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

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 */
 			{""}
 	};