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 | ||
006ebb40 SS |
66 | int cap_ptrace (struct task_struct *parent, struct task_struct *child, |
67 | unsigned int mode) | |
1da177e4 LT |
68 | { |
69 | /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ | |
d4eb82c7 CW |
70 | if (!cap_issubset(child->cap_permitted, parent->cap_permitted) && |
71 | !__capable(parent, CAP_SYS_PTRACE)) | |
1da177e4 LT |
72 | return -EPERM; |
73 | return 0; | |
74 | } | |
75 | ||
76 | int cap_capget (struct task_struct *target, kernel_cap_t *effective, | |
77 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
78 | { | |
79 | /* Derived from kernel/capability.c:sys_capget. */ | |
e338d263 AM |
80 | *effective = target->cap_effective; |
81 | *inheritable = target->cap_inheritable; | |
82 | *permitted = target->cap_permitted; | |
1da177e4 LT |
83 | return 0; |
84 | } | |
85 | ||
72c2d582 AM |
86 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
87 | ||
88 | static inline int cap_block_setpcap(struct task_struct *target) | |
89 | { | |
90 | /* | |
91 | * No support for remote process capability manipulation with | |
92 | * filesystem capability support. | |
93 | */ | |
94 | return (target != current); | |
95 | } | |
96 | ||
97 | static inline int cap_inh_is_capped(void) | |
98 | { | |
99 | /* | |
a6dbb1ef AM |
100 | * Return 1 if changes to the inheritable set are limited |
101 | * to the old permitted set. That is, if the current task | |
102 | * does *not* possess the CAP_SETPCAP capability. | |
72c2d582 | 103 | */ |
a6dbb1ef | 104 | return (cap_capable(current, CAP_SETPCAP) != 0); |
72c2d582 AM |
105 | } |
106 | ||
1209726c AM |
107 | static inline int cap_limit_ptraced_target(void) { return 1; } |
108 | ||
72c2d582 AM |
109 | #else /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ |
110 | ||
111 | static inline int cap_block_setpcap(struct task_struct *t) { return 0; } | |
112 | static inline int cap_inh_is_capped(void) { return 1; } | |
1209726c AM |
113 | static inline int cap_limit_ptraced_target(void) |
114 | { | |
115 | return !capable(CAP_SETPCAP); | |
116 | } | |
72c2d582 AM |
117 | |
118 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
119 | ||
1da177e4 LT |
120 | int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, |
121 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
122 | { | |
72c2d582 AM |
123 | if (cap_block_setpcap(target)) { |
124 | return -EPERM; | |
125 | } | |
126 | if (cap_inh_is_capped() | |
127 | && !cap_issubset(*inheritable, | |
128 | cap_combine(target->cap_inheritable, | |
129 | current->cap_permitted))) { | |
130 | /* incapable of using this inheritable set */ | |
1da177e4 LT |
131 | return -EPERM; |
132 | } | |
3b7391de SH |
133 | if (!cap_issubset(*inheritable, |
134 | cap_combine(target->cap_inheritable, | |
135 | current->cap_bset))) { | |
136 | /* no new pI capabilities outside bounding set */ | |
137 | return -EPERM; | |
138 | } | |
1da177e4 LT |
139 | |
140 | /* verify restrictions on target's new Permitted set */ | |
141 | if (!cap_issubset (*permitted, | |
142 | cap_combine (target->cap_permitted, | |
143 | current->cap_permitted))) { | |
144 | return -EPERM; | |
145 | } | |
146 | ||
147 | /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ | |
148 | if (!cap_issubset (*effective, *permitted)) { | |
149 | return -EPERM; | |
150 | } | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | void cap_capset_set (struct task_struct *target, kernel_cap_t *effective, | |
156 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
157 | { | |
158 | target->cap_effective = *effective; | |
159 | target->cap_inheritable = *inheritable; | |
160 | target->cap_permitted = *permitted; | |
161 | } | |
162 | ||
b5376771 SH |
163 | static inline void bprm_clear_caps(struct linux_binprm *bprm) |
164 | { | |
5459c164 | 165 | cap_clear(bprm->cap_post_exec_permitted); |
b5376771 SH |
166 | bprm->cap_effective = false; |
167 | } | |
168 | ||
169 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
170 | ||
171 | int cap_inode_need_killpriv(struct dentry *dentry) | |
172 | { | |
173 | struct inode *inode = dentry->d_inode; | |
174 | int error; | |
175 | ||
176 | if (!inode->i_op || !inode->i_op->getxattr) | |
177 | return 0; | |
178 | ||
179 | error = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0); | |
180 | if (error <= 0) | |
181 | return 0; | |
182 | return 1; | |
183 | } | |
184 | ||
185 | int cap_inode_killpriv(struct dentry *dentry) | |
186 | { | |
187 | struct inode *inode = dentry->d_inode; | |
188 | ||
189 | if (!inode->i_op || !inode->i_op->removexattr) | |
190 | return 0; | |
191 | ||
192 | return inode->i_op->removexattr(dentry, XATTR_NAME_CAPS); | |
193 | } | |
194 | ||
e338d263 AM |
195 | static inline int cap_from_disk(struct vfs_cap_data *caps, |
196 | struct linux_binprm *bprm, unsigned size) | |
b5376771 SH |
197 | { |
198 | __u32 magic_etc; | |
e338d263 | 199 | unsigned tocopy, i; |
5459c164 | 200 | int ret; |
b5376771 | 201 | |
e338d263 | 202 | if (size < sizeof(magic_etc)) |
b5376771 SH |
203 | return -EINVAL; |
204 | ||
e338d263 | 205 | magic_etc = le32_to_cpu(caps->magic_etc); |
b5376771 SH |
206 | |
207 | switch ((magic_etc & VFS_CAP_REVISION_MASK)) { | |
e338d263 AM |
208 | case VFS_CAP_REVISION_1: |
209 | if (size != XATTR_CAPS_SZ_1) | |
210 | return -EINVAL; | |
211 | tocopy = VFS_CAP_U32_1; | |
212 | break; | |
213 | case VFS_CAP_REVISION_2: | |
214 | if (size != XATTR_CAPS_SZ_2) | |
215 | return -EINVAL; | |
216 | tocopy = VFS_CAP_U32_2; | |
217 | break; | |
b5376771 SH |
218 | default: |
219 | return -EINVAL; | |
220 | } | |
e338d263 AM |
221 | |
222 | if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) { | |
223 | bprm->cap_effective = true; | |
224 | } else { | |
225 | bprm->cap_effective = false; | |
226 | } | |
227 | ||
5459c164 AM |
228 | ret = 0; |
229 | ||
230 | CAP_FOR_EACH_U32(i) { | |
231 | __u32 value_cpu; | |
232 | ||
233 | if (i >= tocopy) { | |
234 | /* | |
235 | * Legacy capability sets have no upper bits | |
236 | */ | |
237 | bprm->cap_post_exec_permitted.cap[i] = 0; | |
238 | continue; | |
239 | } | |
240 | /* | |
241 | * pP' = (X & fP) | (pI & fI) | |
242 | */ | |
243 | value_cpu = le32_to_cpu(caps->data[i].permitted); | |
244 | bprm->cap_post_exec_permitted.cap[i] = | |
245 | (current->cap_bset.cap[i] & value_cpu) | | |
246 | (current->cap_inheritable.cap[i] & | |
247 | le32_to_cpu(caps->data[i].inheritable)); | |
248 | if (value_cpu & ~bprm->cap_post_exec_permitted.cap[i]) { | |
249 | /* | |
250 | * insufficient to execute correctly | |
251 | */ | |
252 | ret = -EPERM; | |
253 | } | |
e338d263 AM |
254 | } |
255 | ||
5459c164 AM |
256 | /* |
257 | * For legacy apps, with no internal support for recognizing they | |
258 | * do not have enough capabilities, we return an error if they are | |
259 | * missing some "forced" (aka file-permitted) capabilities. | |
260 | */ | |
261 | return bprm->cap_effective ? ret : 0; | |
b5376771 SH |
262 | } |
263 | ||
264 | /* Locate any VFS capabilities: */ | |
265 | static int get_file_caps(struct linux_binprm *bprm) | |
266 | { | |
267 | struct dentry *dentry; | |
268 | int rc = 0; | |
e338d263 | 269 | struct vfs_cap_data vcaps; |
b5376771 SH |
270 | struct inode *inode; |
271 | ||
272 | if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) { | |
273 | bprm_clear_caps(bprm); | |
274 | return 0; | |
275 | } | |
276 | ||
277 | dentry = dget(bprm->file->f_dentry); | |
278 | inode = dentry->d_inode; | |
279 | if (!inode->i_op || !inode->i_op->getxattr) | |
280 | goto out; | |
281 | ||
e338d263 AM |
282 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps, |
283 | XATTR_CAPS_SZ); | |
b5376771 SH |
284 | if (rc == -ENODATA || rc == -EOPNOTSUPP) { |
285 | /* no data, that's ok */ | |
286 | rc = 0; | |
287 | goto out; | |
288 | } | |
289 | if (rc < 0) | |
290 | goto out; | |
291 | ||
e338d263 | 292 | rc = cap_from_disk(&vcaps, bprm, rc); |
5459c164 | 293 | if (rc == -EINVAL) |
b5376771 | 294 | printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", |
5459c164 | 295 | __func__, rc, bprm->filename); |
b5376771 SH |
296 | |
297 | out: | |
298 | dput(dentry); | |
299 | if (rc) | |
300 | bprm_clear_caps(bprm); | |
301 | ||
302 | return rc; | |
303 | } | |
304 | ||
305 | #else | |
306 | int cap_inode_need_killpriv(struct dentry *dentry) | |
307 | { | |
308 | return 0; | |
309 | } | |
310 | ||
311 | int cap_inode_killpriv(struct dentry *dentry) | |
312 | { | |
313 | return 0; | |
314 | } | |
315 | ||
316 | static inline int get_file_caps(struct linux_binprm *bprm) | |
317 | { | |
318 | bprm_clear_caps(bprm); | |
319 | return 0; | |
320 | } | |
321 | #endif | |
322 | ||
1da177e4 LT |
323 | int cap_bprm_set_security (struct linux_binprm *bprm) |
324 | { | |
b5376771 | 325 | int ret; |
1da177e4 | 326 | |
b5376771 | 327 | ret = get_file_caps(bprm); |
1da177e4 | 328 | |
5459c164 AM |
329 | if (!issecure(SECURE_NOROOT)) { |
330 | /* | |
331 | * To support inheritance of root-permissions and suid-root | |
332 | * executables under compatibility mode, we override the | |
333 | * capability sets for the file. | |
334 | * | |
335 | * If only the real uid is 0, we do not set the effective | |
336 | * bit. | |
337 | */ | |
1da177e4 | 338 | if (bprm->e_uid == 0 || current->uid == 0) { |
5459c164 AM |
339 | /* pP' = (cap_bset & ~0) | (pI & ~0) */ |
340 | bprm->cap_post_exec_permitted = cap_combine( | |
341 | current->cap_bset, current->cap_inheritable | |
342 | ); | |
343 | bprm->cap_effective = (bprm->e_uid == 0); | |
344 | ret = 0; | |
1da177e4 | 345 | } |
1da177e4 | 346 | } |
b5376771 SH |
347 | |
348 | return ret; | |
1da177e4 LT |
349 | } |
350 | ||
351 | void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) | |
352 | { | |
1da177e4 | 353 | if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || |
5459c164 AM |
354 | !cap_issubset(bprm->cap_post_exec_permitted, |
355 | current->cap_permitted)) { | |
6c5d5238 | 356 | set_dumpable(current->mm, suid_dumpable); |
b5376771 | 357 | current->pdeath_signal = 0; |
1da177e4 LT |
358 | |
359 | if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { | |
360 | if (!capable(CAP_SETUID)) { | |
361 | bprm->e_uid = current->uid; | |
362 | bprm->e_gid = current->gid; | |
363 | } | |
1209726c | 364 | if (cap_limit_ptraced_target()) { |
5459c164 AM |
365 | bprm->cap_post_exec_permitted = cap_intersect( |
366 | bprm->cap_post_exec_permitted, | |
367 | current->cap_permitted); | |
1da177e4 LT |
368 | } |
369 | } | |
370 | } | |
371 | ||
372 | current->suid = current->euid = current->fsuid = bprm->e_uid; | |
373 | current->sgid = current->egid = current->fsgid = bprm->e_gid; | |
374 | ||
375 | /* For init, we want to retain the capabilities set | |
376 | * in the init_task struct. Thus we skip the usual | |
377 | * capability rules */ | |
b460cbc5 | 378 | if (!is_global_init(current)) { |
5459c164 | 379 | current->cap_permitted = bprm->cap_post_exec_permitted; |
e338d263 | 380 | if (bprm->cap_effective) |
5459c164 | 381 | current->cap_effective = bprm->cap_post_exec_permitted; |
e338d263 AM |
382 | else |
383 | cap_clear(current->cap_effective); | |
1da177e4 LT |
384 | } |
385 | ||
386 | /* AUD: Audit candidate if current->cap_effective is set */ | |
387 | ||
3898b1b4 | 388 | current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); |
1da177e4 LT |
389 | } |
390 | ||
391 | int cap_bprm_secureexec (struct linux_binprm *bprm) | |
392 | { | |
b5376771 SH |
393 | if (current->uid != 0) { |
394 | if (bprm->cap_effective) | |
395 | return 1; | |
5459c164 | 396 | if (!cap_isclear(bprm->cap_post_exec_permitted)) |
b5376771 SH |
397 | return 1; |
398 | } | |
399 | ||
1da177e4 LT |
400 | return (current->euid != current->uid || |
401 | current->egid != current->gid); | |
402 | } | |
403 | ||
8f0cfa52 DH |
404 | int cap_inode_setxattr(struct dentry *dentry, const char *name, |
405 | const void *value, size_t size, int flags) | |
1da177e4 | 406 | { |
b5376771 SH |
407 | if (!strcmp(name, XATTR_NAME_CAPS)) { |
408 | if (!capable(CAP_SETFCAP)) | |
409 | return -EPERM; | |
410 | return 0; | |
411 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
1da177e4 LT |
412 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
413 | !capable(CAP_SYS_ADMIN)) | |
414 | return -EPERM; | |
415 | return 0; | |
416 | } | |
417 | ||
8f0cfa52 | 418 | int cap_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 419 | { |
b5376771 SH |
420 | if (!strcmp(name, XATTR_NAME_CAPS)) { |
421 | if (!capable(CAP_SETFCAP)) | |
422 | return -EPERM; | |
423 | return 0; | |
424 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
1da177e4 LT |
425 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
426 | !capable(CAP_SYS_ADMIN)) | |
427 | return -EPERM; | |
428 | return 0; | |
429 | } | |
430 | ||
431 | /* moved from kernel/sys.c. */ | |
432 | /* | |
433 | * cap_emulate_setxuid() fixes the effective / permitted capabilities of | |
434 | * a process after a call to setuid, setreuid, or setresuid. | |
435 | * | |
436 | * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of | |
437 | * {r,e,s}uid != 0, the permitted and effective capabilities are | |
438 | * cleared. | |
439 | * | |
440 | * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective | |
441 | * capabilities of the process are cleared. | |
442 | * | |
443 | * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective | |
444 | * capabilities are set to the permitted capabilities. | |
445 | * | |
446 | * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should | |
447 | * never happen. | |
448 | * | |
449 | * -astor | |
450 | * | |
451 | * cevans - New behaviour, Oct '99 | |
452 | * A process may, via prctl(), elect to keep its capabilities when it | |
453 | * calls setuid() and switches away from uid==0. Both permitted and | |
454 | * effective sets will be retained. | |
455 | * Without this change, it was impossible for a daemon to drop only some | |
456 | * of its privilege. The call to setuid(!=0) would drop all privileges! | |
457 | * Keeping uid 0 is not an option because uid 0 owns too many vital | |
458 | * files.. | |
459 | * Thanks to Olaf Kirch and Peter Benie for spotting this. | |
460 | */ | |
461 | static inline void cap_emulate_setxuid (int old_ruid, int old_euid, | |
462 | int old_suid) | |
463 | { | |
464 | if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && | |
465 | (current->uid != 0 && current->euid != 0 && current->suid != 0) && | |
3898b1b4 | 466 | !issecure(SECURE_KEEP_CAPS)) { |
1da177e4 LT |
467 | cap_clear (current->cap_permitted); |
468 | cap_clear (current->cap_effective); | |
469 | } | |
470 | if (old_euid == 0 && current->euid != 0) { | |
471 | cap_clear (current->cap_effective); | |
472 | } | |
473 | if (old_euid != 0 && current->euid == 0) { | |
474 | current->cap_effective = current->cap_permitted; | |
475 | } | |
476 | } | |
477 | ||
478 | int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, | |
479 | int flags) | |
480 | { | |
481 | switch (flags) { | |
482 | case LSM_SETID_RE: | |
483 | case LSM_SETID_ID: | |
484 | case LSM_SETID_RES: | |
485 | /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ | |
486 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
487 | cap_emulate_setxuid (old_ruid, old_euid, old_suid); | |
488 | } | |
489 | break; | |
490 | case LSM_SETID_FS: | |
491 | { | |
492 | uid_t old_fsuid = old_ruid; | |
493 | ||
494 | /* Copied from kernel/sys.c:setfsuid. */ | |
495 | ||
496 | /* | |
497 | * FIXME - is fsuser used for all CAP_FS_MASK capabilities? | |
498 | * if not, we might be a bit too harsh here. | |
499 | */ | |
500 | ||
501 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
502 | if (old_fsuid == 0 && current->fsuid != 0) { | |
e338d263 AM |
503 | current->cap_effective = |
504 | cap_drop_fs_set( | |
505 | current->cap_effective); | |
1da177e4 LT |
506 | } |
507 | if (old_fsuid != 0 && current->fsuid == 0) { | |
e338d263 AM |
508 | current->cap_effective = |
509 | cap_raise_fs_set( | |
510 | current->cap_effective, | |
511 | current->cap_permitted); | |
1da177e4 LT |
512 | } |
513 | } | |
514 | break; | |
515 | } | |
516 | default: | |
517 | return -EINVAL; | |
518 | } | |
519 | ||
520 | return 0; | |
521 | } | |
522 | ||
b5376771 SH |
523 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
524 | /* | |
525 | * Rationale: code calling task_setscheduler, task_setioprio, and | |
526 | * task_setnice, assumes that | |
527 | * . if capable(cap_sys_nice), then those actions should be allowed | |
528 | * . if not capable(cap_sys_nice), but acting on your own processes, | |
529 | * then those actions should be allowed | |
530 | * This is insufficient now since you can call code without suid, but | |
531 | * yet with increased caps. | |
532 | * So we check for increased caps on the target process. | |
533 | */ | |
534 | static inline int cap_safe_nice(struct task_struct *p) | |
535 | { | |
536 | if (!cap_issubset(p->cap_permitted, current->cap_permitted) && | |
537 | !__capable(current, CAP_SYS_NICE)) | |
538 | return -EPERM; | |
539 | return 0; | |
540 | } | |
541 | ||
542 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
543 | struct sched_param *lp) | |
544 | { | |
545 | return cap_safe_nice(p); | |
546 | } | |
547 | ||
548 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
549 | { | |
550 | return cap_safe_nice(p); | |
551 | } | |
552 | ||
553 | int cap_task_setnice (struct task_struct *p, int nice) | |
554 | { | |
555 | return cap_safe_nice(p); | |
556 | } | |
557 | ||
3b7391de SH |
558 | /* |
559 | * called from kernel/sys.c for prctl(PR_CABSET_DROP) | |
560 | * done without task_capability_lock() because it introduces | |
561 | * no new races - i.e. only another task doing capget() on | |
562 | * this task could get inconsistent info. There can be no | |
563 | * racing writer bc a task can only change its own caps. | |
564 | */ | |
3898b1b4 | 565 | static long cap_prctl_drop(unsigned long cap) |
3b7391de SH |
566 | { |
567 | if (!capable(CAP_SETPCAP)) | |
568 | return -EPERM; | |
569 | if (!cap_valid(cap)) | |
570 | return -EINVAL; | |
571 | cap_lower(current->cap_bset, cap); | |
572 | return 0; | |
573 | } | |
3898b1b4 | 574 | |
b5376771 SH |
575 | #else |
576 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
577 | struct sched_param *lp) | |
578 | { | |
579 | return 0; | |
580 | } | |
581 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
582 | { | |
583 | return 0; | |
584 | } | |
585 | int cap_task_setnice (struct task_struct *p, int nice) | |
586 | { | |
587 | return 0; | |
588 | } | |
b5376771 SH |
589 | #endif |
590 | ||
3898b1b4 AM |
591 | int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, |
592 | unsigned long arg4, unsigned long arg5, long *rc_p) | |
593 | { | |
594 | long error = 0; | |
595 | ||
596 | switch (option) { | |
597 | case PR_CAPBSET_READ: | |
598 | if (!cap_valid(arg2)) | |
599 | error = -EINVAL; | |
600 | else | |
601 | error = !!cap_raised(current->cap_bset, arg2); | |
602 | break; | |
603 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
604 | case PR_CAPBSET_DROP: | |
605 | error = cap_prctl_drop(arg2); | |
606 | break; | |
607 | ||
608 | /* | |
609 | * The next four prctl's remain to assist with transitioning a | |
610 | * system from legacy UID=0 based privilege (when filesystem | |
611 | * capabilities are not in use) to a system using filesystem | |
612 | * capabilities only - as the POSIX.1e draft intended. | |
613 | * | |
614 | * Note: | |
615 | * | |
616 | * PR_SET_SECUREBITS = | |
617 | * issecure_mask(SECURE_KEEP_CAPS_LOCKED) | |
618 | * | issecure_mask(SECURE_NOROOT) | |
619 | * | issecure_mask(SECURE_NOROOT_LOCKED) | |
620 | * | issecure_mask(SECURE_NO_SETUID_FIXUP) | |
621 | * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED) | |
622 | * | |
623 | * will ensure that the current process and all of its | |
624 | * children will be locked into a pure | |
625 | * capability-based-privilege environment. | |
626 | */ | |
627 | case PR_SET_SECUREBITS: | |
628 | if ((((current->securebits & SECURE_ALL_LOCKS) >> 1) | |
629 | & (current->securebits ^ arg2)) /*[1]*/ | |
630 | || ((current->securebits & SECURE_ALL_LOCKS | |
631 | & ~arg2)) /*[2]*/ | |
632 | || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ | |
633 | || (cap_capable(current, CAP_SETPCAP) != 0)) { /*[4]*/ | |
634 | /* | |
635 | * [1] no changing of bits that are locked | |
636 | * [2] no unlocking of locks | |
637 | * [3] no setting of unsupported bits | |
638 | * [4] doing anything requires privilege (go read about | |
639 | * the "sendmail capabilities bug") | |
640 | */ | |
641 | error = -EPERM; /* cannot change a locked bit */ | |
642 | } else { | |
643 | current->securebits = arg2; | |
644 | } | |
645 | break; | |
646 | case PR_GET_SECUREBITS: | |
647 | error = current->securebits; | |
648 | break; | |
649 | ||
650 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
651 | ||
652 | case PR_GET_KEEPCAPS: | |
653 | if (issecure(SECURE_KEEP_CAPS)) | |
654 | error = 1; | |
655 | break; | |
656 | case PR_SET_KEEPCAPS: | |
657 | if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ | |
658 | error = -EINVAL; | |
659 | else if (issecure(SECURE_KEEP_CAPS_LOCKED)) | |
660 | error = -EPERM; | |
661 | else if (arg2) | |
662 | current->securebits |= issecure_mask(SECURE_KEEP_CAPS); | |
663 | else | |
664 | current->securebits &= | |
665 | ~issecure_mask(SECURE_KEEP_CAPS); | |
666 | break; | |
667 | ||
668 | default: | |
669 | /* No functionality available - continue with default */ | |
670 | return 0; | |
671 | } | |
672 | ||
673 | /* Functionality provided */ | |
674 | *rc_p = error; | |
675 | return 1; | |
676 | } | |
677 | ||
1da177e4 LT |
678 | void cap_task_reparent_to_init (struct task_struct *p) |
679 | { | |
e338d263 AM |
680 | cap_set_init_eff(p->cap_effective); |
681 | cap_clear(p->cap_inheritable); | |
682 | cap_set_full(p->cap_permitted); | |
3898b1b4 | 683 | p->securebits = SECUREBITS_DEFAULT; |
1da177e4 LT |
684 | return; |
685 | } | |
686 | ||
687 | int cap_syslog (int type) | |
688 | { | |
689 | if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) | |
690 | return -EPERM; | |
691 | return 0; | |
692 | } | |
693 | ||
34b4e4aa | 694 | int cap_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
695 | { |
696 | int cap_sys_admin = 0; | |
697 | ||
698 | if (cap_capable(current, CAP_SYS_ADMIN) == 0) | |
699 | cap_sys_admin = 1; | |
34b4e4aa | 700 | return __vm_enough_memory(mm, pages, cap_sys_admin); |
1da177e4 LT |
701 | } |
702 |