Commit | Line | Data |
---|---|---|
e338d263 | 1 | /* Common capabilities, needed by capability.o and root_plug.o |
1da177e4 LT |
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 | ||
c59ede7b | 10 | #include <linux/capability.h> |
1da177e4 LT |
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> | |
1da177e4 LT |
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> | |
b5376771 | 25 | #include <linux/mount.h> |
b460cbc5 | 26 | #include <linux/sched.h> |
3898b1b4 AM |
27 | #include <linux/prctl.h> |
28 | #include <linux/securebits.h> | |
72c2d582 | 29 | |
1da177e4 LT |
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 | ||
c7bdb545 | 36 | int cap_netlink_recv(struct sk_buff *skb, int cap) |
1da177e4 | 37 | { |
c7bdb545 | 38 | if (!cap_raised(NETLINK_CB(skb).eff_cap, cap)) |
1da177e4 LT |
39 | return -EPERM; |
40 | return 0; | |
41 | } | |
42 | ||
43 | EXPORT_SYMBOL(cap_netlink_recv); | |
44 | ||
a6dbb1ef AM |
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 | */ | |
1da177e4 LT |
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 (struct task_struct *parent, struct task_struct *child) | |
67 | { | |
68 | /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ | |
d4eb82c7 CW |
69 | if (!cap_issubset(child->cap_permitted, parent->cap_permitted) && |
70 | !__capable(parent, CAP_SYS_PTRACE)) | |
1da177e4 LT |
71 | return -EPERM; |
72 | return 0; | |
73 | } | |
74 | ||
75 | int cap_capget (struct task_struct *target, kernel_cap_t *effective, | |
76 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
77 | { | |
78 | /* Derived from kernel/capability.c:sys_capget. */ | |
e338d263 AM |
79 | *effective = target->cap_effective; |
80 | *inheritable = target->cap_inheritable; | |
81 | *permitted = target->cap_permitted; | |
1da177e4 LT |
82 | return 0; |
83 | } | |
84 | ||
72c2d582 AM |
85 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
86 | ||
87 | static inline int cap_block_setpcap(struct task_struct *target) | |
88 | { | |
89 | /* | |
90 | * No support for remote process capability manipulation with | |
91 | * filesystem capability support. | |
92 | */ | |
93 | return (target != current); | |
94 | } | |
95 | ||
96 | static inline int cap_inh_is_capped(void) | |
97 | { | |
98 | /* | |
a6dbb1ef AM |
99 | * Return 1 if changes to the inheritable set are limited |
100 | * to the old permitted set. That is, if the current task | |
101 | * does *not* possess the CAP_SETPCAP capability. | |
72c2d582 | 102 | */ |
a6dbb1ef | 103 | return (cap_capable(current, CAP_SETPCAP) != 0); |
72c2d582 AM |
104 | } |
105 | ||
106 | #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ | |
107 | ||
108 | static inline int cap_block_setpcap(struct task_struct *t) { return 0; } | |
109 | static inline int cap_inh_is_capped(void) { return 1; } | |
110 | ||
111 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
112 | ||
1da177e4 LT |
113 | int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, |
114 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
115 | { | |
72c2d582 AM |
116 | if (cap_block_setpcap(target)) { |
117 | return -EPERM; | |
118 | } | |
119 | if (cap_inh_is_capped() | |
120 | && !cap_issubset(*inheritable, | |
121 | cap_combine(target->cap_inheritable, | |
122 | current->cap_permitted))) { | |
123 | /* incapable of using this inheritable set */ | |
1da177e4 LT |
124 | return -EPERM; |
125 | } | |
3b7391de SH |
126 | if (!cap_issubset(*inheritable, |
127 | cap_combine(target->cap_inheritable, | |
128 | current->cap_bset))) { | |
129 | /* no new pI capabilities outside bounding set */ | |
130 | return -EPERM; | |
131 | } | |
1da177e4 LT |
132 | |
133 | /* verify restrictions on target's new Permitted set */ | |
134 | if (!cap_issubset (*permitted, | |
135 | cap_combine (target->cap_permitted, | |
136 | current->cap_permitted))) { | |
137 | return -EPERM; | |
138 | } | |
139 | ||
140 | /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ | |
141 | if (!cap_issubset (*effective, *permitted)) { | |
142 | return -EPERM; | |
143 | } | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | void cap_capset_set (struct task_struct *target, kernel_cap_t *effective, | |
149 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
150 | { | |
151 | target->cap_effective = *effective; | |
152 | target->cap_inheritable = *inheritable; | |
153 | target->cap_permitted = *permitted; | |
154 | } | |
155 | ||
b5376771 SH |
156 | static inline void bprm_clear_caps(struct linux_binprm *bprm) |
157 | { | |
158 | cap_clear(bprm->cap_inheritable); | |
159 | cap_clear(bprm->cap_permitted); | |
160 | bprm->cap_effective = false; | |
161 | } | |
162 | ||
163 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
164 | ||
165 | int cap_inode_need_killpriv(struct dentry *dentry) | |
166 | { | |
167 | struct inode *inode = dentry->d_inode; | |
168 | int error; | |
169 | ||
170 | if (!inode->i_op || !inode->i_op->getxattr) | |
171 | return 0; | |
172 | ||
173 | error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0); | |
174 | if (error <= 0) | |
175 | return 0; | |
176 | return 1; | |
177 | } | |
178 | ||
179 | int cap_inode_killpriv(struct dentry *dentry) | |
180 | { | |
181 | struct inode *inode = dentry->d_inode; | |
182 | ||
183 | if (!inode->i_op || !inode->i_op->removexattr) | |
184 | return 0; | |
185 | ||
186 | return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); | |
187 | } | |
188 | ||
e338d263 AM |
189 | static inline int cap_from_disk(struct vfs_cap_data *caps, |
190 | struct linux_binprm *bprm, unsigned size) | |
b5376771 SH |
191 | { |
192 | __u32 magic_etc; | |
e338d263 | 193 | unsigned tocopy, i; |
b5376771 | 194 | |
e338d263 | 195 | if (size < sizeof(magic_etc)) |
b5376771 SH |
196 | return -EINVAL; |
197 | ||
e338d263 | 198 | magic_etc = le32_to_cpu(caps->magic_etc); |
b5376771 SH |
199 | |
200 | switch ((magic_etc & VFS_CAP_REVISION_MASK)) { | |
e338d263 AM |
201 | case VFS_CAP_REVISION_1: |
202 | if (size != XATTR_CAPS_SZ_1) | |
203 | return -EINVAL; | |
204 | tocopy = VFS_CAP_U32_1; | |
205 | break; | |
206 | case VFS_CAP_REVISION_2: | |
207 | if (size != XATTR_CAPS_SZ_2) | |
208 | return -EINVAL; | |
209 | tocopy = VFS_CAP_U32_2; | |
210 | break; | |
b5376771 SH |
211 | default: |
212 | return -EINVAL; | |
213 | } | |
e338d263 AM |
214 | |
215 | if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) { | |
216 | bprm->cap_effective = true; | |
217 | } else { | |
218 | bprm->cap_effective = false; | |
219 | } | |
220 | ||
221 | for (i = 0; i < tocopy; ++i) { | |
222 | bprm->cap_permitted.cap[i] = | |
223 | le32_to_cpu(caps->data[i].permitted); | |
224 | bprm->cap_inheritable.cap[i] = | |
225 | le32_to_cpu(caps->data[i].inheritable); | |
226 | } | |
227 | while (i < VFS_CAP_U32) { | |
228 | bprm->cap_permitted.cap[i] = 0; | |
229 | bprm->cap_inheritable.cap[i] = 0; | |
230 | i++; | |
231 | } | |
232 | ||
233 | return 0; | |
b5376771 SH |
234 | } |
235 | ||
236 | /* Locate any VFS capabilities: */ | |
237 | static int get_file_caps(struct linux_binprm *bprm) | |
238 | { | |
239 | struct dentry *dentry; | |
240 | int rc = 0; | |
e338d263 | 241 | struct vfs_cap_data vcaps; |
b5376771 SH |
242 | struct inode *inode; |
243 | ||
244 | if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) { | |
245 | bprm_clear_caps(bprm); | |
246 | return 0; | |
247 | } | |
248 | ||
249 | dentry = dget(bprm->file->f_dentry); | |
250 | inode = dentry->d_inode; | |
251 | if (!inode->i_op || !inode->i_op->getxattr) | |
252 | goto out; | |
253 | ||
e338d263 AM |
254 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps, |
255 | XATTR_CAPS_SZ); | |
b5376771 SH |
256 | if (rc == -ENODATA || rc == -EOPNOTSUPP) { |
257 | /* no data, that's ok */ | |
258 | rc = 0; | |
259 | goto out; | |
260 | } | |
261 | if (rc < 0) | |
262 | goto out; | |
263 | ||
e338d263 | 264 | rc = cap_from_disk(&vcaps, bprm, rc); |
b5376771 SH |
265 | if (rc) |
266 | printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", | |
dd6f953a | 267 | __func__, rc, bprm->filename); |
b5376771 SH |
268 | |
269 | out: | |
270 | dput(dentry); | |
271 | if (rc) | |
272 | bprm_clear_caps(bprm); | |
273 | ||
274 | return rc; | |
275 | } | |
276 | ||
277 | #else | |
278 | int cap_inode_need_killpriv(struct dentry *dentry) | |
279 | { | |
280 | return 0; | |
281 | } | |
282 | ||
283 | int cap_inode_killpriv(struct dentry *dentry) | |
284 | { | |
285 | return 0; | |
286 | } | |
287 | ||
288 | static inline int get_file_caps(struct linux_binprm *bprm) | |
289 | { | |
290 | bprm_clear_caps(bprm); | |
291 | return 0; | |
292 | } | |
293 | #endif | |
294 | ||
1da177e4 LT |
295 | int cap_bprm_set_security (struct linux_binprm *bprm) |
296 | { | |
b5376771 | 297 | int ret; |
1da177e4 | 298 | |
b5376771 SH |
299 | ret = get_file_caps(bprm); |
300 | if (ret) | |
301 | printk(KERN_NOTICE "%s: get_file_caps returned %d for %s\n", | |
dd6f953a | 302 | __func__, ret, bprm->filename); |
1da177e4 LT |
303 | |
304 | /* To support inheritance of root-permissions and suid-root | |
305 | * executables under compatibility mode, we raise all three | |
306 | * capability sets for the file. | |
307 | * | |
308 | * If only the real uid is 0, we only raise the inheritable | |
309 | * and permitted sets of the executable file. | |
310 | */ | |
311 | ||
312 | if (!issecure (SECURE_NOROOT)) { | |
313 | if (bprm->e_uid == 0 || current->uid == 0) { | |
314 | cap_set_full (bprm->cap_inheritable); | |
315 | cap_set_full (bprm->cap_permitted); | |
316 | } | |
317 | if (bprm->e_uid == 0) | |
b5376771 | 318 | bprm->cap_effective = true; |
1da177e4 | 319 | } |
b5376771 SH |
320 | |
321 | return ret; | |
1da177e4 LT |
322 | } |
323 | ||
324 | void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) | |
325 | { | |
326 | /* Derived from fs/exec.c:compute_creds. */ | |
327 | kernel_cap_t new_permitted, working; | |
328 | ||
3b7391de SH |
329 | new_permitted = cap_intersect(bprm->cap_permitted, |
330 | current->cap_bset); | |
331 | working = cap_intersect(bprm->cap_inheritable, | |
1da177e4 | 332 | current->cap_inheritable); |
3b7391de | 333 | new_permitted = cap_combine(new_permitted, working); |
1da177e4 LT |
334 | |
335 | if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || | |
336 | !cap_issubset (new_permitted, current->cap_permitted)) { | |
6c5d5238 | 337 | set_dumpable(current->mm, suid_dumpable); |
b5376771 | 338 | current->pdeath_signal = 0; |
1da177e4 LT |
339 | |
340 | if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { | |
341 | if (!capable(CAP_SETUID)) { | |
342 | bprm->e_uid = current->uid; | |
343 | bprm->e_gid = current->gid; | |
344 | } | |
345 | if (!capable (CAP_SETPCAP)) { | |
346 | new_permitted = cap_intersect (new_permitted, | |
347 | current->cap_permitted); | |
348 | } | |
349 | } | |
350 | } | |
351 | ||
352 | current->suid = current->euid = current->fsuid = bprm->e_uid; | |
353 | current->sgid = current->egid = current->fsgid = bprm->e_gid; | |
354 | ||
355 | /* For init, we want to retain the capabilities set | |
356 | * in the init_task struct. Thus we skip the usual | |
357 | * capability rules */ | |
b460cbc5 | 358 | if (!is_global_init(current)) { |
1da177e4 | 359 | current->cap_permitted = new_permitted; |
e338d263 AM |
360 | if (bprm->cap_effective) |
361 | current->cap_effective = new_permitted; | |
362 | else | |
363 | cap_clear(current->cap_effective); | |
1da177e4 LT |
364 | } |
365 | ||
366 | /* AUD: Audit candidate if current->cap_effective is set */ | |
367 | ||
3898b1b4 | 368 | current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); |
1da177e4 LT |
369 | } |
370 | ||
371 | int cap_bprm_secureexec (struct linux_binprm *bprm) | |
372 | { | |
b5376771 SH |
373 | if (current->uid != 0) { |
374 | if (bprm->cap_effective) | |
375 | return 1; | |
376 | if (!cap_isclear(bprm->cap_permitted)) | |
377 | return 1; | |
378 | if (!cap_isclear(bprm->cap_inheritable)) | |
379 | return 1; | |
380 | } | |
381 | ||
1da177e4 LT |
382 | return (current->euid != current->uid || |
383 | current->egid != current->gid); | |
384 | } | |
385 | ||
8f0cfa52 DH |
386 | int cap_inode_setxattr(struct dentry *dentry, const char *name, |
387 | const void *value, size_t size, int flags) | |
1da177e4 | 388 | { |
b5376771 SH |
389 | if (!strcmp(name, XATTR_NAME_CAPS)) { |
390 | if (!capable(CAP_SETFCAP)) | |
391 | return -EPERM; | |
392 | return 0; | |
393 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
1da177e4 LT |
394 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
395 | !capable(CAP_SYS_ADMIN)) | |
396 | return -EPERM; | |
397 | return 0; | |
398 | } | |
399 | ||
8f0cfa52 | 400 | int cap_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 401 | { |
b5376771 SH |
402 | if (!strcmp(name, XATTR_NAME_CAPS)) { |
403 | if (!capable(CAP_SETFCAP)) | |
404 | return -EPERM; | |
405 | return 0; | |
406 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
1da177e4 LT |
407 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
408 | !capable(CAP_SYS_ADMIN)) | |
409 | return -EPERM; | |
410 | return 0; | |
411 | } | |
412 | ||
413 | /* moved from kernel/sys.c. */ | |
414 | /* | |
415 | * cap_emulate_setxuid() fixes the effective / permitted capabilities of | |
416 | * a process after a call to setuid, setreuid, or setresuid. | |
417 | * | |
418 | * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of | |
419 | * {r,e,s}uid != 0, the permitted and effective capabilities are | |
420 | * cleared. | |
421 | * | |
422 | * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective | |
423 | * capabilities of the process are cleared. | |
424 | * | |
425 | * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective | |
426 | * capabilities are set to the permitted capabilities. | |
427 | * | |
428 | * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should | |
429 | * never happen. | |
430 | * | |
431 | * -astor | |
432 | * | |
433 | * cevans - New behaviour, Oct '99 | |
434 | * A process may, via prctl(), elect to keep its capabilities when it | |
435 | * calls setuid() and switches away from uid==0. Both permitted and | |
436 | * effective sets will be retained. | |
437 | * Without this change, it was impossible for a daemon to drop only some | |
438 | * of its privilege. The call to setuid(!=0) would drop all privileges! | |
439 | * Keeping uid 0 is not an option because uid 0 owns too many vital | |
440 | * files.. | |
441 | * Thanks to Olaf Kirch and Peter Benie for spotting this. | |
442 | */ | |
443 | static inline void cap_emulate_setxuid (int old_ruid, int old_euid, | |
444 | int old_suid) | |
445 | { | |
446 | if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && | |
447 | (current->uid != 0 && current->euid != 0 && current->suid != 0) && | |
3898b1b4 | 448 | !issecure(SECURE_KEEP_CAPS)) { |
1da177e4 LT |
449 | cap_clear (current->cap_permitted); |
450 | cap_clear (current->cap_effective); | |
451 | } | |
452 | if (old_euid == 0 && current->euid != 0) { | |
453 | cap_clear (current->cap_effective); | |
454 | } | |
455 | if (old_euid != 0 && current->euid == 0) { | |
456 | current->cap_effective = current->cap_permitted; | |
457 | } | |
458 | } | |
459 | ||
460 | int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, | |
461 | int flags) | |
462 | { | |
463 | switch (flags) { | |
464 | case LSM_SETID_RE: | |
465 | case LSM_SETID_ID: | |
466 | case LSM_SETID_RES: | |
467 | /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ | |
468 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
469 | cap_emulate_setxuid (old_ruid, old_euid, old_suid); | |
470 | } | |
471 | break; | |
472 | case LSM_SETID_FS: | |
473 | { | |
474 | uid_t old_fsuid = old_ruid; | |
475 | ||
476 | /* Copied from kernel/sys.c:setfsuid. */ | |
477 | ||
478 | /* | |
479 | * FIXME - is fsuser used for all CAP_FS_MASK capabilities? | |
480 | * if not, we might be a bit too harsh here. | |
481 | */ | |
482 | ||
483 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
484 | if (old_fsuid == 0 && current->fsuid != 0) { | |
e338d263 AM |
485 | current->cap_effective = |
486 | cap_drop_fs_set( | |
487 | current->cap_effective); | |
1da177e4 LT |
488 | } |
489 | if (old_fsuid != 0 && current->fsuid == 0) { | |
e338d263 AM |
490 | current->cap_effective = |
491 | cap_raise_fs_set( | |
492 | current->cap_effective, | |
493 | current->cap_permitted); | |
1da177e4 LT |
494 | } |
495 | } | |
496 | break; | |
497 | } | |
498 | default: | |
499 | return -EINVAL; | |
500 | } | |
501 | ||
502 | return 0; | |
503 | } | |
504 | ||
b5376771 SH |
505 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
506 | /* | |
507 | * Rationale: code calling task_setscheduler, task_setioprio, and | |
508 | * task_setnice, assumes that | |
509 | * . if capable(cap_sys_nice), then those actions should be allowed | |
510 | * . if not capable(cap_sys_nice), but acting on your own processes, | |
511 | * then those actions should be allowed | |
512 | * This is insufficient now since you can call code without suid, but | |
513 | * yet with increased caps. | |
514 | * So we check for increased caps on the target process. | |
515 | */ | |
516 | static inline int cap_safe_nice(struct task_struct *p) | |
517 | { | |
518 | if (!cap_issubset(p->cap_permitted, current->cap_permitted) && | |
519 | !__capable(current, CAP_SYS_NICE)) | |
520 | return -EPERM; | |
521 | return 0; | |
522 | } | |
523 | ||
524 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
525 | struct sched_param *lp) | |
526 | { | |
527 | return cap_safe_nice(p); | |
528 | } | |
529 | ||
530 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
531 | { | |
532 | return cap_safe_nice(p); | |
533 | } | |
534 | ||
535 | int cap_task_setnice (struct task_struct *p, int nice) | |
536 | { | |
537 | return cap_safe_nice(p); | |
538 | } | |
539 | ||
3b7391de SH |
540 | /* |
541 | * called from kernel/sys.c for prctl(PR_CABSET_DROP) | |
542 | * done without task_capability_lock() because it introduces | |
543 | * no new races - i.e. only another task doing capget() on | |
544 | * this task could get inconsistent info. There can be no | |
545 | * racing writer bc a task can only change its own caps. | |
546 | */ | |
3898b1b4 | 547 | static long cap_prctl_drop(unsigned long cap) |
3b7391de SH |
548 | { |
549 | if (!capable(CAP_SETPCAP)) | |
550 | return -EPERM; | |
551 | if (!cap_valid(cap)) | |
552 | return -EINVAL; | |
553 | cap_lower(current->cap_bset, cap); | |
554 | return 0; | |
555 | } | |
3898b1b4 | 556 | |
b5376771 SH |
557 | #else |
558 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
559 | struct sched_param *lp) | |
560 | { | |
561 | return 0; | |
562 | } | |
563 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
564 | { | |
565 | return 0; | |
566 | } | |
567 | int cap_task_setnice (struct task_struct *p, int nice) | |
568 | { | |
569 | return 0; | |
570 | } | |
b5376771 SH |
571 | #endif |
572 | ||
3898b1b4 AM |
573 | int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, |
574 | unsigned long arg4, unsigned long arg5, long *rc_p) | |
575 | { | |
576 | long error = 0; | |
577 | ||
578 | switch (option) { | |
579 | case PR_CAPBSET_READ: | |
580 | if (!cap_valid(arg2)) | |
581 | error = -EINVAL; | |
582 | else | |
583 | error = !!cap_raised(current->cap_bset, arg2); | |
584 | break; | |
585 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
586 | case PR_CAPBSET_DROP: | |
587 | error = cap_prctl_drop(arg2); | |
588 | break; | |
589 | ||
590 | /* | |
591 | * The next four prctl's remain to assist with transitioning a | |
592 | * system from legacy UID=0 based privilege (when filesystem | |
593 | * capabilities are not in use) to a system using filesystem | |
594 | * capabilities only - as the POSIX.1e draft intended. | |
595 | * | |
596 | * Note: | |
597 | * | |
598 | * PR_SET_SECUREBITS = | |
599 | * issecure_mask(SECURE_KEEP_CAPS_LOCKED) | |
600 | * | issecure_mask(SECURE_NOROOT) | |
601 | * | issecure_mask(SECURE_NOROOT_LOCKED) | |
602 | * | issecure_mask(SECURE_NO_SETUID_FIXUP) | |
603 | * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED) | |
604 | * | |
605 | * will ensure that the current process and all of its | |
606 | * children will be locked into a pure | |
607 | * capability-based-privilege environment. | |
608 | */ | |
609 | case PR_SET_SECUREBITS: | |
610 | if ((((current->securebits & SECURE_ALL_LOCKS) >> 1) | |
611 | & (current->securebits ^ arg2)) /*[1]*/ | |
612 | || ((current->securebits & SECURE_ALL_LOCKS | |
613 | & ~arg2)) /*[2]*/ | |
614 | || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ | |
615 | || (cap_capable(current, CAP_SETPCAP) != 0)) { /*[4]*/ | |
616 | /* | |
617 | * [1] no changing of bits that are locked | |
618 | * [2] no unlocking of locks | |
619 | * [3] no setting of unsupported bits | |
620 | * [4] doing anything requires privilege (go read about | |
621 | * the "sendmail capabilities bug") | |
622 | */ | |
623 | error = -EPERM; /* cannot change a locked bit */ | |
624 | } else { | |
625 | current->securebits = arg2; | |
626 | } | |
627 | break; | |
628 | case PR_GET_SECUREBITS: | |
629 | error = current->securebits; | |
630 | break; | |
631 | ||
632 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
633 | ||
634 | case PR_GET_KEEPCAPS: | |
635 | if (issecure(SECURE_KEEP_CAPS)) | |
636 | error = 1; | |
637 | break; | |
638 | case PR_SET_KEEPCAPS: | |
639 | if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ | |
640 | error = -EINVAL; | |
641 | else if (issecure(SECURE_KEEP_CAPS_LOCKED)) | |
642 | error = -EPERM; | |
643 | else if (arg2) | |
644 | current->securebits |= issecure_mask(SECURE_KEEP_CAPS); | |
645 | else | |
646 | current->securebits &= | |
647 | ~issecure_mask(SECURE_KEEP_CAPS); | |
648 | break; | |
649 | ||
650 | default: | |
651 | /* No functionality available - continue with default */ | |
652 | return 0; | |
653 | } | |
654 | ||
655 | /* Functionality provided */ | |
656 | *rc_p = error; | |
657 | return 1; | |
658 | } | |
659 | ||
1da177e4 LT |
660 | void cap_task_reparent_to_init (struct task_struct *p) |
661 | { | |
e338d263 AM |
662 | cap_set_init_eff(p->cap_effective); |
663 | cap_clear(p->cap_inheritable); | |
664 | cap_set_full(p->cap_permitted); | |
3898b1b4 | 665 | p->securebits = SECUREBITS_DEFAULT; |
1da177e4 LT |
666 | return; |
667 | } | |
668 | ||
669 | int cap_syslog (int type) | |
670 | { | |
671 | if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) | |
672 | return -EPERM; | |
673 | return 0; | |
674 | } | |
675 | ||
34b4e4aa | 676 | int cap_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
677 | { |
678 | int cap_sys_admin = 0; | |
679 | ||
680 | if (cap_capable(current, CAP_SYS_ADMIN) == 0) | |
681 | cap_sys_admin = 1; | |
34b4e4aa | 682 | return __vm_enough_memory(mm, pages, cap_sys_admin); |
1da177e4 LT |
683 | } |
684 |