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[PATCH v3 00/11] Smack namespace

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  [PATCH v3 00/11] Smack namespace Lukasz Pawelczyk <l.pawelczyk@samsung.com> - 2015-07-24 12:10 +0200
    [PATCH v3 11/11] smack: documentation for the Smack namespace Lukasz Pawelczyk <l.pawelczyk@samsung.com> - 2015-07-24 12:10 +0200
      Re: [PATCH v3 11/11] smack: documentation for the Smack namespace "Serge E. Hallyn" <serge@hallyn.com> - 2015-07-30 21:20 +0200
    [PATCH v3 06/11] smack: don't use implicit star to display  smackfs/syslog Lukasz Pawelczyk <l.pawelczyk@samsung.com> - 2015-07-24 12:10 +0200
    [PATCH v3 07/11] smack: abstraction layer for 2 common Smack operations Lukasz Pawelczyk <l.pawelczyk@samsung.com> - 2015-07-24 12:10 +0200

#1191670 — [PATCH v3 00/11] Smack namespace

Third version of Smack namespace. Changes here are mostly because of
Stephen Smalley's review:

https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg899383.html
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg898638.html

1. the label map should be in /proc/.../attr/label_map and be handled
   generically.
2. The proper file system label (unmapped) should be written only once
   to remove a state where an incorrect label is on the filesystem.

Ad 1: Contrary to what Stephen said this unfortunately required LSM
modifications.

For reading: the map can be long, in principle longer than PAGE_SIZE to
which normal getprocattr hook is limited. So I invented a way for
getprocattr to be handled by seq operations. I think it is generic and
can be reused nicely by other LSMs. Also it doesn't break current LSM
code in any way. This created a new patch.

For writing: the default setprocattr arguments were not enough for me
to securely decide if the write access should be granted. To be in
parallel with user namespace I also needed credentials of the process
that actually opened the map (in addition to current). So I added a new
argument. This is also a new patch.

Ad 2: I really tried to make it work without introducing a new LSM
hook but changing a little semantics behind the current ones. Finally
I just added a simple inode_pre_setxattr hook that can swap the label
before it is written to the filesystem.  Hopefully this is ok. I
couldn't do this in inode_setxattr hook as Stephen suggested as this
hook is called before __vfs_setxattr_noperm which is an exported
symbol and is used sometimes without setxattr hence the logic had to
be inside that one. This is also a new patch.

I also added a new patch that "fixes" smackfs/syslog. I've noticed that
inside a namespace when I cat the file it shows "*". Even when I
remapped the star. After looking at the code it had it implicitly
displayed when it's not set. There were few problems with it:

1. In a namespace we can see a label that is not mapped.
2. There was no way to actually reset the value to default (NULL)
3. It was inconsistent from user space point of view:

# cat /smack/syslog
*

After the reboot the syslog hook doesn't limit anything, the
smack_syslog_label is NULL, but it displays star.

# echo '*' > /smack/syslog
# cat /smack/syslog
*

From user space POV this is the same, file has star inside, but now for
the hook to pass the current needs to be star as well. And there is no
way to reset it back to NULL. So I treated syslog file the same way
unconfined and onlycap are handled. If it's empty, there is no label
set, hook doesn't limit anything (except for the cap). When it's filled
current needs to be equal for the hook to pass (as was before). But now
it can be reset back to NULL by writing EINVAL value (e.g. -syslog).
The syslog hook itself was not modified, only the file handling.

Changes from v2:
- fix for config ifdefs in user_ns LSM hooks patch (CONFIG_USER_NS
  should've been used instead of CONFIG_SECURITY in several places)
- new patch for "smack_map" -> "attr/label_map" and new related
  getprocattr_seq lsm hook. With this change the code in further
  patches for handling smack_map has been moved to this new method
- new patch for setprocattr hook new argument, file's opener creds
- new patch for inode_pre_setxattr LSM hook
- new patch related to handling smackfs/syslog

Changes from v1:
- "kernel/exit.c: make sure current's nsproxy != NULL while checking
  caps" patch has been dropped
- fixed the title of the user_ns operations patch

Lukasz Pawelczyk (11):
  user_ns: 3 new LSM hooks for user namespace operations
  lsm: /proc/$PID/attr/label_map file and getprocattr_seq hook
  lsm: add file opener's cred to a setprocattr arguments
  lsm: inode_pre_setxattr hook
  smack: extend capability functions and fix 2 checks
  smack: don't use implicit star to display smackfs/syslog
  smack: abstraction layer for 2 common Smack operations
  smack: misc cleanups in preparation for a namespace patch
  smack: namespace groundwork
  smack: namespace implementation
  smack: documentation for the Smack namespace

 Documentation/security/00-INDEX            |   2 +
 Documentation/security/Smack-namespace.txt | 231 +++++++++++
 MAINTAINERS                                |   1 +
 fs/proc/base.c                             |  83 +++-
 fs/xattr.c                                 |  10 +
 include/linux/lsm_hooks.h                  |  70 +++-
 include/linux/security.h                   |  49 ++-
 include/linux/user_namespace.h             |   4 +
 kernel/user.c                              |   3 +
 kernel/user_namespace.c                    |  18 +
 security/apparmor/lsm.c                    |   5 +-
 security/security.c                        |  54 ++-
 security/selinux/hooks.c                   |   2 +-
 security/smack/Kconfig                     |  12 +
 security/smack/Makefile                    |   1 +
 security/smack/smack.h                     | 125 +++++-
 security/smack/smack_access.c              | 262 ++++++++++--
 security/smack/smack_lsm.c                 | 615 +++++++++++++++++++++--------
 security/smack/smack_ns.c                  | 443 +++++++++++++++++++++
 security/smack/smackfs.c                   | 188 +++++----
 20 files changed, 1892 insertions(+), 286 deletions(-)
 create mode 100644 Documentation/security/Smack-namespace.txt
 create mode 100644 security/smack/smack_ns.c

-- 
2.4.3

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#1191671 — [PATCH v3 11/11] smack: documentation for the Smack namespace

Adds Documentation/smack-namespace.txt.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
---
 Documentation/security/00-INDEX            |   2 +
 Documentation/security/Smack-namespace.txt | 231 +++++++++++++++++++++++++++++
 MAINTAINERS                                |   1 +
 security/smack/Kconfig                     |   2 +
 4 files changed, 236 insertions(+)
 create mode 100644 Documentation/security/Smack-namespace.txt

diff --git a/Documentation/security/00-INDEX b/Documentation/security/00-INDEX
index 45c82fd..c03a220 100644
--- a/Documentation/security/00-INDEX
+++ b/Documentation/security/00-INDEX
@@ -6,6 +6,8 @@ SELinux.txt
 	- how to get started with the SELinux security enhancement.
 Smack.txt
 	- documentation on the Smack Linux Security Module.
+Smack-namespace.txt
+	- documentation on the Smack namespace implementation.
 Yama.txt
 	- documentation on the Yama Linux Security Module.
 apparmor.txt
diff --git a/Documentation/security/Smack-namespace.txt b/Documentation/security/Smack-namespace.txt
new file mode 100644
index 0000000..120314d
--- /dev/null
+++ b/Documentation/security/Smack-namespace.txt
@@ -0,0 +1,231 @@
+
+                                      "Quis custodiet ipsos custodes?"
+                                                 - Satires of Juvenal
+
+
+--- What is a Smack namespace ---
+
+Smack namespace was developed to make it possible for Smack to work
+nicely with Linux containers where there is a full operating system
+with its own init inside the namespace. Such a system working with
+Smack expects to have at least partially working SMACK_MAC_ADMIN to be
+able to change labels of processes and files. This is required to be
+able to securely start applications under the control of Smack and
+manage their access rights.
+
+It was implemented using new LSM hooks added to the user namespace
+that were developed together with Smack namespace.
+
+
+--- Design ideas ---
+
+"Smack namespace" is rather "Smack labels namespace" as not the whole
+MAC is namespaced, only the labels. There is a great analogy between
+Smack labels namespace and the user namespace part that remaps UIDs.
+
+The idea is to create a map of labels for a namespace so the namespace
+is only allowed to use those labels. Smack rules are always the same
+as in the init namespace (limited only by what labels are mapped) and
+cannot be manipulated from the child namespace. The map is actually
+only for labels' names. The underlying structures for labels remain
+the same. The filesystem also stores the "unmapped" labels from the
+init namespace.
+
+Let's say we have those labels in the init namespace:
+label1
+label2
+label3
+
+and those rules:
+label1 label2 rwx
+label1 label3 rwx
+label2 label3 rwx
+
+We create a map for a namespace:
+label1 -> mapped1
+label2 -> mapped2
+
+This means that 'label3' is completely invisible in the namespace. As if
+it didn't exist. All the rules that include it are ignored.
+
+Effectively in the namespace we have only one rule:
+mapped1 mapped2 rwx
+
+Which in reality is:
+label1 label2 rwx
+
+All requests to access an object with a 'label3' will be denied. If it
+ever comes to a situation where 'label3' would have to be printed
+(e.g. reading an exec or mmap label from a file to which we have
+access) then huh sign '?' will be printed instead.
+
+All the operations in the namespace on the remaining labels will have
+to be performed using their mapped names. Things like changing own
+process's label, changing filesystem label. Labels will also be
+printed with their mapped names.
+
+You cannot import new labels in a namespace. Every operation that
+would do so in an init namespace will return an error in the child
+namespace. You cannot assign an unmapped or not existing label to an
+object. You can only operate on labels that have been explicitly
+mapped.
+
+
+--- Capabilities ---
+
+Enabling Smack related capabilities (CAP_MAC_ADMIN and
+CAP_MAC_OVERRIDE) is main goal of Smack namespace, so it can work
+properly in the container. And those capabilities do work to some
+extent. In several places where capabilities are checked compatibility
+with Smack namespace has been introduced. Capabilities are of course
+limited to operate only on mapped labels.
+
+CAP_MAC_OVERRIDE works fully, will allow you to ignore Smack access
+rules, but only between objects that have labels mapped. So in the
+example above having this CAP will allow e.g. label2 to write to
+label1, but will not allow any access to label3.
+
+With CAP_MAC_ADMIN the following operations has been allowed inside
+the namespace:
+- setting and removing xattr on files, including the security.* ones
+- setting process's own label (/proc/self/attr/current)
+- mounting in a privileged Smack mode, which means one can specify
+  additional mount options like: smackfsdef, smackfsfloor etc.
+
+Again this is also allowed only on the mapped labels. Labels on the
+filesystem will be stored in unmapped form so they are preserved
+through reboots.
+
+Such a namespace construct allows e.g. systemd (with Smack support)
+working in a container to assign labels properly to daemons and other
+processes.
+
+
+--- Usage ---
+
+Smack namespace is written using LSM hooks inside user namespace. That
+means it's connected to it.
+
+To create a new Smack namespace you need to unshare() user namespace
+as usual. If that is all you do though, than there is no difference to
+what is now. To activate the Smack namespace you need to fill the
+labels' map. It is in a file /proc/$PID/attr/label_map.
+
+By default the map is empty and Smack namespaces are inactive (labels
+are taken directly from a parent namespace). It also means that the
+Smack capabilities will be inactive. After you fill the map it starts
+to take effect in the namespace and Smack capabilities (only on mapped
+labels) start to work.
+
+Due to the way Smack works only CAP_MAC_ADMIN from the parent
+namespace (init_user_ns for now, see the "Current limitations" below)
+is allowed to fill the map. That means that an unprivileged user is
+still allowed to create the user namespace but it will not be able to
+fill the labels' map (activate Smack namespace). An administrator
+intervention is required.
+
+The attr_map write format is:
+unmapped_label mapped_label
+
+When reading the file it shows an active map for a namespace the
+process in question is in in the format:
+unmapped_label -> mapped_label
+
+If the label_map file is empty it means the namespace is not mapped
+and Smack namespace is inactive (no mappings, MAC related capabilities
+behave as they did before, meaning they are active only in
+init_user_ns). For init_user_ns the map will always be empty.
+
+Writing to the map file is not disabled after the first write as it is
+in uid_map. For Smack we have no means to map ranges of labels, hence
+it can really be advantageous to be able to expand the map later
+on. But you can only add to the map. You cannot remove already mapped
+labels. You cannot change the already existing mappings. Also mappings
+has to be 1-1. All requests to create a map where either the unmapped
+or the mapped label already exists in the map will be denied.
+
+setns() with Smack namespace active has an additional check that the
+label of a process that is calling setns() has to be already mapped in
+the target Smack namespace for the call to succeed.
+
+
+--- Special labels ---
+
+Smack is using some special labels that have built-in rules. Things
+like floor '_', dash '^', star '*', etc. Those labels are not
+automatically mapped to the namespace. Moreover, you can choose to map
+a different label from the init namespace to behave e.g. like floor
+inside the namespace.
+
+Let's say we have no rules and those labels in the init namespace:
+_
+floor_to_be
+label
+
+Both 'label' and 'floor_to_be' can read objects with '_'. But they
+have no access rights to each other.
+
+Now let's create a map like this:
+_             ordinary_label
+floor_to_be   _
+label         mapped
+
+Right now label 'mapped' can read label '_' which means that
+effectively inside this namespace label 'label' has gained read access
+to the 'floor_to_be'. The label 'ordinary_label' is exactly it, an
+ordinary label that the built-in rules no longer apply to inside the
+namespace.
+
+To sum up, special labels in the namespace behave the same as in the
+init namespace. Not the original special labels though, but the ones
+we map to specials. This is the only case where a namespace can have
+access rights the init namespace does not have (like the 'label' to
+'floor_to_be' in the example above).
+
+Of course mappings like these are perfectly legal:
+_   _
+*   *
+^   ^
+
+
+--- Current limitations ---
+
+The Smack namespace is not hierarchical yet. It is currently not
+possible to fill a label_map of a nested user namespace (you can still
+create nested user namespace, it will just inherit its parent's map
+and won't have active Smack capabilities). When hierarchy will be
+implemented the process creating another namespace will be allowed to
+map only labels that it has permission to itself (those that it has in
+its own map).
+
+Special files inside the virtual smackfs needs to be reviewed whether
+it's beneficial to have some of their functionality namespaced as well
+(e.g. onlycap, syslog. ambient, etc). This would increase
+CAP_MAC_ADMIN privileges inside the namespace.
+
+
+--- Error codes ---
+
+While working in the namespace patches the error codes has been made
+to propagate properly from a place they occurred. New error codes has
+also been introduced for Smack in the context of namespace usage. This
+is a complete summary of error codes used throughout the Smack now:
+
+ENOMEM      and other system errors that might come from low level
+            kernel functions like memory allocations
+EOPNOTSUPP  means the underlying system operation is not
+            supported (eg. getxattr)
+EINVAL      means invalid syntax (e.g. empty label or one starting
+            with '-')
+EEXIST      when creating map means that a label is already mapped
+EBADR       is used for wrong namespace usage:
+            - trying to import a label inside a namespace (like trying
+              to use an unmapped label that would otherwise be imported)
+            - trying to create a Smack label map in the init namespace
+ENOENT      when failed to find a label we expected to exist (will not
+            be propagated to user-space)
+EPERM       means no permission to operate on an object, e.g. due to
+            insufficient capabilities or simply because the object
+	    cannot be operated on in the current context
+EACCESS     when access has been denied due to Smack access checks
+            (including object being outside of a namespace)
diff --git a/MAINTAINERS b/MAINTAINERS
index a226416..6effb1a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9377,6 +9377,7 @@ W:	http://schaufler-ca.com
 T:	git git://git.gitorious.org/smack-next/kernel.git
 S:	Maintained
 F:	Documentation/security/Smack.txt
+F:	Documentation/security/Smack-namespace.txt
 F:	security/smack/
 
 DRIVERS FOR ADAPTIVE VOLTAGE SCALING (AVS)
diff --git a/security/smack/Kconfig b/security/smack/Kconfig
index b19a7fb..a6e0f3f 100644
--- a/security/smack/Kconfig
+++ b/security/smack/Kconfig
@@ -49,4 +49,6 @@ config SECURITY_SMACK_NS
 	  This enables Smack namespace that makes it possible to map
 	  specific labels within user namespace (analogously to mapping
 	  UIDs) and to gain MAC capabilities over them.
+	  Documentation is availabile here:
+	  Documentation/security/Smack-namespace.txt
 	  If you are unsure how to answer this question, answer N.
-- 
2.4.3

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#1196382 — Re: [PATCH v3 11/11] smack: documentation for the Smack namespace

On Wed, Jul 29, 2015 at 07:05:19PM +0200, Lukasz Pawelczyk wrote:
> > Anyway, if this patchset is simply about making smack work in user_ns
> > at all, I'll reread with that in mind :)
> 
> Would appreciate.

Ok - thanks for your patience.  I "get" it now.  Will go back to the
actual patches and review hopefully tonight and monday.

thanks,
-serge
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#1191672 — [PATCH v3 06/11] smack: don't use implicit star to display smackfs/syslog

Smackfs/syslog is analogous to onlycap and unconfined. When not filled
they don't do anything. In such cases onlycap and unconfined displayed
nothing when read, but syslog unconditionally displayed star. This
doesn't work well with namespaces where the star could have been
unmapped. Besides the meaning of this star was different then a star
that could be written to this file. This was misleading.

This also brings syslog read/write functions on par with onlycap and
unconfined where it is possible to reset the value to NULL as should be
possible according to comment in smackfs.c describing smack_syslog_label
variable.

Before that the initial state was to allow (smack_syslog_label was
NULL), but after writing star to it the current had to be labeled star
as well to have an access, even thought reading the smackfs/syslog
returned the same result in both cases.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
---
 security/smack/smackfs.c | 42 +++++++++++++++++++++++++++---------------
 1 file changed, 27 insertions(+), 15 deletions(-)

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 81a2888..89f847bba 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -2362,23 +2362,20 @@ static const struct file_operations smk_change_rule_ops = {
 static ssize_t smk_read_syslog(struct file *filp, char __user *buf,
 				size_t cn, loff_t *ppos)
 {
-	struct smack_known *skp;
+	char *smack = "";
 	ssize_t rc = -EINVAL;
 	int asize;
 
 	if (*ppos != 0)
 		return 0;
 
-	if (smack_syslog_label == NULL)
-		skp = &smack_known_star;
-	else
-		skp = smack_syslog_label;
+	if (smack_syslog_label != NULL)
+		smack = smack_syslog_label->smk_known;
 
-	asize = strlen(skp->smk_known) + 1;
+	asize = strlen(smack) + 1;
 
 	if (cn >= asize)
-		rc = simple_read_from_buffer(buf, cn, ppos, skp->smk_known,
-						asize);
+		rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
 
 	return rc;
 }
@@ -2406,16 +2403,31 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
 	if (data == NULL)
 		return -ENOMEM;
 
-	if (copy_from_user(data, buf, count) != 0)
+	if (copy_from_user(data, buf, count) != 0) {
 		rc = -EFAULT;
-	else {
-		skp = smk_import_entry(data, count);
-		if (IS_ERR(skp))
-			rc = PTR_ERR(skp);
-		else
-			smack_syslog_label = skp;
+		goto freeout;
 	}
 
+	/*
+	 * Clear the smack_syslog_label on invalid label errors. This means
+	 * that we can pass a null string to unset the syslog value.
+	 *
+	 * Importing will also reject a label beginning with '-',
+	 * so "-syslog" will also work.
+	 *
+	 * But do so only on invalid label, not on system errors.
+	 */
+	skp = smk_import_entry(data, count);
+	if (PTR_ERR(skp) == -EINVAL)
+		skp = NULL;
+	else if (IS_ERR(skp)) {
+		rc = PTR_ERR(skp);
+		goto freeout;
+	}
+
+	smack_syslog_label = skp;
+
+freeout:
 	kfree(data);
 	return rc;
 }
-- 
2.4.3

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#1191674 — [PATCH v3 07/11] smack: abstraction layer for 2 common Smack operations

This patch adds two new functions that provide an abstraction layer for
two common internal Smack operations:

smk_find_label_name() - returns a label name (char*) from a struct
                        smack_known pointer
smk_get_label()       - either finds or imports a label from a raw label
                        name (char*) and returns struct smack_known
                        pointer

This patch also simplifies some pieces of code due to addition of those
2 functions (e.g. smack_inode_post_setxattr, smk_fill_rule,
smk_write_revoke_subj).

It is meant as a preparation for namespaces patches. Those 2 functions
will serve as entry points for namespace operations.

This patch should not change the Smack behaviour in any way.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@samsung.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/smack/smack.h        |   2 +
 security/smack/smack_access.c |  41 +++++++++++++
 security/smack/smack_lsm.c    |  76 ++++++++++++------------
 security/smack/smackfs.c      | 131 +++++++++++++++++++++++-------------------
 4 files changed, 154 insertions(+), 96 deletions(-)

diff --git a/security/smack/smack.h b/security/smack/smack.h
index e11cc13..1e225b0 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -278,6 +278,8 @@ int smack_has_ns_privilege(struct task_struct *task,
 int smack_has_privilege(struct task_struct *task, int cap);
 int smack_ns_privileged(struct user_namespace *user_ns, int cap);
 int smack_privileged(int cap);
+char *smk_find_label_name(struct smack_known *skp);
+struct smack_known *smk_get_label(const char *string, int len, bool import);
 
 /*
  * Shared data.
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 188b354..eb7c1cc 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -710,3 +710,44 @@ int smack_privileged(int cap)
 {
 	return smack_ns_privileged(&init_user_ns, cap);
 }
+
+/**
+ * smk_find_label_name - A helper to get a string value of a label
+ * @skp: a label we want a string value from
+ *
+ * Returns a pointer to a label name or NULL if label name not found.
+ */
+char *smk_find_label_name(struct smack_known *skp)
+{
+	return skp->smk_known;
+}
+
+/**
+ * smk_get_label - A helper to get the smack_known value from a string using
+ *                 either import or find functions if it already exists
+ * @string: a name of a label we look for or want to import
+ * @len: the string size, or zero if it is NULL terminated
+ * @import: whether we should import the label if not found
+ *
+ * Returns a smack_known label that is either imported or found.
+ * NULL if label not found (only when import == false).
+ * Error code otherwise.
+ */
+struct smack_known *smk_get_label(const char *string, int len, bool import)
+{
+	struct smack_known *skp;
+	char *cp;
+
+	if (import) {
+		skp = smk_import_entry(string, len);
+	} else {
+		cp = smk_parse_smack(string, len);
+		if (IS_ERR(cp))
+			return ERR_CAST(cp);
+
+		skp = smk_find_entry(cp);
+		kfree(cp);
+	}
+
+	return skp;
+}
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 6098518..8fe6ccc 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -742,31 +742,31 @@ static int smack_set_mnt_opts(struct super_block *sb,
 	for (i = 0; i < num_opts; i++) {
 		switch (opts->mnt_opts_flags[i]) {
 		case FSDEFAULT_MNT:
-			skp = smk_import_entry(opts->mnt_opts[i], 0);
+			skp = smk_get_label(opts->mnt_opts[i], 0, true);
 			if (IS_ERR(skp))
 				return PTR_ERR(skp);
 			sp->smk_default = skp;
 			break;
 		case FSFLOOR_MNT:
-			skp = smk_import_entry(opts->mnt_opts[i], 0);
+			skp = smk_get_label(opts->mnt_opts[i], 0, true);
 			if (IS_ERR(skp))
 				return PTR_ERR(skp);
 			sp->smk_floor = skp;
 			break;
 		case FSHAT_MNT:
-			skp = smk_import_entry(opts->mnt_opts[i], 0);
+			skp = smk_get_label(opts->mnt_opts[i], 0, true);
 			if (IS_ERR(skp))
 				return PTR_ERR(skp);
 			sp->smk_hat = skp;
 			break;
 		case FSROOT_MNT:
-			skp = smk_import_entry(opts->mnt_opts[i], 0);
+			skp = smk_get_label(opts->mnt_opts[i], 0, true);
 			if (IS_ERR(skp))
 				return PTR_ERR(skp);
 			sp->smk_root = skp;
 			break;
 		case FSTRANS_MNT:
-			skp = smk_import_entry(opts->mnt_opts[i], 0);
+			skp = smk_get_label(opts->mnt_opts[i], 0, true);
 			if (IS_ERR(skp))
 				return PTR_ERR(skp);
 			sp->smk_root = skp;
@@ -1284,7 +1284,7 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name,
 		rc = -EPERM;
 
 	if (rc == 0 && check_import) {
-		skp = size ? smk_import_entry(value, size) : NULL;
+		skp = size ? smk_get_label(value, size, true) : NULL;
 		if (IS_ERR(skp))
 			rc = PTR_ERR(skp);
 		else if (skp == NULL || (check_star &&
@@ -1318,6 +1318,7 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
 				      const void *value, size_t size, int flags)
 {
 	struct smack_known *skp;
+	struct smack_known **skpp = NULL;
 	struct inode_smack *isp = d_backing_inode(dentry)->i_security;
 
 	if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
@@ -1325,27 +1326,21 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
 		return;
 	}
 
-	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
-		skp = smk_import_entry(value, size);
-		if (!IS_ERR(skp))
-			isp->smk_inode = skp;
-		else
-			isp->smk_inode = &smack_known_invalid;
-	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
-		skp = smk_import_entry(value, size);
-		if (!IS_ERR(skp))
-			isp->smk_task = skp;
-		else
-			isp->smk_task = &smack_known_invalid;
-	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
-		skp = smk_import_entry(value, size);
+	if (strcmp(name, XATTR_NAME_SMACK) == 0)
+		skpp = &isp->smk_inode;
+	else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
+		skpp = &isp->smk_task;
+	else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
+		skpp = &isp->smk_mmap;
+
+	if (skpp) {
+		skp = smk_get_label(value, size, true);
+
 		if (!IS_ERR(skp))
-			isp->smk_mmap = skp;
+			*skpp = skp;
 		else
-			isp->smk_mmap = &smack_known_invalid;
+			*skpp = &smack_known_invalid;
 	}
-
-	return;
 }
 
 /**
@@ -1439,15 +1434,17 @@ static int smack_inode_getsecurity(const struct inode *inode,
 	struct socket *sock;
 	struct super_block *sbp;
 	struct inode *ip = (struct inode *)inode;
-	struct smack_known *isp;
-	int ilen;
+	struct smack_known *isp = NULL;
 	int rc = 0;
 
-	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
+	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
 		isp = smk_of_inode(inode);
-		ilen = strlen(isp->smk_known);
-		*buffer = isp->smk_known;
-		return ilen;
+
+	if (isp) {
+		*buffer = smk_find_label_name(isp);
+		if (*buffer == NULL)
+			*buffer = smack_known_huh.smk_known;
+		return strlen(*buffer);
 	}
 
 	/*
@@ -1470,10 +1467,11 @@ static int smack_inode_getsecurity(const struct inode *inode,
 	else
 		return -EOPNOTSUPP;
 
-	ilen = strlen(isp->smk_known);
 	if (rc == 0) {
-		*buffer = isp->smk_known;
-		rc = ilen;
+		*buffer = smk_find_label_name(isp);
+		if (*buffer == NULL)
+			*buffer = smack_known_huh.smk_known;
+		rc = strlen(*buffer);
 	}
 
 	return rc;
@@ -3429,7 +3427,10 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
 	if (strcmp(name, "current") != 0)
 		return -EINVAL;
 
-	cp = kstrdup(skp->smk_known, GFP_KERNEL);
+	cp = smk_find_label_name(skp);
+	if (cp == NULL)
+		cp = smack_known_huh.smk_known;
+	cp = kstrdup(cp, GFP_KERNEL);
 	if (cp == NULL)
 		return -ENOMEM;
 
@@ -3473,7 +3474,7 @@ static int smack_setprocattr(struct task_struct *p, const struct cred *f_cred,
 	if (strcmp(name, "current") != 0)
 		return -EINVAL;
 
-	skp = smk_import_entry(value, size);
+	skp = smk_get_label(value, size, true);
 	if (IS_ERR(skp))
 		return PTR_ERR(skp);
 
@@ -4201,7 +4202,10 @@ static int smack_key_getsecurity(struct key *key, char **_buffer)
 		return 0;
 	}
 
-	copy = kstrdup(skp->smk_known, GFP_KERNEL);
+	copy = smk_find_label_name(skp);
+	if (copy == NULL)
+		copy = smack_known_huh.smk_known;
+	copy = kstrdup(copy, GFP_KERNEL);
 	if (copy == NULL)
 		return -ENOMEM;
 	length = strlen(copy) + 1;
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 89f847bba..6a0a1ec 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -335,36 +335,17 @@ static int smk_fill_rule(const char *subject, const char *object,
 				struct smack_parsed_rule *rule, int import,
 				int len)
 {
-	const char *cp;
-	struct smack_known *skp;
-
-	if (import) {
-		rule->smk_subject = smk_import_entry(subject, len);
-		if (IS_ERR(rule->smk_subject))
-			return PTR_ERR(rule->smk_subject);
-
-		rule->smk_object = smk_import_entry(object, len);
-		if (IS_ERR(rule->smk_object))
-			return PTR_ERR(rule->smk_object);
-	} else {
-		cp = smk_parse_smack(subject, len);
-		if (IS_ERR(cp))
-			return PTR_ERR(cp);
-		skp = smk_find_entry(cp);
-		kfree(cp);
-		if (skp == NULL)
-			return -ENOENT;
-		rule->smk_subject = skp;
-
-		cp = smk_parse_smack(object, len);
-		if (IS_ERR(cp))
-			return PTR_ERR(cp);
-		skp = smk_find_entry(cp);
-		kfree(cp);
-		if (skp == NULL)
-			return -ENOENT;
-		rule->smk_object = skp;
-	}
+	rule->smk_subject = smk_get_label(subject, len, import);
+	if (IS_ERR(rule->smk_subject))
+		return PTR_ERR(rule->smk_subject);
+	if (rule->smk_subject == NULL)
+		return -ENOENT;
+
+	rule->smk_object = smk_get_label(object, len, import);
+	if (IS_ERR(rule->smk_object))
+		return PTR_ERR(rule->smk_object);
+	if (rule->smk_object == NULL)
+		return -ENOENT;
 
 	rule->smk_access1 = smk_perm_from_str(access1);
 	if (access2)
@@ -587,6 +568,9 @@ static void smk_seq_stop(struct seq_file *s, void *v)
 
 static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max)
 {
+	char *sbj;
+	char *obj;
+
 	/*
 	 * Don't show any rules with label names too long for
 	 * interface file (/smack/load or /smack/load2)
@@ -600,9 +584,13 @@ static void smk_rule_show(struct seq_file *s, struct smack_rule *srp, int max)
 	if (srp->smk_access == 0)
 		return;
 
-	seq_printf(s, "%s %s",
-		   srp->smk_subject->smk_known,
-		   srp->smk_object->smk_known);
+	sbj = smk_find_label_name(srp->smk_subject);
+	obj = smk_find_label_name(srp->smk_object);
+
+	if (sbj == NULL || obj == NULL)
+		return;
+
+	seq_printf(s, "%s %s", sbj, obj);
 
 	seq_putc(s, ' ');
 
@@ -793,6 +781,7 @@ static int cipso_seq_show(struct seq_file *s, void *v)
 		list_entry_rcu(list, struct smack_known, list);
 	struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat;
 	char sep = '/';
+	char *cp;
 	int i;
 
 	/*
@@ -806,7 +795,11 @@ static int cipso_seq_show(struct seq_file *s, void *v)
 	if (strlen(skp->smk_known) >= SMK_LABELLEN)
 		return 0;
 
-	seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl);
+	cp = smk_find_label_name(skp);
+	if (cp == NULL)
+		return 0;
+
+	seq_printf(s, "%s %3d", cp, skp->smk_netlabel.attr.mls.lvl);
 
 	for (i = netlbl_catmap_walk(cmp, 0); i >= 0;
 	     i = netlbl_catmap_walk(cmp, i + 1)) {
@@ -895,7 +888,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
 	 */
 	mutex_lock(&smack_cipso_lock);
 
-	skp = smk_import_entry(rule, 0);
+	skp = smk_get_label(rule, 0, true);
 	if (IS_ERR(skp)) {
 		rc = PTR_ERR(skp);
 		goto out;
@@ -984,9 +977,14 @@ static int cipso2_seq_show(struct seq_file *s, void *v)
 		list_entry_rcu(list, struct smack_known, list);
 	struct netlbl_lsm_catmap *cmp = skp->smk_netlabel.attr.mls.cat;
 	char sep = '/';
+	char *cp;
 	int i;
 
-	seq_printf(s, "%s %3d", skp->smk_known, skp->smk_netlabel.attr.mls.lvl);
+	cp = smk_find_label_name(skp);
+	if (cp == NULL)
+		return 0;
+
+	seq_printf(s, "%s %3d", cp, skp->smk_netlabel.attr.mls.lvl);
 
 	for (i = netlbl_catmap_walk(cmp, 0); i >= 0;
 	     i = netlbl_catmap_walk(cmp, i + 1)) {
@@ -1069,11 +1067,15 @@ static int netlbladdr_seq_show(struct seq_file *s, void *v)
 	unsigned char *hp = (char *) &skp->smk_host.sin_addr.s_addr;
 	int maskn;
 	u32 temp_mask = be32_to_cpu(skp->smk_mask.s_addr);
+	char *label = smk_find_label_name(skp->smk_label);
+
+	if (label == NULL)
+		return 0;
 
 	for (maskn = 0; temp_mask; temp_mask <<= 1, maskn++);
 
 	seq_printf(s, "%u.%u.%u.%u/%d %s\n",
-		hp[0], hp[1], hp[2], hp[3], maskn, skp->smk_label->smk_known);
+		hp[0], hp[1], hp[2], hp[3], maskn, label);
 
 	return 0;
 }
@@ -1219,7 +1221,7 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
 	 * If smack begins with '-', it is an option, don't import it
 	 */
 	if (smack[0] != '-') {
-		skp = smk_import_entry(smack, 0);
+		skp = smk_get_label(smack, 0, true);
 		if (IS_ERR(skp)) {
 			rc = PTR_ERR(skp);
 			goto free_out;
@@ -1548,6 +1550,7 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
 				size_t cn, loff_t *ppos)
 {
 	ssize_t rc;
+	char *cp;
 	int asize;
 
 	if (*ppos != 0)
@@ -1558,12 +1561,14 @@ static ssize_t smk_read_ambient(struct file *filp, char __user *buf,
 	 */
 	mutex_lock(&smack_ambient_lock);
 
-	asize = strlen(smack_net_ambient->smk_known) + 1;
+	cp = smk_find_label_name(smack_net_ambient);
+	if (cp == NULL)
+		cp = smack_known_huh.smk_known;
+
+	asize = strlen(cp) + 1;
 
 	if (cn >= asize)
-		rc = simple_read_from_buffer(buf, cn, ppos,
-					     smack_net_ambient->smk_known,
-					     asize);
+		rc = simple_read_from_buffer(buf, cn, ppos, cp, asize);
 	else
 		rc = -EINVAL;
 
@@ -1601,7 +1606,7 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
 		goto out;
 	}
 
-	skp = smk_import_entry(data, count);
+	skp = smk_get_label(data, count, true);
 	if (IS_ERR(skp)) {
 		rc = PTR_ERR(skp);
 		goto out;
@@ -1641,11 +1646,16 @@ static void *onlycap_seq_next(struct seq_file *s, void *v, loff_t *pos)
 
 static int onlycap_seq_show(struct seq_file *s, void *v)
 {
+	char *smack;
 	struct list_head *list = v;
 	struct smack_onlycap *sop =
 		list_entry_rcu(list, struct smack_onlycap, list);
 
-	seq_puts(s, sop->smk_label->smk_known);
+	smack = smk_find_label_name(sop->smk_label);
+	if (smack == NULL)
+		smack = smack_known_huh.smk_known;
+
+	seq_puts(s, smack);
 	seq_putc(s, ' ');
 
 	return 0;
@@ -1739,7 +1749,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
 		if (!*tok)
 			continue;
 
-		skp = smk_import_entry(tok, 0);
+		skp = smk_get_label(tok, 0, true);
 		if (IS_ERR(skp)) {
 			rc = PTR_ERR(skp);
 			break;
@@ -1809,8 +1819,11 @@ static ssize_t smk_read_unconfined(struct file *filp, char __user *buf,
 	if (*ppos != 0)
 		return 0;
 
-	if (smack_unconfined != NULL)
-		smack = smack_unconfined->smk_known;
+	if (smack_unconfined != NULL) {
+		smack = smk_find_label_name(smack_unconfined);
+		if (smack == NULL)
+			smack = smack_known_huh.smk_known;
+	}
 
 	asize = strlen(smack) + 1;
 
@@ -1857,7 +1870,7 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf,
 	 *
 	 * But do so only on invalid label, not on system errors.
 	 */
-	skp = smk_import_entry(data, count);
+	skp = smk_get_label(data, count, true);
 	if (PTR_ERR(skp) == -EINVAL)
 		skp = NULL;
 	else if (IS_ERR(skp)) {
@@ -2254,7 +2267,6 @@ static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf,
 				size_t count, loff_t *ppos)
 {
 	char *data;
-	const char *cp;
 	struct smack_known *skp;
 	struct smack_rule *sp;
 	struct list_head *rule_list;
@@ -2279,15 +2291,13 @@ static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf,
 		goto out_data;
 	}
 
-	cp = smk_parse_smack(data, count);
-	if (IS_ERR(cp)) {
-		rc = PTR_ERR(cp);
+	skp = smk_get_label(data, count, false);
+	if (IS_ERR(skp)) {
+		rc = PTR_ERR(skp);
 		goto out_data;
 	}
-
-	skp = smk_find_entry(cp);
 	if (skp == NULL)
-		goto out_cp;
+		goto out_data;
 
 	rule_list = &skp->smk_rules;
 	rule_lock = &skp->smk_rules_lock;
@@ -2299,8 +2309,6 @@ static ssize_t smk_write_revoke_subj(struct file *file, const char __user *buf,
 
 	mutex_unlock(rule_lock);
 
-out_cp:
-	kfree(cp);
 out_data:
 	kfree(data);
 
@@ -2369,8 +2377,11 @@ static ssize_t smk_read_syslog(struct file *filp, char __user *buf,
 	if (*ppos != 0)
 		return 0;
 
-	if (smack_syslog_label != NULL)
-		smack = smack_syslog_label->smk_known;
+	if (smack_syslog_label != NULL) {
+		smack = smk_find_label_name(smack_syslog_label);
+		if (smack == NULL)
+			smack = smack_known_huh.smk_known;
+	}
 
 	asize = strlen(smack) + 1;
 
@@ -2417,7 +2428,7 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
 	 *
 	 * But do so only on invalid label, not on system errors.
 	 */
-	skp = smk_import_entry(data, count);
+	skp = smk_get_label(data, count, true);
 	if (PTR_ERR(skp) == -EINVAL)
 		skp = NULL;
 	else if (IS_ERR(skp)) {
-- 
2.4.3

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