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

Pull security subsystem updates from James Morris:
 "Generally pretty quiet for this release. Highlights:

  Yama:
   - allow ptrace access for original parent after re-parenting

  TPM:
   - add documentation
   - many bugfixes & cleanups
   - define a generic open() method for ascii & bios measurements

  Integrity:
   - Harden against malformed xattrs

  SELinux:
   - bugfixes & cleanups

  Smack:
   - Remove unnecessary smack_known_invalid label
   - Do not apply star label in smack_setprocattr hook
   - parse mnt opts after privileges check (fixes unpriv DoS vuln)"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (56 commits)
  Yama: allow access for the current ptrace parent
  tpm: adjust return value of tpm_read_log
  tpm: vtpm_proxy: conditionally call tpm_chip_unregister
  tpm: Fix handling of missing event log
  tpm: Check the bios_dir entry for NULL before accessing it
  tpm: return -ENODEV if np is not set
  tpm: cleanup of printk error messages
  tpm: replace of_find_node_by_name() with dev of_node property
  tpm: redefine read_log() to handle ACPI/OF at runtime
  tpm: fix the missing .owner in tpm_bios_measurements_ops
  tpm: have event log use the tpm_chip
  tpm: drop tpm1_chip_register(/unregister)
  tpm: replace dynamically allocated bios_dir with a static array
  tpm: replace symbolic permission with octal for securityfs files
  char: tpm: fix kerneldoc tpm2_unseal_trusted name typo
  tpm_tis: Allow tpm_tis to be bound using DT
  tpm, tpm_vtpm_proxy: add kdoc comments for VTPM_PROXY_IOC_NEW_DEV
  tpm: Only call pm_runtime_get_sync if device has a parent
  tpm: define a generic open() method for ascii & bios measurements
  Documentation: tpm: add the Physical TPM device tree binding documentation
  ...

14 files changed, 166 insertions, 137 deletions

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 4304372..106e855 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -51,7 +51,7 @@ static bool init_keyring __initdata;
 int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
 			    const char *digest, int digestlen)
 {
-	if (id >= INTEGRITY_KEYRING_MAX)
+	if (id >= INTEGRITY_KEYRING_MAX || siglen < 2)
 		return -EINVAL;
 
 	if (!keyring[id]) {
diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index ba86155..e2ed498 100644
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -145,6 +145,10 @@ static enum integrity_status evm_verify_hmac(struct dentry *dentry,
 	/* check value type */
 	switch (xattr_data->type) {
 	case EVM_XATTR_HMAC:
+		if (xattr_len != sizeof(struct evm_ima_xattr_data)) {
+			evm_status = INTEGRITY_FAIL;
+			goto out;
+		}
 		rc = evm_calc_hmac(dentry, xattr_name, xattr_value,
 				   xattr_value_len, calc.digest);
 		if (rc)
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 389325a..1fd9539 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -130,6 +130,7 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
 				 int xattr_len)
 {
 	struct signature_v2_hdr *sig;
+	enum hash_algo ret;
 
 	if (!xattr_value || xattr_len < 2)
 		/* return default hash algo */
@@ -143,7 +144,9 @@ enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
 		return sig->hash_algo;
 		break;
 	case IMA_XATTR_DIGEST_NG:
-		return xattr_value->digest[0];
+		ret = xattr_value->digest[0];
+		if (ret < HASH_ALGO__LAST)
+			return ret;
 		break;
 	case IMA_XATTR_DIGEST:
 		/* this is for backward compatibility */
@@ -384,14 +387,10 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
 	result = ima_protect_xattr(dentry, xattr_name, xattr_value,
 				   xattr_value_len);
 	if (result == 1) {
-		bool digsig;
-
 		if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST))
 			return -EINVAL;
-		digsig = (xvalue->type == EVM_IMA_XATTR_DIGSIG);
-		if (!digsig && (ima_appraise & IMA_APPRAISE_ENFORCE))
-			return -EPERM;
-		ima_reset_appraise_flags(d_backing_inode(dentry), digsig);
+		ima_reset_appraise_flags(d_backing_inode(dentry),
+			 (xvalue->type == EVM_IMA_XATTR_DIGSIG) ? 1 : 0);
 		result = 0;
 	}
 	return result;
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index c07a384..3df4690 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -401,7 +401,7 @@ static int ima_release_policy(struct inode *inode, struct file *file)
 	const char *cause = valid_policy ? "completed" : "failed";
 
 	if ((file->f_flags & O_ACCMODE) == O_RDONLY)
-		return 0;
+		return seq_release(inode, file);
 
 	if (valid_policy && ima_check_policy() < 0) {
 		cause = "failed";
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 32912bd..2ac1f41 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -115,7 +115,8 @@ int __init ima_init(void)
 		ima_used_chip = 1;
 
 	if (!ima_used_chip)
-		pr_info("No TPM chip found, activating TPM-bypass!\n");
+		pr_info("No TPM chip found, activating TPM-bypass! (rc=%d)\n",
+			rc);
 
 	rc = integrity_init_keyring(INTEGRITY_KEYRING_IMA);
 	if (rc)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 38b79d7..c7c6619 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -231,12 +231,13 @@ static int inode_alloc_security(struct inode *inode)
 	if (!isec)
 		return -ENOMEM;
 
-	mutex_init(&isec->lock);
+	spin_lock_init(&isec->lock);
 	INIT_LIST_HEAD(&isec->list);
 	isec->inode = inode;
 	isec->sid = SECINITSID_UNLABELED;
 	isec->sclass = SECCLASS_FILE;
 	isec->task_sid = sid;
+	isec->initialized = LABEL_INVALID;
 	inode->i_security = isec;
 
 	return 0;
@@ -247,7 +248,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 /*
  * 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
+ * allowed; when set to false, returns -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.
  */
@@ -1100,11 +1101,12 @@ static int selinux_parse_opts_str(char *options,
 	}
 
 	rc = -ENOMEM;
-	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
+	opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_KERNEL);
 	if (!opts->mnt_opts)
 		goto out_err;
 
-	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
+	opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int),
+				       GFP_KERNEL);
 	if (!opts->mnt_opts_flags) {
 		kfree(opts->mnt_opts);
 		goto out_err;
@@ -1380,7 +1382,8 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 {
 	struct superblock_security_struct *sbsec = NULL;
 	struct inode_security_struct *isec = inode->i_security;
-	u32 sid;
+	u32 task_sid, sid = 0;
+	u16 sclass;
 	struct dentry *dentry;
 #define INITCONTEXTLEN 255
 	char *context = NULL;
@@ -1388,12 +1391,15 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 	int rc = 0;
 
 	if (isec->initialized == LABEL_INITIALIZED)
-		goto out;
+		return 0;
 
-	mutex_lock(&isec->lock);
+	spin_lock(&isec->lock);
 	if (isec->initialized == LABEL_INITIALIZED)
 		goto out_unlock;
 
+	if (isec->sclass == SECCLASS_FILE)
+		isec->sclass = inode_mode_to_security_class(inode->i_mode);
+
 	sbsec = inode->i_sb->s_security;
 	if (!(sbsec->flags & SE_SBINITIALIZED)) {
 		/* Defer initialization until selinux_complete_init,
@@ -1406,12 +1412,18 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 		goto out_unlock;
 	}
 
+	sclass = isec->sclass;
+	task_sid = isec->task_sid;
+	sid = isec->sid;
+	isec->initialized = LABEL_PENDING;
+	spin_unlock(&isec->lock);
+
 	switch (sbsec->behavior) {
 	case SECURITY_FS_USE_NATIVE:
 		break;
 	case SECURITY_FS_USE_XATTR:
 		if (!(inode->i_opflags & IOP_XATTR)) {
-			isec->sid = sbsec->def_sid;
+			sid = sbsec->def_sid;
 			break;
 		}
 		/* Need a dentry, since the xattr API requires one.
@@ -1433,7 +1445,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 			 * inode_doinit with a dentry, before these inodes could
 			 * be used again by userspace.
 			 */
-			goto out_unlock;
+			goto out;
 		}
 
 		len = INITCONTEXTLEN;
@@ -1441,7 +1453,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 		if (!context) {
 			rc = -ENOMEM;
 			dput(dentry);
-			goto out_unlock;
+			goto out;
 		}
 		context[len] = '\0';
 		rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
@@ -1452,14 +1464,14 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, NULL, 0);
 			if (rc < 0) {
 				dput(dentry);
-				goto out_unlock;
+				goto out;
 			}
 			len = rc;
 			context = kmalloc(len+1, GFP_NOFS);
 			if (!context) {
 				rc = -ENOMEM;
 				dput(dentry);
-				goto out_unlock;
+				goto out;
 			}
 			context[len] = '\0';
 			rc = __vfs_getxattr(dentry, inode, XATTR_NAME_SELINUX, context, len);
@@ -1471,7 +1483,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 				       "%d for dev=%s ino=%ld\n", __func__,
 				       -rc, inode->i_sb->s_id, inode->i_ino);
 				kfree(context);
-				goto out_unlock;
+				goto out;
 			}
 			/* Map ENODATA to the default file SID */
 			sid = sbsec->def_sid;
@@ -1501,29 +1513,25 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 			}
 		}
 		kfree(context);
-		isec->sid = sid;
 		break;
 	case SECURITY_FS_USE_TASK:
-		isec->sid = isec->task_sid;
+		sid = task_sid;
 		break;
 	case SECURITY_FS_USE_TRANS:
 		/* Default to the fs SID. */
-		isec->sid = sbsec->sid;
+		sid = sbsec->sid;
 
 		/* Try to obtain a transition SID. */
-		isec->sclass = inode_mode_to_security_class(inode->i_mode);
-		rc = security_transition_sid(isec->task_sid, sbsec->sid,
-					     isec->sclass, NULL, &sid);
+		rc = security_transition_sid(task_sid, sid, sclass, NULL, &sid);
 		if (rc)
-			goto out_unlock;
-		isec->sid = sid;
+			goto out;
 		break;
 	case SECURITY_FS_USE_MNTPOINT:
-		isec->sid = sbsec->mntpoint_sid;
+		sid = sbsec->mntpoint_sid;
 		break;
 	default:
 		/* Default to the fs superblock SID. */
-		isec->sid = sbsec->sid;
+		sid = sbsec->sid;
 
 		if ((sbsec->flags & SE_SBGENFS) && !S_ISLNK(inode->i_mode)) {
 			/* We must have a dentry to determine the label on
@@ -1546,25 +1554,30 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
 			 * could be used again by userspace.
 			 */
 			if (!dentry)
-				goto out_unlock;
-			isec->sclass = inode_mode_to_security_class(inode->i_mode);
-			rc = selinux_genfs_get_sid(dentry, isec->sclass,
+				goto out;
+			rc = selinux_genfs_get_sid(dentry, sclass,
 						   sbsec->flags, &sid);
 			dput(dentry);
 			if (rc)
-				goto out_unlock;
-			isec->sid = sid;
+				goto out;
 		}
 		break;
 	}
 
-	isec->initialized = LABEL_INITIALIZED;
+out:
+	spin_lock(&isec->lock);
+	if (isec->initialized == LABEL_PENDING) {
+		if (!sid || rc) {
+			isec->initialized = LABEL_INVALID;
+			goto out_unlock;
+		}
+
+		isec->initialized = LABEL_INITIALIZED;
+		isec->sid = sid;
+	}
 
 out_unlock:
-	mutex_unlock(&isec->lock);
-out:
-	if (isec->sclass == SECCLASS_FILE)
-		isec->sclass = inode_mode_to_security_class(inode->i_mode);
+	spin_unlock(&isec->lock);
 	return rc;
 }
 
@@ -3198,9 +3211,11 @@ static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
 	}
 
 	isec = backing_inode_security(dentry);
+	spin_lock(&isec->lock);
 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
 	isec->sid = newsid;
 	isec->initialized = LABEL_INITIALIZED;
+	spin_unlock(&isec->lock);
 
 	return;
 }
@@ -3293,9 +3308,11 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
 	if (rc)
 		return rc;
 
+	spin_lock(&isec->lock);
 	isec->sclass = inode_mode_to_security_class(inode->i_mode);
 	isec->sid = newsid;
 	isec->initialized = LABEL_INITIALIZED;
+	spin_unlock(&isec->lock);
 	return 0;
 }
 
@@ -3956,8 +3973,11 @@ static void selinux_task_to_inode(struct task_struct *p,
 	struct inode_security_struct *isec = inode->i_security;
 	u32 sid = task_sid(p);
 
+	spin_lock(&isec->lock);
+	isec->sclass = inode_mode_to_security_class(inode->i_mode);
 	isec->sid = sid;
 	isec->initialized = LABEL_INITIALIZED;
+	spin_unlock(&isec->lock);
 }
 
 /* Returns error only if unable to parse addresses */
@@ -4276,24 +4296,24 @@ static int selinux_socket_post_create(struct socket *sock, int family,
 	const struct task_security_struct *tsec = current_security();
 	struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
 	struct sk_security_struct *sksec;
+	u16 sclass = socket_type_to_security_class(family, type, protocol);
+	u32 sid = SECINITSID_KERNEL;
 	int err = 0;
 
-	isec->sclass = socket_type_to_security_class(family, type, protocol);
-
-	if (kern)
-		isec->sid = SECINITSID_KERNEL;
-	else {
-		err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
+	if (!kern) {
+		err = socket_sockcreate_sid(tsec, sclass, &sid);
 		if (err)
 			return err;
 	}
 
+	isec->sclass = sclass;
+	isec->sid = sid;
 	isec->initialized = LABEL_INITIALIZED;
 
 	if (sock->sk) {
 		sksec = sock->sk->sk_security;
-		sksec->sid = isec->sid;
-		sksec->sclass = isec->sclass;
+		sksec->sclass = sclass;
+		sksec->sid = sid;
 		err = selinux_netlbl_socket_post_create(sock->sk, family);
 	}
 
@@ -4469,16 +4489,22 @@ static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
 	int err;
 	struct inode_security_struct *isec;
 	struct inode_security_struct *newisec;
+	u16 sclass;
+	u32 sid;
 
 	err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
 	if (err)
 		return err;
 
-	newisec = inode_security_novalidate(SOCK_INODE(newsock));
-
 	isec = inode_security_novalidate(SOCK_INODE(sock));
-	newisec->sclass = isec->sclass;
-	newisec->sid = isec->sid;
+	spin_lock(&isec->lock);
+	sclass = isec->sclass;
+	sid = isec->sid;
+	spin_unlock(&isec->lock);
+
+	newisec = inode_security_novalidate(SOCK_INODE(newsock));
+	newisec->sclass = sclass;
+	newisec->sid = sid;
 	newisec->initialized = LABEL_INITIALIZED;
 
 	return 0;
@@ -5981,9 +6007,9 @@ static void selinux_inode_invalidate_secctx(struct inode *inode)
 {
 	struct inode_security_struct *isec = inode->i_security;
 
-	mutex_lock(&isec->lock);
+	spin_lock(&isec->lock);
 	isec->initialized = LABEL_INVALID;
-	mutex_unlock(&isec->lock);
+	spin_unlock(&isec->lock);
 }
 
 /*
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 1f1f4b2..e2d4ad3 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -24,6 +24,10 @@
 #define COMMON_CAP2_PERMS  "mac_override", "mac_admin", "syslog", \
 		"wake_alarm", "block_suspend", "audit_read"
 
+#if CAP_LAST_CAP > CAP_AUDIT_READ
+#error New capability defined, please update COMMON_CAP2_PERMS.
+#endif
+
 /*
  * Note: The name for any socket class should be suffixed by "socket",
  *	 and doesn't contain more than one substr of "socket".
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index c21e135..e8dab0f 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -39,7 +39,8 @@ struct task_security_struct {
 
 enum label_initialized {
 	LABEL_INVALID,		/* invalid or not initialized */
-	LABEL_INITIALIZED	/* initialized */
+	LABEL_INITIALIZED,	/* initialized */
+	LABEL_PENDING
 };
 
 struct inode_security_struct {
@@ -52,7 +53,7 @@ struct inode_security_struct {
 	u32 sid;		/* SID of this object */
 	u16 sclass;		/* security class of this object */
 	unsigned char initialized;	/* initialization flag */
-	struct mutex lock;
+	spinlock_t lock;
 };
 
 struct file_security_struct {
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 72c145d..cf9293e 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -163,6 +163,8 @@ static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
 	if (sscanf(page, "%d", &new_value) != 1)
 		goto out;
 
+	new_value = !!new_value;
+
 	if (new_value != selinux_enforcing) {
 		length = task_has_security(current, SECURITY__SETENFORCE);
 		if (length)
@@ -1301,7 +1303,7 @@ static int sel_make_bools(void)
 			goto out;
 
 		isec->sid = sid;
-		isec->initialized = 1;
+		isec->initialized = LABEL_INITIALIZED;
 		inode->i_fop = &sel_bool_ops;
 		inode->i_ino = i|SEL_BOOL_INO_OFFSET;
 		d_add(dentry, inode);
@@ -1834,7 +1836,7 @@ static int sel_fill_super(struct super_block *sb, void *data, int silent)
 	isec = (struct inode_security_struct *)inode->i_security;
 	isec->sid = SECINITSID_DEVNULL;
 	isec->sclass = SECCLASS_CHR_FILE;
-	isec->initialized = 1;
+	isec->initialized = LABEL_INITIALIZED;
 
 	init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
 	d_add(dentry, inode);
diff --git a/security/smack/smack.h b/security/smack/smack.h
index 51fd301..77abe2e 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -336,7 +336,6 @@ extern int smack_ptrace_rule;
 extern struct smack_known smack_known_floor;
 extern struct smack_known smack_known_hat;
 extern struct smack_known smack_known_huh;
-extern struct smack_known smack_known_invalid;
 extern struct smack_known smack_known_star;
 extern struct smack_known smack_known_web;
 
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 23e5808..356e376 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -36,11 +36,6 @@ struct smack_known smack_known_floor = {
 	.smk_secid	= 5,
 };
 
-struct smack_known smack_known_invalid = {
-	.smk_known	= "",
-	.smk_secid	= 6,
-};
-
 struct smack_known smack_known_web = {
 	.smk_known	= "@",
 	.smk_secid	= 7,
@@ -615,7 +610,7 @@ struct smack_known *smack_from_secid(const u32 secid)
 	 * of a secid that is not on the list.
 	 */
 	rcu_read_unlock();
-	return &smack_known_invalid;
+	return &smack_known_huh;
 }
 
 /*
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 1cb0602..4d90257 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -692,12 +692,12 @@ static int smack_parse_opts_str(char *options,
 		}
 	}
 
-	opts->mnt_opts = kcalloc(NUM_SMK_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
+	opts->mnt_opts = kcalloc(NUM_SMK_MNT_OPTS, sizeof(char *), GFP_KERNEL);
 	if (!opts->mnt_opts)
 		goto out_err;
 
 	opts->mnt_opts_flags = kcalloc(NUM_SMK_MNT_OPTS, sizeof(int),
-			GFP_ATOMIC);
+			GFP_KERNEL);
 	if (!opts->mnt_opts_flags) {
 		kfree(opts->mnt_opts);
 		goto out_err;
@@ -769,6 +769,31 @@ static int smack_set_mnt_opts(struct super_block *sb,
 	if (sp->smk_flags & SMK_SB_INITIALIZED)
 		return 0;
 
+	if (!smack_privileged(CAP_MAC_ADMIN)) {
+		/*
+		 * Unprivileged mounts don't get to specify Smack values.
+		 */
+		if (num_opts)
+			return -EPERM;
+		/*
+		 * Unprivileged mounts get root and default from the caller.
+		 */
+		skp = smk_of_current();
+		sp->smk_root = skp;
+		sp->smk_default = skp;
+		/*
+		 * For a handful of fs types with no user-controlled
+		 * backing store it's okay to trust security labels
+		 * in the filesystem. The rest are untrusted.
+		 */
+		if (sb->s_user_ns != &init_user_ns &&
+		    sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
+		    sb->s_magic != RAMFS_MAGIC) {
+			transmute = 1;
+			sp->smk_flags |= SMK_SB_UNTRUSTED;
+		}
+	}
+
 	sp->smk_flags |= SMK_SB_INITIALIZED;
 
 	for (i = 0; i < num_opts; i++) {
@@ -809,31 +834,6 @@ static int smack_set_mnt_opts(struct super_block *sb,
 		}
 	}
 
-	if (!smack_privileged(CAP_MAC_ADMIN)) {
-		/*
-		 * Unprivileged mounts don't get to specify Smack values.
-		 */
-		if (num_opts)
-			return -EPERM;
-		/*
-		 * Unprivileged mounts get root and default from the caller.
-		 */
-		skp = smk_of_current();
-		sp->smk_root = skp;
-		sp->smk_default = skp;
-		/*
-		 * For a handful of fs types with no user-controlled
-		 * backing store it's okay to trust security labels
-		 * in the filesystem. The rest are untrusted.
-		 */
-		if (sb->s_user_ns != &init_user_ns &&
-		    sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
-		    sb->s_magic != RAMFS_MAGIC) {
-			transmute = 1;
-			sp->smk_flags |= SMK_SB_UNTRUSTED;
-		}
-	}
-
 	/*
 	 * Initialize the root inode.
 	 */
@@ -1384,20 +1384,14 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
 		skp = smk_import_entry(value, size);
 		if (!IS_ERR(skp))
 			isp->smk_inode = skp;
-		else
-			isp->smk_inode = &smack_known_invalid;
 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
 		skp = smk_import_entry(value, size);
 		if (!IS_ERR(skp))
 			isp->smk_task = skp;
-		else
-			isp->smk_task = &smack_known_invalid;
 	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
 		skp = smk_import_entry(value, size);
 		if (!IS_ERR(skp))
 			isp->smk_mmap = skp;
-		else
-			isp->smk_mmap = &smack_known_invalid;
 	}
 
 	return;
@@ -2023,6 +2017,8 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old,
 	if (new_tsp == NULL)
 		return -ENOMEM;
 
+	new->security = new_tsp;
+
 	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
 	if (rc != 0)
 		return rc;
@@ -2032,7 +2028,6 @@ static int smack_cred_prepare(struct cred *new, const struct cred *old,
 	if (rc != 0)
 		return rc;
 
-	new->security = new_tsp;
 	return 0;
 }
 
@@ -2067,12 +2062,8 @@ static void smack_cred_transfer(struct cred *new, const struct cred *old)
 static int smack_kernel_act_as(struct cred *new, u32 secid)
 {
 	struct task_smack *new_tsp = new->security;
-	struct smack_known *skp = smack_from_secid(secid);
-
-	if (skp == NULL)
-		return -EINVAL;
 
-	new_tsp->smk_task = skp;
+	new_tsp->smk_task = smack_from_secid(secid);
 	return 0;
 }
 
@@ -2337,8 +2328,16 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
 	if (ssp == NULL)
 		return -ENOMEM;
 
-	ssp->smk_in = skp;
-	ssp->smk_out = skp;
+	/*
+	 * Sockets created by kernel threads receive web label.
+	 */
+	if (unlikely(current->flags & PF_KTHREAD)) {
+		ssp->smk_in = &smack_known_web;
+		ssp->smk_out = &smack_known_web;
+	} else {
+		ssp->smk_in = skp;
+		ssp->smk_out = skp;
+	}
 	ssp->smk_packet = NULL;
 
 	sk->sk_security = ssp;
@@ -2435,17 +2434,17 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
 
 	list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
 		/*
+		 * If the label is NULL the entry has
+		 * been renounced. Ignore it.
+		 */
+		if (snp->smk_label == NULL)
+			continue;
+		/*
 		* we break after finding the first match because
 		* the list is sorted from longest to shortest mask
 		* so we have found the most specific match
 		*/
 		for (found = 1, i = 0; i < 8; i++) {
-			/*
-			 * If the label is NULL the entry has
-			 * been renounced. Ignore it.
-			 */
-			if (snp->smk_label == NULL)
-				continue;
 			if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
 			    snp->smk_host.s6_addr16[i]) {
 				found = 0;
@@ -3661,10 +3660,11 @@ static int smack_setprocattr(struct task_struct *p, char *name,
 		return PTR_ERR(skp);
 
 	/*
-	 * No process is ever allowed the web ("@") label.
+	 * No process is ever allowed the web ("@") label
+	 * and the star ("*") label.
 	 */
-	if (skp == &smack_known_web)
-		return -EPERM;
+	if (skp == &smack_known_web || skp == &smack_known_star)
+		return -EINVAL;
 
 	if (!smack_privileged(CAP_MAC_ADMIN)) {
 		rc = -EPERM;
@@ -3884,21 +3884,11 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
 			return &smack_known_web;
 		return &smack_known_star;
 	}
-	if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
+	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
 		/*
 		 * Looks like a fallback, which gives us a secid.
 		 */
-		skp = smack_from_secid(sap->attr.secid);
-		/*
-		 * This has got to be a bug because it is
-		 * impossible to specify a fallback without
-		 * specifying the label, which will ensure
-		 * it has a secid, and the only way to get a
-		 * secid is from a fallback.
-		 */
-		BUG_ON(skp == NULL);
-		return skp;
-	}
+		return smack_from_secid(sap->attr.secid);
 	/*
 	 * Without guidance regarding the smack value
 	 * for the packet fall back on the network
@@ -4761,7 +4751,6 @@ static __init void init_smack_known_list(void)
 	mutex_init(&smack_known_hat.smk_rules_lock);
 	mutex_init(&smack_known_floor.smk_rules_lock);
 	mutex_init(&smack_known_star.smk_rules_lock);
-	mutex_init(&smack_known_invalid.smk_rules_lock);
 	mutex_init(&smack_known_web.smk_rules_lock);
 	/*
 	 * Initialize rule lists
@@ -4770,7 +4759,6 @@ static __init void init_smack_known_list(void)
 	INIT_LIST_HEAD(&smack_known_hat.smk_rules);
 	INIT_LIST_HEAD(&smack_known_star.smk_rules);
 	INIT_LIST_HEAD(&smack_known_floor.smk_rules);
-	INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
 	INIT_LIST_HEAD(&smack_known_web.smk_rules);
 	/*
 	 * Create the known labels list
@@ -4779,7 +4767,6 @@ static __init void init_smack_known_list(void)
 	smk_insert_entry(&smack_known_hat);
 	smk_insert_entry(&smack_known_star);
 	smk_insert_entry(&smack_known_floor);
-	smk_insert_entry(&smack_known_invalid);
 	smk_insert_entry(&smack_known_web);
 }
 
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 6492fe9..13743a0 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -2998,9 +2998,6 @@ static int __init init_smk_fs(void)
 	rc = smk_preset_netlabel(&smack_known_huh);
 	if (err == 0 && rc < 0)
 		err = rc;
-	rc = smk_preset_netlabel(&smack_known_invalid);
-	if (err == 0 && rc < 0)
-		err = rc;
 	rc = smk_preset_netlabel(&smack_known_star);
 	if (err == 0 && rc < 0)
 		err = rc;
diff --git a/security/yama/yama_lsm.c b/security/yama/yama_lsm.c
index 0309f21..968e5e0 100644
--- a/security/yama/yama_lsm.c
+++ b/security/yama/yama_lsm.c
@@ -309,7 +309,7 @@ static int task_is_descendant(struct task_struct *parent,
  * @tracer: the task_struct of the process attempting ptrace
  * @tracee: the task_struct of the process to be ptraced
  *
- * Returns 1 if tracer has is ptracer exception ancestor for tracee.
+ * Returns 1 if tracer has a ptracer exception ancestor for tracee.
  */
 static int ptracer_exception_found(struct task_struct *tracer,
 				   struct task_struct *tracee)
@@ -320,6 +320,18 @@ static int ptracer_exception_found(struct task_struct *tracer,
 	bool found = false;
 
 	rcu_read_lock();
+
+	/*
+	 * If there's already an active tracing relationship, then make an
+	 * exception for the sake of other accesses, like process_vm_rw().
+	 */
+	parent = ptrace_parent(tracee);
+	if (parent != NULL && same_thread_group(parent, tracer)) {
+		rc = 1;
+		goto unlock;
+	}
+
+	/* Look for a PR_SET_PTRACER relationship. */
 	if (!thread_group_leader(tracee))
 		tracee = rcu_dereference(tracee->group_leader);
 	list_for_each_entry_rcu(relation, &ptracer_relations, node) {
@@ -334,6 +346,8 @@ static int ptracer_exception_found(struct task_struct *tracer,
 
 	if (found && (parent == NULL || task_is_descendant(parent, tracer)))
 		rc = 1;
+
+unlock:
 	rcu_read_unlock();
 
 	return rc;