| /* 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, |
| 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; |
| 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; |
| inode_unlock(inode); |
| |
| 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=%s", |
| from_kuid(&init_user_ns, audit_get_loginuid(current)), |
| audit_get_sessionid(current), 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, const void *data, int data_type, |
| const unsigned char *dname, u32 cookie) |
| { |
| struct audit_fsnotify_mark *audit_mark; |
| const 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 = ((const struct path *)data)->dentry->d_inode; |
| break; |
| case (FSNOTIFY_EVENT_INODE): |
| inode = (const 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); |