Merge tag 'Smack-for-6.9' of https://github.com/cschaufler/smack-next

Pull smack updates from Casey Schaufler:

 - Improvements to the initialization of in-memory inodes

 - A fix in ramfs to propery ensure the initialization of in-memory
   inodes

 - Removal of duplicated code in smack_cred_transfer()

* tag 'Smack-for-6.9' of https://github.com/cschaufler/smack-next:
  Smack: use init_task_smack() in smack_cred_transfer()
  ramfs: Initialize security of in-memory inodes
  smack: Initialize the in-memory inode in smack_inode_init_security()
  smack: Always determine inode labels in smack_inode_init_security()
  smack: Handle SMACK64TRANSMUTE in smack_inode_setsecurity()
  smack: Set SMACK64TRANSMUTE only for dirs in smack_inode_setxattr()

Author: torvalds

fs/ramfs/inode.c

@@ -102,11 +102,20 @@ ramfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 	int error = -ENOSPC;
 
 	if (inode) {
+		error = security_inode_init_security(inode, dir,
+						     &dentry->d_name, NULL,
+						     NULL);
+		if (error) {
+			iput(inode);
+			goto out;
+		}
+
 		d_instantiate(dentry, inode);
 		dget(dentry);	/* Extra count - pin the dentry in core */
 		error = 0;
 		inode_set_mtime_to_ts(dir, inode_set_ctime_current(dir));
 	}
+out:
 	return error;
 }
 
@@ -134,6 +143,15 @@ static int ramfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 	inode = ramfs_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0);
 	if (inode) {
 		int l = strlen(symname)+1;
+
+		error = security_inode_init_security(inode, dir,
+						     &dentry->d_name, NULL,
+						     NULL);
+		if (error) {
+			iput(inode);
+			goto out;
+		}
+
 		error = page_symlink(inode, symname, l);
 		if (!error) {
 			d_instantiate(dentry, inode);
@@ -143,19 +161,31 @@ static int ramfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
 		} else
 			iput(inode);
 	}
+out:
 	return error;
 }
 
 static int ramfs_tmpfile(struct mnt_idmap *idmap,
 			 struct inode *dir, struct file *file, umode_t mode)
 {
 	struct inode *inode;
+	int error;
 
 	inode = ramfs_get_inode(dir->i_sb, dir, mode, 0);
 	if (!inode)
 		return -ENOSPC;
+
+	error = security_inode_init_security(inode, dir,
+					     &file_dentry(file)->d_name, NULL,
+					     NULL);
+	if (error) {
+		iput(inode);
+		goto out;
+	}
+
 	d_tmpfile(file, inode);
-	return finish_open_simple(file, 0);
+out:
+	return finish_open_simple(file, error);
 }
 
 static const struct inode_operations ramfs_dir_inode_operations = {

security/smack/smack_lsm.c

@@ -994,57 +994,62 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 				     struct xattr *xattrs, int *xattr_count)
 {
 	struct task_smack *tsp = smack_cred(current_cred());
+	struct inode_smack *issp = smack_inode(inode);
 	struct smack_known *skp = smk_of_task(tsp);
 	struct smack_known *isp = smk_of_inode(inode);
 	struct smack_known *dsp = smk_of_inode(dir);
 	struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
 	int may;
 
-	if (xattr) {
-		/*
-		 * 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 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();
+	}
+
+	/*
+	 * 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 ((tsp->smk_task == tsp->smk_transmuted) ||
+	    (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
+	     smk_inode_transmutable(dir))) {
+		struct xattr *xattr_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.
+		 * 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) ||
-		    (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
-		     smk_inode_transmutable(dir))) {
-			struct xattr *xattr_transmute;
+		if (tsp->smk_task != tsp->smk_transmuted)
+			isp = issp->smk_inode = dsp;
+
+		issp->smk_flags |= SMK_INODE_TRANSMUTE;
+		xattr_transmute = lsm_get_xattr_slot(xattrs,
+						     xattr_count);
+		if (xattr_transmute) {
+			xattr_transmute->value = kmemdup(TRANS_TRUE,
+							 TRANS_TRUE_SIZE,
+							 GFP_NOFS);
+			if (!xattr_transmute->value)
+				return -ENOMEM;
 
-			/*
-			 * 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;
-			xattr_transmute = lsm_get_xattr_slot(xattrs,
-							     xattr_count);
-			if (xattr_transmute) {
-				xattr_transmute->value = kmemdup(TRANS_TRUE,
-								 TRANS_TRUE_SIZE,
-								 GFP_NOFS);
-				if (!xattr_transmute->value)
-					return -ENOMEM;
-
-				xattr_transmute->value_len = TRANS_TRUE_SIZE;
-				xattr_transmute->name = XATTR_SMACK_TRANSMUTE;
-			}
+			xattr_transmute->value_len = TRANS_TRUE_SIZE;
+			xattr_transmute->name = XATTR_SMACK_TRANSMUTE;
 		}
+	}
 
+	issp->smk_flags |= SMK_INODE_INSTANT;
+
+	if (xattr) {
 		xattr->value = kstrdup(isp->smk_known, GFP_NOFS);
 		if (!xattr->value)
 			return -ENOMEM;
@@ -1314,7 +1319,8 @@ static int smack_inode_setxattr(struct mnt_idmap *idmap,
 		check_star = 1;
 	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
 		check_priv = 1;
-		if (size != TRANS_TRUE_SIZE ||
+		if (!S_ISDIR(d_backing_inode(dentry)->i_mode) ||
+		    size != TRANS_TRUE_SIZE ||
 		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
 			rc = -EINVAL;
 	} else
@@ -2095,12 +2101,7 @@ static void smack_cred_transfer(struct cred *new, const struct cred *old)
 	struct task_smack *old_tsp = smack_cred(old);
 	struct task_smack *new_tsp = smack_cred(new);
 
-	new_tsp->smk_task = old_tsp->smk_task;
-	new_tsp->smk_forked = old_tsp->smk_task;
-	mutex_init(&new_tsp->smk_rules_lock);
-	INIT_LIST_HEAD(&new_tsp->smk_rules);
-
-	/* cbs copy rule list */
+	init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
 }
 
 /**
@@ -2855,6 +2856,15 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
 	if (value == NULL || size > SMK_LONGLABEL || size == 0)
 		return -EINVAL;
 
+	if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) {
+		if (!S_ISDIR(inode->i_mode) || size != TRANS_TRUE_SIZE ||
+		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
+			return -EINVAL;
+
+		nsp->smk_flags |= SMK_INODE_TRANSMUTE;
+		return 0;
+	}
+
 	skp = smk_import_entry(value, size);
 	if (IS_ERR(skp))
 		return PTR_ERR(skp);