selinux: wrap AVC state

Wrap the AVC state within the selinux_state structure and pass it explicitly to all AVC functions. The AVC private state is encapsulated in a selinux_avc structure that is referenced from the selinux_state. This change should have no effect on SELinux behavior or APIs (userspace or LSM). Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: James Morris <james.morris@microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
mariux64 · Mar 20, 2018 · 6b6bc62 · 6b6bc62
1 parent 0619f0f
commit 6b6bc62
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Showing 9 changed files with 512 additions and 297 deletions.
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h
@@ -52,6 +52,7 @@ struct selinux_audit_data {
 	u32 audited;
 	u32 denied;
 	int result;
+	struct selinux_state *state;
 };
 
 /*
@@ -96,7 +97,8 @@ static inline u32 avc_audit_required(u32 requested,
 	return audited;
 }
 
-int slow_avc_audit(u32 ssid, u32 tsid, u16 tclass,
+int slow_avc_audit(struct selinux_state *state,
+		   u32 ssid, u32 tsid, u16 tclass,
 		   u32 requested, u32 audited, u32 denied, int result,
 		   struct common_audit_data *a,
 		   unsigned flags);
@@ -121,7 +123,8 @@ int slow_avc_audit(u32 ssid, u32 tsid, u16 tclass,
  * be performed under a lock, to allow the lock to be released
  * before calling the auditing code.
  */
-static inline int avc_audit(u32 ssid, u32 tsid,
+static inline int avc_audit(struct selinux_state *state,
+			    u32 ssid, u32 tsid,
 			    u16 tclass, u32 requested,
 			    struct av_decision *avd,
 			    int result,
@@ -132,31 +135,35 @@ static inline int avc_audit(u32 ssid, u32 tsid,
 	audited = avc_audit_required(requested, avd, result, 0, &denied);
 	if (likely(!audited))
 		return 0;
-	return slow_avc_audit(ssid, tsid, tclass,
+	return slow_avc_audit(state, ssid, tsid, tclass,
 			      requested, audited, denied, result,
 			      a, flags);
 }
 
 #define AVC_STRICT 1 /* Ignore permissive mode. */
 #define AVC_EXTENDED_PERMS 2	/* update extended permissions */
-int avc_has_perm_noaudit(u32 ssid, u32 tsid,
+int avc_has_perm_noaudit(struct selinux_state *state,
+			 u32 ssid, u32 tsid,
 			 u16 tclass, u32 requested,
 			 unsigned flags,
 			 struct av_decision *avd);
 
-int avc_has_perm(u32 ssid, u32 tsid,
+int avc_has_perm(struct selinux_state *state,
+		 u32 ssid, u32 tsid,
 		 u16 tclass, u32 requested,
 		 struct common_audit_data *auditdata);
-int avc_has_perm_flags(u32 ssid, u32 tsid,
+int avc_has_perm_flags(struct selinux_state *state,
+		       u32 ssid, u32 tsid,
 		       u16 tclass, u32 requested,
 		       struct common_audit_data *auditdata,
 		       int flags);
 
-int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested,
-		u8 driver, u8 perm, struct common_audit_data *ad);
+int avc_has_extended_perms(struct selinux_state *state,
+			   u32 ssid, u32 tsid, u16 tclass, u32 requested,
+			   u8 driver, u8 perm, struct common_audit_data *ad);
 
 
-u32 avc_policy_seqno(void);
+u32 avc_policy_seqno(struct selinux_state *state);
 
 #define AVC_CALLBACK_GRANT		1
 #define AVC_CALLBACK_TRY_REVOKE		2
@@ -171,8 +178,11 @@ u32 avc_policy_seqno(void);
 int avc_add_callback(int (*callback)(u32 event), u32 events);
 
 /* Exported to selinuxfs */
-int avc_get_hash_stats(char *page);
-extern unsigned int avc_cache_threshold;
+struct selinux_avc;
+int avc_get_hash_stats(struct selinux_avc *avc, char *page);
+unsigned int avc_get_cache_threshold(struct selinux_avc *avc);
+void avc_set_cache_threshold(struct selinux_avc *avc,
+			     unsigned int cache_threshold);
 
 /* Attempt to free avc node cache */
 void avc_disable(void);

diff --git a/security/selinux/include/avc_ss.h b/security/selinux/include/avc_ss.h
@@ -9,7 +9,8 @@
 
 #include "flask.h"
 
-int avc_ss_reset(u32 seqno);
+struct selinux_avc;
+int avc_ss_reset(struct selinux_avc *avc, u32 seqno);
 
 /* Class/perm mapping support */
 struct security_class_mapping {

diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
@@ -93,6 +93,7 @@ extern char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX];
 /* limitation of boundary depth  */
 #define POLICYDB_BOUNDS_MAXDEPTH	4
 
+struct selinux_avc;
 struct selinux_ss;
 
 struct selinux_state {
@@ -103,10 +104,12 @@ struct selinux_state {
 	bool checkreqprot;
 	bool initialized;
 	bool policycap[__POLICYDB_CAPABILITY_MAX];
+	struct selinux_avc *avc;
 	struct selinux_ss *ss;
 };
 
 void selinux_ss_init(struct selinux_ss **ss);
+void selinux_avc_init(struct selinux_avc **avc);
 
 extern struct selinux_state selinux_state;
 

diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
@@ -478,7 +478,8 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec,
 		perm = RAWIP_SOCKET__RECVFROM;
 	}
 
-	rc = avc_has_perm(sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
+	rc = avc_has_perm(&selinux_state,
+			  sksec->sid, nlbl_sid, sksec->sclass, perm, ad);
 	if (rc == 0)
 		return 0;
 

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
@@ -161,7 +161,8 @@ static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 
 	old_value = enforcing_enabled(state);
 	if (new_value != old_value) {
-		length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+		length = avc_has_perm(&selinux_state,
+				      current_sid(), SECINITSID_SECURITY,
 				      SECCLASS_SECURITY, SECURITY__SETENFORCE,
 				      NULL);
 		if (length)
@@ -173,7 +174,7 @@ static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 			audit_get_sessionid(current));
 		enforcing_set(state, new_value);
 		if (new_value)
-			avc_ss_reset(0);
+			avc_ss_reset(state->avc, 0);
 		selnl_notify_setenforce(new_value);
 		selinux_status_update_setenforce(state, new_value);
 		if (!new_value)
@@ -375,7 +376,8 @@ static int sel_open_policy(struct inode *inode, struct file *filp)
 
 	mutex_lock(&fsi->mutex);
 
-	rc = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	rc = avc_has_perm(&selinux_state,
+			  current_sid(), SECINITSID_SECURITY,
 			  SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 	if (rc)
 		goto err;
@@ -439,7 +441,8 @@ static ssize_t sel_read_policy(struct file *filp, char __user *buf,
 
 	mutex_lock(&fsi->mutex);
 
-	ret = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	ret = avc_has_perm(&selinux_state,
+			   current_sid(), SECINITSID_SECURITY,
 			  SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 	if (ret)
 		goto out;
@@ -535,7 +538,8 @@ static ssize_t sel_write_load(struct file *file, const char __user *buf,
 
 	mutex_lock(&fsi->mutex);
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL);
 	if (length)
 		goto out;
@@ -594,7 +598,8 @@ static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 	u32 sid, len;
 	ssize_t length;
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL);
 	if (length)
 		goto out;
@@ -640,7 +645,8 @@ static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 	ssize_t length;
 	unsigned int new_value;
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT,
 			      NULL);
 	if (length)
@@ -685,7 +691,8 @@ static ssize_t sel_write_validatetrans(struct file *file,
 	u16 tclass;
 	int rc;
 
-	rc = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	rc = avc_has_perm(&selinux_state,
+			  current_sid(), SECINITSID_SECURITY,
 			  SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL);
 	if (rc)
 		goto out;
@@ -813,7 +820,8 @@ static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 	struct av_decision avd;
 	ssize_t length;
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL);
 	if (length)
 		goto out;
@@ -866,7 +874,8 @@ static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 	u32 len;
 	int nargs;
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE,
 			      NULL);
 	if (length)
@@ -967,7 +976,8 @@ static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 	char *newcon = NULL;
 	u32 len;
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL,
 			      NULL);
 	if (length)
@@ -1027,7 +1037,8 @@ static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 	int i, rc;
 	u32 len, nsids;
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__COMPUTE_USER,
 			      NULL);
 	if (length)
@@ -1091,7 +1102,8 @@ static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 	char *newcon = NULL;
 	u32 len;
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER,
 			      NULL);
 	if (length)
@@ -1203,7 +1215,8 @@ static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
 
 	mutex_lock(&fsi->mutex);
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__SETBOOL,
 			      NULL);
 	if (length)
@@ -1263,7 +1276,8 @@ static ssize_t sel_commit_bools_write(struct file *filep,
 
 	mutex_lock(&fsi->mutex);
 
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	length = avc_has_perm(&selinux_state,
+			      current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__SETBOOL,
 			      NULL);
 	if (length)
@@ -1403,10 +1417,13 @@ static int sel_make_bools(struct selinux_fs_info *fsi)
 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
 					    size_t count, loff_t *ppos)
 {
+	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
+	struct selinux_state *state = fsi->state;
 	char tmpbuf[TMPBUFLEN];
 	ssize_t length;
 
-	length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
+	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
+			   avc_get_cache_threshold(state->avc));
 	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
 }
 
@@ -1415,11 +1432,14 @@ static ssize_t sel_write_avc_cache_threshold(struct file *file,
 					     size_t count, loff_t *ppos)
 
 {
+	struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
+	struct selinux_state *state = fsi->state;
 	char *page;
 	ssize_t ret;
 	unsigned int new_value;
 
-	ret = avc_has_perm(current_sid(), SECINITSID_SECURITY,
+	ret = avc_has_perm(&selinux_state,
+			   current_sid(), SECINITSID_SECURITY,
 			   SECCLASS_SECURITY, SECURITY__SETSECPARAM,
 			   NULL);
 	if (ret)
@@ -1440,7 +1460,7 @@ static ssize_t sel_write_avc_cache_threshold(struct file *file,
 	if (sscanf(page, "%u", &new_value) != 1)
 		goto out;
 
-	avc_cache_threshold = new_value;
+	avc_set_cache_threshold(state->avc, new_value);
 
 	ret = count;
 out:
@@ -1451,14 +1471,16 @@ static ssize_t sel_write_avc_cache_threshold(struct file *file,
 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
 				       size_t count, loff_t *ppos)
 {
+	struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
+	struct selinux_state *state = fsi->state;
 	char *page;
 	ssize_t length;
 
 	page = (char *)__get_free_page(GFP_KERNEL);
 	if (!page)
 		return -ENOMEM;
 
-	length = avc_get_hash_stats(page);
+	length = avc_get_hash_stats(state->avc, page);
 	if (length >= 0)
 		length = simple_read_from_buffer(buf, count, ppos, page, length);
 	free_page((unsigned long)page);

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
@@ -2151,7 +2151,7 @@ int security_load_policy(struct selinux_state *state, void *data, size_t len)
 		state->initialized = 1;
 		seqno = ++state->ss->latest_granting;
 		selinux_complete_init();
-		avc_ss_reset(seqno);
+		avc_ss_reset(state->avc, seqno);
 		selnl_notify_policyload(seqno);
 		selinux_status_update_policyload(state, seqno);
 		selinux_netlbl_cache_invalidate();
@@ -2233,7 +2233,7 @@ int security_load_policy(struct selinux_state *state, void *data, size_t len)
 	sidtab_destroy(&oldsidtab);
 	kfree(oldmapping);
 
-	avc_ss_reset(seqno);
+	avc_ss_reset(state->avc, seqno);
 	selnl_notify_policyload(seqno);
 	selinux_status_update_policyload(state, seqno);
 	selinux_netlbl_cache_invalidate();
@@ -2649,7 +2649,8 @@ int security_get_user_sids(struct selinux_state *state,
 	}
 	for (i = 0, j = 0; i < mynel; i++) {
 		struct av_decision dummy_avd;
-		rc = avc_has_perm_noaudit(fromsid, mysids[i],
+		rc = avc_has_perm_noaudit(state,
+					  fromsid, mysids[i],
 					  SECCLASS_PROCESS, /* kernel value */
 					  PROCESS__TRANSITION, AVC_STRICT,
 					  &dummy_avd);
@@ -2907,7 +2908,7 @@ int security_set_bools(struct selinux_state *state, int len, int *values)
 out:
 	write_unlock_irq(&state->ss->policy_rwlock);
 	if (!rc) {
-		avc_ss_reset(seqno);
+		avc_ss_reset(state->avc, seqno);
 		selnl_notify_policyload(seqno);
 		selinux_status_update_policyload(state, seqno);
 		selinux_xfrm_notify_policyload();