1
2
3
4
5
6
7
8
9#include <linux/kernel.h>
10#include <linux/audit.h>
11#include <linux/kthread.h>
12#include <linux/mutex.h>
13#include <linux/fs.h>
14#include <linux/fsnotify_backend.h>
15#include <linux/namei.h>
16#include <linux/netlink.h>
17#include <linux/sched.h>
18#include <linux/slab.h>
19#include <linux/security.h>
20#include "audit.h"
21
22
23
24
25
26struct audit_fsnotify_mark {
27 dev_t dev;
28 unsigned long ino;
29 char *path;
30 struct fsnotify_mark mark;
31 struct audit_krule *rule;
32};
33
34
35static struct fsnotify_group *audit_fsnotify_group;
36
37
38#define AUDIT_FS_EVENTS (FS_MOVE | FS_CREATE | FS_DELETE | FS_DELETE_SELF |\
39 FS_MOVE_SELF | FS_EVENT_ON_CHILD)
40
41static void audit_fsnotify_mark_free(struct audit_fsnotify_mark *audit_mark)
42{
43 kfree(audit_mark->path);
44 kfree(audit_mark);
45}
46
47static void audit_fsnotify_free_mark(struct fsnotify_mark *mark)
48{
49 struct audit_fsnotify_mark *audit_mark;
50
51 audit_mark = container_of(mark, struct audit_fsnotify_mark, mark);
52 audit_fsnotify_mark_free(audit_mark);
53}
54
55char *audit_mark_path(struct audit_fsnotify_mark *mark)
56{
57 return mark->path;
58}
59
60int audit_mark_compare(struct audit_fsnotify_mark *mark, unsigned long ino, dev_t dev)
61{
62 if (mark->ino == AUDIT_INO_UNSET)
63 return 0;
64 return (mark->ino == ino) && (mark->dev == dev);
65}
66
67static void audit_update_mark(struct audit_fsnotify_mark *audit_mark,
68 const struct inode *inode)
69{
70 audit_mark->dev = inode ? inode->i_sb->s_dev : AUDIT_DEV_UNSET;
71 audit_mark->ino = inode ? inode->i_ino : AUDIT_INO_UNSET;
72}
73
74struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule, char *pathname, int len)
75{
76 struct audit_fsnotify_mark *audit_mark;
77 struct path path;
78 struct dentry *dentry;
79 struct inode *inode;
80 int ret;
81
82 if (pathname[0] != '/' || pathname[len-1] == '/')
83 return ERR_PTR(-EINVAL);
84
85 dentry = kern_path_locked(pathname, &path);
86 if (IS_ERR(dentry))
87 return (void *)dentry;
88 inode = path.dentry->d_inode;
89 inode_unlock(inode);
90
91 audit_mark = kzalloc(sizeof(*audit_mark), GFP_KERNEL);
92 if (unlikely(!audit_mark)) {
93 audit_mark = ERR_PTR(-ENOMEM);
94 goto out;
95 }
96
97 fsnotify_init_mark(&audit_mark->mark, audit_fsnotify_group);
98 audit_mark->mark.mask = AUDIT_FS_EVENTS;
99 audit_mark->path = pathname;
100 audit_update_mark(audit_mark, dentry->d_inode);
101 audit_mark->rule = krule;
102
103 ret = fsnotify_add_inode_mark(&audit_mark->mark, inode, true);
104 if (ret < 0) {
105 fsnotify_put_mark(&audit_mark->mark);
106 audit_mark = ERR_PTR(ret);
107 }
108out:
109 dput(dentry);
110 path_put(&path);
111 return audit_mark;
112}
113
114static void audit_mark_log_rule_change(struct audit_fsnotify_mark *audit_mark, char *op)
115{
116 struct audit_buffer *ab;
117 struct audit_krule *rule = audit_mark->rule;
118
119 if (!audit_enabled)
120 return;
121 ab = audit_log_start(audit_context(), GFP_NOFS, AUDIT_CONFIG_CHANGE);
122 if (unlikely(!ab))
123 return;
124 audit_log_session_info(ab);
125 audit_log_format(ab, " op=%s path=", op);
126 audit_log_untrustedstring(ab, audit_mark->path);
127 audit_log_key(ab, rule->filterkey);
128 audit_log_format(ab, " list=%d res=1", rule->listnr);
129 audit_log_end(ab);
130}
131
132void audit_remove_mark(struct audit_fsnotify_mark *audit_mark)
133{
134 fsnotify_destroy_mark(&audit_mark->mark, audit_fsnotify_group);
135 fsnotify_put_mark(&audit_mark->mark);
136}
137
138void audit_remove_mark_rule(struct audit_krule *krule)
139{
140 struct audit_fsnotify_mark *mark = krule->exe;
141
142 audit_remove_mark(mark);
143}
144
145static void audit_autoremove_mark_rule(struct audit_fsnotify_mark *audit_mark)
146{
147 struct audit_krule *rule = audit_mark->rule;
148 struct audit_entry *entry = container_of(rule, struct audit_entry, rule);
149
150 audit_mark_log_rule_change(audit_mark, "autoremove_rule");
151 audit_del_rule(entry);
152}
153
154
155static int audit_mark_handle_event(struct fsnotify_group *group,
156 struct inode *to_tell,
157 u32 mask, const void *data, int data_type,
158 const struct qstr *dname, u32 cookie,
159 struct fsnotify_iter_info *iter_info)
160{
161 struct fsnotify_mark *inode_mark = fsnotify_iter_inode_mark(iter_info);
162 struct audit_fsnotify_mark *audit_mark;
163 const struct inode *inode = NULL;
164
165 audit_mark = container_of(inode_mark, struct audit_fsnotify_mark, mark);
166
167 BUG_ON(group != audit_fsnotify_group);
168
169 switch (data_type) {
170 case (FSNOTIFY_EVENT_PATH):
171 inode = ((const struct path *)data)->dentry->d_inode;
172 break;
173 case (FSNOTIFY_EVENT_INODE):
174 inode = (const struct inode *)data;
175 break;
176 default:
177 BUG();
178 return 0;
179 }
180
181 if (mask & (FS_CREATE|FS_MOVED_TO|FS_DELETE|FS_MOVED_FROM)) {
182 if (audit_compare_dname_path(dname, audit_mark->path, AUDIT_NAME_FULL))
183 return 0;
184 audit_update_mark(audit_mark, inode);
185 } else if (mask & (FS_DELETE_SELF|FS_UNMOUNT|FS_MOVE_SELF))
186 audit_autoremove_mark_rule(audit_mark);
187
188 return 0;
189}
190
191static const struct fsnotify_ops audit_mark_fsnotify_ops = {
192 .handle_event = audit_mark_handle_event,
193 .free_mark = audit_fsnotify_free_mark,
194};
195
196static int __init audit_fsnotify_init(void)
197{
198 audit_fsnotify_group = fsnotify_alloc_group(&audit_mark_fsnotify_ops);
199 if (IS_ERR(audit_fsnotify_group)) {
200 audit_fsnotify_group = NULL;
201 audit_panic("cannot create audit fsnotify group");
202 }
203 return 0;
204}
205device_initcall(audit_fsnotify_init);
206
