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60f067b4 JS |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
22 | #include <sys/ipc.h> | |
23 | #include <sys/shm.h> | |
24 | #include <sys/sem.h> | |
25 | #include <sys/msg.h> | |
26 | #include <sys/stat.h> | |
60f067b4 JS |
27 | #include <fcntl.h> |
28 | #include <dirent.h> | |
29 | #include <mqueue.h> | |
30 | ||
31 | #include "util.h" | |
e3bff60a | 32 | #include "formats-util.h" |
60f067b4 JS |
33 | #include "strv.h" |
34 | #include "clean-ipc.h" | |
35 | ||
36 | static int clean_sysvipc_shm(uid_t delete_uid) { | |
37 | _cleanup_fclose_ FILE *f = NULL; | |
38 | char line[LINE_MAX]; | |
39 | bool first = true; | |
40 | int ret = 0; | |
41 | ||
42 | f = fopen("/proc/sysvipc/shm", "re"); | |
43 | if (!f) { | |
44 | if (errno == ENOENT) | |
45 | return 0; | |
46 | ||
f47781d8 | 47 | log_warning_errno(errno, "Failed to open /proc/sysvipc/shm: %m"); |
60f067b4 JS |
48 | return -errno; |
49 | } | |
50 | ||
51 | FOREACH_LINE(line, f, goto fail) { | |
52 | unsigned n_attached; | |
53 | pid_t cpid, lpid; | |
54 | uid_t uid, cuid; | |
55 | gid_t gid, cgid; | |
56 | int shmid; | |
57 | ||
58 | if (first) { | |
59 | first = false; | |
60 | continue; | |
61 | } | |
62 | ||
63 | truncate_nl(line); | |
64 | ||
65 | if (sscanf(line, "%*i %i %*o %*u " PID_FMT " " PID_FMT " %u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT, | |
66 | &shmid, &cpid, &lpid, &n_attached, &uid, &gid, &cuid, &cgid) != 8) | |
67 | continue; | |
68 | ||
69 | if (n_attached > 0) | |
70 | continue; | |
71 | ||
72 | if (uid != delete_uid) | |
73 | continue; | |
74 | ||
75 | if (shmctl(shmid, IPC_RMID, NULL) < 0) { | |
76 | ||
77 | /* Ignore entries that are already deleted */ | |
78 | if (errno == EIDRM || errno == EINVAL) | |
79 | continue; | |
80 | ||
f47781d8 | 81 | log_warning_errno(errno, "Failed to remove SysV shared memory segment %i: %m", shmid); |
60f067b4 JS |
82 | ret = -errno; |
83 | } | |
84 | } | |
85 | ||
86 | return ret; | |
87 | ||
88 | fail: | |
f47781d8 | 89 | log_warning_errno(errno, "Failed to read /proc/sysvipc/shm: %m"); |
60f067b4 JS |
90 | return -errno; |
91 | } | |
92 | ||
93 | static int clean_sysvipc_sem(uid_t delete_uid) { | |
94 | _cleanup_fclose_ FILE *f = NULL; | |
95 | char line[LINE_MAX]; | |
96 | bool first = true; | |
97 | int ret = 0; | |
98 | ||
99 | f = fopen("/proc/sysvipc/sem", "re"); | |
100 | if (!f) { | |
101 | if (errno == ENOENT) | |
102 | return 0; | |
103 | ||
f47781d8 | 104 | log_warning_errno(errno, "Failed to open /proc/sysvipc/sem: %m"); |
60f067b4 JS |
105 | return -errno; |
106 | } | |
107 | ||
108 | FOREACH_LINE(line, f, goto fail) { | |
109 | uid_t uid, cuid; | |
110 | gid_t gid, cgid; | |
111 | int semid; | |
112 | ||
113 | if (first) { | |
114 | first = false; | |
115 | continue; | |
116 | } | |
117 | ||
118 | truncate_nl(line); | |
119 | ||
120 | if (sscanf(line, "%*i %i %*o %*u " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT, | |
121 | &semid, &uid, &gid, &cuid, &cgid) != 5) | |
122 | continue; | |
123 | ||
124 | if (uid != delete_uid) | |
125 | continue; | |
126 | ||
127 | if (semctl(semid, 0, IPC_RMID) < 0) { | |
128 | ||
129 | /* Ignore entries that are already deleted */ | |
130 | if (errno == EIDRM || errno == EINVAL) | |
131 | continue; | |
132 | ||
f47781d8 | 133 | log_warning_errno(errno, "Failed to remove SysV semaphores object %i: %m", semid); |
60f067b4 JS |
134 | ret = -errno; |
135 | } | |
136 | } | |
137 | ||
138 | return ret; | |
139 | ||
140 | fail: | |
f47781d8 | 141 | log_warning_errno(errno, "Failed to read /proc/sysvipc/sem: %m"); |
60f067b4 JS |
142 | return -errno; |
143 | } | |
144 | ||
145 | static int clean_sysvipc_msg(uid_t delete_uid) { | |
146 | _cleanup_fclose_ FILE *f = NULL; | |
147 | char line[LINE_MAX]; | |
148 | bool first = true; | |
149 | int ret = 0; | |
150 | ||
151 | f = fopen("/proc/sysvipc/msg", "re"); | |
152 | if (!f) { | |
153 | if (errno == ENOENT) | |
154 | return 0; | |
155 | ||
f47781d8 | 156 | log_warning_errno(errno, "Failed to open /proc/sysvipc/msg: %m"); |
60f067b4 JS |
157 | return -errno; |
158 | } | |
159 | ||
160 | FOREACH_LINE(line, f, goto fail) { | |
161 | uid_t uid, cuid; | |
162 | gid_t gid, cgid; | |
163 | pid_t cpid, lpid; | |
164 | int msgid; | |
165 | ||
166 | if (first) { | |
167 | first = false; | |
168 | continue; | |
169 | } | |
170 | ||
171 | truncate_nl(line); | |
172 | ||
173 | if (sscanf(line, "%*i %i %*o %*u %*u " PID_FMT " " PID_FMT " " UID_FMT " " GID_FMT " " UID_FMT " " GID_FMT, | |
174 | &msgid, &cpid, &lpid, &uid, &gid, &cuid, &cgid) != 7) | |
175 | continue; | |
176 | ||
177 | if (uid != delete_uid) | |
178 | continue; | |
179 | ||
180 | if (msgctl(msgid, IPC_RMID, NULL) < 0) { | |
181 | ||
182 | /* Ignore entries that are already deleted */ | |
183 | if (errno == EIDRM || errno == EINVAL) | |
184 | continue; | |
185 | ||
f47781d8 | 186 | log_warning_errno(errno, "Failed to remove SysV message queue %i: %m", msgid); |
60f067b4 JS |
187 | ret = -errno; |
188 | } | |
189 | } | |
190 | ||
191 | return ret; | |
192 | ||
193 | fail: | |
f47781d8 | 194 | log_warning_errno(errno, "Failed to read /proc/sysvipc/msg: %m"); |
60f067b4 JS |
195 | return -errno; |
196 | } | |
197 | ||
198 | static int clean_posix_shm_internal(DIR *dir, uid_t uid) { | |
199 | struct dirent *de; | |
200 | int ret = 0, r; | |
201 | ||
202 | assert(dir); | |
203 | ||
204 | FOREACH_DIRENT(de, dir, goto fail) { | |
205 | struct stat st; | |
206 | ||
207 | if (STR_IN_SET(de->d_name, "..", ".")) | |
208 | continue; | |
209 | ||
210 | if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) { | |
211 | if (errno == ENOENT) | |
212 | continue; | |
213 | ||
f47781d8 | 214 | log_warning_errno(errno, "Failed to stat() POSIX shared memory segment %s: %m", de->d_name); |
60f067b4 JS |
215 | ret = -errno; |
216 | continue; | |
217 | } | |
218 | ||
219 | if (st.st_uid != uid) | |
220 | continue; | |
221 | ||
222 | if (S_ISDIR(st.st_mode)) { | |
223 | _cleanup_closedir_ DIR *kid; | |
224 | ||
225 | kid = xopendirat(dirfd(dir), de->d_name, O_NOFOLLOW|O_NOATIME); | |
226 | if (!kid) { | |
227 | if (errno != ENOENT) { | |
f47781d8 | 228 | log_warning_errno(errno, "Failed to enter shared memory directory %s: %m", de->d_name); |
60f067b4 JS |
229 | ret = -errno; |
230 | } | |
231 | } else { | |
232 | r = clean_posix_shm_internal(kid, uid); | |
233 | if (r < 0) | |
234 | ret = r; | |
235 | } | |
236 | ||
237 | if (unlinkat(dirfd(dir), de->d_name, AT_REMOVEDIR) < 0) { | |
238 | ||
239 | if (errno == ENOENT) | |
240 | continue; | |
241 | ||
f47781d8 | 242 | log_warning_errno(errno, "Failed to remove POSIX shared memory directory %s: %m", de->d_name); |
60f067b4 JS |
243 | ret = -errno; |
244 | } | |
245 | } else { | |
246 | ||
247 | if (unlinkat(dirfd(dir), de->d_name, 0) < 0) { | |
248 | ||
249 | if (errno == ENOENT) | |
250 | continue; | |
251 | ||
f47781d8 | 252 | log_warning_errno(errno, "Failed to remove POSIX shared memory segment %s: %m", de->d_name); |
60f067b4 JS |
253 | ret = -errno; |
254 | } | |
255 | } | |
256 | } | |
257 | ||
258 | return ret; | |
259 | ||
260 | fail: | |
f47781d8 | 261 | log_warning_errno(errno, "Failed to read /dev/shm: %m"); |
60f067b4 JS |
262 | return -errno; |
263 | } | |
264 | ||
265 | static int clean_posix_shm(uid_t uid) { | |
266 | _cleanup_closedir_ DIR *dir = NULL; | |
267 | ||
268 | dir = opendir("/dev/shm"); | |
269 | if (!dir) { | |
270 | if (errno == ENOENT) | |
271 | return 0; | |
272 | ||
f47781d8 | 273 | log_warning_errno(errno, "Failed to open /dev/shm: %m"); |
60f067b4 JS |
274 | return -errno; |
275 | } | |
276 | ||
277 | return clean_posix_shm_internal(dir, uid); | |
278 | } | |
279 | ||
280 | static int clean_posix_mq(uid_t uid) { | |
281 | _cleanup_closedir_ DIR *dir = NULL; | |
282 | struct dirent *de; | |
283 | int ret = 0; | |
284 | ||
285 | dir = opendir("/dev/mqueue"); | |
286 | if (!dir) { | |
287 | if (errno == ENOENT) | |
288 | return 0; | |
289 | ||
f47781d8 | 290 | log_warning_errno(errno, "Failed to open /dev/mqueue: %m"); |
60f067b4 JS |
291 | return -errno; |
292 | } | |
293 | ||
294 | FOREACH_DIRENT(de, dir, goto fail) { | |
295 | struct stat st; | |
296 | char fn[1+strlen(de->d_name)+1]; | |
297 | ||
298 | if (STR_IN_SET(de->d_name, "..", ".")) | |
299 | continue; | |
300 | ||
301 | if (fstatat(dirfd(dir), de->d_name, &st, AT_SYMLINK_NOFOLLOW) < 0) { | |
302 | if (errno == ENOENT) | |
303 | continue; | |
304 | ||
f47781d8 | 305 | log_warning_errno(errno, "Failed to stat() MQ segment %s: %m", de->d_name); |
60f067b4 JS |
306 | ret = -errno; |
307 | continue; | |
308 | } | |
309 | ||
310 | if (st.st_uid != uid) | |
311 | continue; | |
312 | ||
313 | fn[0] = '/'; | |
314 | strcpy(fn+1, de->d_name); | |
315 | ||
316 | if (mq_unlink(fn) < 0) { | |
317 | if (errno == ENOENT) | |
318 | continue; | |
319 | ||
f47781d8 | 320 | log_warning_errno(errno, "Failed to unlink POSIX message queue %s: %m", fn); |
60f067b4 JS |
321 | ret = -errno; |
322 | } | |
323 | } | |
324 | ||
325 | return ret; | |
326 | ||
327 | fail: | |
f47781d8 | 328 | log_warning_errno(errno, "Failed to read /dev/mqueue: %m"); |
60f067b4 JS |
329 | return -errno; |
330 | } | |
331 | ||
332 | int clean_ipc(uid_t uid) { | |
333 | int ret = 0, r; | |
334 | ||
335 | /* Refuse to clean IPC of the root and system users */ | |
336 | if (uid <= SYSTEM_UID_MAX) | |
337 | return 0; | |
338 | ||
339 | r = clean_sysvipc_shm(uid); | |
340 | if (r < 0) | |
341 | ret = r; | |
342 | ||
343 | r = clean_sysvipc_sem(uid); | |
344 | if (r < 0) | |
345 | ret = r; | |
346 | ||
347 | r = clean_sysvipc_msg(uid); | |
348 | if (r < 0) | |
349 | ret = r; | |
350 | ||
351 | r = clean_posix_shm(uid); | |
352 | if (r < 0) | |
353 | ret = r; | |
354 | ||
355 | r = clean_posix_mq(uid); | |
356 | if (r < 0) | |
357 | ret = r; | |
358 | ||
359 | return ret; | |
360 | } |