Merge remote branch 'smack/smack-for-4.10' into next

4 files changed, 53 insertions, 75 deletions

diff --git a/security/smack/smack.h b/security/smack/smack.h
index 51fd30192c08..77abe2efacae 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 23e5808a0970..356e3764cad9 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 1cb060293505..4d90257d03ad 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 6492fe96cae4..13743a01b35b 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;