Merge branch 'smack-for-4.1' of git://github.com/cschaufler/smack-next into next

Documentation/security/Smack.txt

@@ -33,11 +33,18 @@ The current git repository for Smack user space is:
 	git://github.com/smack-team/smack.git
 
 This should make and install on most modern distributions.
-There are three commands included in smackutil:
+There are five commands included in smackutil:
 
-smackload  - properly formats data for writing to /smack/load
-smackcipso - properly formats data for writing to /smack/cipso
 chsmack    - display or set Smack extended attribute values
+smackctl   - load the Smack access rules
+smackaccess - report if a process with one label has access
+              to an object with another
+
+These two commands are obsolete with the introduction of
+the smackfs/load2 and smackfs/cipso2 interfaces.
+
+smackload  - properly formats data for writing to smackfs/load
+smackcipso - properly formats data for writing to smackfs/cipso
 
 In keeping with the intent of Smack, configuration data is
 minimal and not strictly required. The most important
@@ -47,9 +54,9 @@ of this, but it can be manually as well.
 
 Add this line to /etc/fstab:
 
-    smackfs /smack smackfs smackfsdef=* 0 0
+    smackfs /sys/fs/smackfs smackfs defaults 0 0
 
-and create the /smack directory for mounting.
+The /sys/fs/smackfs directory is created by the kernel.
 
 Smack uses extended attributes (xattrs) to store labels on filesystem
 objects. The attributes are stored in the extended attribute security
@@ -92,13 +99,13 @@ There are multiple ways to set a Smack label on a file:
     # attr -S -s SMACK64 -V "value" path
     # chsmack -a value path
 
-A process can see the smack label it is running with by
+A process can see the Smack label it is running with by
 reading /proc/self/attr/current. A process with CAP_MAC_ADMIN
-can set the process smack by writing there.
+can set the process Smack by writing there.
 
 Most Smack configuration is accomplished by writing to files
-in the smackfs filesystem. This pseudo-filesystem is usually
-mounted on /smack.
+in the smackfs filesystem. This pseudo-filesystem is mounted
+on /sys/fs/smackfs.
 
 access
 	This interface reports whether a subject with the specified
@@ -206,23 +213,30 @@ onlycap
 	file or cleared by writing "-" to the file.
 ptrace
 	This is used to define the current ptrace policy
-	0 - default: this is the policy that relies on smack access rules.
+	0 - default: this is the policy that relies on Smack access rules.
 	    For the PTRACE_READ a subject needs to have a read access on
 	    object. For the PTRACE_ATTACH a read-write access is required.
 	1 - exact: this is the policy that limits PTRACE_ATTACH. Attach is
 	    only allowed when subject's and object's labels are equal.
-	    PTRACE_READ is not affected. Can be overriden with CAP_SYS_PTRACE.
+	    PTRACE_READ is not affected. Can be overridden with CAP_SYS_PTRACE.
 	2 - draconian: this policy behaves like the 'exact' above with an
-	    exception that it can't be overriden with CAP_SYS_PTRACE.
+	    exception that it can't be overridden with CAP_SYS_PTRACE.
 revoke-subject
 	Writing a Smack label here sets the access to '-' for all access
 	rules with that subject label.
+unconfined
+	If the kernel is configured with CONFIG_SECURITY_SMACK_BRINGUP
+	a process with CAP_MAC_ADMIN can write a label into this interface.
+	Thereafter, accesses that involve that label will be logged and
+	the access permitted if it wouldn't be otherwise. Note that this
+	is dangerous and can ruin the proper labeling of your system.
+	It should never be used in production.
 
 You can add access rules in /etc/smack/accesses. They take the form:
 
     subjectlabel objectlabel access
 
-access is a combination of the letters rwxa which specify the
+access is a combination of the letters rwxatb which specify the
 kind of access permitted a subject with subjectlabel on an
 object with objectlabel. If there is no rule no access is allowed.
 
@@ -318,8 +332,9 @@ each of the subject and the object.
 
 Labels
 
-Smack labels are ASCII character strings, one to twenty-three characters in
-length. Single character labels using special characters, that being anything
+Smack labels are ASCII character strings. They can be up to 255 characters
+long, but keeping them to twenty-three characters is recommended.
+Single character labels using special characters, that being anything
 other than a letter or digit, are reserved for use by the Smack development
 team. Smack labels are unstructured, case sensitive, and the only operation
 ever performed on them is comparison for equality. Smack labels cannot
@@ -335,10 +350,9 @@ There are some predefined labels:
 	? 	Pronounced "huh", a single question mark character.
 	@ 	Pronounced "web", a single at sign character.
 
-Every task on a Smack system is assigned a label. System tasks, such as
-init(8) and systems daemons, are run with the floor ("_") label. User tasks
-are assigned labels according to the specification found in the
-/etc/smack/user configuration file.
+Every task on a Smack system is assigned a label. The Smack label
+of a process will usually be assigned by the system initialization
+mechanism.
 
 Access Rules
 
@@ -393,6 +407,7 @@ describe access modes:
 	w: indicates that write access should be granted.
 	x: indicates that execute access should be granted.
 	t: indicates that the rule requests transmutation.
+	b: indicates that the rule should be reported for bring-up.
 
 Uppercase values for the specification letters are allowed as well.
 Access mode specifications can be in any order. Examples of acceptable rules
@@ -402,6 +417,7 @@ are:
 	Secret    Unclass R
 	Manager   Game    x
 	User      HR      w
+	Snap      Crackle rwxatb
 	New       Old     rRrRr
 	Closed    Off     -
 
@@ -413,7 +429,7 @@ Examples of unacceptable rules are:
 
 Spaces are not allowed in labels. Since a subject always has access to files
 with the same label specifying a rule for that case is pointless. Only
-valid letters (rwxatRWXAT) and the dash ('-') character are allowed in
+valid letters (rwxatbRWXATB) and the dash ('-') character are allowed in
 access specifications. The dash is a placeholder, so "a-r" is the same
 as "ar". A lone dash is used to specify that no access should be allowed.
 
@@ -462,16 +478,11 @@ receiver. The receiver is not required to have read access to the sender.
 Setting Access Rules
 
 The configuration file /etc/smack/accesses contains the rules to be set at
-system startup. The contents are written to the special file /smack/load.
-Rules can be written to /smack/load at any time and take effect immediately.
-For any pair of subject and object labels there can be only one rule, with the
-most recently specified overriding any earlier specification.
-
-The program smackload is provided to ensure data is formatted
-properly when written to /smack/load. This program reads lines
-of the form
-
-    subjectlabel objectlabel mode.
+system startup. The contents are written to the special file
+/sys/fs/smackfs/load2. Rules can be added at any time and take effect
+immediately. For any pair of subject and object labels there can be only
+one rule, with the most recently specified overriding any earlier
+specification.
 
 Task Attribute
 
@@ -488,7 +499,10 @@ only be changed by a process with privilege.
 
 Privilege
 
-A process with CAP_MAC_OVERRIDE is privileged.
+A process with CAP_MAC_OVERRIDE or CAP_MAC_ADMIN is privileged.
+CAP_MAC_OVERRIDE allows the process access to objects it would
+be denied otherwise. CAP_MAC_ADMIN allows a process to change
+Smack data, including rules and attributes.
 
 Smack Networking
 
@@ -510,14 +524,14 @@ intervention. Unlabeled packets that come into the system will be given the
 ambient label.
 
 Smack requires configuration in the case where packets from a system that is
-not smack that speaks CIPSO may be encountered. Usually this will be a Trusted
+not Smack that speaks CIPSO may be encountered. Usually this will be a Trusted
 Solaris system, but there are other, less widely deployed systems out there.
 CIPSO provides 3 important values, a Domain Of Interpretation (DOI), a level,
 and a category set with each packet. The DOI is intended to identify a group
 of systems that use compatible labeling schemes, and the DOI specified on the
-smack system must match that of the remote system or packets will be
-discarded. The DOI is 3 by default. The value can be read from /smack/doi and
-can be changed by writing to /smack/doi.
+Smack system must match that of the remote system or packets will be
+discarded. The DOI is 3 by default. The value can be read from
+/sys/fs/smackfs/doi and can be changed by writing to /sys/fs/smackfs/doi.
 
 The label and category set are mapped to a Smack label as defined in
 /etc/smack/cipso.
@@ -539,15 +553,13 @@ The ":" and "," characters are permitted in a Smack label but have no special
 meaning.
 
 The mapping of Smack labels to CIPSO values is defined by writing to
-/smack/cipso. Again, the format of data written to this special file
-is highly restrictive, so the program smackcipso is provided to
-ensure the writes are done properly. This program takes mappings
-on the standard input and sends them to /smack/cipso properly.
+/sys/fs/smackfs/cipso2.
 
 In addition to explicit mappings Smack supports direct CIPSO mappings. One
 CIPSO level is used to indicate that the category set passed in the packet is
 in fact an encoding of the Smack label. The level used is 250 by default. The
-value can be read from /smack/direct and changed by writing to /smack/direct.
+value can be read from /sys/fs/smackfs/direct and changed by writing to
+/sys/fs/smackfs/direct.
 
 Socket Attributes
 
@@ -565,8 +577,8 @@ sockets.
 Smack Netlabel Exceptions
 
 You will often find that your labeled application has to talk to the outside,
-unlabeled world. To do this there's a special file /smack/netlabel where you can
-add some exceptions in the form of :
+unlabeled world. To do this there's a special file /sys/fs/smackfs/netlabel
+where you can add some exceptions in the form of :
 @IP1	   LABEL1 or
 @IP2/MASK  LABEL2
 
@@ -574,22 +586,22 @@ It means that your application will have unlabeled access to @IP1 if it has
 write access on LABEL1, and access to the subnet @IP2/MASK if it has write
 access on LABEL2.
 
-Entries in the /smack/netlabel file are matched by longest mask first, like in
-classless IPv4 routing.
+Entries in the /sys/fs/smackfs/netlabel file are matched by longest mask
+first, like in classless IPv4 routing.
 
 A special label '@' and an option '-CIPSO' can be used there :
 @      means Internet, any application with any label has access to it
 -CIPSO means standard CIPSO networking
 
 If you don't know what CIPSO is and don't plan to use it, you can just do :
-echo 127.0.0.1 -CIPSO > /smack/netlabel
-echo 0.0.0.0/0 @      > /smack/netlabel
+echo 127.0.0.1 -CIPSO > /sys/fs/smackfs/netlabel
+echo 0.0.0.0/0 @      > /sys/fs/smackfs/netlabel
 
 If you use CIPSO on your 192.168.0.0/16 local network and need also unlabeled
 Internet access, you can have :
-echo 127.0.0.1      -CIPSO > /smack/netlabel
-echo 192.168.0.0/16 -CIPSO > /smack/netlabel
-echo 0.0.0.0/0      @      > /smack/netlabel
+echo 127.0.0.1      -CIPSO > /sys/fs/smackfs/netlabel
+echo 192.168.0.0/16 -CIPSO > /sys/fs/smackfs/netlabel
+echo 0.0.0.0/0      @      > /sys/fs/smackfs/netlabel
 
 
 Writing Applications for Smack
@@ -676,7 +688,7 @@ Smack auditing
 If you want Smack auditing of security events, you need to set CONFIG_AUDIT
 in your kernel configuration.
 By default, all denied events will be audited. You can change this behavior by
-writing a single character to the /smack/logging file :
+writing a single character to the /sys/fs/smackfs/logging file :
 0 : no logging
 1 : log denied (default)
 2 : log accepted
@@ -686,3 +698,20 @@ Events are logged as 'key=value' pairs, for each event you at least will get
 the subject, the object, the rights requested, the action, the kernel function
 that triggered the event, plus other pairs depending on the type of event
 audited.
+
+Bringup Mode
+
+Bringup mode provides logging features that can make application
+configuration and system bringup easier. Configure the kernel with
+CONFIG_SECURITY_SMACK_BRINGUP to enable these features. When bringup
+mode is enabled accesses that succeed due to rules marked with the "b"
+access mode will logged. When a new label is introduced for processes
+rules can be added aggressively, marked with the "b". The logging allows
+tracking of which rules actual get used for that label.
+
+Another feature of bringup mode is the "unconfined" option. Writing
+a label to /sys/fs/smackfs/unconfined makes subjects with that label
+able to access any object, and objects with that label accessible to
+all subjects. Any access that is granted because a label is unconfined
+is logged. This feature is dangerous, as files and directories may
+be created in places they couldn't if the policy were being enforced.

security/smack/smack.h

@@ -105,6 +105,7 @@ struct task_smack {
 #define	SMK_INODE_INSTANT	0x01	/* inode is instantiated */
 #define	SMK_INODE_TRANSMUTE	0x02	/* directory is transmuting */
 #define	SMK_INODE_CHANGED	0x04	/* smack was transmuted */
+#define	SMK_INODE_IMPURE	0x08	/* involved in an impure transaction */
 
 /*
  * A label access rule.
@@ -193,6 +194,10 @@ struct smk_port_label {
 #define MAY_LOCK	0x00002000	/* Locks should be writes, but ... */
 #define MAY_BRINGUP	0x00004000	/* Report use of this rule */
 
+#define SMACK_BRINGUP_ALLOW		1	/* Allow bringup mode */
+#define SMACK_UNCONFINED_SUBJECT	2	/* Allow unconfined label */
+#define SMACK_UNCONFINED_OBJECT		3	/* Allow unconfined label */
+
 /*
  * Just to make the common cases easier to deal with
  */
@@ -254,6 +259,9 @@ extern int smack_cipso_mapped;
 extern struct smack_known *smack_net_ambient;
 extern struct smack_known *smack_onlycap;
 extern struct smack_known *smack_syslog_label;
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+extern struct smack_known *smack_unconfined;
+#endif
 extern struct smack_known smack_cipso_option;
 extern int smack_ptrace_rule;
 

security/smack/smack_access.c

@@ -130,7 +130,8 @@ int smk_access(struct smack_known *subject, struct smack_known *object,
 
 	/*
 	 * Hardcoded comparisons.
-	 *
+	 */
+	/*
 	 * A star subject can't access any object.
 	 */
 	if (subject == &smack_known_star) {
@@ -189,10 +190,20 @@ int smk_access(struct smack_known *subject, struct smack_known *object,
 	 * succeed because of "b" rules.
 	 */
 	if (may & MAY_BRINGUP)
-		rc = MAY_BRINGUP;
+		rc = SMACK_BRINGUP_ALLOW;
 #endif
 
 out_audit:
+
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+	if (rc < 0) {
+		if (object == smack_unconfined)
+			rc = SMACK_UNCONFINED_OBJECT;
+		if (subject == smack_unconfined)
+			rc = SMACK_UNCONFINED_SUBJECT;
+	}
+#endif
+
 #ifdef CONFIG_AUDIT
 	if (a)
 		smack_log(subject->smk_known, object->smk_known,
@@ -338,19 +349,16 @@ static void smack_log_callback(struct audit_buffer *ab, void *a)
 void smack_log(char *subject_label, char *object_label, int request,
 	       int result, struct smk_audit_info *ad)
 {
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+	char request_buffer[SMK_NUM_ACCESS_TYPE + 5];
+#else
 	char request_buffer[SMK_NUM_ACCESS_TYPE + 1];
+#endif
 	struct smack_audit_data *sad;
 	struct common_audit_data *a = &ad->a;
 
-#ifdef CONFIG_SECURITY_SMACK_BRINGUP
-	/*
-	 * The result may be positive in bringup mode.
-	 */
-	if (result > 0)
-		result = 0;
-#endif
 	/* check if we have to log the current event */
-	if (result != 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
+	if (result < 0 && (log_policy & SMACK_AUDIT_DENIED) == 0)
 		return;
 	if (result == 0 && (log_policy & SMACK_AUDIT_ACCEPT) == 0)
 		return;
@@ -364,6 +372,21 @@ void smack_log(char *subject_label, char *object_label, int request,
 	smack_str_from_perm(request_buffer, request);
 	sad->subject = subject_label;
 	sad->object  = object_label;
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+	/*
+	 * The result may be positive in bringup mode.
+	 * A positive result is an allow, but not for normal reasons.
+	 * Mark it as successful, but don't filter it out even if
+	 * the logging policy says to do so.
+	 */
+	if (result == SMACK_UNCONFINED_SUBJECT)
+		strcat(request_buffer, "(US)");
+	else if (result == SMACK_UNCONFINED_OBJECT)
+		strcat(request_buffer, "(UO)");
+
+	if (result > 0)
+		result = 0;
+#endif
 	sad->request = request_buffer;
 	sad->result  = result;
 

security/smack/smack_lsm.c

@@ -57,6 +57,13 @@ static struct kmem_cache *smack_inode_cache;
 int smack_enabled;
 
 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
+static char *smk_bu_mess[] = {
+	"Bringup Error",	/* Unused */
+	"Bringup",		/* SMACK_BRINGUP_ALLOW */
+	"Unconfined Subject",	/* SMACK_UNCONFINED_SUBJECT */
+	"Unconfined Object",	/* SMACK_UNCONFINED_OBJECT */
+};
+
 static void smk_bu_mode(int mode, char *s)
 {
 	int i = 0;
@@ -87,9 +94,11 @@ static int smk_bu_note(char *note, struct smack_known *sskp,
 
 	if (rc <= 0)
 		return rc;
+	if (rc > SMACK_UNCONFINED_OBJECT)
+		rc = 0;
 
 	smk_bu_mode(mode, acc);
-	pr_info("Smack Bringup: (%s %s %s) %s\n",
+	pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
 		sskp->smk_known, oskp->smk_known, acc, note);
 	return 0;
 }
@@ -106,9 +115,11 @@ static int smk_bu_current(char *note, struct smack_known *oskp,
 
 	if (rc <= 0)
 		return rc;
+	if (rc > SMACK_UNCONFINED_OBJECT)
+		rc = 0;
 
 	smk_bu_mode(mode, acc);
-	pr_info("Smack Bringup: (%s %s %s) %s %s\n",
+	pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
 		tsp->smk_task->smk_known, oskp->smk_known,
 		acc, current->comm, note);
 	return 0;
@@ -126,9 +137,11 @@ static int smk_bu_task(struct task_struct *otp, int mode, int rc)
 
 	if (rc <= 0)
 		return rc;
+	if (rc > SMACK_UNCONFINED_OBJECT)
+		rc = 0;
 
 	smk_bu_mode(mode, acc);
-	pr_info("Smack Bringup: (%s %s %s) %s to %s\n",
+	pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
 		tsp->smk_task->smk_known, smk_task->smk_known, acc,
 		current->comm, otp->comm);
 	return 0;
@@ -141,14 +154,25 @@ static int smk_bu_task(struct task_struct *otp, int mode, int rc)
 static int smk_bu_inode(struct inode *inode, int mode, int rc)
 {
 	struct task_smack *tsp = current_security();
+	struct inode_smack *isp = inode->i_security;
 	char acc[SMK_NUM_ACCESS_TYPE + 1];
 
+	if (isp->smk_flags & SMK_INODE_IMPURE)
+		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
+			inode->i_sb->s_id, inode->i_ino, current->comm);
+
 	if (rc <= 0)
 		return rc;
+	if (rc > SMACK_UNCONFINED_OBJECT)
+		rc = 0;
+	if (rc == SMACK_UNCONFINED_SUBJECT &&
+	    (mode & (MAY_WRITE | MAY_APPEND)))
+		isp->smk_flags |= SMK_INODE_IMPURE;
 
 	smk_bu_mode(mode, acc);
-	pr_info("Smack Bringup: (%s %s %s) inode=(%s %ld) %s\n",
-		tsp->smk_task->smk_known, smk_of_inode(inode)->smk_known, acc,
+
+	pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
+		tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
 		inode->i_sb->s_id, inode->i_ino, current->comm);
 	return 0;
 }
@@ -162,13 +186,20 @@ static int smk_bu_file(struct file *file, int mode, int rc)
 	struct task_smack *tsp = current_security();
 	struct smack_known *sskp = tsp->smk_task;
 	struct inode *inode = file_inode(file);
+	struct inode_smack *isp = inode->i_security;
 	char acc[SMK_NUM_ACCESS_TYPE + 1];
 
+	if (isp->smk_flags & SMK_INODE_IMPURE)
+		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
+			inode->i_sb->s_id, inode->i_ino, current->comm);
+
 	if (rc <= 0)
 		return rc;
+	if (rc > SMACK_UNCONFINED_OBJECT)
+		rc = 0;
 
 	smk_bu_mode(mode, acc);
-	pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
+	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
 		inode->i_sb->s_id, inode->i_ino, file,
 		current->comm);
@@ -185,13 +216,20 @@ static int smk_bu_credfile(const struct cred *cred, struct file *file,
 	struct task_smack *tsp = cred->security;
 	struct smack_known *sskp = tsp->smk_task;
 	struct inode *inode = file->f_inode;
+	struct inode_smack *isp = inode->i_security;
 	char acc[SMK_NUM_ACCESS_TYPE + 1];
 
+	if (isp->smk_flags & SMK_INODE_IMPURE)
+		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
+			inode->i_sb->s_id, inode->i_ino, current->comm);
+
 	if (rc <= 0)
 		return rc;
+	if (rc > SMACK_UNCONFINED_OBJECT)
+		rc = 0;
 
 	smk_bu_mode(mode, acc);
-	pr_info("Smack Bringup: (%s %s %s) file=(%s %ld %pD) %s\n",
+	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
 		inode->i_sb->s_id, inode->i_ino, file,
 		current->comm);
@@ -2452,7 +2490,21 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
 static int smack_socket_post_create(struct socket *sock, int family,
 				    int type, int protocol, int kern)
 {
-	if (family != PF_INET || sock->sk == NULL)
+	struct socket_smack *ssp;
+
+	if (sock->sk == NULL)
+		return 0;
+
+	/*
+	 * Sockets created by kernel threads receive web label.
+	 */
+	if (unlikely(current->flags & PF_KTHREAD)) {
+		ssp = sock->sk->sk_security;
+		ssp->smk_in = &smack_known_web;
+		ssp->smk_out = &smack_known_web;
+	}
+
+	if (family != PF_INET)
 		return 0;
 	/*
 	 * Set the outbound netlbl.
@@ -3986,6 +4038,36 @@ static int smack_key_permission(key_ref_t key_ref,
 	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
 	return rc;
 }
+
+/*
+ * smack_key_getsecurity - Smack label tagging the key
+ * @key points to the key to be queried
+ * @_buffer points to a pointer that should be set to point to the
+ * resulting string (if no label or an error occurs).
+ * Return the length of the string (including terminating NUL) or -ve if
+ * an error.
+ * May also return 0 (and a NULL buffer pointer) if there is no label.
+ */
+static int smack_key_getsecurity(struct key *key, char **_buffer)
+{
+	struct smack_known *skp = key->security;
+	size_t length;
+	char *copy;
+
+	if (key->security == NULL) {
+		*_buffer = NULL;
+		return 0;
+	}
+
+	copy = kstrdup(skp->smk_known, GFP_KERNEL);
+	if (copy == NULL)
+		return -ENOMEM;
+	length = strlen(copy) + 1;
+
+	*_buffer = copy;
+	return length;
+}
+
 #endif /* CONFIG_KEYS */
 
 /*
@@ -4310,6 +4392,7 @@ struct security_operations smack_ops = {
 	.key_alloc = 			smack_key_alloc,
 	.key_free = 			smack_key_free,
 	.key_permission = 		smack_key_permission,
+	.key_getsecurity =		smack_key_getsecurity,
 #endif /* CONFIG_KEYS */
 
  /* Audit hooks */

security/smack/smackfs.c

@@ -54,6 +54,9 @@ enum smk_inos {
 	SMK_CHANGE_RULE	= 19,	/* change or add rules (long labels) */
 	SMK_SYSLOG	= 20,	/* change syslog label) */
 	SMK_PTRACE	= 21,	/* set ptrace rule */
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+	SMK_UNCONFINED	= 22,	/* define an unconfined label */
+#endif
 };
 
 /*
@@ -61,7 +64,6 @@ enum smk_inos {
  */
 static DEFINE_MUTEX(smack_cipso_lock);
 static DEFINE_MUTEX(smack_ambient_lock);
-static DEFINE_MUTEX(smack_syslog_lock);
 static DEFINE_MUTEX(smk_netlbladdr_lock);
 
 /*
@@ -95,6 +97,16 @@ int smack_cipso_mapped = SMACK_CIPSO_MAPPED_DEFAULT;
  */
 struct smack_known *smack_onlycap;
 
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+/*
+ * Allow one label to be unconfined. This is for
+ * debugging and application bring-up purposes only.
+ * It is bad and wrong, but everyone seems to expect
+ * to have it.
+ */
+struct smack_known *smack_unconfined;
+#endif
+
 /*
  * If this value is set restrict syslog use to the label specified.
  * It can be reset via smackfs/syslog
@@ -1717,6 +1729,85 @@ static const struct file_operations smk_onlycap_ops = {
 	.llseek		= default_llseek,
 };
 
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+/**
+ * smk_read_unconfined - read() for smackfs/unconfined
+ * @filp: file pointer, not actually used
+ * @buf: where to put the result
+ * @cn: maximum to send along
+ * @ppos: where to start
+ *
+ * Returns number of bytes read or error code, as appropriate
+ */
+static ssize_t smk_read_unconfined(struct file *filp, char __user *buf,
+					size_t cn, loff_t *ppos)
+{
+	char *smack = "";
+	ssize_t rc = -EINVAL;
+	int asize;
+
+	if (*ppos != 0)
+		return 0;
+
+	if (smack_unconfined != NULL)
+		smack = smack_unconfined->smk_known;
+
+	asize = strlen(smack) + 1;
+
+	if (cn >= asize)
+		rc = simple_read_from_buffer(buf, cn, ppos, smack, asize);
+
+	return rc;
+}
+
+/**
+ * smk_write_unconfined - write() for smackfs/unconfined
+ * @file: file pointer, not actually used
+ * @buf: where to get the data from
+ * @count: bytes sent
+ * @ppos: where to start
+ *
+ * Returns number of bytes written or error code, as appropriate
+ */
+static ssize_t smk_write_unconfined(struct file *file, const char __user *buf,
+					size_t count, loff_t *ppos)
+{
+	char *data;
+	int rc = count;
+
+	if (!smack_privileged(CAP_MAC_ADMIN))
+		return -EPERM;
+
+	data = kzalloc(count + 1, GFP_KERNEL);
+	if (data == NULL)
+		return -ENOMEM;
+
+	/*
+	 * Should the null string be passed in unset the unconfined value.
+	 * This seems like something to be careful with as usually
+	 * smk_import only expects to return NULL for errors. It
+	 * is usually the case that a nullstring or "\n" would be
+	 * bad to pass to smk_import but in fact this is useful here.
+	 *
+	 * smk_import will also reject a label beginning with '-',
+	 * so "-confine" will also work.
+	 */
+	if (copy_from_user(data, buf, count) != 0)
+		rc = -EFAULT;
+	else
+		smack_unconfined = smk_import_entry(data, count);
+
+	kfree(data);
+	return rc;
+}
+
+static const struct file_operations smk_unconfined_ops = {
+	.read		= smk_read_unconfined,
+	.write		= smk_write_unconfined,
+	.llseek		= default_llseek,
+};
+#endif /* CONFIG_SECURITY_SMACK_BRINGUP */
+
 /**
  * smk_read_logging - read() for /smack/logging
  * @filp: file pointer, not actually used
@@ -2384,6 +2475,10 @@ static int smk_fill_super(struct super_block *sb, void *data, int silent)
 			"syslog", &smk_syslog_ops, S_IRUGO|S_IWUSR},
 		[SMK_PTRACE] = {
 			"ptrace", &smk_ptrace_ops, S_IRUGO|S_IWUSR},
+#ifdef CONFIG_SECURITY_SMACK_BRINGUP
+		[SMK_UNCONFINED] = {
+			"unconfined", &smk_unconfined_ops, S_IRUGO|S_IWUSR},
+#endif
 		/* last one */
 			{""}
 	};