Commit | Line | Data |
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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
9f46080c MH |
2 | /* |
3 | * cn_proc.c - process events connector | |
4 | * | |
5 | * Copyright (C) Matt Helsley, IBM Corp. 2005 | |
6 | * Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net> | |
7 | * Original copyright notice follows: | |
8 | * Copyright (C) 2005 BULL SA. | |
9f46080c MH |
9 | */ |
10 | ||
9f46080c | 11 | #include <linux/kernel.h> |
caf3c9dc | 12 | #include <linux/ktime.h> |
9f46080c | 13 | #include <linux/init.h> |
1d31a4ea | 14 | #include <linux/connector.h> |
5a0e3ad6 | 15 | #include <linux/gfp.h> |
f701e5b7 | 16 | #include <linux/ptrace.h> |
60063497 | 17 | #include <linux/atomic.h> |
9582d901 | 18 | #include <linux/pid_namespace.h> |
60063497 | 19 | |
9f46080c MH |
20 | #include <linux/cn_proc.h> |
21 | ||
1ca1a4cf CM |
22 | /* |
23 | * Size of a cn_msg followed by a proc_event structure. Since the | |
24 | * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we | |
25 | * add one 4-byte word to the size here, and then start the actual | |
26 | * cn_msg structure 4 bytes into the stack buffer. The result is that | |
27 | * the immediately following proc_event structure is aligned to 8 bytes. | |
28 | */ | |
29 | #define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4) | |
30 | ||
31 | /* See comment above; we test our assumption about sizeof struct cn_msg here. */ | |
32 | static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer) | |
33 | { | |
34 | BUILD_BUG_ON(sizeof(struct cn_msg) != 20); | |
35 | return (struct cn_msg *)(buffer + 4); | |
36 | } | |
9f46080c MH |
37 | |
38 | static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); | |
39 | static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; | |
40 | ||
cc398c2e | 41 | /* proc_event_counts is used as the sequence number of the netlink message */ |
9f46080c MH |
42 | static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; |
43 | ||
ab8ed951 | 44 | static inline void send_msg(struct cn_msg *msg) |
9f46080c | 45 | { |
3ea9f683 | 46 | preempt_disable(); |
ab8ed951 AC |
47 | |
48 | msg->seq = __this_cpu_inc_return(proc_event_counts) - 1; | |
49 | ((struct proc_event *)msg->data)->cpu = smp_processor_id(); | |
50 | ||
51 | /* | |
52 | * Preemption remains disabled during send to ensure the messages are | |
53 | * ordered according to their sequence numbers. | |
54 | * | |
55 | * If cn_netlink_send() fails, the data is not sent. | |
56 | */ | |
57 | cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_NOWAIT); | |
58 | ||
3ea9f683 | 59 | preempt_enable(); |
9f46080c MH |
60 | } |
61 | ||
62 | void proc_fork_connector(struct task_struct *task) | |
63 | { | |
64 | struct cn_msg *msg; | |
65 | struct proc_event *ev; | |
1ca1a4cf | 66 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9e8f90df | 67 | struct task_struct *parent; |
9f46080c MH |
68 | |
69 | if (atomic_read(&proc_event_num_listeners) < 1) | |
70 | return; | |
71 | ||
1ca1a4cf | 72 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 73 | ev = (struct proc_event *)msg->data; |
e727ca82 | 74 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 75 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c | 76 | ev->what = PROC_EVENT_FORK; |
9e8f90df ON |
77 | rcu_read_lock(); |
78 | parent = rcu_dereference(task->real_parent); | |
79 | ev->event_data.fork.parent_pid = parent->pid; | |
80 | ev->event_data.fork.parent_tgid = parent->tgid; | |
81 | rcu_read_unlock(); | |
9f46080c MH |
82 | ev->event_data.fork.child_pid = task->pid; |
83 | ev->event_data.fork.child_tgid = task->tgid; | |
84 | ||
85 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
86 | msg->ack = 0; /* not used */ | |
87 | msg->len = sizeof(*ev); | |
e727ca82 | 88 | msg->flags = 0; /* not used */ |
ab8ed951 | 89 | send_msg(msg); |
9f46080c MH |
90 | } |
91 | ||
92 | void proc_exec_connector(struct task_struct *task) | |
93 | { | |
94 | struct cn_msg *msg; | |
95 | struct proc_event *ev; | |
1ca1a4cf | 96 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9f46080c MH |
97 | |
98 | if (atomic_read(&proc_event_num_listeners) < 1) | |
99 | return; | |
100 | ||
1ca1a4cf | 101 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 102 | ev = (struct proc_event *)msg->data; |
e727ca82 | 103 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 104 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
105 | ev->what = PROC_EVENT_EXEC; |
106 | ev->event_data.exec.process_pid = task->pid; | |
107 | ev->event_data.exec.process_tgid = task->tgid; | |
108 | ||
109 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
110 | msg->ack = 0; /* not used */ | |
111 | msg->len = sizeof(*ev); | |
e727ca82 | 112 | msg->flags = 0; /* not used */ |
ab8ed951 | 113 | send_msg(msg); |
9f46080c MH |
114 | } |
115 | ||
116 | void proc_id_connector(struct task_struct *task, int which_id) | |
117 | { | |
118 | struct cn_msg *msg; | |
119 | struct proc_event *ev; | |
1ca1a4cf | 120 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
c69e8d9c | 121 | const struct cred *cred; |
9f46080c MH |
122 | |
123 | if (atomic_read(&proc_event_num_listeners) < 1) | |
124 | return; | |
125 | ||
1ca1a4cf | 126 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 127 | ev = (struct proc_event *)msg->data; |
e727ca82 | 128 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9f46080c MH |
129 | ev->what = which_id; |
130 | ev->event_data.id.process_pid = task->pid; | |
131 | ev->event_data.id.process_tgid = task->tgid; | |
c69e8d9c DH |
132 | rcu_read_lock(); |
133 | cred = __task_cred(task); | |
9f46080c | 134 | if (which_id == PROC_EVENT_UID) { |
9582d901 EB |
135 | ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid); |
136 | ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid); | |
9f46080c | 137 | } else if (which_id == PROC_EVENT_GID) { |
9582d901 EB |
138 | ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid); |
139 | ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid); | |
c69e8d9c DH |
140 | } else { |
141 | rcu_read_unlock(); | |
f3c48ecc | 142 | return; |
c69e8d9c DH |
143 | } |
144 | rcu_read_unlock(); | |
9e93f21b | 145 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
146 | |
147 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
148 | msg->ack = 0; /* not used */ | |
149 | msg->len = sizeof(*ev); | |
e727ca82 | 150 | msg->flags = 0; /* not used */ |
ab8ed951 | 151 | send_msg(msg); |
9f46080c MH |
152 | } |
153 | ||
02b51df1 SJR |
154 | void proc_sid_connector(struct task_struct *task) |
155 | { | |
156 | struct cn_msg *msg; | |
157 | struct proc_event *ev; | |
1ca1a4cf | 158 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
02b51df1 SJR |
159 | |
160 | if (atomic_read(&proc_event_num_listeners) < 1) | |
161 | return; | |
162 | ||
1ca1a4cf | 163 | msg = buffer_to_cn_msg(buffer); |
02b51df1 | 164 | ev = (struct proc_event *)msg->data; |
e727ca82 | 165 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 166 | ev->timestamp_ns = ktime_get_ns(); |
02b51df1 SJR |
167 | ev->what = PROC_EVENT_SID; |
168 | ev->event_data.sid.process_pid = task->pid; | |
169 | ev->event_data.sid.process_tgid = task->tgid; | |
170 | ||
171 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
172 | msg->ack = 0; /* not used */ | |
173 | msg->len = sizeof(*ev); | |
e727ca82 | 174 | msg->flags = 0; /* not used */ |
ab8ed951 | 175 | send_msg(msg); |
02b51df1 SJR |
176 | } |
177 | ||
f701e5b7 VZ |
178 | void proc_ptrace_connector(struct task_struct *task, int ptrace_id) |
179 | { | |
180 | struct cn_msg *msg; | |
181 | struct proc_event *ev; | |
1ca1a4cf | 182 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
f701e5b7 VZ |
183 | |
184 | if (atomic_read(&proc_event_num_listeners) < 1) | |
185 | return; | |
186 | ||
1ca1a4cf | 187 | msg = buffer_to_cn_msg(buffer); |
f701e5b7 | 188 | ev = (struct proc_event *)msg->data; |
e727ca82 | 189 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 190 | ev->timestamp_ns = ktime_get_ns(); |
f701e5b7 VZ |
191 | ev->what = PROC_EVENT_PTRACE; |
192 | ev->event_data.ptrace.process_pid = task->pid; | |
193 | ev->event_data.ptrace.process_tgid = task->tgid; | |
194 | if (ptrace_id == PTRACE_ATTACH) { | |
195 | ev->event_data.ptrace.tracer_pid = current->pid; | |
196 | ev->event_data.ptrace.tracer_tgid = current->tgid; | |
197 | } else if (ptrace_id == PTRACE_DETACH) { | |
198 | ev->event_data.ptrace.tracer_pid = 0; | |
199 | ev->event_data.ptrace.tracer_tgid = 0; | |
200 | } else | |
201 | return; | |
202 | ||
203 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
204 | msg->ack = 0; /* not used */ | |
205 | msg->len = sizeof(*ev); | |
e727ca82 | 206 | msg->flags = 0; /* not used */ |
ab8ed951 | 207 | send_msg(msg); |
f701e5b7 VZ |
208 | } |
209 | ||
f786ecba VZ |
210 | void proc_comm_connector(struct task_struct *task) |
211 | { | |
212 | struct cn_msg *msg; | |
213 | struct proc_event *ev; | |
1ca1a4cf | 214 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
f786ecba VZ |
215 | |
216 | if (atomic_read(&proc_event_num_listeners) < 1) | |
217 | return; | |
218 | ||
1ca1a4cf | 219 | msg = buffer_to_cn_msg(buffer); |
f786ecba | 220 | ev = (struct proc_event *)msg->data; |
e727ca82 | 221 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 222 | ev->timestamp_ns = ktime_get_ns(); |
f786ecba VZ |
223 | ev->what = PROC_EVENT_COMM; |
224 | ev->event_data.comm.process_pid = task->pid; | |
225 | ev->event_data.comm.process_tgid = task->tgid; | |
226 | get_task_comm(ev->event_data.comm.comm, task); | |
227 | ||
228 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
229 | msg->ack = 0; /* not used */ | |
230 | msg->len = sizeof(*ev); | |
e727ca82 | 231 | msg->flags = 0; /* not used */ |
ab8ed951 | 232 | send_msg(msg); |
2b5faa4c JD |
233 | } |
234 | ||
235 | void proc_coredump_connector(struct task_struct *task) | |
236 | { | |
237 | struct cn_msg *msg; | |
238 | struct proc_event *ev; | |
6d2b0f02 | 239 | struct task_struct *parent; |
1ca1a4cf | 240 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
2b5faa4c JD |
241 | |
242 | if (atomic_read(&proc_event_num_listeners) < 1) | |
243 | return; | |
244 | ||
1ca1a4cf | 245 | msg = buffer_to_cn_msg(buffer); |
2b5faa4c | 246 | ev = (struct proc_event *)msg->data; |
e727ca82 | 247 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 248 | ev->timestamp_ns = ktime_get_ns(); |
2b5faa4c JD |
249 | ev->what = PROC_EVENT_COREDUMP; |
250 | ev->event_data.coredump.process_pid = task->pid; | |
251 | ev->event_data.coredump.process_tgid = task->tgid; | |
6d2b0f02 LR |
252 | |
253 | rcu_read_lock(); | |
254 | if (pid_alive(task)) { | |
255 | parent = rcu_dereference(task->real_parent); | |
256 | ev->event_data.coredump.parent_pid = parent->pid; | |
257 | ev->event_data.coredump.parent_tgid = parent->tgid; | |
258 | } | |
259 | rcu_read_unlock(); | |
2b5faa4c JD |
260 | |
261 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
262 | msg->ack = 0; /* not used */ | |
263 | msg->len = sizeof(*ev); | |
e727ca82 | 264 | msg->flags = 0; /* not used */ |
ab8ed951 | 265 | send_msg(msg); |
f786ecba VZ |
266 | } |
267 | ||
9f46080c MH |
268 | void proc_exit_connector(struct task_struct *task) |
269 | { | |
270 | struct cn_msg *msg; | |
271 | struct proc_event *ev; | |
6d2b0f02 | 272 | struct task_struct *parent; |
1ca1a4cf | 273 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9f46080c MH |
274 | |
275 | if (atomic_read(&proc_event_num_listeners) < 1) | |
276 | return; | |
277 | ||
1ca1a4cf | 278 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 279 | ev = (struct proc_event *)msg->data; |
e727ca82 | 280 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9e93f21b | 281 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
282 | ev->what = PROC_EVENT_EXIT; |
283 | ev->event_data.exit.process_pid = task->pid; | |
284 | ev->event_data.exit.process_tgid = task->tgid; | |
285 | ev->event_data.exit.exit_code = task->exit_code; | |
286 | ev->event_data.exit.exit_signal = task->exit_signal; | |
6d2b0f02 LR |
287 | |
288 | rcu_read_lock(); | |
289 | if (pid_alive(task)) { | |
290 | parent = rcu_dereference(task->real_parent); | |
291 | ev->event_data.exit.parent_pid = parent->pid; | |
292 | ev->event_data.exit.parent_tgid = parent->tgid; | |
293 | } | |
294 | rcu_read_unlock(); | |
9f46080c MH |
295 | |
296 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
297 | msg->ack = 0; /* not used */ | |
298 | msg->len = sizeof(*ev); | |
e727ca82 | 299 | msg->flags = 0; /* not used */ |
ab8ed951 | 300 | send_msg(msg); |
9f46080c MH |
301 | } |
302 | ||
303 | /* | |
304 | * Send an acknowledgement message to userspace | |
305 | * | |
306 | * Use 0 for success, EFOO otherwise. | |
307 | * Note: this is the negative of conventional kernel error | |
308 | * values because it's not being returned via syscall return | |
309 | * mechanisms. | |
310 | */ | |
311 | static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) | |
312 | { | |
313 | struct cn_msg *msg; | |
314 | struct proc_event *ev; | |
1ca1a4cf | 315 | __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8); |
9f46080c MH |
316 | |
317 | if (atomic_read(&proc_event_num_listeners) < 1) | |
318 | return; | |
319 | ||
1ca1a4cf | 320 | msg = buffer_to_cn_msg(buffer); |
f3c48ecc | 321 | ev = (struct proc_event *)msg->data; |
e727ca82 | 322 | memset(&ev->event_data, 0, sizeof(ev->event_data)); |
9f46080c | 323 | msg->seq = rcvd_seq; |
9e93f21b | 324 | ev->timestamp_ns = ktime_get_ns(); |
9f46080c MH |
325 | ev->cpu = -1; |
326 | ev->what = PROC_EVENT_NONE; | |
327 | ev->event_data.ack.err = err; | |
328 | memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); | |
329 | msg->ack = rcvd_ack + 1; | |
330 | msg->len = sizeof(*ev); | |
e727ca82 | 331 | msg->flags = 0; /* not used */ |
ab8ed951 | 332 | send_msg(msg); |
9f46080c MH |
333 | } |
334 | ||
335 | /** | |
336 | * cn_proc_mcast_ctl | |
337 | * @data: message sent from userspace via the connector | |
338 | */ | |
f0b25932 SB |
339 | static void cn_proc_mcast_ctl(struct cn_msg *msg, |
340 | struct netlink_skb_parms *nsp) | |
9f46080c | 341 | { |
9f46080c MH |
342 | enum proc_cn_mcast_op *mc_op = NULL; |
343 | int err = 0; | |
344 | ||
345 | if (msg->len != sizeof(*mc_op)) | |
346 | return; | |
347 | ||
9582d901 EB |
348 | /* |
349 | * Events are reported with respect to the initial pid | |
350 | * and user namespaces so ignore requestors from | |
351 | * other namespaces. | |
352 | */ | |
353 | if ((current_user_ns() != &init_user_ns) || | |
354 | (task_active_pid_ns(current) != &init_pid_ns)) | |
355 | return; | |
356 | ||
e70ab977 | 357 | /* Can only change if privileged. */ |
90f62cf3 | 358 | if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) { |
e70ab977 KC |
359 | err = EPERM; |
360 | goto out; | |
361 | } | |
362 | ||
f3c48ecc | 363 | mc_op = (enum proc_cn_mcast_op *)msg->data; |
9f46080c MH |
364 | switch (*mc_op) { |
365 | case PROC_CN_MCAST_LISTEN: | |
366 | atomic_inc(&proc_event_num_listeners); | |
367 | break; | |
368 | case PROC_CN_MCAST_IGNORE: | |
369 | atomic_dec(&proc_event_num_listeners); | |
370 | break; | |
371 | default: | |
372 | err = EINVAL; | |
373 | break; | |
374 | } | |
e70ab977 KC |
375 | |
376 | out: | |
9f46080c MH |
377 | cn_proc_ack(err, msg->seq, msg->ack); |
378 | } | |
379 | ||
380 | /* | |
381 | * cn_proc_init - initialization entry point | |
382 | * | |
383 | * Adds the connector callback to the connector driver. | |
384 | */ | |
385 | static int __init cn_proc_init(void) | |
386 | { | |
f3c48ecc VI |
387 | int err = cn_add_callback(&cn_proc_event_id, |
388 | "cn_proc", | |
389 | &cn_proc_mcast_ctl); | |
390 | if (err) { | |
391 | pr_warn("cn_proc failed to register\n"); | |
9f46080c MH |
392 | return err; |
393 | } | |
394 | return 0; | |
395 | } | |
8297f2d9 | 396 | device_initcall(cn_proc_init); |