]>
Commit | Line | Data |
---|---|---|
1 | /* Common capabilities, needed by capability.o and root_plug.o | |
2 | * | |
3 | * This program is free software; you can redistribute it and/or modify | |
4 | * it under the terms of the GNU General Public License as published by | |
5 | * the Free Software Foundation; either version 2 of the License, or | |
6 | * (at your option) any later version. | |
7 | * | |
8 | */ | |
9 | ||
10 | #include <linux/capability.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/security.h> | |
15 | #include <linux/file.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/mman.h> | |
18 | #include <linux/pagemap.h> | |
19 | #include <linux/swap.h> | |
20 | #include <linux/skbuff.h> | |
21 | #include <linux/netlink.h> | |
22 | #include <linux/ptrace.h> | |
23 | #include <linux/xattr.h> | |
24 | #include <linux/hugetlb.h> | |
25 | #include <linux/mount.h> | |
26 | #include <linux/sched.h> | |
27 | #include <linux/prctl.h> | |
28 | #include <linux/securebits.h> | |
29 | ||
30 | int cap_netlink_send(struct sock *sk, struct sk_buff *skb) | |
31 | { | |
32 | NETLINK_CB(skb).eff_cap = current->cap_effective; | |
33 | return 0; | |
34 | } | |
35 | ||
36 | int cap_netlink_recv(struct sk_buff *skb, int cap) | |
37 | { | |
38 | if (!cap_raised(NETLINK_CB(skb).eff_cap, cap)) | |
39 | return -EPERM; | |
40 | return 0; | |
41 | } | |
42 | ||
43 | EXPORT_SYMBOL(cap_netlink_recv); | |
44 | ||
45 | /* | |
46 | * NOTE WELL: cap_capable() cannot be used like the kernel's capable() | |
47 | * function. That is, it has the reverse semantics: cap_capable() | |
48 | * returns 0 when a task has a capability, but the kernel's capable() | |
49 | * returns 1 for this case. | |
50 | */ | |
51 | int cap_capable (struct task_struct *tsk, int cap) | |
52 | { | |
53 | /* Derived from include/linux/sched.h:capable. */ | |
54 | if (cap_raised(tsk->cap_effective, cap)) | |
55 | return 0; | |
56 | return -EPERM; | |
57 | } | |
58 | ||
59 | int cap_settime(struct timespec *ts, struct timezone *tz) | |
60 | { | |
61 | if (!capable(CAP_SYS_TIME)) | |
62 | return -EPERM; | |
63 | return 0; | |
64 | } | |
65 | ||
66 | int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) | |
67 | { | |
68 | /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ | |
69 | if (cap_issubset(child->cap_permitted, current->cap_permitted)) | |
70 | return 0; | |
71 | if (capable(CAP_SYS_PTRACE)) | |
72 | return 0; | |
73 | return -EPERM; | |
74 | } | |
75 | ||
76 | int cap_ptrace_traceme(struct task_struct *parent) | |
77 | { | |
78 | /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ | |
79 | if (cap_issubset(current->cap_permitted, parent->cap_permitted)) | |
80 | return 0; | |
81 | if (has_capability(parent, CAP_SYS_PTRACE)) | |
82 | return 0; | |
83 | return -EPERM; | |
84 | } | |
85 | ||
86 | int cap_capget (struct task_struct *target, kernel_cap_t *effective, | |
87 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
88 | { | |
89 | /* Derived from kernel/capability.c:sys_capget. */ | |
90 | *effective = target->cap_effective; | |
91 | *inheritable = target->cap_inheritable; | |
92 | *permitted = target->cap_permitted; | |
93 | return 0; | |
94 | } | |
95 | ||
96 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
97 | ||
98 | static inline int cap_block_setpcap(struct task_struct *target) | |
99 | { | |
100 | /* | |
101 | * No support for remote process capability manipulation with | |
102 | * filesystem capability support. | |
103 | */ | |
104 | return (target != current); | |
105 | } | |
106 | ||
107 | static inline int cap_inh_is_capped(void) | |
108 | { | |
109 | /* | |
110 | * Return 1 if changes to the inheritable set are limited | |
111 | * to the old permitted set. That is, if the current task | |
112 | * does *not* possess the CAP_SETPCAP capability. | |
113 | */ | |
114 | return (cap_capable(current, CAP_SETPCAP) != 0); | |
115 | } | |
116 | ||
117 | static inline int cap_limit_ptraced_target(void) { return 1; } | |
118 | ||
119 | #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ | |
120 | ||
121 | static inline int cap_block_setpcap(struct task_struct *t) { return 0; } | |
122 | static inline int cap_inh_is_capped(void) { return 1; } | |
123 | static inline int cap_limit_ptraced_target(void) | |
124 | { | |
125 | return !capable(CAP_SETPCAP); | |
126 | } | |
127 | ||
128 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
129 | ||
130 | int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, | |
131 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
132 | { | |
133 | if (cap_block_setpcap(target)) { | |
134 | return -EPERM; | |
135 | } | |
136 | if (cap_inh_is_capped() | |
137 | && !cap_issubset(*inheritable, | |
138 | cap_combine(target->cap_inheritable, | |
139 | current->cap_permitted))) { | |
140 | /* incapable of using this inheritable set */ | |
141 | return -EPERM; | |
142 | } | |
143 | if (!cap_issubset(*inheritable, | |
144 | cap_combine(target->cap_inheritable, | |
145 | current->cap_bset))) { | |
146 | /* no new pI capabilities outside bounding set */ | |
147 | return -EPERM; | |
148 | } | |
149 | ||
150 | /* verify restrictions on target's new Permitted set */ | |
151 | if (!cap_issubset (*permitted, | |
152 | cap_combine (target->cap_permitted, | |
153 | current->cap_permitted))) { | |
154 | return -EPERM; | |
155 | } | |
156 | ||
157 | /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ | |
158 | if (!cap_issubset (*effective, *permitted)) { | |
159 | return -EPERM; | |
160 | } | |
161 | ||
162 | return 0; | |
163 | } | |
164 | ||
165 | void cap_capset_set (struct task_struct *target, kernel_cap_t *effective, | |
166 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
167 | { | |
168 | target->cap_effective = *effective; | |
169 | target->cap_inheritable = *inheritable; | |
170 | target->cap_permitted = *permitted; | |
171 | } | |
172 | ||
173 | static inline void bprm_clear_caps(struct linux_binprm *bprm) | |
174 | { | |
175 | cap_clear(bprm->cap_post_exec_permitted); | |
176 | bprm->cap_effective = false; | |
177 | } | |
178 | ||
179 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
180 | ||
181 | int cap_inode_need_killpriv(struct dentry *dentry) | |
182 | { | |
183 | struct inode *inode = dentry->d_inode; | |
184 | int error; | |
185 | ||
186 | if (!inode->i_op || !inode->i_op->getxattr) | |
187 | return 0; | |
188 | ||
189 | error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0); | |
190 | if (error <= 0) | |
191 | return 0; | |
192 | return 1; | |
193 | } | |
194 | ||
195 | int cap_inode_killpriv(struct dentry *dentry) | |
196 | { | |
197 | struct inode *inode = dentry->d_inode; | |
198 | ||
199 | if (!inode->i_op || !inode->i_op->removexattr) | |
200 | return 0; | |
201 | ||
202 | return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); | |
203 | } | |
204 | ||
205 | static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, | |
206 | struct linux_binprm *bprm) | |
207 | { | |
208 | unsigned i; | |
209 | int ret = 0; | |
210 | ||
211 | if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE) | |
212 | bprm->cap_effective = true; | |
213 | else | |
214 | bprm->cap_effective = false; | |
215 | ||
216 | CAP_FOR_EACH_U32(i) { | |
217 | __u32 permitted = caps->permitted.cap[i]; | |
218 | __u32 inheritable = caps->inheritable.cap[i]; | |
219 | ||
220 | /* | |
221 | * pP' = (X & fP) | (pI & fI) | |
222 | */ | |
223 | bprm->cap_post_exec_permitted.cap[i] = | |
224 | (current->cap_bset.cap[i] & permitted) | | |
225 | (current->cap_inheritable.cap[i] & inheritable); | |
226 | ||
227 | if (permitted & ~bprm->cap_post_exec_permitted.cap[i]) { | |
228 | /* | |
229 | * insufficient to execute correctly | |
230 | */ | |
231 | ret = -EPERM; | |
232 | } | |
233 | } | |
234 | ||
235 | /* | |
236 | * For legacy apps, with no internal support for recognizing they | |
237 | * do not have enough capabilities, we return an error if they are | |
238 | * missing some "forced" (aka file-permitted) capabilities. | |
239 | */ | |
240 | return bprm->cap_effective ? ret : 0; | |
241 | } | |
242 | ||
243 | int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) | |
244 | { | |
245 | struct inode *inode = dentry->d_inode; | |
246 | __u32 magic_etc; | |
247 | unsigned tocopy, i; | |
248 | int size; | |
249 | struct vfs_cap_data caps; | |
250 | ||
251 | memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); | |
252 | ||
253 | if (!inode || !inode->i_op || !inode->i_op->getxattr) | |
254 | return -ENODATA; | |
255 | ||
256 | size = inode->i_op->getxattr((struct dentry *)dentry, XATTR_NAME_CAPS, &caps, | |
257 | XATTR_CAPS_SZ); | |
258 | if (size == -ENODATA || size == -EOPNOTSUPP) { | |
259 | /* no data, that's ok */ | |
260 | return -ENODATA; | |
261 | } | |
262 | if (size < 0) | |
263 | return size; | |
264 | ||
265 | if (size < sizeof(magic_etc)) | |
266 | return -EINVAL; | |
267 | ||
268 | cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps.magic_etc); | |
269 | ||
270 | switch ((magic_etc & VFS_CAP_REVISION_MASK)) { | |
271 | case VFS_CAP_REVISION_1: | |
272 | if (size != XATTR_CAPS_SZ_1) | |
273 | return -EINVAL; | |
274 | tocopy = VFS_CAP_U32_1; | |
275 | break; | |
276 | case VFS_CAP_REVISION_2: | |
277 | if (size != XATTR_CAPS_SZ_2) | |
278 | return -EINVAL; | |
279 | tocopy = VFS_CAP_U32_2; | |
280 | break; | |
281 | default: | |
282 | return -EINVAL; | |
283 | } | |
284 | ||
285 | CAP_FOR_EACH_U32(i) { | |
286 | if (i >= tocopy) | |
287 | break; | |
288 | cpu_caps->permitted.cap[i] = le32_to_cpu(caps.data[i].permitted); | |
289 | cpu_caps->inheritable.cap[i] = le32_to_cpu(caps.data[i].inheritable); | |
290 | } | |
291 | return 0; | |
292 | } | |
293 | ||
294 | /* Locate any VFS capabilities: */ | |
295 | static int get_file_caps(struct linux_binprm *bprm) | |
296 | { | |
297 | struct dentry *dentry; | |
298 | int rc = 0; | |
299 | struct cpu_vfs_cap_data vcaps; | |
300 | ||
301 | bprm_clear_caps(bprm); | |
302 | ||
303 | if (!file_caps_enabled) | |
304 | return 0; | |
305 | ||
306 | if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) | |
307 | return 0; | |
308 | ||
309 | dentry = dget(bprm->file->f_dentry); | |
310 | ||
311 | rc = get_vfs_caps_from_disk(dentry, &vcaps); | |
312 | if (rc < 0) { | |
313 | if (rc == -EINVAL) | |
314 | printk(KERN_NOTICE "%s: get_vfs_caps_from_disk returned %d for %s\n", | |
315 | __func__, rc, bprm->filename); | |
316 | else if (rc == -ENODATA) | |
317 | rc = 0; | |
318 | goto out; | |
319 | } | |
320 | ||
321 | rc = bprm_caps_from_vfs_caps(&vcaps, bprm); | |
322 | ||
323 | out: | |
324 | dput(dentry); | |
325 | if (rc) | |
326 | bprm_clear_caps(bprm); | |
327 | ||
328 | return rc; | |
329 | } | |
330 | ||
331 | #else | |
332 | int cap_inode_need_killpriv(struct dentry *dentry) | |
333 | { | |
334 | return 0; | |
335 | } | |
336 | ||
337 | int cap_inode_killpriv(struct dentry *dentry) | |
338 | { | |
339 | return 0; | |
340 | } | |
341 | ||
342 | static inline int get_file_caps(struct linux_binprm *bprm) | |
343 | { | |
344 | bprm_clear_caps(bprm); | |
345 | return 0; | |
346 | } | |
347 | #endif | |
348 | ||
349 | int cap_bprm_set_security (struct linux_binprm *bprm) | |
350 | { | |
351 | int ret; | |
352 | ||
353 | ret = get_file_caps(bprm); | |
354 | ||
355 | if (!issecure(SECURE_NOROOT)) { | |
356 | /* | |
357 | * To support inheritance of root-permissions and suid-root | |
358 | * executables under compatibility mode, we override the | |
359 | * capability sets for the file. | |
360 | * | |
361 | * If only the real uid is 0, we do not set the effective | |
362 | * bit. | |
363 | */ | |
364 | if (bprm->e_uid == 0 || current->uid == 0) { | |
365 | /* pP' = (cap_bset & ~0) | (pI & ~0) */ | |
366 | bprm->cap_post_exec_permitted = cap_combine( | |
367 | current->cap_bset, current->cap_inheritable | |
368 | ); | |
369 | bprm->cap_effective = (bprm->e_uid == 0); | |
370 | ret = 0; | |
371 | } | |
372 | } | |
373 | ||
374 | return ret; | |
375 | } | |
376 | ||
377 | void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) | |
378 | { | |
379 | if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || | |
380 | !cap_issubset(bprm->cap_post_exec_permitted, | |
381 | current->cap_permitted)) { | |
382 | set_dumpable(current->mm, suid_dumpable); | |
383 | current->pdeath_signal = 0; | |
384 | ||
385 | if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { | |
386 | if (!capable(CAP_SETUID)) { | |
387 | bprm->e_uid = current->uid; | |
388 | bprm->e_gid = current->gid; | |
389 | } | |
390 | if (cap_limit_ptraced_target()) { | |
391 | bprm->cap_post_exec_permitted = cap_intersect( | |
392 | bprm->cap_post_exec_permitted, | |
393 | current->cap_permitted); | |
394 | } | |
395 | } | |
396 | } | |
397 | ||
398 | current->suid = current->euid = current->fsuid = bprm->e_uid; | |
399 | current->sgid = current->egid = current->fsgid = bprm->e_gid; | |
400 | ||
401 | /* For init, we want to retain the capabilities set | |
402 | * in the init_task struct. Thus we skip the usual | |
403 | * capability rules */ | |
404 | if (!is_global_init(current)) { | |
405 | current->cap_permitted = bprm->cap_post_exec_permitted; | |
406 | if (bprm->cap_effective) | |
407 | current->cap_effective = bprm->cap_post_exec_permitted; | |
408 | else | |
409 | cap_clear(current->cap_effective); | |
410 | } | |
411 | ||
412 | /* AUD: Audit candidate if current->cap_effective is set */ | |
413 | ||
414 | current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); | |
415 | } | |
416 | ||
417 | int cap_bprm_secureexec (struct linux_binprm *bprm) | |
418 | { | |
419 | if (current->uid != 0) { | |
420 | if (bprm->cap_effective) | |
421 | return 1; | |
422 | if (!cap_isclear(bprm->cap_post_exec_permitted)) | |
423 | return 1; | |
424 | } | |
425 | ||
426 | return (current->euid != current->uid || | |
427 | current->egid != current->gid); | |
428 | } | |
429 | ||
430 | int cap_inode_setxattr(struct dentry *dentry, const char *name, | |
431 | const void *value, size_t size, int flags) | |
432 | { | |
433 | if (!strcmp(name, XATTR_NAME_CAPS)) { | |
434 | if (!capable(CAP_SETFCAP)) | |
435 | return -EPERM; | |
436 | return 0; | |
437 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
438 | sizeof(XATTR_SECURITY_PREFIX) - 1) && | |
439 | !capable(CAP_SYS_ADMIN)) | |
440 | return -EPERM; | |
441 | return 0; | |
442 | } | |
443 | ||
444 | int cap_inode_removexattr(struct dentry *dentry, const char *name) | |
445 | { | |
446 | if (!strcmp(name, XATTR_NAME_CAPS)) { | |
447 | if (!capable(CAP_SETFCAP)) | |
448 | return -EPERM; | |
449 | return 0; | |
450 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
451 | sizeof(XATTR_SECURITY_PREFIX) - 1) && | |
452 | !capable(CAP_SYS_ADMIN)) | |
453 | return -EPERM; | |
454 | return 0; | |
455 | } | |
456 | ||
457 | /* moved from kernel/sys.c. */ | |
458 | /* | |
459 | * cap_emulate_setxuid() fixes the effective / permitted capabilities of | |
460 | * a process after a call to setuid, setreuid, or setresuid. | |
461 | * | |
462 | * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of | |
463 | * {r,e,s}uid != 0, the permitted and effective capabilities are | |
464 | * cleared. | |
465 | * | |
466 | * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective | |
467 | * capabilities of the process are cleared. | |
468 | * | |
469 | * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective | |
470 | * capabilities are set to the permitted capabilities. | |
471 | * | |
472 | * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should | |
473 | * never happen. | |
474 | * | |
475 | * -astor | |
476 | * | |
477 | * cevans - New behaviour, Oct '99 | |
478 | * A process may, via prctl(), elect to keep its capabilities when it | |
479 | * calls setuid() and switches away from uid==0. Both permitted and | |
480 | * effective sets will be retained. | |
481 | * Without this change, it was impossible for a daemon to drop only some | |
482 | * of its privilege. The call to setuid(!=0) would drop all privileges! | |
483 | * Keeping uid 0 is not an option because uid 0 owns too many vital | |
484 | * files.. | |
485 | * Thanks to Olaf Kirch and Peter Benie for spotting this. | |
486 | */ | |
487 | static inline void cap_emulate_setxuid (int old_ruid, int old_euid, | |
488 | int old_suid) | |
489 | { | |
490 | if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && | |
491 | (current->uid != 0 && current->euid != 0 && current->suid != 0) && | |
492 | !issecure(SECURE_KEEP_CAPS)) { | |
493 | cap_clear (current->cap_permitted); | |
494 | cap_clear (current->cap_effective); | |
495 | } | |
496 | if (old_euid == 0 && current->euid != 0) { | |
497 | cap_clear (current->cap_effective); | |
498 | } | |
499 | if (old_euid != 0 && current->euid == 0) { | |
500 | current->cap_effective = current->cap_permitted; | |
501 | } | |
502 | } | |
503 | ||
504 | int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, | |
505 | int flags) | |
506 | { | |
507 | switch (flags) { | |
508 | case LSM_SETID_RE: | |
509 | case LSM_SETID_ID: | |
510 | case LSM_SETID_RES: | |
511 | /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ | |
512 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
513 | cap_emulate_setxuid (old_ruid, old_euid, old_suid); | |
514 | } | |
515 | break; | |
516 | case LSM_SETID_FS: | |
517 | { | |
518 | uid_t old_fsuid = old_ruid; | |
519 | ||
520 | /* Copied from kernel/sys.c:setfsuid. */ | |
521 | ||
522 | /* | |
523 | * FIXME - is fsuser used for all CAP_FS_MASK capabilities? | |
524 | * if not, we might be a bit too harsh here. | |
525 | */ | |
526 | ||
527 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
528 | if (old_fsuid == 0 && current->fsuid != 0) { | |
529 | current->cap_effective = | |
530 | cap_drop_fs_set( | |
531 | current->cap_effective); | |
532 | } | |
533 | if (old_fsuid != 0 && current->fsuid == 0) { | |
534 | current->cap_effective = | |
535 | cap_raise_fs_set( | |
536 | current->cap_effective, | |
537 | current->cap_permitted); | |
538 | } | |
539 | } | |
540 | break; | |
541 | } | |
542 | default: | |
543 | return -EINVAL; | |
544 | } | |
545 | ||
546 | return 0; | |
547 | } | |
548 | ||
549 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
550 | /* | |
551 | * Rationale: code calling task_setscheduler, task_setioprio, and | |
552 | * task_setnice, assumes that | |
553 | * . if capable(cap_sys_nice), then those actions should be allowed | |
554 | * . if not capable(cap_sys_nice), but acting on your own processes, | |
555 | * then those actions should be allowed | |
556 | * This is insufficient now since you can call code without suid, but | |
557 | * yet with increased caps. | |
558 | * So we check for increased caps on the target process. | |
559 | */ | |
560 | static int cap_safe_nice(struct task_struct *p) | |
561 | { | |
562 | if (!cap_issubset(p->cap_permitted, current->cap_permitted) && | |
563 | !capable(CAP_SYS_NICE)) | |
564 | return -EPERM; | |
565 | return 0; | |
566 | } | |
567 | ||
568 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
569 | struct sched_param *lp) | |
570 | { | |
571 | return cap_safe_nice(p); | |
572 | } | |
573 | ||
574 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
575 | { | |
576 | return cap_safe_nice(p); | |
577 | } | |
578 | ||
579 | int cap_task_setnice (struct task_struct *p, int nice) | |
580 | { | |
581 | return cap_safe_nice(p); | |
582 | } | |
583 | ||
584 | /* | |
585 | * called from kernel/sys.c for prctl(PR_CABSET_DROP) | |
586 | * done without task_capability_lock() because it introduces | |
587 | * no new races - i.e. only another task doing capget() on | |
588 | * this task could get inconsistent info. There can be no | |
589 | * racing writer bc a task can only change its own caps. | |
590 | */ | |
591 | static long cap_prctl_drop(unsigned long cap) | |
592 | { | |
593 | if (!capable(CAP_SETPCAP)) | |
594 | return -EPERM; | |
595 | if (!cap_valid(cap)) | |
596 | return -EINVAL; | |
597 | cap_lower(current->cap_bset, cap); | |
598 | return 0; | |
599 | } | |
600 | ||
601 | #else | |
602 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
603 | struct sched_param *lp) | |
604 | { | |
605 | return 0; | |
606 | } | |
607 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
608 | { | |
609 | return 0; | |
610 | } | |
611 | int cap_task_setnice (struct task_struct *p, int nice) | |
612 | { | |
613 | return 0; | |
614 | } | |
615 | #endif | |
616 | ||
617 | int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, | |
618 | unsigned long arg4, unsigned long arg5, long *rc_p) | |
619 | { | |
620 | long error = 0; | |
621 | ||
622 | switch (option) { | |
623 | case PR_CAPBSET_READ: | |
624 | if (!cap_valid(arg2)) | |
625 | error = -EINVAL; | |
626 | else | |
627 | error = !!cap_raised(current->cap_bset, arg2); | |
628 | break; | |
629 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
630 | case PR_CAPBSET_DROP: | |
631 | error = cap_prctl_drop(arg2); | |
632 | break; | |
633 | ||
634 | /* | |
635 | * The next four prctl's remain to assist with transitioning a | |
636 | * system from legacy UID=0 based privilege (when filesystem | |
637 | * capabilities are not in use) to a system using filesystem | |
638 | * capabilities only - as the POSIX.1e draft intended. | |
639 | * | |
640 | * Note: | |
641 | * | |
642 | * PR_SET_SECUREBITS = | |
643 | * issecure_mask(SECURE_KEEP_CAPS_LOCKED) | |
644 | * | issecure_mask(SECURE_NOROOT) | |
645 | * | issecure_mask(SECURE_NOROOT_LOCKED) | |
646 | * | issecure_mask(SECURE_NO_SETUID_FIXUP) | |
647 | * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED) | |
648 | * | |
649 | * will ensure that the current process and all of its | |
650 | * children will be locked into a pure | |
651 | * capability-based-privilege environment. | |
652 | */ | |
653 | case PR_SET_SECUREBITS: | |
654 | if ((((current->securebits & SECURE_ALL_LOCKS) >> 1) | |
655 | & (current->securebits ^ arg2)) /*[1]*/ | |
656 | || ((current->securebits & SECURE_ALL_LOCKS | |
657 | & ~arg2)) /*[2]*/ | |
658 | || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ | |
659 | || (cap_capable(current, CAP_SETPCAP) != 0)) { /*[4]*/ | |
660 | /* | |
661 | * [1] no changing of bits that are locked | |
662 | * [2] no unlocking of locks | |
663 | * [3] no setting of unsupported bits | |
664 | * [4] doing anything requires privilege (go read about | |
665 | * the "sendmail capabilities bug") | |
666 | */ | |
667 | error = -EPERM; /* cannot change a locked bit */ | |
668 | } else { | |
669 | current->securebits = arg2; | |
670 | } | |
671 | break; | |
672 | case PR_GET_SECUREBITS: | |
673 | error = current->securebits; | |
674 | break; | |
675 | ||
676 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
677 | ||
678 | case PR_GET_KEEPCAPS: | |
679 | if (issecure(SECURE_KEEP_CAPS)) | |
680 | error = 1; | |
681 | break; | |
682 | case PR_SET_KEEPCAPS: | |
683 | if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ | |
684 | error = -EINVAL; | |
685 | else if (issecure(SECURE_KEEP_CAPS_LOCKED)) | |
686 | error = -EPERM; | |
687 | else if (arg2) | |
688 | current->securebits |= issecure_mask(SECURE_KEEP_CAPS); | |
689 | else | |
690 | current->securebits &= | |
691 | ~issecure_mask(SECURE_KEEP_CAPS); | |
692 | break; | |
693 | ||
694 | default: | |
695 | /* No functionality available - continue with default */ | |
696 | return 0; | |
697 | } | |
698 | ||
699 | /* Functionality provided */ | |
700 | *rc_p = error; | |
701 | return 1; | |
702 | } | |
703 | ||
704 | void cap_task_reparent_to_init (struct task_struct *p) | |
705 | { | |
706 | cap_set_init_eff(p->cap_effective); | |
707 | cap_clear(p->cap_inheritable); | |
708 | cap_set_full(p->cap_permitted); | |
709 | p->securebits = SECUREBITS_DEFAULT; | |
710 | return; | |
711 | } | |
712 | ||
713 | int cap_syslog (int type) | |
714 | { | |
715 | if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) | |
716 | return -EPERM; | |
717 | return 0; | |
718 | } | |
719 | ||
720 | int cap_vm_enough_memory(struct mm_struct *mm, long pages) | |
721 | { | |
722 | int cap_sys_admin = 0; | |
723 | ||
724 | if (cap_capable(current, CAP_SYS_ADMIN) == 0) | |
725 | cap_sys_admin = 1; | |
726 | return __vm_enough_memory(mm, pages, cap_sys_admin); | |
727 | } | |
728 |