// SPDX-License-Identifier: GPL-2.0-or-later/* audit_fsnotify.c -- tracking inodes * * Copyright 2003-2009,2014-2015 Red Hat, Inc. * Copyright 2005 Hewlett-Packard Development Company, L.P. * Copyright 2005 IBM Corporation */ #include <linux/kernel.h>#include <linux/audit.h>#include <linux/kthread.h>#include <linux/mutex.h>#include <linux/fs.h>#include <linux/fsnotify_backend.h>#include <linux/namei.h>#include <linux/netlink.h>#include <linux/sched.h>#include <linux/slab.h>#include <linux/security.h>#include "audit.h" /* * this mark lives on the parent directory of the inode in question. * but dev, ino, and path are about the child */struct audit_fsnotify_mark {	dev_t dev;		/* associated superblock device */	unsigned long ino;	/* associated inode number */	char *path;		/* insertion path */	struct fsnotify_mark mark; /* fsnotify mark on the inode */	struct audit_krule *rule;}; /* fsnotify handle. */static struct fsnotify_group *audit_fsnotify_group; /* fsnotify events we care about. */#define AUDIT_FS_EVENTS (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\			 FS_MOVE_SELF) static void audit_fsnotify_mark_free(struct audit_fsnotify_mark *audit_mark){	kfree(audit_mark->path);	kfree(audit_mark);} static void audit_fsnotify_free_mark(struct fsnotify_mark *mark){	struct audit_fsnotify_mark *audit_mark; 	audit_mark = container_of(mark, struct audit_fsnotify_mark, mark);	audit_fsnotify_mark_free(audit_mark);} char *audit_mark_path(struct audit_fsnotify_mark *mark){	return mark->path;} int audit_mark_compare(struct audit_fsnotify_mark *mark, unsigned long ino, dev_t dev){	if (mark->ino == AUDIT_INO_UNSET)		return 0;	return (mark->ino == ino) && (mark->dev == dev);} static void audit_update_mark(struct audit_fsnotify_mark *audit_mark,			     const struct inode *inode){	audit_mark->dev = inode ? inode->i_sb->s_dev : AUDIT_DEV_UNSET;	audit_mark->ino = inode ? inode->i_ino : AUDIT_INO_UNSET;} struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule, char *pathname, int len){	struct audit_fsnotify_mark *audit_mark;	struct path path;	struct dentry *dentry;	int ret; 	if (pathname[0] != '/' || pathname[len-1] == '/')		return ERR_PTR(-EINVAL); 	dentry = kern_path_parent(pathname, &path);	if (IS_ERR(dentry))		return ERR_CAST(dentry); /* returning an error */	if (d_really_is_negative(dentry)) {		audit_mark = ERR_PTR(-ENOENT);		goto out;	} 	audit_mark = kzalloc_obj(*audit_mark);	if (unlikely(!audit_mark)) {		audit_mark = ERR_PTR(-ENOMEM);		goto out;	} 	fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_group);	audit_mark->mark.mask = AUDIT_FS_EVENTS;	audit_mark->path = pathname;	audit_update_mark(audit_mark, dentry->d_inode);	audit_mark->rule = krule; 	ret = fsnotify_add_inode_mark(&audit_mark->mark, path.dentry->d_inode, 0);	if (ret < 0) {		audit_mark->path = NULL;		fsnotify_put_mark(&audit_mark->mark);		audit_mark = ERR_PTR(ret);	}out:	dput(dentry);	path_put(&path);	return audit_mark;} static void audit_mark_log_rule_change(struct audit_fsnotify_mark *audit_mark, char *op){	struct audit_buffer *ab;	struct audit_krule *rule = audit_mark->rule; 	if (!audit_enabled)		return;	ab = audit_log_start(audit_context(), GFP_NOFS, AUDIT_CONFIG_CHANGE);	if (unlikely(!ab))		return;	audit_log_session_info(ab);	audit_log_format(ab, " op=%s path=", op);	audit_log_untrustedstring(ab, audit_mark->path);	audit_log_key(ab, rule->filterkey);	audit_log_format(ab, " list=%d res=1", rule->listnr);	audit_log_end(ab);} void audit_remove_mark(struct audit_fsnotify_mark *audit_mark){	fsnotify_destroy_mark(&audit_mark->mark, audit_fsnotify_group);	fsnotify_put_mark(&audit_mark->mark);} void audit_remove_mark_rule(struct audit_krule *krule){	struct audit_fsnotify_mark *mark = krule->exe; 	audit_remove_mark(mark);} static void audit_autoremove_mark_rule(struct audit_fsnotify_mark *audit_mark){	struct audit_krule *rule = audit_mark->rule;	struct audit_entry *entry = container_of(rule, struct audit_entry, rule); 	audit_mark_log_rule_change(audit_mark, "autoremove_rule");	audit_del_rule(entry);} /* Update mark data in audit rules based on fsnotify events. */static int audit_mark_handle_event(struct fsnotify_mark *inode_mark, u32 mask,				   struct inode *inode, struct inode *dir,				   const struct qstr *dname, u32 cookie){	struct audit_fsnotify_mark *audit_mark; 	audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark); 	if (WARN_ON_ONCE(inode_mark->group != audit_fsnotify_group))		return 0; 	if (mask & (FS_CREATE|FS_MOVED_TO|FS_DELETE|FS_MOVED_FROM)) {		if (audit_compare_dname_path(dname, audit_mark->path, AUDIT_NAME_FULL))			return 0;		audit_update_mark(audit_mark, inode);	} else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF)) {		audit_autoremove_mark_rule(audit_mark);	} 	return 0;} static const struct fsnotify_ops audit_mark_fsnotify_ops = {	.handle_inode_event = audit_mark_handle_event,	.free_mark = audit_fsnotify_free_mark,}; static int __init audit_fsnotify_init(void){	audit_fsnotify_group = fsnotify_alloc_group(&audit_mark_fsnotify_ops,						    FSNOTIFY_GROUP_DUPS);	if (IS_ERR(audit_fsnotify_group)) {		audit_fsnotify_group = NULL;		audit_panic("cannot create audit fsnotify group");	}	return 0;}device_initcall(audit_fsnotify_init);