--- /dev/null
+/* 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
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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 | FS_EVENT_ON_CHILD)
+
+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,
+ 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;
+ struct inode *inode;
+ int ret;
+
+ if (pathname[0] != '/' || pathname[len-1] == '/')
+ return ERR_PTR(-EINVAL);
+
+ dentry = kern_path_locked(pathname, &path);
+ if (IS_ERR(dentry))
+ return (void *)dentry; /* returning an error */
+ inode = path.dentry->d_inode;
+ mutex_unlock(&inode->i_mutex);
+
+ audit_mark = kzalloc(sizeof(*audit_mark), GFP_KERNEL);
+ if (unlikely(!audit_mark)) {
+ audit_mark = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_free_mark);
+ 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_mark(&audit_mark->mark, audit_fsnotify_group, inode, NULL, true);
+ if (ret < 0) {
+ audit_fsnotify_mark_free(audit_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(NULL, GFP_NOFS, AUDIT_CONFIG_CHANGE);
+ if (unlikely(!ab))
+ return;
+ audit_log_format(ab, "auid=%u ses=%u op=",
+ from_kuid(&init_user_ns, audit_get_loginuid(current)),
+ audit_get_sessionid(current));
+ audit_log_string(ab, op);
+ audit_log_format(ab, " path=");
+ 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_group *group,
+ struct inode *to_tell,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
+ u32 mask, void *data, int data_type,
+ const unsigned char *dname, u32 cookie)
+{
+ struct audit_fsnotify_mark *audit_mark;
+ struct inode *inode = NULL;
+
+ audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark);
+
+ BUG_ON(group != audit_fsnotify_group);
+
+ switch (data_type) {
+ case (FSNOTIFY_EVENT_PATH):
+ inode = ((struct path *)data)->dentry->d_inode;
+ break;
+ case (FSNOTIFY_EVENT_INODE):
+ inode = (struct inode *)data;
+ break;
+ default:
+ BUG();
+ 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_event = audit_mark_handle_event,
+};
+
+static int __init audit_fsnotify_init(void)
+{
+ audit_fsnotify_group = fsnotify_alloc_group(&audit_mark_fsnotify_ops);
+ if (IS_ERR(audit_fsnotify_group)) {
+ audit_fsnotify_group = NULL;
+ audit_panic("cannot create audit fsnotify group");
+ }
+ return 0;
+}
+device_initcall(audit_fsnotify_init);
Code Review / kvmfornfv.git / blobdiff