xref: /linux/kernel/audit.h (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* audit -- definition of audit_context structure and supporting types
3  *
4  * Copyright 2003-2004 Red Hat, Inc.
5  * Copyright 2005 Hewlett-Packard Development Company, L.P.
6  * Copyright 2005 IBM Corporation
7  */
8 
9 #ifndef _KERNEL_AUDIT_H_
10 #define _KERNEL_AUDIT_H_
11 
12 #include <linux/fs.h>
13 #include <linux/audit.h>
14 #include <linux/security.h>
15 #include <linux/skbuff.h>
16 #include <uapi/linux/mqueue.h>
17 #include <linux/tty.h>
18 #include <uapi/linux/openat2.h> // struct open_how
19 
20 /* AUDIT_NAMES is the number of slots we reserve in the audit_context
21  * for saving names from getname().  If we get more names we will allocate
22  * a name dynamically and also add those to the list anchored by names_list. */
23 #define AUDIT_NAMES	5
24 
25 /* At task start time, the audit_state is set in the audit_context using
26    a per-task filter.  At syscall entry, the audit_state is augmented by
27    the syscall filter. */
28 enum audit_state {
29 	AUDIT_STATE_DISABLED,	/* Do not create per-task audit_context.
30 				 * No syscall-specific audit records can
31 				 * be generated. */
32 	AUDIT_STATE_BUILD,	/* Create the per-task audit_context,
33 				 * and fill it in at syscall
34 				 * entry time.  This makes a full
35 				 * syscall record available if some
36 				 * other part of the kernel decides it
37 				 * should be recorded. */
38 	AUDIT_STATE_RECORD	/* Create the per-task audit_context,
39 				 * always fill it in at syscall entry
40 				 * time, and always write out the audit
41 				 * record at syscall exit time.  */
42 };
43 
44 /* Rule lists */
45 struct audit_watch;
46 struct audit_fsnotify_mark;
47 struct audit_tree;
48 struct audit_chunk;
49 
50 struct audit_entry {
51 	struct list_head	list;
52 	struct rcu_head		rcu;
53 	struct audit_krule	rule;
54 };
55 
56 struct audit_cap_data {
57 	kernel_cap_t		permitted;
58 	kernel_cap_t		inheritable;
59 	union {
60 		unsigned int	fE;		/* effective bit of file cap */
61 		kernel_cap_t	effective;	/* effective set of process */
62 	};
63 	kernel_cap_t		ambient;
64 	kuid_t			rootid;
65 };
66 
67 /* When fs/namei.c:getname() is called, we store the pointer in name and bump
68  * the refcnt in the associated filename struct.
69  *
70  * Further, in fs/namei.c:path_lookup() we store the inode and device.
71  */
72 struct audit_names {
73 	struct list_head	list;		/* audit_context->names_list */
74 
75 	struct filename		*name;
76 	int			name_len;	/* number of chars to log */
77 	bool			hidden;		/* don't log this record */
78 
79 	unsigned long		ino;
80 	dev_t			dev;
81 	umode_t			mode;
82 	kuid_t			uid;
83 	kgid_t			gid;
84 	dev_t			rdev;
85 	struct lsm_prop		oprop;
86 	struct audit_cap_data	fcap;
87 	unsigned int		fcap_ver;
88 	unsigned char		type;		/* record type */
89 	/*
90 	 * This was an allocated audit_names and not from the array of
91 	 * names allocated in the task audit context.  Thus this name
92 	 * should be freed on syscall exit.
93 	 */
94 	bool			should_free;
95 };
96 
97 struct audit_proctitle {
98 	int	len;	/* length of the cmdline field. */
99 	char	*value;	/* the cmdline field */
100 };
101 
102 /* A timestamp/serial pair to identify an event */
103 struct audit_stamp {
104 	struct timespec64	ctime;	/* time of syscall entry */
105 	unsigned int		serial;	/* serial number for record */
106 };
107 
108 /* The per-task audit context. */
109 struct audit_context {
110 	int		    dummy;	/* must be the first element */
111 	enum {
112 		AUDIT_CTX_UNUSED,	/* audit_context is currently unused */
113 		AUDIT_CTX_SYSCALL,	/* in use by syscall */
114 		AUDIT_CTX_URING,	/* in use by io_uring */
115 	} context;
116 	enum audit_state    state, current_state;
117 	struct audit_stamp  stamp;	/* event identifier */
118 	int		    major;      /* syscall number */
119 	int		    uring_op;   /* uring operation */
120 	unsigned long	    argv[4];    /* syscall arguments */
121 	long		    return_code;/* syscall return code */
122 	u64		    prio;
123 	int		    return_valid; /* return code is valid */
124 	/*
125 	 * The names_list is the list of all audit_names collected during this
126 	 * syscall.  The first AUDIT_NAMES entries in the names_list will
127 	 * actually be from the preallocated_names array for performance
128 	 * reasons.  Except during allocation they should never be referenced
129 	 * through the preallocated_names array and should only be found/used
130 	 * by running the names_list.
131 	 */
132 	struct audit_names  preallocated_names[AUDIT_NAMES];
133 	int		    name_count; /* total records in names_list */
134 	struct list_head    names_list;	/* struct audit_names->list anchor */
135 	char		    *filterkey;	/* key for rule that triggered record */
136 	struct path	    pwd;
137 	struct audit_aux_data *aux;
138 	struct audit_aux_data *aux_pids;
139 	struct sockaddr_storage *sockaddr;
140 	size_t sockaddr_len;
141 				/* Save things to print about task_struct */
142 	pid_t		    ppid;
143 	kuid_t		    uid, euid, suid, fsuid;
144 	kgid_t		    gid, egid, sgid, fsgid;
145 	unsigned long	    personality;
146 	int		    arch;
147 
148 	pid_t		    target_pid;
149 	kuid_t		    target_auid;
150 	kuid_t		    target_uid;
151 	unsigned int	    target_sessionid;
152 	struct lsm_prop	    target_ref;
153 	char		    target_comm[TASK_COMM_LEN];
154 
155 	struct audit_tree_refs *trees, *first_trees;
156 	struct list_head killed_trees;
157 	int tree_count;
158 
159 	int type;
160 	union {
161 		struct {
162 			int nargs;
163 			long args[6];
164 		} socketcall;
165 		struct {
166 			kuid_t			uid;
167 			kgid_t			gid;
168 			umode_t			mode;
169 			struct lsm_prop		oprop;
170 			int			has_perm;
171 			uid_t			perm_uid;
172 			gid_t			perm_gid;
173 			umode_t			perm_mode;
174 			unsigned long		qbytes;
175 		} ipc;
176 		struct {
177 			mqd_t			mqdes;
178 			struct mq_attr		mqstat;
179 		} mq_getsetattr;
180 		struct {
181 			mqd_t			mqdes;
182 			int			sigev_signo;
183 		} mq_notify;
184 		struct {
185 			mqd_t			mqdes;
186 			size_t			msg_len;
187 			unsigned int		msg_prio;
188 			struct timespec64	abs_timeout;
189 		} mq_sendrecv;
190 		struct {
191 			int			oflag;
192 			umode_t			mode;
193 			struct mq_attr		attr;
194 		} mq_open;
195 		struct {
196 			pid_t			pid;
197 			struct audit_cap_data	cap;
198 		} capset;
199 		struct {
200 			int			fd;
201 			int			flags;
202 		} mmap;
203 		struct open_how openat2;
204 		struct {
205 			int			argc;
206 		} execve;
207 		struct {
208 			const char		*name;
209 		} module;
210 		struct {
211 			struct audit_ntp_data	ntp_data;
212 			struct timespec64	tk_injoffset;
213 		} time;
214 	};
215 	int fds[2];
216 	struct audit_proctitle proctitle;
217 };
218 
219 extern bool audit_ever_enabled;
220 
221 extern void audit_log_session_info(struct audit_buffer *ab);
222 
223 extern int auditd_test_task(struct task_struct *task);
224 
225 #define AUDIT_INODE_BUCKETS	32
226 extern struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
227 
228 static inline int audit_hash_ino(u32 ino)
229 {
230 	return (ino & (AUDIT_INODE_BUCKETS-1));
231 }
232 
233 /* Indicates that audit should log the full pathname. */
234 #define AUDIT_NAME_FULL -1
235 
236 extern int audit_match_class(int class, unsigned syscall);
237 extern int audit_comparator(const u32 left, const u32 op, const u32 right);
238 extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right);
239 extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right);
240 extern int parent_len(const char *path);
241 extern int audit_compare_dname_path(const struct qstr *dname, const char *path, int plen);
242 extern struct sk_buff *audit_make_reply(int seq, int type, int done, int multi,
243 					const void *payload, int size);
244 extern void		    audit_panic(const char *message);
245 
246 struct audit_netlink_list {
247 	__u32 portid;
248 	struct net *net;
249 	struct sk_buff_head q;
250 };
251 
252 int audit_send_list_thread(void *_dest);
253 
254 extern struct mutex audit_filter_mutex;
255 extern int audit_del_rule(struct audit_entry *entry);
256 extern void audit_free_rule_rcu(struct rcu_head *head);
257 extern struct list_head audit_filter_list[];
258 
259 extern struct audit_entry *audit_dupe_rule(struct audit_krule *old);
260 
261 extern void audit_log_d_path_exe(struct audit_buffer *ab,
262 				 struct mm_struct *mm);
263 
264 extern struct tty_struct *audit_get_tty(void);
265 extern void audit_put_tty(struct tty_struct *tty);
266 
267 /* audit watch/mark/tree functions */
268 extern unsigned int audit_serial(void);
269 #ifdef CONFIG_AUDITSYSCALL
270 extern int auditsc_get_stamp(struct audit_context *ctx,
271 			     struct audit_stamp *stamp);
272 
273 extern void audit_put_watch(struct audit_watch *watch);
274 extern void audit_get_watch(struct audit_watch *watch);
275 extern int audit_to_watch(struct audit_krule *krule, char *path, int len,
276 			  u32 op);
277 extern int audit_add_watch(struct audit_krule *krule, struct list_head **list);
278 extern void audit_remove_watch_rule(struct audit_krule *krule);
279 extern char *audit_watch_path(struct audit_watch *watch);
280 extern int audit_watch_compare(struct audit_watch *watch, unsigned long ino,
281 			       dev_t dev);
282 
283 extern struct audit_fsnotify_mark *audit_alloc_mark(struct audit_krule *krule,
284 						    char *pathname, int len);
285 extern char *audit_mark_path(struct audit_fsnotify_mark *mark);
286 extern void audit_remove_mark(struct audit_fsnotify_mark *audit_mark);
287 extern void audit_remove_mark_rule(struct audit_krule *krule);
288 extern int audit_mark_compare(struct audit_fsnotify_mark *mark,
289 			      unsigned long ino, dev_t dev);
290 extern int audit_dupe_exe(struct audit_krule *new, struct audit_krule *old);
291 extern int audit_exe_compare(struct task_struct *tsk,
292 			     struct audit_fsnotify_mark *mark);
293 
294 extern struct audit_chunk *audit_tree_lookup(const struct inode *inode);
295 extern void audit_put_chunk(struct audit_chunk *chunk);
296 extern bool audit_tree_match(struct audit_chunk *chunk,
297 			     struct audit_tree *tree);
298 extern int audit_make_tree(struct audit_krule *rule, char *pathname, u32 op);
299 extern int audit_add_tree_rule(struct audit_krule *rule);
300 extern int audit_remove_tree_rule(struct audit_krule *rule);
301 extern void audit_trim_trees(void);
302 extern int audit_tag_tree(char *old, char *new);
303 extern const char *audit_tree_path(struct audit_tree *tree);
304 extern void audit_put_tree(struct audit_tree *tree);
305 extern void audit_kill_trees(struct audit_context *context);
306 
307 extern int audit_signal_info_syscall(struct task_struct *t);
308 extern void audit_filter_inodes(struct task_struct *tsk,
309 				struct audit_context *ctx);
310 extern struct list_head *audit_killed_trees(void);
311 #else /* CONFIG_AUDITSYSCALL */
312 #define auditsc_get_stamp(c, s) 0
313 #define audit_put_watch(w) do { } while (0)
314 #define audit_get_watch(w) do { } while (0)
315 #define audit_to_watch(k, p, l, o) (-EINVAL)
316 #define audit_add_watch(k, l) (-EINVAL)
317 #define audit_remove_watch_rule(k) BUG()
318 #define audit_watch_path(w) ""
319 #define audit_watch_compare(w, i, d) 0
320 
321 #define audit_alloc_mark(k, p, l) (ERR_PTR(-EINVAL))
322 #define audit_mark_path(m) ""
323 #define audit_remove_mark(m) do { } while (0)
324 #define audit_remove_mark_rule(k) do { } while (0)
325 #define audit_mark_compare(m, i, d) 0
326 #define audit_exe_compare(t, m) (-EINVAL)
327 #define audit_dupe_exe(n, o) (-EINVAL)
328 
329 #define audit_remove_tree_rule(rule) BUG()
330 #define audit_add_tree_rule(rule) -EINVAL
331 #define audit_make_tree(rule, str, op) -EINVAL
332 #define audit_trim_trees() do { } while (0)
333 #define audit_put_tree(tree) do { } while (0)
334 #define audit_tag_tree(old, new) -EINVAL
335 #define audit_tree_path(rule) ""	/* never called */
336 #define audit_kill_trees(context) BUG()
337 
338 static inline int audit_signal_info_syscall(struct task_struct *t)
339 {
340 	return 0;
341 }
342 
343 #define audit_filter_inodes(t, c) do { } while (0)
344 #endif /* CONFIG_AUDITSYSCALL */
345 
346 extern char *audit_unpack_string(void **bufp, size_t *remain, size_t len);
347 
348 extern int audit_filter(int msgtype, unsigned int listtype);
349 
350 extern void audit_ctl_lock(void);
351 extern void audit_ctl_unlock(void);
352 
353 #endif
354