1 files changed, 146 insertions, 40 deletions

diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 89714308c25b..24192a7667ed 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -32,7 +32,7 @@ static struct inode *anon_inode_inode;
  */
 static char *anon_inodefs_dname(struct dentry *dentry, char *buffer, int buflen)
 {
-	return dynamic_dname(dentry, buffer, buflen, "anon_inode:%s",
+	return dynamic_dname(buffer, buflen, "anon_inode:%s",
 				dentry->d_name.name);
 }
 
@@ -55,6 +55,75 @@ static struct file_system_type anon_inode_fs_type = {
 	.kill_sb	= kill_anon_super,
 };
 
+static struct inode *anon_inode_make_secure_inode(
+	const char *name,
+	const struct inode *context_inode)
+{
+	struct inode *inode;
+	const struct qstr qname = QSTR_INIT(name, strlen(name));
+	int error;
+
+	inode = alloc_anon_inode(anon_inode_mnt->mnt_sb);
+	if (IS_ERR(inode))
+		return inode;
+	inode->i_flags &= ~S_PRIVATE;
+	error =	security_inode_init_security_anon(inode, &qname, context_inode);
+	if (error) {
+		iput(inode);
+		return ERR_PTR(error);
+	}
+	return inode;
+}
+
+static struct file *__anon_inode_getfile(const char *name,
+					 const struct file_operations *fops,
+					 void *priv, int flags,
+					 const struct inode *context_inode,
+					 bool secure)
+{
+	struct inode *inode;
+	struct file *file;
+
+	if (fops->owner && !try_module_get(fops->owner))
+		return ERR_PTR(-ENOENT);
+
+	if (secure) {
+		inode =	anon_inode_make_secure_inode(name, context_inode);
+		if (IS_ERR(inode)) {
+			file = ERR_CAST(inode);
+			goto err;
+		}
+	} else {
+		inode =	anon_inode_inode;
+		if (IS_ERR(inode)) {
+			file = ERR_PTR(-ENODEV);
+			goto err;
+		}
+		/*
+		 * We know the anon_inode inode count is always
+		 * greater than zero, so ihold() is safe.
+		 */
+		ihold(inode);
+	}
+
+	file = alloc_file_pseudo(inode, anon_inode_mnt, name,
+				 flags & (O_ACCMODE | O_NONBLOCK), fops);
+	if (IS_ERR(file))
+		goto err_iput;
+
+	file->f_mapping = inode->i_mapping;
+
+	file->private_data = priv;
+
+	return file;
+
+err_iput:
+	iput(inode);
+err:
+	module_put(fops->owner);
+	return file;
+}
+
 /**
  * anon_inode_getfile - creates a new file instance by hooking it up to an
  *                      anonymous inode, and a dentry that describe the "class"
@@ -75,55 +144,44 @@ struct file *anon_inode_getfile(const char *name,
 				const struct file_operations *fops,
 				void *priv, int flags)
 {
-	struct file *file;
-
-	if (IS_ERR(anon_inode_inode))
-		return ERR_PTR(-ENODEV);
-
-	if (fops->owner && !try_module_get(fops->owner))
-		return ERR_PTR(-ENOENT);
-
-	/*
-	 * We know the anon_inode inode count is always greater than zero,
-	 * so ihold() is safe.
-	 */
-	ihold(anon_inode_inode);
-	file = alloc_file_pseudo(anon_inode_inode, anon_inode_mnt, name,
-				 flags & (O_ACCMODE | O_NONBLOCK), fops);
-	if (IS_ERR(file))
-		goto err;
-
-	file->f_mapping = anon_inode_inode->i_mapping;
-
-	file->private_data = priv;
-
-	return file;
-
-err:
-	iput(anon_inode_inode);
-	module_put(fops->owner);
-	return file;
+	return __anon_inode_getfile(name, fops, priv, flags, NULL, false);
 }
 EXPORT_SYMBOL_GPL(anon_inode_getfile);
 
 /**
- * anon_inode_getfd - creates a new file instance by hooking it up to an
- *                    anonymous inode, and a dentry that describe the "class"
- *                    of the file
+ * anon_inode_getfile_secure - Like anon_inode_getfile(), but creates a new
+ *                             !S_PRIVATE anon inode rather than reuse the
+ *                             singleton anon inode and calls the
+ *                             inode_init_security_anon() LSM hook.  This
+ *                             allows for both the inode to have its own
+ *                             security context and for the LSM to enforce
+ *                             policy on the inode's creation.
  *
  * @name:    [in]    name of the "class" of the new file
  * @fops:    [in]    file operations for the new file
  * @priv:    [in]    private data for the new file (will be file's private_data)
  * @flags:   [in]    flags
+ * @context_inode:
+ *           [in]    the logical relationship with the new inode (optional)
  *
- * Creates a new file by hooking it on a single inode. This is useful for files
- * that do not need to have a full-fledged inode in order to operate correctly.
- * All the files created with anon_inode_getfd() will share a single inode,
- * hence saving memory and avoiding code duplication for the file/inode/dentry
- * setup.  Returns new descriptor or an error code.
+ * The LSM may use @context_inode in inode_init_security_anon(), but a
+ * reference to it is not held.  Returns the newly created file* or an error
+ * pointer.  See the anon_inode_getfile() documentation for more information.
  */
-int anon_inode_getfd(const char *name, const struct file_operations *fops,
-		     void *priv, int flags)
+struct file *anon_inode_getfile_secure(const char *name,
+				       const struct file_operations *fops,
+				       void *priv, int flags,
+				       const struct inode *context_inode)
+{
+	return __anon_inode_getfile(name, fops, priv, flags,
+				    context_inode, true);
+}
+
+static int __anon_inode_getfd(const char *name,
+			      const struct file_operations *fops,
+			      void *priv, int flags,
+			      const struct inode *context_inode,
+			      bool secure)
 {
 	int error, fd;
 	struct file *file;
@@ -133,7 +191,8 @@ int anon_inode_getfd(const char *name, const struct file_operations *fops,
 		return error;
 	fd = error;
 
-	file = anon_inode_getfile(name, fops, priv, flags);
+	file = __anon_inode_getfile(name, fops, priv, flags, context_inode,
+				    secure);
 	if (IS_ERR(file)) {
 		error = PTR_ERR(file);
 		goto err_put_unused_fd;
@@ -146,8 +205,55 @@ err_put_unused_fd:
 	put_unused_fd(fd);
 	return error;
 }
+
+/**
+ * anon_inode_getfd - creates a new file instance by hooking it up to
+ *                    an anonymous inode and a dentry that describe
+ *                    the "class" of the file
+ *
+ * @name:    [in]    name of the "class" of the new file
+ * @fops:    [in]    file operations for the new file
+ * @priv:    [in]    private data for the new file (will be file's private_data)
+ * @flags:   [in]    flags
+ *
+ * Creates a new file by hooking it on a single inode. This is
+ * useful for files that do not need to have a full-fledged inode in
+ * order to operate correctly.  All the files created with
+ * anon_inode_getfd() will use the same singleton inode, reducing
+ * memory use and avoiding code duplication for the file/inode/dentry
+ * setup.  Returns a newly created file descriptor or an error code.
+ */
+int anon_inode_getfd(const char *name, const struct file_operations *fops,
+		     void *priv, int flags)
+{
+	return __anon_inode_getfd(name, fops, priv, flags, NULL, false);
+}
 EXPORT_SYMBOL_GPL(anon_inode_getfd);
 
+/**
+ * anon_inode_getfd_secure - Like anon_inode_getfd(), but creates a new
+ * !S_PRIVATE anon inode rather than reuse the singleton anon inode, and calls
+ * the inode_init_security_anon() LSM hook. This allows the inode to have its
+ * own security context and for a LSM to reject creation of the inode.
+ *
+ * @name:    [in]    name of the "class" of the new file
+ * @fops:    [in]    file operations for the new file
+ * @priv:    [in]    private data for the new file (will be file's private_data)
+ * @flags:   [in]    flags
+ * @context_inode:
+ *           [in]    the logical relationship with the new inode (optional)
+ *
+ * The LSM may use @context_inode in inode_init_security_anon(), but a
+ * reference to it is not held.
+ */
+int anon_inode_getfd_secure(const char *name, const struct file_operations *fops,
+			    void *priv, int flags,
+			    const struct inode *context_inode)
+{
+	return __anon_inode_getfd(name, fops, priv, flags, context_inode, true);
+}
+EXPORT_SYMBOL_GPL(anon_inode_getfd_secure);
+
 static int __init anon_inode_init(void)
 {
 	anon_inode_mnt = kern_mount(&anon_inode_fs_type);