4 files changed, 31 insertions, 292 deletions

diff --git a/Documentation/ABI/obsolete/sysfs-selinux-user b/Documentation/ABI/removed/sysfs-selinux-user
index 8ab7557f283f..8ab7557f283f 100644
--- a/Documentation/ABI/obsolete/sysfs-selinux-user
+++ b/Documentation/ABI/removed/sysfs-selinux-user
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index d1f16d7f684d..0babb8992181 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -312,8 +312,6 @@ int security_context_to_sid_default(const char *scontext, u32 scontext_len,
 int security_context_to_sid_force(const char *scontext, u32 scontext_len,
 				  u32 *sid);
 
-int security_get_user_sids(u32 fromsid, const char *username, u32 **sids, u32 *nel);
-
 int security_port_sid(u8 protocol, u16 port, u32 *out_sid);
 
 int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid);
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 83aa765a09f9..25ca7d714014 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -76,7 +76,6 @@ struct selinux_fs_info {
 	int *bool_pending_values;
 	struct dentry *class_dir;
 	unsigned long last_class_ino;
-	bool policy_opened;
 	unsigned long last_ino;
 	struct super_block *sb;
 };
@@ -272,35 +271,13 @@ static ssize_t sel_write_disable(struct file *file, const char __user *buf,
 				 size_t count, loff_t *ppos)
 
 {
-	char *page;
-	ssize_t length;
-	int new_value;
-
-	if (count >= PAGE_SIZE)
-		return -ENOMEM;
-
-	/* No partial writes. */
-	if (*ppos != 0)
-		return -EINVAL;
-
-	page = memdup_user_nul(buf, count);
-	if (IS_ERR(page))
-		return PTR_ERR(page);
-
-	if (sscanf(page, "%d", &new_value) != 1) {
-		length = -EINVAL;
-		goto out;
-	}
-	length = count;
-
-	if (new_value) {
-		pr_err("SELinux: https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-runtime-disable\n");
-		pr_err("SELinux: Runtime disable is not supported, use selinux=0 on the kernel cmdline.\n");
-	}
-
-out:
-	kfree(page);
-	return length;
+	/*
+	 * Setting disable is no longer supported, see
+	 * https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-runtime-disable
+	 */
+	pr_err_once("SELinux: %s (%d) wrote to disable. This is no longer supported.\n",
+		    current->comm, current->pid);
+	return count;
 }
 
 static const struct file_operations sel_disable_ops = {
@@ -362,44 +339,31 @@ struct policy_load_memory {
 
 static int sel_open_policy(struct inode *inode, struct file *filp)
 {
-	struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
 	struct policy_load_memory *plm = NULL;
 	int rc;
 
-	BUG_ON(filp->private_data);
-
-	mutex_lock(&selinux_state.policy_mutex);
-
 	rc = avc_has_perm(current_sid(), SECINITSID_SECURITY,
 			  SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
 	if (rc)
-		goto err;
-
-	rc = -EBUSY;
-	if (fsi->policy_opened)
-		goto err;
+		return rc;
 
-	rc = -ENOMEM;
 	plm = kzalloc_obj(*plm);
 	if (!plm)
-		goto err;
+		return -ENOMEM;
 
+	mutex_lock(&selinux_state.policy_mutex);
 	rc = security_read_policy(&plm->data, &plm->len);
 	if (rc)
 		goto err;
-
 	if ((size_t)i_size_read(inode) != plm->len) {
 		inode_lock(inode);
 		i_size_write(inode, plm->len);
 		inode_unlock(inode);
 	}
-
-	fsi->policy_opened = 1;
+	mutex_unlock(&selinux_state.policy_mutex);
 
 	filp->private_data = plm;
 
-	mutex_unlock(&selinux_state.policy_mutex);
-
 	return 0;
 err:
 	mutex_unlock(&selinux_state.policy_mutex);
@@ -412,13 +376,8 @@ err:
 
 static int sel_release_policy(struct inode *inode, struct file *filp)
 {
-	struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
 	struct policy_load_memory *plm = filp->private_data;
 
-	BUG_ON(!plm);
-
-	fsi->policy_opened = 0;
-
 	vfree(plm->data);
 	kfree(plm);
 
@@ -594,34 +553,31 @@ static ssize_t sel_write_load(struct file *file, const char __user *buf,
 	if (!count)
 		return -EINVAL;
 
-	mutex_lock(&selinux_state.policy_mutex);
-
 	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
 			      SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL);
 	if (length)
-		goto out;
+		return length;
 
 	data = vmalloc(count);
-	if (!data) {
-		length = -ENOMEM;
-		goto out;
-	}
+	if (!data)
+		return -ENOMEM;
 	if (copy_from_user(data, buf, count) != 0) {
 		length = -EFAULT;
 		goto out;
 	}
 
+	mutex_lock(&selinux_state.policy_mutex);
 	length = security_load_policy(data, count, &load_state);
 	if (length) {
 		pr_warn_ratelimited("SELinux: failed to load policy\n");
-		goto out;
+		goto out_unlock;
 	}
 	fsi = file_inode(file)->i_sb->s_fs_info;
 	length = sel_make_policy_nodes(fsi, load_state.policy);
 	if (length) {
 		pr_warn_ratelimited("SELinux: failed to initialize selinuxfs\n");
 		selinux_policy_cancel(&load_state);
-		goto out;
+		goto out_unlock;
 	}
 
 	selinux_policy_commit(&load_state);
@@ -631,8 +587,9 @@ static ssize_t sel_write_load(struct file *file, const char __user *buf,
 		from_kuid(&init_user_ns, audit_get_loginuid(current)),
 		audit_get_sessionid(current));
 
-out:
+out_unlock:
 	mutex_unlock(&selinux_state.policy_mutex);
+out:
 	vfree(data);
 	return length;
 }
@@ -689,46 +646,13 @@ static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
 				      size_t count, loff_t *ppos)
 {
-	char *page;
-	ssize_t length;
-	unsigned int new_value;
-
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
-			      SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT,
-			      NULL);
-	if (length)
-		return length;
-
-	if (count >= PAGE_SIZE)
-		return -ENOMEM;
-
-	/* No partial writes. */
-	if (*ppos != 0)
-		return -EINVAL;
-
-	page = memdup_user_nul(buf, count);
-	if (IS_ERR(page))
-		return PTR_ERR(page);
-
-	if (sscanf(page, "%u", &new_value) != 1) {
-		length = -EINVAL;
-		goto out;
-	}
-	length = count;
-
-	if (new_value) {
-		char comm[sizeof(current->comm)];
-
-		strscpy(comm, current->comm);
-		pr_err("SELinux: %s (%d) set checkreqprot to 1. This is no longer supported.\n",
-		       comm, current->pid);
-	}
-
-	selinux_ima_measure_state();
-
-out:
-	kfree(page);
-	return length;
+	/*
+	 * Setting checkreqprot is no longer supported, see
+	 * https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-checkreqprot
+	 */
+	pr_err_once("SELinux: %s (%d) wrote to checkreqprot. This is no longer supported.\n",
+		    current->comm, current->pid);
+	return count;
 }
 static const struct file_operations sel_checkreqprot_ops = {
 	.read		= sel_read_checkreqprot,
@@ -1073,69 +997,11 @@ out:
 
 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 {
-	char *con = NULL, *user = NULL, *ptr;
-	u32 sid, *sids = NULL;
-	ssize_t length;
-	char *newcon;
-	int rc;
-	u32 i, len, nsids;
-
-	pr_warn_ratelimited("SELinux: %s (%d) wrote to /sys/fs/selinux/user!"
-		" This will not be supported in the future; please update your"
-		" userspace.\n", current->comm, current->pid);
-	ssleep(5);
-
-	length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
-			      SECCLASS_SECURITY, SECURITY__COMPUTE_USER,
-			      NULL);
-	if (length)
-		goto out;
-
-	length = -ENOMEM;
-	con = kzalloc(size + 1, GFP_KERNEL);
-	if (!con)
-		goto out;
-
-	length = -ENOMEM;
-	user = kzalloc(size + 1, GFP_KERNEL);
-	if (!user)
-		goto out;
-
-	length = -EINVAL;
-	if (sscanf(buf, "%s %s", con, user) != 2)
-		goto out;
-
-	length = security_context_str_to_sid(con, &sid, GFP_KERNEL);
-	if (length)
-		goto out;
-
-	length = security_get_user_sids(sid, user, &sids, &nsids);
-	if (length)
-		goto out;
-
-	length = sprintf(buf, "%u", nsids) + 1;
-	ptr = buf + length;
-	for (i = 0; i < nsids; i++) {
-		rc = security_sid_to_context(sids[i], &newcon, &len);
-		if (rc) {
-			length = rc;
-			goto out;
-		}
-		if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
-			kfree(newcon);
-			length = -ERANGE;
-			goto out;
-		}
-		memcpy(ptr, newcon, len);
-		kfree(newcon);
-		ptr += len;
-		length += len;
-	}
-out:
-	kfree(sids);
-	kfree(user);
-	kfree(con);
-	return length;
+	pr_err_once("SELinux: %s (%d) wrote to user. This is no longer supported.\n",
+		    current->comm, current->pid);
+	buf[0] = '0';
+	buf[1] = 0;
+	return 2;
 }
 
 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index e8e7ccbd1e44..143021c5e326 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2746,131 +2746,6 @@ out:
 	return rc;
 }
 
-#define SIDS_NEL 25
-
-/**
- * security_get_user_sids - Obtain reachable SIDs for a user.
- * @fromsid: starting SID
- * @username: username
- * @sids: array of reachable SIDs for user
- * @nel: number of elements in @sids
- *
- * Generate the set of SIDs for legal security contexts
- * for a given user that can be reached by @fromsid.
- * Set *@sids to point to a dynamically allocated
- * array containing the set of SIDs.  Set *@nel to the
- * number of elements in the array.
- */
-
-int security_get_user_sids(u32 fromsid,
-			   const char *username,
-			   u32 **sids,
-			   u32 *nel)
-{
-	struct selinux_policy *policy;
-	struct policydb *policydb;
-	struct sidtab *sidtab;
-	struct context *fromcon, usercon;
-	u32 *mysids = NULL, *mysids2, sid;
-	u32 i, j, mynel, maxnel = SIDS_NEL;
-	struct user_datum *user;
-	struct role_datum *role;
-	struct ebitmap_node *rnode, *tnode;
-	int rc;
-
-	*sids = NULL;
-	*nel = 0;
-
-	if (!selinux_initialized())
-		return 0;
-
-	mysids = kcalloc(maxnel, sizeof(*mysids), GFP_KERNEL);
-	if (!mysids)
-		return -ENOMEM;
-
-retry:
-	mynel = 0;
-	rcu_read_lock();
-	policy = rcu_dereference(selinux_state.policy);
-	policydb = &policy->policydb;
-	sidtab = policy->sidtab;
-
-	context_init(&usercon);
-
-	rc = -EINVAL;
-	fromcon = sidtab_search(sidtab, fromsid);
-	if (!fromcon)
-		goto out_unlock;
-
-	rc = -EINVAL;
-	user = symtab_search(&policydb->p_users, username);
-	if (!user)
-		goto out_unlock;
-
-	usercon.user = user->value;
-
-	ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
-		role = policydb->role_val_to_struct[i];
-		usercon.role = i + 1;
-		ebitmap_for_each_positive_bit(&role->types, tnode, j) {
-			usercon.type = j + 1;
-
-			if (mls_setup_user_range(policydb, fromcon, user,
-						 &usercon))
-				continue;
-
-			rc = sidtab_context_to_sid(sidtab, &usercon, &sid);
-			if (rc == -ESTALE) {
-				rcu_read_unlock();
-				goto retry;
-			}
-			if (rc)
-				goto out_unlock;
-			if (mynel < maxnel) {
-				mysids[mynel++] = sid;
-			} else {
-				rc = -ENOMEM;
-				maxnel += SIDS_NEL;
-				mysids2 = kcalloc(maxnel, sizeof(*mysids2), GFP_ATOMIC);
-				if (!mysids2)
-					goto out_unlock;
-				memcpy(mysids2, mysids, mynel * sizeof(*mysids2));
-				kfree(mysids);
-				mysids = mysids2;
-				mysids[mynel++] = sid;
-			}
-		}
-	}
-	rc = 0;
-out_unlock:
-	rcu_read_unlock();
-	if (rc || !mynel) {
-		kfree(mysids);
-		return rc;
-	}
-
-	rc = -ENOMEM;
-	mysids2 = kcalloc(mynel, sizeof(*mysids2), GFP_KERNEL);
-	if (!mysids2) {
-		kfree(mysids);
-		return rc;
-	}
-	for (i = 0, j = 0; i < mynel; i++) {
-		struct av_decision dummy_avd;
-		rc = avc_has_perm_noaudit(fromsid, mysids[i],
-					  SECCLASS_PROCESS, /* kernel value */
-					  PROCESS__TRANSITION, AVC_STRICT,
-					  &dummy_avd);
-		if (!rc)
-			mysids2[j++] = mysids[i];
-		cond_resched();
-	}
-	kfree(mysids);
-	*sids = mysids2;
-	*nel = j;
-	return 0;
-}
-
 /**
  * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem
  * @policy: policy