Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 350 insertions, 0 deletions

diff --git a/security/inode.c b/security/inode.c
new file mode 100644
index 000000000..6c3269397
--- /dev/null
+++ b/security/inode.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  inode.c - securityfs
+ *
+ *  Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de>
+ *
+ *  Based on fs/debugfs/inode.c which had the following copyright notice:
+ *    Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
+ *    Copyright (C) 2004 IBM Inc.
+ */
+
+/* #define DEBUG */
+#include <linux/sysfs.h>
+#include <linux/kobject.h>
+#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/security.h>
+#include <linux/lsm_hooks.h>
+#include <linux/magic.h>
+
+static struct vfsmount *mount;
+static int mount_count;
+
+static void securityfs_free_inode(struct inode *inode)
+{
+	if (S_ISLNK(inode->i_mode))
+		kfree(inode->i_link);
+	free_inode_nonrcu(inode);
+}
+
+static const struct super_operations securityfs_super_operations = {
+	.statfs		= simple_statfs,
+	.free_inode	= securityfs_free_inode,
+};
+
+static int securityfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	static const struct tree_descr files[] = {{""}};
+	int error;
+
+	error = simple_fill_super(sb, SECURITYFS_MAGIC, files);
+	if (error)
+		return error;
+
+	sb->s_op = &securityfs_super_operations;
+
+	return 0;
+}
+
+static int securityfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_single(fc, securityfs_fill_super);
+}
+
+static const struct fs_context_operations securityfs_context_ops = {
+	.get_tree	= securityfs_get_tree,
+};
+
+static int securityfs_init_fs_context(struct fs_context *fc)
+{
+	fc->ops = &securityfs_context_ops;
+	return 0;
+}
+
+static struct file_system_type fs_type = {
+	.owner =	THIS_MODULE,
+	.name =		"securityfs",
+	.init_fs_context = securityfs_init_fs_context,
+	.kill_sb =	kill_litter_super,
+};
+
+/**
+ * securityfs_create_dentry - create a dentry in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          file will be created in the root of the securityfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ *        on.  The inode.i_private pointer will point to this value on
+ *        the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ *        this file.
+ * @iops: a point to a struct of inode_operations that should be used for
+ *        this file/dir
+ *
+ * This is the basic "create a file/dir/symlink" function for
+ * securityfs.  It allows for a wide range of flexibility in creating
+ * a file, or a directory (if you want to create a directory, the
+ * securityfs_create_dir() function is recommended to be used
+ * instead).
+ *
+ * This function returns a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the securityfs_remove() function when the
+ * file is to be removed (no automatic cleanup happens if your module
+ * is unloaded, you are responsible here).  If an error occurs, the
+ * function will return the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
+					struct dentry *parent, void *data,
+					const struct file_operations *fops,
+					const struct inode_operations *iops)
+{
+	struct dentry *dentry;
+	struct inode *dir, *inode;
+	int error;
+
+	if (!(mode & S_IFMT))
+		mode = (mode & S_IALLUGO) | S_IFREG;
+
+	pr_debug("securityfs: creating file '%s'\n",name);
+
+	error = simple_pin_fs(&fs_type, &mount, &mount_count);
+	if (error)
+		return ERR_PTR(error);
+
+	if (!parent)
+		parent = mount->mnt_root;
+
+	dir = d_inode(parent);
+
+	inode_lock(dir);
+	dentry = lookup_one_len(name, parent, strlen(name));
+	if (IS_ERR(dentry))
+		goto out;
+
+	if (d_really_is_positive(dentry)) {
+		error = -EEXIST;
+		goto out1;
+	}
+
+	inode = new_inode(dir->i_sb);
+	if (!inode) {
+		error = -ENOMEM;
+		goto out1;
+	}
+
+	inode->i_ino = get_next_ino();
+	inode->i_mode = mode;
+	inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
+	inode->i_private = data;
+	if (S_ISDIR(mode)) {
+		inode->i_op = &simple_dir_inode_operations;
+		inode->i_fop = &simple_dir_operations;
+		inc_nlink(inode);
+		inc_nlink(dir);
+	} else if (S_ISLNK(mode)) {
+		inode->i_op = iops ? iops : &simple_symlink_inode_operations;
+		inode->i_link = data;
+	} else {
+		inode->i_fop = fops;
+	}
+	d_instantiate(dentry, inode);
+	dget(dentry);
+	inode_unlock(dir);
+	return dentry;
+
+out1:
+	dput(dentry);
+	dentry = ERR_PTR(error);
+out:
+	inode_unlock(dir);
+	simple_release_fs(&mount, &mount_count);
+	return dentry;
+}
+
+/**
+ * securityfs_create_file - create a file in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          file will be created in the root of the securityfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ *        on.  The inode.i_private pointer will point to this value on
+ *        the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ *        this file.
+ *
+ * This function creates a file in securityfs with the given @name.
+ *
+ * This function returns a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here).  If an error occurs, the function will return
+ * the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+struct dentry *securityfs_create_file(const char *name, umode_t mode,
+				      struct dentry *parent, void *data,
+				      const struct file_operations *fops)
+{
+	return securityfs_create_dentry(name, mode, parent, data, fops, NULL);
+}
+EXPORT_SYMBOL_GPL(securityfs_create_file);
+
+/**
+ * securityfs_create_dir - create a directory in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the directory to
+ *        create.
+ * @parent: a pointer to the parent dentry for this file.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          directory will be created in the root of the securityfs filesystem.
+ *
+ * This function creates a directory in securityfs with the given @name.
+ *
+ * This function returns a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here).  If an error occurs, the function will return
+ * the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
+{
+	return securityfs_create_file(name, S_IFDIR | 0755, parent, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(securityfs_create_dir);
+
+/**
+ * securityfs_create_symlink - create a symlink in the securityfs filesystem
+ *
+ * @name: a pointer to a string containing the name of the symlink to
+ *        create.
+ * @parent: a pointer to the parent dentry for the symlink.  This should be a
+ *          directory dentry if set.  If this parameter is %NULL, then the
+ *          directory will be created in the root of the securityfs filesystem.
+ * @target: a pointer to a string containing the name of the symlink's target.
+ *          If this parameter is %NULL, then the @iops parameter needs to be
+ *          setup to handle .readlink and .get_link inode_operations.
+ * @iops: a pointer to the struct inode_operations to use for the symlink. If
+ *        this parameter is %NULL, then the default simple_symlink_inode
+ *        operations will be used.
+ *
+ * This function creates a symlink in securityfs with the given @name.
+ *
+ * This function returns a pointer to a dentry if it succeeds.  This
+ * pointer must be passed to the securityfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here).  If an error occurs, the function will return
+ * the error value (via ERR_PTR).
+ *
+ * If securityfs is not enabled in the kernel, the value %-ENODEV is
+ * returned.
+ */
+struct dentry *securityfs_create_symlink(const char *name,
+					 struct dentry *parent,
+					 const char *target,
+					 const struct inode_operations *iops)
+{
+	struct dentry *dent;
+	char *link = NULL;
+
+	if (target) {
+		link = kstrdup(target, GFP_KERNEL);
+		if (!link)
+			return ERR_PTR(-ENOMEM);
+	}
+	dent = securityfs_create_dentry(name, S_IFLNK | 0444, parent,
+					link, NULL, iops);
+	if (IS_ERR(dent))
+		kfree(link);
+
+	return dent;
+}
+EXPORT_SYMBOL_GPL(securityfs_create_symlink);
+
+/**
+ * securityfs_remove - removes a file or directory from the securityfs filesystem
+ *
+ * @dentry: a pointer to a the dentry of the file or directory to be removed.
+ *
+ * This function removes a file or directory in securityfs that was previously
+ * created with a call to another securityfs function (like
+ * securityfs_create_file() or variants thereof.)
+ *
+ * This function is required to be called in order for the file to be
+ * removed. No automatic cleanup of files will happen when a module is
+ * removed; you are responsible here.
+ */
+void securityfs_remove(struct dentry *dentry)
+{
+	struct inode *dir;
+
+	if (!dentry || IS_ERR(dentry))
+		return;
+
+	dir = d_inode(dentry->d_parent);
+	inode_lock(dir);
+	if (simple_positive(dentry)) {
+		if (d_is_dir(dentry))
+			simple_rmdir(dir, dentry);
+		else
+			simple_unlink(dir, dentry);
+		dput(dentry);
+	}
+	inode_unlock(dir);
+	simple_release_fs(&mount, &mount_count);
+}
+EXPORT_SYMBOL_GPL(securityfs_remove);
+
+#ifdef CONFIG_SECURITY
+static struct dentry *lsm_dentry;
+static ssize_t lsm_read(struct file *filp, char __user *buf, size_t count,
+			loff_t *ppos)
+{
+	return simple_read_from_buffer(buf, count, ppos, lsm_names,
+		strlen(lsm_names));
+}
+
+static const struct file_operations lsm_ops = {
+	.read = lsm_read,
+	.llseek = generic_file_llseek,
+};
+#endif
+
+static int __init securityfs_init(void)
+{
+	int retval;
+
+	retval = sysfs_create_mount_point(kernel_kobj, "security");
+	if (retval)
+		return retval;
+
+	retval = register_filesystem(&fs_type);
+	if (retval) {
+		sysfs_remove_mount_point(kernel_kobj, "security");
+		return retval;
+	}
+#ifdef CONFIG_SECURITY
+	lsm_dentry = securityfs_create_file("lsm", 0444, NULL, NULL,
+						&lsm_ops);
+#endif
+	return 0;
+}
+core_initcall(securityfs_init);