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