Merging upstream version 4.19.304.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 50 insertions, 18 deletions

diff --git a/security/smack/smack.h b/security/smack/smack.h
index f7db791fb..62aa4bc25 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -120,6 +120,7 @@ struct inode_smack {
 struct task_smack {
 	struct smack_known	*smk_task;	/* label for access control */
 	struct smack_known	*smk_forked;	/* label when forked */
+	struct smack_known	*smk_transmuted;/* label when transmuted */
 	struct list_head	smk_rules;	/* per task access rules */
 	struct mutex		smk_rules_lock;	/* lock for the rules */
 	struct list_head	smk_relabel;	/* transit allowed labels */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 4f65d953f..266eb8ca3 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1032,8 +1032,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 				     const struct qstr *qstr, const char **name,
 				     void **value, size_t *len)
 {
+	struct task_smack *tsp = current_security();
 	struct inode_smack *issp = inode->i_security;
-	struct smack_known *skp = smk_of_current();
+	struct smack_known *skp = smk_of_task(tsp);
 	struct smack_known *isp = smk_of_inode(inode);
 	struct smack_known *dsp = smk_of_inode(dir);
 	int may;
@@ -1042,20 +1043,34 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 		*name = XATTR_SMACK_SUFFIX;
 
 	if (value && len) {
-		rcu_read_lock();
-		may = smk_access_entry(skp->smk_known, dsp->smk_known,
-				       &skp->smk_rules);
-		rcu_read_unlock();
+		/*
+		 * If equal, transmuting already occurred in
+		 * smack_dentry_create_files_as(). No need to check again.
+		 */
+		if (tsp->smk_task != tsp->smk_transmuted) {
+			rcu_read_lock();
+			may = smk_access_entry(skp->smk_known, dsp->smk_known,
+					       &skp->smk_rules);
+			rcu_read_unlock();
+		}
 
 		/*
-		 * If the access rule allows transmutation and
-		 * the directory requests transmutation then
-		 * by all means transmute.
+		 * In addition to having smk_task equal to smk_transmuted,
+		 * if the access rule allows transmutation and the directory
+		 * requests transmutation then by all means transmute.
 		 * Mark the inode as changed.
 		 */
-		if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
-		    smk_inode_transmutable(dir)) {
-			isp = dsp;
+		if ((tsp->smk_task == tsp->smk_transmuted) ||
+		    (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
+		     smk_inode_transmutable(dir))) {
+			/*
+			 * The caller of smack_dentry_create_files_as()
+			 * should have overridden the current cred, so the
+			 * inode label was already set correctly in
+			 * smack_inode_alloc_security().
+			 */
+			if (tsp->smk_task != tsp->smk_transmuted)
+				isp = dsp;
 			issp->smk_flags |= SMK_INODE_CHANGED;
 		}
 
@@ -1490,10 +1505,19 @@ static int smack_inode_getsecurity(struct inode *inode,
 	struct super_block *sbp;
 	struct inode *ip = (struct inode *)inode;
 	struct smack_known *isp;
+	struct inode_smack *ispp;
+	size_t label_len;
+	char *label = NULL;
 
-	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
+	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
 		isp = smk_of_inode(inode);
-	else {
+	} else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) {
+		ispp = inode->i_security;
+		if (ispp->smk_flags & SMK_INODE_TRANSMUTE)
+			label = TRANS_TRUE;
+		else
+			label = "";
+	} else {
 		/*
 		 * The rest of the Smack xattrs are only on sockets.
 		 */
@@ -1515,13 +1539,18 @@ static int smack_inode_getsecurity(struct inode *inode,
 			return -EOPNOTSUPP;
 	}
 
+	if (!label)
+		label = isp->smk_known;
+
+	label_len = strlen(label);
+
 	if (alloc) {
-		*buffer = kstrdup(isp->smk_known, GFP_KERNEL);
+		*buffer = kstrdup(label, GFP_KERNEL);
 		if (*buffer == NULL)
 			return -ENOMEM;
 	}
 
-	return strlen(isp->smk_known);
+	return label_len;
 }
 
 
@@ -4612,7 +4641,7 @@ static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
 	/*
 	 * Get label from overlay inode and set it in create_sid
 	 */
-	isp = d_inode(dentry->d_parent)->i_security;
+	isp = d_inode(dentry)->i_security;
 	skp = isp->smk_inode;
 	tsp->smk_task = skp;
 	*new = new_creds;
@@ -4663,8 +4692,10 @@ static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
 		 * providing access is transmuting use the containing
 		 * directory label instead of the process label.
 		 */
-		if (may > 0 && (may & MAY_TRANSMUTE))
+		if (may > 0 && (may & MAY_TRANSMUTE)) {
 			ntsp->smk_task = isp->smk_inode;
+			ntsp->smk_transmuted = ntsp->smk_task;
+		}
 	}
 	return 0;
 }
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index a9c516362..61e734baa 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -923,7 +923,7 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
 	}
 
 	ret = sscanf(rule, "%d", &catlen);
-	if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM)
+	if (ret != 1 || catlen < 0 || catlen > SMACK_CIPSO_MAXCATNUM)
 		goto out;
 
 	if (format == SMK_FIXED24_FMT &&