Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris:

 - EVM gains support for loading an x509 cert from the kernel
   (EVM_LOAD_X509), into the EVM trusted kernel keyring.

 - Smack implements 'file receive' process-based permission checking for
   sockets, rather than just depending on inode checks.

 - Misc enhancments for TPM & TPM2.

 - Cleanups and bugfixes for SELinux, Keys, and IMA.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits)
  selinux: Inode label revalidation performance fix
  KEYS: refcount bug fix
  ima: ima_write_policy() limit locking
  IMA: policy can be updated zero times
  selinux: rate-limit netlink message warnings in selinux_nlmsg_perm()
  selinux: export validatetrans decisions
  gfs2: Invalid security labels of inodes when they go invalid
  selinux: Revalidate invalid inode security labels
  security: Add hook to invalidate inode security labels
  selinux: Add accessor functions for inode->i_security
  security: Make inode argument of inode_getsecid non-const
  security: Make inode argument of inode_getsecurity non-const
  selinux: Remove unused variable in selinux_inode_init_security
  keys, trusted: seal with a TPM2 authorization policy
  keys, trusted: select hash algorithm for TPM2 chips
  keys, trusted: fix: *do not* allow duplicate key options
  tpm_ibmvtpm: properly handle interrupted packet receptions
  tpm_tis: Tighten IRQ auto-probing
  tpm_tis: Refactor the interrupt setup
  tpm_tis: Get rid of the duplicate IRQ probing code
  ...

security/selinux/hooks.c

@@ -242,6 +242,72 @@ static int inode_alloc_security(struct inode *inode)
 	return 0;
 }
 
+static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
+
+/*
+ * Try reloading inode security labels that have been marked as invalid.  The
+ * @may_sleep parameter indicates when sleeping and thus reloading labels is
+ * allowed; when set to false, returns ERR_PTR(-ECHILD) when the label is
+ * invalid.  The @opt_dentry parameter should be set to a dentry of the inode;
+ * when no dentry is available, set it to NULL instead.
+ */
+static int __inode_security_revalidate(struct inode *inode,
+				       struct dentry *opt_dentry,
+				       bool may_sleep)
+{
+	struct inode_security_struct *isec = inode->i_security;
+
+	might_sleep_if(may_sleep);
+
+	if (isec->initialized == LABEL_INVALID) {
+		if (!may_sleep)
+			return -ECHILD;
+
+		/*
+		 * Try reloading the inode security label.  This will fail if
+		 * @opt_dentry is NULL and no dentry for this inode can be
+		 * found; in that case, continue using the old label.
+		 */
+		inode_doinit_with_dentry(inode, opt_dentry);
+	}
+	return 0;
+}
+
+static struct inode_security_struct *inode_security_novalidate(struct inode *inode)
+{
+	return inode->i_security;
+}
+
+static struct inode_security_struct *inode_security_rcu(struct inode *inode, bool rcu)
+{
+	int error;
+
+	error = __inode_security_revalidate(inode, NULL, !rcu);
+	if (error)
+		return ERR_PTR(error);
+	return inode->i_security;
+}
+
+/*
+ * Get the security label of an inode.
+ */
+static struct inode_security_struct *inode_security(struct inode *inode)
+{
+	__inode_security_revalidate(inode, NULL, true);
+	return inode->i_security;
+}
+
+/*
+ * Get the security label of a dentry's backing inode.
+ */
+static struct inode_security_struct *backing_inode_security(struct dentry *dentry)
+{
+	struct inode *inode = d_backing_inode(dentry);
+
+	__inode_security_revalidate(inode, dentry, true);
+	return inode->i_security;
+}
+
 static void inode_free_rcu(struct rcu_head *head)
 {
 	struct inode_security_struct *isec;
@@ -345,8 +411,6 @@ static const char *labeling_behaviors[7] = {
 	"uses native labeling",
 };
 
-static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
-
 static inline int inode_doinit(struct inode *inode)
 {
 	return inode_doinit_with_dentry(inode, NULL);
@@ -565,8 +629,8 @@ static int selinux_get_mnt_opts(const struct super_block *sb,
 		opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
 	}
 	if (sbsec->flags & ROOTCONTEXT_MNT) {
-		struct inode *root = d_backing_inode(sbsec->sb->s_root);
-		struct inode_security_struct *isec = root->i_security;
+		struct dentry *root = sbsec->sb->s_root;
+		struct inode_security_struct *isec = backing_inode_security(root);
 
 		rc = security_sid_to_context(isec->sid, &context, &len);
 		if (rc)
@@ -621,8 +685,8 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 	int rc = 0, i;
 	struct superblock_security_struct *sbsec = sb->s_security;
 	const char *name = sb->s_type->name;
-	struct inode *inode = d_backing_inode(sbsec->sb->s_root);
-	struct inode_security_struct *root_isec = inode->i_security;
+	struct dentry *root = sbsec->sb->s_root;
+	struct inode_security_struct *root_isec = backing_inode_security(root);
 	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
 	u32 defcontext_sid = 0;
 	char **mount_options = opts->mnt_opts;
@@ -802,7 +866,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 			goto out;
 
 		root_isec->sid = rootcontext_sid;
-		root_isec->initialized = 1;
+		root_isec->initialized = LABEL_INITIALIZED;
 	}
 
 	if (defcontext_sid) {
@@ -852,8 +916,8 @@ static int selinux_cmp_sb_context(const struct super_block *oldsb,
 	if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
 		goto mismatch;
 	if (oldflags & ROOTCONTEXT_MNT) {
-		struct inode_security_struct *oldroot = d_backing_inode(oldsb->s_root)->i_security;
-		struct inode_security_struct *newroot = d_backing_inode(newsb->s_root)->i_security;
+		struct inode_security_struct *oldroot = backing_inode_security(oldsb->s_root);
+		struct inode_security_struct *newroot = backing_inode_security(newsb->s_root);
 		if (oldroot->sid != newroot->sid)
 			goto mismatch;
 	}
@@ -903,17 +967,14 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 		if (!set_fscontext)
 			newsbsec->sid = sid;
 		if (!set_rootcontext) {
-			struct inode *newinode = d_backing_inode(newsb->s_root);
-			struct inode_security_struct *newisec = newinode->i_security;
+			struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
 			newisec->sid = sid;
 		}
 		newsbsec->mntpoint_sid = sid;
 	}
 	if (set_rootcontext) {
-		const struct inode *oldinode = d_backing_inode(oldsb->s_root);
-		const struct inode_security_struct *oldisec = oldinode->i_security;
-		struct inode *newinode = d_backing_inode(newsb->s_root);
-		struct inode_security_struct *newisec = newinode->i_security;
+		const struct inode_security_struct *oldisec = backing_inode_security(oldsb->s_root);
+		struct inode_security_struct *newisec = backing_inode_security(newsb->s_root);
 
 		newisec->sid = oldisec->sid;
 	}
@@ -1293,11 +1354,11 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 	unsigned len = 0;
 	int rc = 0;
 
-	if (isec->initialized)
+	if (isec->initialized == LABEL_INITIALIZED)
 		goto out;
 
 	mutex_lock(&isec->lock);
-	if (isec->initialized)
+	if (isec->initialized == LABEL_INITIALIZED)
 		goto out_unlock;
 
 	sbsec = inode->i_sb->s_security;
@@ -1469,7 +1530,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 		break;
 	}
 
-	isec->initialized = 1;
+	isec->initialized = LABEL_INITIALIZED;
 
 out_unlock:
 	mutex_unlock(&isec->lock);
@@ -1640,6 +1701,7 @@ static inline int dentry_has_perm(const struct cred *cred,
 
 	ad.type = LSM_AUDIT_DATA_DENTRY;
 	ad.u.dentry = dentry;
+	__inode_security_revalidate(inode, dentry, true);
 	return inode_has_perm(cred, inode, av, &ad);
 }
 
@@ -1655,6 +1717,7 @@ static inline int path_has_perm(const struct cred *cred,
 
 	ad.type = LSM_AUDIT_DATA_PATH;
 	ad.u.path = *path;
+	__inode_security_revalidate(inode, path->dentry, true);
 	return inode_has_perm(cred, inode, av, &ad);
 }
 
@@ -1712,13 +1775,13 @@ out:
 /*
  * Determine the label for an inode that might be unioned.
  */
-static int selinux_determine_inode_label(const struct inode *dir,
+static int selinux_determine_inode_label(struct inode *dir,
 					 const struct qstr *name,
 					 u16 tclass,
 					 u32 *_new_isid)
 {
 	const struct superblock_security_struct *sbsec = dir->i_sb->s_security;
-	const struct inode_security_struct *dsec = dir->i_security;
+	const struct inode_security_struct *dsec = inode_security(dir);
 	const struct task_security_struct *tsec = current_security();
 
 	if ((sbsec->flags & SE_SBINITIALIZED) &&
@@ -1747,7 +1810,7 @@ static int may_create(struct inode *dir,
 	struct common_audit_data ad;
 	int rc;
 
-	dsec = dir->i_security;
+	dsec = inode_security(dir);
 	sbsec = dir->i_sb->s_security;
 
 	sid = tsec->sid;
@@ -1800,8 +1863,8 @@ static int may_link(struct inode *dir,
 	u32 av;
 	int rc;
 
-	dsec = dir->i_security;
-	isec = d_backing_inode(dentry)->i_security;
+	dsec = inode_security(dir);
+	isec = backing_inode_security(dentry);
 
 	ad.type = LSM_AUDIT_DATA_DENTRY;
 	ad.u.dentry = dentry;
@@ -1844,10 +1907,10 @@ static inline int may_rename(struct inode *old_dir,
 	int old_is_dir, new_is_dir;
 	int rc;
 
-	old_dsec = old_dir->i_security;
-	old_isec = d_backing_inode(old_dentry)->i_security;
+	old_dsec = inode_security(old_dir);
+	old_isec = backing_inode_security(old_dentry);
 	old_is_dir = d_is_dir(old_dentry);
-	new_dsec = new_dir->i_security;
+	new_dsec = inode_security(new_dir);
 
 	ad.type = LSM_AUDIT_DATA_DENTRY;
 
@@ -1875,7 +1938,7 @@ static inline int may_rename(struct inode *old_dir,
 	if (rc)
 		return rc;
 	if (d_is_positive(new_dentry)) {
-		new_isec = d_backing_inode(new_dentry)->i_security;
+		new_isec = backing_inode_security(new_dentry);
 		new_is_dir = d_is_dir(new_dentry);
 		rc = avc_has_perm(sid, new_isec->sid,
 				  new_isec->sclass,
@@ -2011,8 +2074,8 @@ static int selinux_binder_transfer_file(struct task_struct *from,
 {
 	u32 sid = task_sid(to);
 	struct file_security_struct *fsec = file->f_security;
-	struct inode *inode = d_backing_inode(file->f_path.dentry);
-	struct inode_security_struct *isec = inode->i_security;
+	struct dentry *dentry = file->f_path.dentry;
+	struct inode_security_struct *isec = backing_inode_security(dentry);
 	struct common_audit_data ad;
 	int rc;
 
@@ -2028,7 +2091,7 @@ static int selinux_binder_transfer_file(struct task_struct *from,
 			return rc;
 	}
 
-	if (unlikely(IS_PRIVATE(inode)))
+	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
 		return 0;
 
 	return avc_has_perm(sid, isec->sid, isec->sclass, file_to_av(file),
@@ -2217,7 +2280,7 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
 
 	old_tsec = current_security();
 	new_tsec = bprm->cred->security;
-	isec = inode->i_security;
+	isec = inode_security(inode);
 
 	/* Default to the current task SID. */
 	new_tsec->sid = old_tsec->sid;
@@ -2639,7 +2702,7 @@ static int selinux_sb_remount(struct super_block *sb, void *data)
 			break;
 		case ROOTCONTEXT_MNT: {
 			struct inode_security_struct *root_isec;
-			root_isec = d_backing_inode(sb->s_root)->i_security;
+			root_isec = backing_inode_security(sb->s_root);
 
 			if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
 				goto out_bad_option;
@@ -2753,13 +2816,11 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
 				       void **value, size_t *len)
 {
 	const struct task_security_struct *tsec = current_security();
-	struct inode_security_struct *dsec;
 	struct superblock_security_struct *sbsec;
 	u32 sid, newsid, clen;
 	int rc;
 	char *context;
 
-	dsec = dir->i_security;
 	sbsec = dir->i_sb->s_security;
 
 	sid = tsec->sid;
@@ -2777,7 +2838,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
 		struct inode_security_struct *isec = inode->i_security;
 		isec->sclass = inode_mode_to_security_class(inode->i_mode);
 		isec->sid = newsid;
-		isec->initialized = 1;
+		isec->initialized = LABEL_INITIALIZED;
 	}
 
 	if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT))
@@ -2858,7 +2919,9 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
 	ad.type = LSM_AUDIT_DATA_DENTRY;
 	ad.u.dentry = dentry;
 	sid = cred_sid(cred);
-	isec = inode->i_security;
+	isec = inode_security_rcu(inode, rcu);
+	if (IS_ERR(isec))
+		return PTR_ERR(isec);
 
 	return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad,
 				  rcu ? MAY_NOT_BLOCK : 0);
@@ -2910,7 +2973,9 @@ static int selinux_inode_permission(struct inode *inode, int mask)
 	perms = file_mask_to_av(inode->i_mode, mask);
 
 	sid = cred_sid(cred);
-	isec = inode->i_security;
+	isec = inode_security_rcu(inode, flags & MAY_NOT_BLOCK);
+	if (IS_ERR(isec))
+		return PTR_ERR(isec);
 
 	rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
 	audited = avc_audit_required(perms, &avd, rc,
@@ -2980,7 +3045,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
 				  const void *value, size_t size, int flags)
 {
 	struct inode *inode = d_backing_inode(dentry);
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec = backing_inode_security(dentry);
 	struct superblock_security_struct *sbsec;
 	struct common_audit_data ad;
 	u32 newsid, sid = current_sid();
@@ -3057,7 +3122,7 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
 					int flags)
 {
 	struct inode *inode = d_backing_inode(dentry);
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec = backing_inode_security(dentry);
 	u32 newsid;
 	int rc;
 
@@ -3076,7 +3141,7 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
 
 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
 	isec->sid = newsid;
-	isec->initialized = 1;
+	isec->initialized = LABEL_INITIALIZED;
 
 	return;
 }
@@ -3110,12 +3175,12 @@ static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
  *
  * Permission check is handled by selinux_inode_getxattr hook.
  */
-static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
+static int selinux_inode_getsecurity(struct inode *inode, const char *name, void **buffer, bool alloc)
 {
 	u32 size;
 	int error;
 	char *context = NULL;
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec = inode_security(inode);
 
 	if (strcmp(name, XATTR_SELINUX_SUFFIX))
 		return -EOPNOTSUPP;
@@ -3154,7 +3219,7 @@ out_nofree:
 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
 				     const void *value, size_t size, int flags)
 {
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec = inode_security(inode);
 	u32 newsid;
 	int rc;
 
@@ -3170,7 +3235,7 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
 
 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
 	isec->sid = newsid;
-	isec->initialized = 1;
+	isec->initialized = LABEL_INITIALIZED;
 	return 0;
 }
 
@@ -3182,9 +3247,9 @@ static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t
 	return len;
 }
 
-static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
+static void selinux_inode_getsecid(struct inode *inode, u32 *secid)
 {
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec = inode_security(inode);
 	*secid = isec->sid;
 }
 
@@ -3207,13 +3272,14 @@ static int selinux_file_permission(struct file *file, int mask)
 {
 	struct inode *inode = file_inode(file);
 	struct file_security_struct *fsec = file->f_security;
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec;
 	u32 sid = current_sid();
 
 	if (!mask)
 		/* No permission to check.  Existence test. */
 		return 0;
 
+	isec = inode_security(inode);
 	if (sid == fsec->sid && fsec->isid == isec->sid &&
 	    fsec->pseqno == avc_policy_seqno())
 		/* No change since file_open check. */
@@ -3242,7 +3308,7 @@ static int ioctl_has_perm(const struct cred *cred, struct file *file,
 	struct common_audit_data ad;
 	struct file_security_struct *fsec = file->f_security;
 	struct inode *inode = file_inode(file);
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec = inode_security(inode);
 	struct lsm_ioctlop_audit ioctl;
 	u32 ssid = cred_sid(cred);
 	int rc;
@@ -3506,7 +3572,7 @@ static int selinux_file_open(struct file *file, const struct cred *cred)
 	struct inode_security_struct *isec;
 
 	fsec = file->f_security;
-	isec = file_inode(file)->i_security;
+	isec = inode_security(file_inode(file));
 	/*
 	 * Save inode label and policy sequence number
 	 * at open-time so that selinux_file_permission
@@ -3624,7 +3690,7 @@ static int selinux_kernel_act_as(struct cred *new, u32 secid)
  */
 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
 {
-	struct inode_security_struct *isec = inode->i_security;
+	struct inode_security_struct *isec = inode_security(inode);
 	struct task_security_struct *tsec = new->security;
 	u32 sid = current_sid();
 	int ret;
@@ -3748,7 +3814,7 @@ static void selinux_task_to_inode(struct task_struct *p,
 	u32 sid = task_sid(p);
 
 	isec->sid = sid;
-	isec->initialized = 1;
+	isec->initialized = LABEL_INITIALIZED;
 }
 
 /* Returns error only if unable to parse addresses */
@@ -4065,7 +4131,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
 				      int type, int protocol, int kern)
 {
 	const struct task_security_struct *tsec = current_security();
-	struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
+	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
 	struct sk_security_struct *sksec;
 	int err = 0;
 
@@ -4079,7 +4145,7 @@ static int selinux_socket_post_create(struct socket *sock, int family,
 			return err;
 	}
 
-	isec->initialized = 1;
+	isec->initialized = LABEL_INITIALIZED;
 
 	if (sock->sk) {
 		sksec = sock->sk->sk_security;
@@ -4265,12 +4331,12 @@ static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
 	if (err)
 		return err;
 
-	newisec = SOCK_INODE(newsock)->i_security;
+	newisec = inode_security_novalidate(SOCK_INODE(newsock));
 
-	isec = SOCK_INODE(sock)->i_security;
+	isec = inode_security_novalidate(SOCK_INODE(sock));
 	newisec->sclass = isec->sclass;
 	newisec->sid = isec->sid;
-	newisec->initialized = 1;
+	newisec->initialized = LABEL_INITIALIZED;
 
 	return 0;
 }
@@ -4605,7 +4671,8 @@ static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
 
 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
 {
-	struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
+	struct inode_security_struct *isec =
+		inode_security_novalidate(SOCK_INODE(parent));
 	struct sk_security_struct *sksec = sk->sk_security;
 
 	if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
@@ -4785,11 +4852,12 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
 	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
 	if (err) {
 		if (err == -EINVAL) {
-			printk(KERN_WARNING
-			       "SELinux: unrecognized netlink message:"
-			       " protocol=%hu nlmsg_type=%hu sclass=%s\n",
+			pr_warn_ratelimited("SELinux: unrecognized netlink"
+			       " message: protocol=%hu nlmsg_type=%hu sclass=%s"
+			       " pig=%d comm=%s\n",
 			       sk->sk_protocol, nlh->nlmsg_type,
-			       secclass_map[sksec->sclass - 1].name);
+			       secclass_map[sksec->sclass - 1].name,
+			       task_pid_nr(current), current->comm);
 			if (!selinux_enforcing || security_get_allow_unknown())
 				err = 0;
 		}
@@ -5762,6 +5830,15 @@ static void selinux_release_secctx(char *secdata, u32 seclen)
 	kfree(secdata);
 }
 
+static void selinux_inode_invalidate_secctx(struct inode *inode)
+{
+	struct inode_security_struct *isec = inode->i_security;
+
+	mutex_lock(&isec->lock);
+	isec->initialized = LABEL_INVALID;
+	mutex_unlock(&isec->lock);
+}
+
 /*
  *	called with inode->i_mutex locked
  */
@@ -5993,6 +6070,7 @@ static struct security_hook_list selinux_hooks[] = {
 	LSM_HOOK_INIT(secid_to_secctx, selinux_secid_to_secctx),
 	LSM_HOOK_INIT(secctx_to_secid, selinux_secctx_to_secid),
 	LSM_HOOK_INIT(release_secctx, selinux_release_secctx),
+	LSM_HOOK_INIT(inode_invalidate_secctx, selinux_inode_invalidate_secctx),
 	LSM_HOOK_INIT(inode_notifysecctx, selinux_inode_notifysecctx),
 	LSM_HOOK_INIT(inode_setsecctx, selinux_inode_setsecctx),
 	LSM_HOOK_INIT(inode_getsecctx, selinux_inode_getsecctx),

security/selinux/include/classmap.h

@@ -21,7 +21,7 @@ struct security_class_mapping secclass_map[] = {
 	  { "compute_av", "compute_create", "compute_member",
 	    "check_context", "load_policy", "compute_relabel",
 	    "compute_user", "setenforce", "setbool", "setsecparam",
-	    "setcheckreqprot", "read_policy", NULL } },
+	    "setcheckreqprot", "read_policy", "validate_trans", NULL } },
 	{ "process",
 	  { "fork", "transition", "sigchld", "sigkill",
 	    "sigstop", "signull", "signal", "ptrace", "getsched", "setsched",

security/selinux/include/objsec.h

@@ -37,6 +37,12 @@ struct task_security_struct {
 	u32 sockcreate_sid;	/* fscreate SID */
 };
 
+enum label_initialized {
+	LABEL_MISSING,		/* not initialized */
+	LABEL_INITIALIZED,	/* inizialized */
+	LABEL_INVALID		/* invalid */
+};
+
 struct inode_security_struct {
 	struct inode *inode;	/* back pointer to inode object */
 	union {

security/selinux/include/security.h

@@ -187,6 +187,9 @@ int security_node_sid(u16 domain, void *addr, u32 addrlen,
 int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 				 u16 tclass);
 
+int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
+				      u16 tclass);
+
 int security_bounded_transition(u32 oldsid, u32 newsid);
 
 int security_sid_mls_copy(u32 sid, u32 mls_sid, u32 *new_sid);

security/selinux/selinuxfs.c

@@ -116,6 +116,7 @@ enum sel_inos {
 	SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
 	SEL_STATUS,	/* export current status using mmap() */
 	SEL_POLICY,	/* allow userspace to read the in kernel policy */
+	SEL_VALIDATE_TRANS, /* compute validatetrans decision */
 	SEL_INO_NEXT,	/* The next inode number to use */
 };
 
@@ -632,6 +633,83 @@ static const struct file_operations sel_checkreqprot_ops = {
 	.llseek		= generic_file_llseek,
 };
 
+static ssize_t sel_write_validatetrans(struct file *file,
+					const char __user *buf,
+					size_t count, loff_t *ppos)
+{
+	char *oldcon = NULL, *newcon = NULL, *taskcon = NULL;
+	char *req = NULL;
+	u32 osid, nsid, tsid;
+	u16 tclass;
+	int rc;
+
+	rc = task_has_security(current, SECURITY__VALIDATE_TRANS);
+	if (rc)
+		goto out;
+
+	rc = -ENOMEM;
+	if (count >= PAGE_SIZE)
+		goto out;
+
+	/* No partial writes. */
+	rc = -EINVAL;
+	if (*ppos != 0)
+		goto out;
+
+	rc = -ENOMEM;
+	req = kzalloc(count + 1, GFP_KERNEL);
+	if (!req)
+		goto out;
+
+	rc = -EFAULT;
+	if (copy_from_user(req, buf, count))
+		goto out;
+
+	rc = -ENOMEM;
+	oldcon = kzalloc(count + 1, GFP_KERNEL);
+	if (!oldcon)
+		goto out;
+
+	newcon = kzalloc(count + 1, GFP_KERNEL);
+	if (!newcon)
+		goto out;
+
+	taskcon = kzalloc(count + 1, GFP_KERNEL);
+	if (!taskcon)
+		goto out;
+
+	rc = -EINVAL;
+	if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4)
+		goto out;
+
+	rc = security_context_str_to_sid(oldcon, &osid, GFP_KERNEL);
+	if (rc)
+		goto out;
+
+	rc = security_context_str_to_sid(newcon, &nsid, GFP_KERNEL);
+	if (rc)
+		goto out;
+
+	rc = security_context_str_to_sid(taskcon, &tsid, GFP_KERNEL);
+	if (rc)
+		goto out;
+
+	rc = security_validate_transition_user(osid, nsid, tsid, tclass);
+	if (!rc)
+		rc = count;
+out:
+	kfree(req);
+	kfree(oldcon);
+	kfree(newcon);
+	kfree(taskcon);
+	return rc;
+}
+
+static const struct file_operations sel_transition_ops = {
+	.write		= sel_write_validatetrans,
+	.llseek		= generic_file_llseek,
+};
+
 /*
  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
  */
@@ -1727,6 +1805,8 @@ static int sel_fill_super(struct super_block *sb, void *data, int silent)
 		[SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
 		[SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
 		[SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
+		[SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
+					S_IWUGO},
 		/* last one */ {""}
 	};
 	ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);

security/selinux/ss/services.c

@@ -778,8 +778,8 @@ out:
 	return -EPERM;
 }
 
-int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
-				 u16 orig_tclass)
+static int security_compute_validatetrans(u32 oldsid, u32 newsid, u32 tasksid,
+					  u16 orig_tclass, bool user)
 {
 	struct context *ocontext;
 	struct context *ncontext;
@@ -794,11 +794,12 @@ int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 
 	read_lock(&policy_rwlock);
 
-	tclass = unmap_class(orig_tclass);
+	if (!user)
+		tclass = unmap_class(orig_tclass);
+	else
+		tclass = orig_tclass;
 
 	if (!tclass || tclass > policydb.p_classes.nprim) {
-		printk(KERN_ERR "SELinux: %s:  unrecognized class %d\n",
-			__func__, tclass);
 		rc = -EINVAL;
 		goto out;
 	}
@@ -832,8 +833,13 @@ int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
 	while (constraint) {
 		if (!constraint_expr_eval(ocontext, ncontext, tcontext,
 					  constraint->expr)) {
-			rc = security_validtrans_handle_fail(ocontext, ncontext,
-							     tcontext, tclass);
+			if (user)
+				rc = -EPERM;
+			else
+				rc = security_validtrans_handle_fail(ocontext,
+								     ncontext,
+								     tcontext,
+								     tclass);
 			goto out;
 		}
 		constraint = constraint->next;
@@ -844,6 +850,20 @@ out:
 	return rc;
 }
 
+int security_validate_transition_user(u32 oldsid, u32 newsid, u32 tasksid,
+					u16 tclass)
+{
+	return security_compute_validatetrans(oldsid, newsid, tasksid,
+						tclass, true);
+}
+
+int security_validate_transition(u32 oldsid, u32 newsid, u32 tasksid,
+				 u16 orig_tclass)
+{
+	return security_compute_validatetrans(oldsid, newsid, tasksid,
+						orig_tclass, false);
+}
+
 /*
  * security_bounded_transition - check whether the given
  * transition is directed to bounded, or not.