[NetLabel]: add audit support for configuration changes

This patch adds audit support to NetLabel, including six new audit message
types shown below.

 #define AUDIT_MAC_UNLBL_ACCEPT 1406
 #define AUDIT_MAC_UNLBL_DENY   1407
 #define AUDIT_MAC_CIPSOV4_ADD  1408
 #define AUDIT_MAC_CIPSOV4_DEL  1409
 #define AUDIT_MAC_MAP_ADD      1410
 #define AUDIT_MAC_MAP_DEL      1411
Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/audit.h

@@ -95,6 +95,12 @@
 #define AUDIT_MAC_POLICY_LOAD	1403	/* Policy file load */
 #define AUDIT_MAC_STATUS	1404	/* Changed enforcing,permissive,off */
 #define AUDIT_MAC_CONFIG_CHANGE	1405	/* Changes to booleans */
+#define AUDIT_MAC_UNLBL_ACCEPT	1406	/* NetLabel: allow unlabeled traffic */
+#define AUDIT_MAC_UNLBL_DENY	1407	/* NetLabel: deny unlabeled traffic */
+#define AUDIT_MAC_CIPSOV4_ADD	1408	/* NetLabel: add CIPSOv4 DOI entry */
+#define AUDIT_MAC_CIPSOV4_DEL	1409	/* NetLabel: del CIPSOv4 DOI entry */
+#define AUDIT_MAC_MAP_ADD	1410	/* NetLabel: add LSM domain mapping */
+#define AUDIT_MAC_MAP_DEL	1411	/* NetLabel: del LSM domain mapping */
 
 #define AUDIT_FIRST_KERN_ANOM_MSG   1700
 #define AUDIT_LAST_KERN_ANOM_MSG    1799

include/net/cipso_ipv4.h

@@ -128,7 +128,9 @@ extern int cipso_v4_rbm_strictvalid;
 
 #ifdef CONFIG_NETLABEL
 int cipso_v4_doi_add(struct cipso_v4_doi *doi_def);
-int cipso_v4_doi_remove(u32 doi, void (*callback) (struct rcu_head * head));
+int cipso_v4_doi_remove(u32 doi,
+			u32 audit_secid,
+			void (*callback) (struct rcu_head * head));
 struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi);
 int cipso_v4_doi_walk(u32 *skip_cnt,
 		     int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
@@ -143,6 +145,7 @@ static inline int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
 }
 
 static inline int cipso_v4_doi_remove(u32 doi,
+				    u32 audit_secid,
 				    void (*callback) (struct rcu_head * head))
 {
 	return 0;

include/net/netlabel.h

@@ -96,7 +96,7 @@
 struct netlbl_dom_map;
 
 /* Domain mapping operations */
-int netlbl_domhsh_remove(const char *domain);
+int netlbl_domhsh_remove(const char *domain, u32 audit_secid);
 
 /* LSM security attributes */
 struct netlbl_lsm_cache {

net/ipv4/cipso_ipv4.c

@@ -474,6 +474,7 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
 /**
  * cipso_v4_doi_remove - Remove an existing DOI from the CIPSO protocol engine
  * @doi: the DOI value
+ * @audit_secid: the LSM secid to use in the audit message
  * @callback: the DOI cleanup/free callback
  *
  * Description:
@@ -483,7 +484,9 @@ int cipso_v4_doi_add(struct cipso_v4_doi *doi_def)
  * success and negative values on failure.
  *
  */
-int cipso_v4_doi_remove(u32 doi, void (*callback) (struct rcu_head * head))
+int cipso_v4_doi_remove(u32 doi,
+			u32 audit_secid,
+			void (*callback) (struct rcu_head * head))
 {
 	struct cipso_v4_doi *doi_def;
 	struct cipso_v4_domhsh_entry *dom_iter;
@@ -502,7 +505,8 @@ int cipso_v4_doi_remove(u32 doi, void (*callback) (struct rcu_head * head))
 		spin_unlock(&cipso_v4_doi_list_lock);
 		list_for_each_entry_rcu(dom_iter, &doi_def->dom_list, list)
 			if (dom_iter->valid)
-				netlbl_domhsh_remove(dom_iter->domain);
+				netlbl_domhsh_remove(dom_iter->domain,
+						     audit_secid);
 		cipso_v4_cache_invalidate();
 		rcu_read_unlock();
 

net/netlabel/netlabel_cipso_v4.c

@@ -32,6 +32,7 @@
 #include <linux/socket.h>
 #include <linux/string.h>
 #include <linux/skbuff.h>
+#include <linux/audit.h>
 #include <net/sock.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
@@ -162,8 +163,7 @@ static int netlbl_cipsov4_add_std(struct genl_info *info)
 	int nla_a_rem;
 	int nla_b_rem;
 
-	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
-	    !info->attrs[NLBL_CIPSOV4_A_TAGLST] ||
+	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST] ||
 	    !info->attrs[NLBL_CIPSOV4_A_MLSLVLLST])
 		return -EINVAL;
 
@@ -344,8 +344,7 @@ static int netlbl_cipsov4_add_pass(struct genl_info *info)
 	int ret_val;
 	struct cipso_v4_doi *doi_def = NULL;
 
-	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
-	    !info->attrs[NLBL_CIPSOV4_A_TAGLST])
+	if (!info->attrs[NLBL_CIPSOV4_A_TAGLST])
 		return -EINVAL;
 
 	doi_def = kmalloc(sizeof(*doi_def), GFP_KERNEL);
@@ -381,21 +380,35 @@ static int netlbl_cipsov4_add(struct sk_buff *skb, struct genl_info *info)
 
 {
 	int ret_val = -EINVAL;
-	u32 map_type;
+	u32 type;
+	u32 doi;
+	const char *type_str = "(unknown)";
+	struct audit_buffer *audit_buf;
 
-	if (!info->attrs[NLBL_CIPSOV4_A_MTYPE])
+	if (!info->attrs[NLBL_CIPSOV4_A_DOI] ||
+	    !info->attrs[NLBL_CIPSOV4_A_MTYPE])
 		return -EINVAL;
 
-	map_type = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_MTYPE]);
-	switch (map_type) {
+	type = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_MTYPE]);
+	switch (type) {
 	case CIPSO_V4_MAP_STD:
+		type_str = "std";
 		ret_val = netlbl_cipsov4_add_std(info);
 		break;
 	case CIPSO_V4_MAP_PASS:
+		type_str = "pass";
 		ret_val = netlbl_cipsov4_add_pass(info);
 		break;
 	}
 
+	if (ret_val == 0) {
+		doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_ADD,
+						      NETLINK_CB(skb).sid);
+		audit_log_format(audit_buf, " doi=%u type=%s", doi, type_str);
+		audit_log_end(audit_buf);
+	}
+
 	return ret_val;
 }
 
@@ -653,11 +666,21 @@ static int netlbl_cipsov4_listall(struct sk_buff *skb,
 static int netlbl_cipsov4_remove(struct sk_buff *skb, struct genl_info *info)
 {
 	int ret_val = -EINVAL;
-	u32 doi;
+	u32 doi = 0;
+	struct audit_buffer *audit_buf;
 
 	if (info->attrs[NLBL_CIPSOV4_A_DOI]) {
 		doi = nla_get_u32(info->attrs[NLBL_CIPSOV4_A_DOI]);
-		ret_val = cipso_v4_doi_remove(doi, netlbl_cipsov4_doi_free);
+		ret_val = cipso_v4_doi_remove(doi,
+					      NETLINK_CB(skb).sid,
+					      netlbl_cipsov4_doi_free);
+	}
+
+	if (ret_val == 0) {
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_CIPSOV4_DEL,
+						      NETLINK_CB(skb).sid);
+		audit_log_format(audit_buf, " doi=%u", doi);
+		audit_log_end(audit_buf);
 	}
 
 	return ret_val;

net/netlabel/netlabel_domainhash.c

@@ -35,12 +35,14 @@
 #include <linux/skbuff.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
+#include <linux/audit.h>
 #include <net/netlabel.h>
 #include <net/cipso_ipv4.h>
 #include <asm/bug.h>
 
 #include "netlabel_mgmt.h"
 #include "netlabel_domainhash.h"
+#include "netlabel_user.h"
 
 struct netlbl_domhsh_tbl {
 	struct list_head *tbl;
@@ -186,6 +188,7 @@ int netlbl_domhsh_init(u32 size)
 /**
  * netlbl_domhsh_add - Adds a entry to the domain hash table
  * @entry: the entry to add
+ * @audit_secid: the LSM secid to use in the audit message
  *
  * Description:
  * Adds a new entry to the domain hash table and handles any updates to the
@@ -193,10 +196,12 @@ int netlbl_domhsh_init(u32 size)
  * negative on failure.
  *
  */
-int netlbl_domhsh_add(struct netlbl_dom_map *entry)
+int netlbl_domhsh_add(struct netlbl_dom_map *entry, u32 audit_secid)
 {
 	int ret_val;
 	u32 bkt;
+	struct audit_buffer *audit_buf;
+	char *audit_domain;
 
 	switch (entry->type) {
 	case NETLBL_NLTYPE_UNLABELED:
@@ -236,6 +241,26 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry)
 		spin_unlock(&netlbl_domhsh_def_lock);
 	} else
 		ret_val = -EINVAL;
+	if (ret_val == 0) {
+		if (entry->domain != NULL)
+			audit_domain = entry->domain;
+		else
+			audit_domain = "(default)";
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD,
+						      audit_secid);
+		audit_log_format(audit_buf, " domain=%s", audit_domain);
+		switch (entry->type) {
+		case NETLBL_NLTYPE_UNLABELED:
+			audit_log_format(audit_buf, " protocol=unlbl");
+			break;
+		case NETLBL_NLTYPE_CIPSOV4:
+			audit_log_format(audit_buf,
+					 " protocol=cipsov4 doi=%u",
+					 entry->type_def.cipsov4->doi);
+			break;
+		}
+		audit_log_end(audit_buf);
+	}
 	rcu_read_unlock();
 
 	if (ret_val != 0) {
@@ -254,6 +279,7 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry)
 /**
  * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
  * @entry: the entry to add
+ * @audit_secid: the LSM secid to use in the audit message
  *
  * Description:
  * Adds a new default entry to the domain hash table and handles any updates
@@ -261,14 +287,15 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry)
  * negative on failure.
  *
  */
-int netlbl_domhsh_add_default(struct netlbl_dom_map *entry)
+int netlbl_domhsh_add_default(struct netlbl_dom_map *entry, u32 audit_secid)
 {
-	return netlbl_domhsh_add(entry);
+	return netlbl_domhsh_add(entry, audit_secid);
 }
 
 /**
  * netlbl_domhsh_remove - Removes an entry from the domain hash table
  * @domain: the domain to remove
+ * @audit_secid: the LSM secid to use in the audit message
  *
  * Description:
  * Removes an entry from the domain hash table and handles any updates to the
@@ -276,10 +303,12 @@ int netlbl_domhsh_add_default(struct netlbl_dom_map *entry)
  * negative on failure.
  *
  */
-int netlbl_domhsh_remove(const char *domain)
+int netlbl_domhsh_remove(const char *domain, u32 audit_secid)
 {
 	int ret_val = -ENOENT;
 	struct netlbl_dom_map *entry;
+	struct audit_buffer *audit_buf;
+	char *audit_domain;
 
 	rcu_read_lock();
 	if (domain != NULL)
@@ -316,8 +345,18 @@ int netlbl_domhsh_remove(const char *domain)
 			ret_val = -ENOENT;
 		spin_unlock(&netlbl_domhsh_def_lock);
 	}
-	if (ret_val == 0)
+	if (ret_val == 0) {
+		if (entry->domain != NULL)
+			audit_domain = entry->domain;
+		else
+			audit_domain = "(default)";
+		audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL,
+						      audit_secid);
+		audit_log_format(audit_buf, " domain=%s", audit_domain);
+		audit_log_end(audit_buf);
+
 		call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
+	}
 
 remove_return:
 	rcu_read_unlock();
@@ -326,6 +365,7 @@ int netlbl_domhsh_remove(const char *domain)
 
 /**
  * netlbl_domhsh_remove_default - Removes the default entry from the table
+ * @audit_secid: the LSM secid to use in the audit message
  *
  * Description:
  * Removes/resets the default entry for the domain hash table and handles any
@@ -333,9 +373,9 @@ int netlbl_domhsh_remove(const char *domain)
  * success, non-zero on failure.
  *
  */
-int netlbl_domhsh_remove_default(void)
+int netlbl_domhsh_remove_default(u32 audit_secid)
 {
-	return netlbl_domhsh_remove(NULL);
+	return netlbl_domhsh_remove(NULL, audit_secid);
 }
 
 /**

net/netlabel/netlabel_domainhash.h

@@ -57,9 +57,9 @@ struct netlbl_dom_map {
 int netlbl_domhsh_init(u32 size);
 
 /* Manipulate the domain hash table */
-int netlbl_domhsh_add(struct netlbl_dom_map *entry);
-int netlbl_domhsh_add_default(struct netlbl_dom_map *entry);
-int netlbl_domhsh_remove_default(void);
+int netlbl_domhsh_add(struct netlbl_dom_map *entry, u32 audit_secid);
+int netlbl_domhsh_add_default(struct netlbl_dom_map *entry, u32 audit_secid);
+int netlbl_domhsh_remove_default(u32 audit_secid);
 struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain);
 int netlbl_domhsh_walk(u32 *skip_bkt,
 		     u32 *skip_chain,

net/netlabel/netlabel_mgmt.c

@@ -108,7 +108,7 @@ static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
 
 	switch (entry->type) {
 	case NETLBL_NLTYPE_UNLABELED:
-		ret_val = netlbl_domhsh_add(entry);
+		ret_val = netlbl_domhsh_add(entry, NETLINK_CB(skb).sid);
 		break;
 	case NETLBL_NLTYPE_CIPSOV4:
 		if (!info->attrs[NLBL_MGMT_A_CV4DOI])
@@ -125,7 +125,7 @@ static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
 			rcu_read_unlock();
 			goto add_failure;
 		}
-		ret_val = netlbl_domhsh_add(entry);
+		ret_val = netlbl_domhsh_add(entry, NETLINK_CB(skb).sid);
 		rcu_read_unlock();
 		break;
 	default:
@@ -161,7 +161,7 @@ static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
 		return -EINVAL;
 
 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
-	return netlbl_domhsh_remove(domain);
+	return netlbl_domhsh_remove(domain, NETLINK_CB(skb).sid);
 }
 
 /**
@@ -277,7 +277,8 @@ static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
 
 	switch (entry->type) {
 	case NETLBL_NLTYPE_UNLABELED:
-		ret_val = netlbl_domhsh_add_default(entry);
+		ret_val = netlbl_domhsh_add_default(entry,
+						    NETLINK_CB(skb).sid);
 		break;
 	case NETLBL_NLTYPE_CIPSOV4:
 		if (!info->attrs[NLBL_MGMT_A_CV4DOI])
@@ -294,7 +295,8 @@ static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
 			rcu_read_unlock();
 			goto adddef_failure;
 		}
-		ret_val = netlbl_domhsh_add_default(entry);
+		ret_val = netlbl_domhsh_add_default(entry,
+						    NETLINK_CB(skb).sid);
 		rcu_read_unlock();
 		break;
 	default:
@@ -322,7 +324,7 @@ static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
  */
 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
 {
-	return netlbl_domhsh_remove_default();
+	return netlbl_domhsh_remove_default(NETLINK_CB(skb).sid);
 }
 
 /**

net/netlabel/netlabel_unlabeled.c

@@ -63,6 +63,27 @@ static struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
 	[NLBL_UNLABEL_A_ACPTFLG] = { .type = NLA_U8 },
 };
 
+/*
+ * Helper Functions
+ */
+
+/**
+ * netlbl_unlabel_acceptflg_set - Set the unlabeled accept flag
+ * @value: desired value
+ * @audit_secid: the LSM secid to use in the audit message
+ *
+ * Description:
+ * Set the value of the unlabeled accept flag to @value.
+ *
+ */
+static void netlbl_unlabel_acceptflg_set(u8 value, u32 audit_secid)
+{
+	atomic_set(&netlabel_unlabel_accept_flg, value);
+	netlbl_audit_nomsg((value ?
+			    AUDIT_MAC_UNLBL_ACCEPT : AUDIT_MAC_UNLBL_DENY),
+			   audit_secid);
+}
+
 /*
  * NetLabel Command Handlers
  */
@@ -79,18 +100,18 @@ static struct nla_policy netlbl_unlabel_genl_policy[NLBL_UNLABEL_A_MAX + 1] = {
  */
 static int netlbl_unlabel_accept(struct sk_buff *skb, struct genl_info *info)
 {
-	int ret_val = -EINVAL;
 	u8 value;
 
 	if (info->attrs[NLBL_UNLABEL_A_ACPTFLG]) {
 		value = nla_get_u8(info->attrs[NLBL_UNLABEL_A_ACPTFLG]);
 		if (value == 1 || value == 0) {
-			atomic_set(&netlabel_unlabel_accept_flg, value);
-			ret_val = 0;
+			netlbl_unlabel_acceptflg_set(value,
+						     NETLINK_CB(skb).sid);
+			return 0;
 		}
 	}
 
-	return ret_val;
+	return -EINVAL;
 }
 
 /**
@@ -229,16 +250,19 @@ int netlbl_unlabel_defconf(void)
 {
 	int ret_val;
 	struct netlbl_dom_map *entry;
+	u32 secid;
+
+	security_task_getsecid(current, &secid);
 
 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 	if (entry == NULL)
 		return -ENOMEM;
 	entry->type = NETLBL_NLTYPE_UNLABELED;
-	ret_val = netlbl_domhsh_add_default(entry);
+	ret_val = netlbl_domhsh_add_default(entry, secid);
 	if (ret_val != 0)
 		return ret_val;
 
-	atomic_set(&netlabel_unlabel_accept_flg, 1);
+	netlbl_unlabel_acceptflg_set(1, secid);
 
 	return 0;
 }

net/netlabel/netlabel_user.c

@@ -32,6 +32,9 @@
 #include <linux/types.h>
 #include <linux/list.h>
 #include <linux/socket.h>
+#include <linux/audit.h>
+#include <linux/tty.h>
+#include <linux/security.h>
 #include <net/sock.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
@@ -74,3 +77,91 @@ int netlbl_netlink_init(void)
 
 	return 0;
 }
+
+/*
+ * NetLabel Audit Functions
+ */
+
+/**
+ * netlbl_audit_start_common - Start an audit message
+ * @type: audit message type
+ * @secid: LSM context ID
+ *
+ * Description:
+ * Start an audit message using the type specified in @type and fill the audit
+ * message with some fields common to all NetLabel audit messages.  Returns
+ * a pointer to the audit buffer on success, NULL on failure.
+ *
+ */
+struct audit_buffer *netlbl_audit_start_common(int type, u32 secid)
+{
+	struct audit_context *audit_ctx = current->audit_context;
+	struct audit_buffer *audit_buf;
+	uid_t audit_loginuid;
+	const char *audit_tty;
+	char audit_comm[sizeof(current->comm)];
+	struct vm_area_struct *vma;
+	char *secctx;
+	u32 secctx_len;
+
+	audit_buf = audit_log_start(audit_ctx, GFP_ATOMIC, type);
+	if (audit_buf == NULL)
+		return NULL;
+
+	audit_loginuid = audit_get_loginuid(audit_ctx);
+	if (current->signal &&
+	    current->signal->tty &&
+	    current->signal->tty->name)
+		audit_tty = current->signal->tty->name;
+	else
+		audit_tty = "(none)";
+	get_task_comm(audit_comm, current);
+
+	audit_log_format(audit_buf,
+			 "netlabel: auid=%u uid=%u tty=%s pid=%d",
+			 audit_loginuid,
+			 current->uid,
+			 audit_tty,
+			 current->pid);
+	audit_log_format(audit_buf, " comm=");
+	audit_log_untrustedstring(audit_buf, audit_comm);
+	if (current->mm) {
+		down_read(&current->mm->mmap_sem);
+		vma = current->mm->mmap;
+		while (vma) {
+			if ((vma->vm_flags & VM_EXECUTABLE) &&
+			    vma->vm_file) {
+				audit_log_d_path(audit_buf,
+						 " exe=",
+						 vma->vm_file->f_dentry,
+						 vma->vm_file->f_vfsmnt);
+				break;
+			}
+			vma = vma->vm_next;
+		}
+		up_read(&current->mm->mmap_sem);
+	}
+
+	if (secid != 0 &&
+	    security_secid_to_secctx(secid, &secctx, &secctx_len) == 0)
+		audit_log_format(audit_buf, " subj=%s", secctx);
+
+	return audit_buf;
+}
+
+/**
+ * netlbl_audit_nomsg - Send an audit message without additional text
+ * @type: audit message type
+ * @secid: LSM context ID
+ *
+ * Description:
+ * Send an audit message with only the common NetLabel audit fields.
+ *
+ */
+void netlbl_audit_nomsg(int type, u32 secid)
+{
+	struct audit_buffer *audit_buf;
+
+	audit_buf = netlbl_audit_start_common(type, secid);
+	audit_log_end(audit_buf);
+}

net/netlabel/netlabel_user.h

@@ -34,6 +34,7 @@
 #include <linux/types.h>
 #include <linux/skbuff.h>
 #include <linux/capability.h>
+#include <linux/audit.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>
 #include <net/netlabel.h>
@@ -75,4 +76,9 @@ static inline void *netlbl_netlink_hdr_put(struct sk_buff *skb,
 
 int netlbl_netlink_init(void);
 
+/* NetLabel Audit Functions */
+
+struct audit_buffer *netlbl_audit_start_common(int type, u32 secid);
+void netlbl_audit_nomsg(int type, u32 secid);
+
 #endif