------+
  | Wild card | Meaning and example                                          |
  +-----------+--------------------------------------------------------------+
  |   \*      | More than or equals to 0 character other than '/'.           |
  |           |           /var/log/samba/\*                                  |
  +-----------+--------------------------------------------------------------+
  |   \@      | More than or equals to 0 character other than '/' or '.'.    |
  |           |           /var/www/html/\@.html                              |
  +-----------+--------------------------------------------------------------+
  |   \?      | 1 byte character other than '/'.                             |
  |           |           /tmp/mail.\?\?\?\?\?\?                             |
  +-----------+--------------------------------------------------------------+
  |   \$      | More than or equals to 1 decimal digit.                      |
  |           |           /proc/\$/cmdline                                   |
  +-----------+--------------------------------------------------------------+
  |   \+      | 1 decimal digit.                                             |
  |           |           /var/tmp/my_work.\+                                |
  +-----------+--------------------------------------------------------------+
  |   \X      | More than or equals to 1 hexadecimal digit.                  |
  |           |           /var/tmp/my-work.\X                                |
  +-----------+--------------------------------------------------------------+
  |   \x      | 1 hexadecimal digit.                                         |
  |           |           /tmp/my-work.\x                                    |
  +-----------+--------------------------------------------------------------+
  |   \A      | More than or equals to 1 alphabet character.                 |
  |           |           /var/log/my-work/\$-\A-\$.log                      |
  +-----------+--------------------------------------------------------------+
  |   \a      | 1 alphabet character.                                        |
  |           |           /home/users/\a/\*/public_html/\*.html              |
  +-----------+--------------------------------------------------------------+
  |   \-      | Pathname subtraction operator.                               |
  |           | +---------------------+------------------------------------+ |
  |           | | Example             | Meaning                            | |
  |           | +---------------------+------------------------------------+ |
  |           | | /etc/\*             | All files in /etc/ directory.      | |
  |           | +---------------------+------------------------------------+ |
  |           | | /etc/\*\-\*shadow\* | /etc/\* other than /etc/\*shadow\* | |
  |           | +---------------------+------------------------------------+ |
  |           | | /\*\-proc\-sys/     | /\*/ other than /proc/ /sys/       | |
  |           | +---------------------+------------------------------------+ |
  +-----------+--------------------------------------------------------------+

  +----------------+---------------------------------------------------------+
  | Representation | Meaning and example                                     |
  +----------------+---------------------------------------------------------+
  |   \\           | backslash character itself.                             |
  +----------------+---------------------------------------------------------+
  |   \ooo         | 1 byte character.                                       |
  |                | ooo is 001 <= ooo <= 040 || 177 <= ooo <= 377.          |
  |                |                                                         |
  |                |           \040 for space character.                     |
  |                |           \177 for del character.                       |
  |                |                                                         |
  +----------------+---------------------------------------------------------+

----- Part 5: Advantages -----

We can obtain extensibility.

  Since our proposed approach adds \ to a character to interpret as a wild
  card, we can introduce new wild card in future while maintaining backward
  compatibility.

We can process monotonically.

  Since our proposed approach separates strings using a space character,
  we can split strings using existing string manipulation functions.

We can reliably analyze access logs.

  It is guaranteed that a string doesn't contain space character (0x20) and
  new line character (0x0A).

  It is guaranteed that a string won't be converted by FTP and won't be damaged
  by a terminal's settings.

  It is guaranteed that a string won't be affected by encoding converters
  (except encodings which insert NUL character (e.g. UTF-16)).

----- Part 6: conclusion -----

TOMOYO Linux is using its own encoding with reasons described above.
There is a disadvantage that we need to introduce a series of new string
manipulation functions. But TOMOYO Linux's encoding is useful for all users
(including audit and AppArmor) who want to perform pattern matching and
safely exchange string information between the kernel and the userspace.

-------------------- About policy interface --------------------

TOMOYO Linux creates the following files on securityfs (normally
mounted on /sys/kernel/security) as interfaces between kernel and
userspace. These files are for TOMOYO Linux management tools *only*,
not for general programs.

  * profile
  * exception_policy
  * domain_policy
  * manager
  * meminfo
  * self_domain
  * version
  * .domain_status
  * .process_status

** /sys/kernel/security/tomoyo/profile **

This file is used to read or write profiles.

"profile" means a running mode of process. A profile lists up
functions and their modes in "$number-$variable=$value" format. The
$number is profile number between 0 and 255. Each domain is assigned
one profile. To assign profile to domains, use "ccs-setprofile" or
"ccs-editpolicy" or "ccs-loadpolicy" commands.

(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/profile
0-COMMENT=-----Disabled Mode-----
0-MAC_FOR_FILE=disabled
0-MAX_ACCEPT_ENTRY=2048
0-TOMOYO_VERBOSE=disabled
1-COMMENT=-----Learning Mode-----
1-MAC_FOR_FILE=learning
1-MAX_ACCEPT_ENTRY=2048
1-TOMOYO_VERBOSE=disabled
2-COMMENT=-----Permissive Mode-----
2-MAC_FOR_FILE=permissive
2-MAX_ACCEPT_ENTRY=2048
2-TOMOYO_VERBOSE=enabled
3-COMMENT=-----Enforcing Mode-----
3-MAC_FOR_FILE=enforcing
3-MAX_ACCEPT_ENTRY=2048
3-TOMOYO_VERBOSE=enabled

- MAC_FOR_FILE:
Specifies access control level regarding file access requests.
- MAX_ACCEPT_ENTRY:
Limits the max number of ACL entries that are automatically appended
during learning mode. Default is 2048.
- TOMOYO_VERBOSE:
Specifies whether to print domain policy violation messages or not.

** /sys/kernel/security/tomoyo/manager **

This file is used to read or append the list of programs or domains
that can write to /sys/kernel/security/tomoyo interface. By default,
only processes with both UID = 0 and EUID = 0 can modify policy via
/sys/kernel/security/tomoyo interface. You can use keyword
"manage_by_non_root" to allow policy modification by non root user.

(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/manager
/usr/lib/ccs/loadpolicy
/usr/lib/ccs/editpolicy
/usr/lib/ccs/setlevel
/usr/lib/ccs/setprofile
/usr/lib/ccs/ld-watch
/usr/lib/ccs/ccs-queryd

** /sys/kernel/security/tomoyo/exception_policy **

This file is used to read and write system global settings. Each line
has a directive and operand pair. Directives are listed below.

- initialize_domain:
To initialize domain transition when specific program is executed,
use initialize_domain directive.
  * initialize_domain "program" from "domain"
  * initialize_domain "program" from "the last program part of domain"
  * initialize_domain "program"
If the part "from" and after is not given, the entry is applied to
all domain. If the "domain" doesn't start with "<kernel>", the entry
is applied to all domain whose domainname ends with "the last program
part of domain".
This directive is intended to aggregate domain transitions for daemon
program and program that are invoked by the kernel on demand, by
transiting to different domain.

- keep_domain
To prevent domain transition when program is executed from specific
domain, use keep_domain directive.
  * keep_domain "program" from "domain"
  * keep_domain "program" from "the last program part of domain"
  * keep_domain "domain"
  * keep_domain "the last program part of domain"
If the part "from" and before is not given, this entry is applied to
all program. If the "domain" doesn't start with "<kernel>", the entry
is applied to all domain whose domainname ends with "the last program
part of domain".
This directive is intended to reduce total number of domains and
memory usage by suppressing unneeded domain transitions.
To declare domain keepers, use keep_domain directive followed by
domain definition.
Any process that belongs to any domain declared with this directive,
the process stays at the same domain unless any program registered
with initialize_domain directive is executed.

In order to control domain transition in detail, you can use
no_keep_domain/no_initialize_domain keywrods.

- alias:
To allow executing programs using the name of symbolic links, use
alias keyword followed by dereferenced pathname and reference
pathname. For example, /sbin/pidof is a symbolic link to
/sbin/killall5 . In normal case, if /sbin/pidof is executed, the
domain is defined as if /sbin/killall5 is executed. By specifying
"alias /sbin/killall5 /sbin/pidof", you can run /sbin/pidof in the
domain for /sbin/pidof .
(Example)
alias /sbin/killall5 /sbin/pidof

- allow_read:
To grant unconditionally readable permissions, use allow_read keyword
followed by canonicalized file. This keyword is intended to reduce
size of domain policy by granting read access to library files such
as GLIBC and locale files. Exception is, if ignore_global_allow_read
keyword is given to a domain, entries specified by this keyword are
ignored.
(Example)
allow_read /lib/libc-2.5.so

- file_pattern:
To declare pathname pattern, use file_pattern keyword followed by
pathname pattern. The pathname pattern must be a canonicalized
Pathname. This keyword is not applicable to neither granting execute
permissions nor domain definitions.
For example, canonicalized pathname that contains a process ID
(i.e. /proc/PID/ files) needs to be grouped in order to make access
control work well.
(Example)
file_pattern /proc/\$/cmdline

- path_group
To declare pathname group, use path_group keyword followed by name of
the group and pathname pattern. For example, if you want to group all
files under home directory, you can define
   path_group HOME-DIR-FILE /home/\*/\*
   path_group HOME-DIR-FILE /home/\*/\*/\*
   path_group HOME-DIR-FILE /home/\*/\*/\*/\*
in the exception policy and use like
   allow_read @HOME-DIR-FILE
to grant file access permission.

- deny_rewrite:
To deny overwriting already written contents of file (such as log
files) by default, use deny_rewrite keyword followed by pathname
pattern. Files whose pathname match the patterns are not permitted to
open for writing without append mode or truncate unless the pathnames
are explicitly granted using allow_rewrite keyword in domain policy.
(Example)
deny_rewrite /var/log/\*

- aggregator
To deal multiple programs as a single program, use aggregator keyword
followed by name of original program and aggregated program. This
keyword is intended to aggregate similar programs.
For example, /usr/bin/tac and /bin/cat are similar. By specifying
"aggregator /usr/bin/tac /bin/cat", you can run /usr/bin/tac in the
domain for /bin/cat .
For example, /usr/sbin/logrotate for Fedora Core 3 generates programs
like /tmp/logrotate.\?\?\?\?\?\? and run them, but TOMOYO Linux
doesn't allow using patterns for granting execute permission and
defining domains. By specifying
"aggregator /tmp/logrotate.\?\?\?\?\?\? /tmp/logrotate.tmp", you can
run /tmp/logrotate.\?\?\?\?\?\? as if /tmp/logrotate.tmp is running.

** /sys/kernel/security/tomoyo/domain_policy **

This file contains definition of all domains and permissions that are
granted to each domain.

Lines from the next line to a domain definition ( any lines starting
with "<kernel>") to the previous line to the next domain definitions
are interpreted as access permissions for that domain.

** /sys/kernel/security/tomoyo/meminfo **

This file is to show the total RAM used to keep policy in the kernel
by TOMOYO Linux in bytes.
(Example)
[root@tomoyo]# cat /sys/kernel/security/tomoyo/meminfo
Shared:       61440
Private:      69632
Dynamic:        768
Total:       131840

You can set memory quota by writing to this file.
(Example)
[root@tomoyo]# echo Shared: 2097152 > /sys/kernel/security/tomoyo/meminfo
[root@tomoyo]# echo Private: 2097152 > /sys/kernel/security/tomoyo/meminfo

** /sys/kernel/security/tomoyo/self_domain **

This file is to show the name of domain the caller process belongs to.
(Example)
[root@etch]# cat /sys/kernel/security/tomoyo/self_domain
<kernel> /usr/sbin/sshd /bin/zsh /bin/cat

** /sys/kernel/security/tomoyo/version **

This file is used for getting TOMOYO Linux's version.
(Example)
[root@etch]# cat /sys/kernel/security/tomoyo/version
2.2.0-pre

** /sys/kernel/security/tomoyo/.domain_status **

This is a view (of a DBMS) that contains only profile number and
domainnames of domain so that "ccs-setprofile" command can do
line-oriented processing easily.

** /sys/kernel/security/tomoyo/.process_status **

This file is used by "ccs-ccstree" command to show "list of processes
currently running" and "domains which each process belongs to" and
"profile number which the domain is currently assigned" like "pstree"
command. This file is writable by programs that aren't registered as
policy manager.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 15:15:04 +11:00
Kentaro Takeda
c73bd6d473 Memory and pathname management functions.
TOMOYO Linux performs pathname based access control.
To remove factors that make pathname based access control difficult
(e.g. symbolic links, "..", "//" etc.), TOMOYO Linux derives realpath
of requested pathname from "struct dentry" and "struct vfsmount".

The maximum length of string data is limited to 4000 including trailing '\0'.
Since TOMOYO Linux uses '\ooo' style representation for non ASCII printable
characters, maybe TOMOYO Linux should be able to support 16336 (which means
(NAME_MAX * (PATH_MAX / (NAME_MAX + 1)) * 4 + (PATH_MAX / (NAME_MAX + 1)))
including trailing '\0'), but I think 4000 is enough for practical use.

TOMOYO uses only 0x21 - 0x7E (as printable characters) and 0x20 (as word
delimiter) and 0x0A (as line delimiter).
0x01 - 0x20 and 0x80 - 0xFF is handled in \ooo style representation.
The reason to use \ooo is to guarantee that "%s" won't damage logs.
Userland program can request

 open("/tmp/file granted.\nAccess /tmp/file ", O_WRONLY | O_CREAT, 0600)

and logging such crazy pathname using "Access %s denied.\n" format will cause
"fabrication of logs" like

 Access /tmp/file granted.
 Access /tmp/file denied.

TOMOYO converts such characters to \ooo so that the logs will become

 Access /tmp/file\040granted.\012Access\040/tmp/file denied.

and the administrator can read the logs safely using /bin/cat .
Likewise, a crazy request like

 open("/tmp/\x01\x02\x03\x04\x05\x06\x07\x08\x09", O_WRONLY | O_CREAT, 0600)

will be processed safely by converting to

 Access /tmp/\001\002\003\004\005\006\007\010\011 denied.

Signed-off-by: Kentaro Takeda <takedakn@nttdata.co.jp>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Toshiharu Harada <haradats@nttdata.co.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-02-12 15:15:04 +11:00