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 | ||
5cd9c58f | 66 | int cap_ptrace_may_access(struct task_struct *child, unsigned int mode) |
1da177e4 LT |
67 | { |
68 | /* Derived from arch/i386/kernel/ptrace.c:sys_ptrace. */ | |
5cd9c58f DH |
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; | |
1da177e4 LT |
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. */ | |
e338d263 AM |
90 | *effective = target->cap_effective; |
91 | *inheritable = target->cap_inheritable; | |
92 | *permitted = target->cap_permitted; | |
1da177e4 LT |
93 | return 0; |
94 | } | |
95 | ||
72c2d582 AM |
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 | /* | |
a6dbb1ef AM |
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. | |
72c2d582 | 113 | */ |
a6dbb1ef | 114 | return (cap_capable(current, CAP_SETPCAP) != 0); |
72c2d582 AM |
115 | } |
116 | ||
1209726c AM |
117 | static inline int cap_limit_ptraced_target(void) { return 1; } |
118 | ||
72c2d582 AM |
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; } | |
1209726c AM |
123 | static inline int cap_limit_ptraced_target(void) |
124 | { | |
125 | return !capable(CAP_SETPCAP); | |
126 | } | |
72c2d582 AM |
127 | |
128 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
129 | ||
1da177e4 LT |
130 | int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, |
131 | kernel_cap_t *inheritable, kernel_cap_t *permitted) | |
132 | { | |
72c2d582 AM |
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 */ | |
1da177e4 LT |
141 | return -EPERM; |
142 | } | |
3b7391de SH |
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 | } | |
1da177e4 LT |
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 | ||
b5376771 SH |
173 | static inline void bprm_clear_caps(struct linux_binprm *bprm) |
174 | { | |
5459c164 | 175 | cap_clear(bprm->cap_post_exec_permitted); |
b5376771 SH |
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 | ||
e338d263 AM |
205 | static inline int cap_from_disk(struct vfs_cap_data *caps, |
206 | struct linux_binprm *bprm, unsigned size) | |
b5376771 SH |
207 | { |
208 | __u32 magic_etc; | |
e338d263 | 209 | unsigned tocopy, i; |
5459c164 | 210 | int ret; |
b5376771 | 211 | |
e338d263 | 212 | if (size < sizeof(magic_etc)) |
b5376771 SH |
213 | return -EINVAL; |
214 | ||
e338d263 | 215 | magic_etc = le32_to_cpu(caps->magic_etc); |
b5376771 SH |
216 | |
217 | switch ((magic_etc & VFS_CAP_REVISION_MASK)) { | |
e338d263 AM |
218 | case VFS_CAP_REVISION_1: |
219 | if (size != XATTR_CAPS_SZ_1) | |
220 | return -EINVAL; | |
221 | tocopy = VFS_CAP_U32_1; | |
222 | break; | |
223 | case VFS_CAP_REVISION_2: | |
224 | if (size != XATTR_CAPS_SZ_2) | |
225 | return -EINVAL; | |
226 | tocopy = VFS_CAP_U32_2; | |
227 | break; | |
b5376771 SH |
228 | default: |
229 | return -EINVAL; | |
230 | } | |
e338d263 AM |
231 | |
232 | if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) { | |
233 | bprm->cap_effective = true; | |
234 | } else { | |
235 | bprm->cap_effective = false; | |
236 | } | |
237 | ||
5459c164 AM |
238 | ret = 0; |
239 | ||
240 | CAP_FOR_EACH_U32(i) { | |
241 | __u32 value_cpu; | |
242 | ||
243 | if (i >= tocopy) { | |
244 | /* | |
245 | * Legacy capability sets have no upper bits | |
246 | */ | |
247 | bprm->cap_post_exec_permitted.cap[i] = 0; | |
248 | continue; | |
249 | } | |
250 | /* | |
251 | * pP' = (X & fP) | (pI & fI) | |
252 | */ | |
253 | value_cpu = le32_to_cpu(caps->data[i].permitted); | |
254 | bprm->cap_post_exec_permitted.cap[i] = | |
255 | (current->cap_bset.cap[i] & value_cpu) | | |
256 | (current->cap_inheritable.cap[i] & | |
257 | le32_to_cpu(caps->data[i].inheritable)); | |
258 | if (value_cpu & ~bprm->cap_post_exec_permitted.cap[i]) { | |
259 | /* | |
260 | * insufficient to execute correctly | |
261 | */ | |
262 | ret = -EPERM; | |
263 | } | |
e338d263 AM |
264 | } |
265 | ||
5459c164 AM |
266 | /* |
267 | * For legacy apps, with no internal support for recognizing they | |
268 | * do not have enough capabilities, we return an error if they are | |
269 | * missing some "forced" (aka file-permitted) capabilities. | |
270 | */ | |
271 | return bprm->cap_effective ? ret : 0; | |
b5376771 SH |
272 | } |
273 | ||
274 | /* Locate any VFS capabilities: */ | |
275 | static int get_file_caps(struct linux_binprm *bprm) | |
276 | { | |
277 | struct dentry *dentry; | |
278 | int rc = 0; | |
e338d263 | 279 | struct vfs_cap_data vcaps; |
b5376771 SH |
280 | struct inode *inode; |
281 | ||
282 | if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) { | |
283 | bprm_clear_caps(bprm); | |
284 | return 0; | |
285 | } | |
286 | ||
287 | dentry = dget(bprm->file->f_dentry); | |
288 | inode = dentry->d_inode; | |
289 | if (!inode->i_op || !inode->i_op->getxattr) | |
290 | goto out; | |
291 | ||
e338d263 AM |
292 | rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps, |
293 | XATTR_CAPS_SZ); | |
b5376771 SH |
294 | if (rc == -ENODATA || rc == -EOPNOTSUPP) { |
295 | /* no data, that's ok */ | |
296 | rc = 0; | |
297 | goto out; | |
298 | } | |
299 | if (rc < 0) | |
300 | goto out; | |
301 | ||
e338d263 | 302 | rc = cap_from_disk(&vcaps, bprm, rc); |
5459c164 | 303 | if (rc == -EINVAL) |
b5376771 | 304 | printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", |
5459c164 | 305 | __func__, rc, bprm->filename); |
b5376771 SH |
306 | |
307 | out: | |
308 | dput(dentry); | |
309 | if (rc) | |
310 | bprm_clear_caps(bprm); | |
311 | ||
312 | return rc; | |
313 | } | |
314 | ||
315 | #else | |
316 | int cap_inode_need_killpriv(struct dentry *dentry) | |
317 | { | |
318 | return 0; | |
319 | } | |
320 | ||
321 | int cap_inode_killpriv(struct dentry *dentry) | |
322 | { | |
323 | return 0; | |
324 | } | |
325 | ||
326 | static inline int get_file_caps(struct linux_binprm *bprm) | |
327 | { | |
328 | bprm_clear_caps(bprm); | |
329 | return 0; | |
330 | } | |
331 | #endif | |
332 | ||
1da177e4 LT |
333 | int cap_bprm_set_security (struct linux_binprm *bprm) |
334 | { | |
b5376771 | 335 | int ret; |
1da177e4 | 336 | |
b5376771 | 337 | ret = get_file_caps(bprm); |
1da177e4 | 338 | |
5459c164 AM |
339 | if (!issecure(SECURE_NOROOT)) { |
340 | /* | |
341 | * To support inheritance of root-permissions and suid-root | |
342 | * executables under compatibility mode, we override the | |
343 | * capability sets for the file. | |
344 | * | |
345 | * If only the real uid is 0, we do not set the effective | |
346 | * bit. | |
347 | */ | |
1da177e4 | 348 | if (bprm->e_uid == 0 || current->uid == 0) { |
5459c164 AM |
349 | /* pP' = (cap_bset & ~0) | (pI & ~0) */ |
350 | bprm->cap_post_exec_permitted = cap_combine( | |
351 | current->cap_bset, current->cap_inheritable | |
352 | ); | |
353 | bprm->cap_effective = (bprm->e_uid == 0); | |
354 | ret = 0; | |
1da177e4 | 355 | } |
1da177e4 | 356 | } |
b5376771 SH |
357 | |
358 | return ret; | |
1da177e4 LT |
359 | } |
360 | ||
361 | void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) | |
362 | { | |
1da177e4 | 363 | if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || |
5459c164 AM |
364 | !cap_issubset(bprm->cap_post_exec_permitted, |
365 | current->cap_permitted)) { | |
6c5d5238 | 366 | set_dumpable(current->mm, suid_dumpable); |
b5376771 | 367 | current->pdeath_signal = 0; |
1da177e4 LT |
368 | |
369 | if (unsafe & ~LSM_UNSAFE_PTRACE_CAP) { | |
370 | if (!capable(CAP_SETUID)) { | |
371 | bprm->e_uid = current->uid; | |
372 | bprm->e_gid = current->gid; | |
373 | } | |
1209726c | 374 | if (cap_limit_ptraced_target()) { |
5459c164 AM |
375 | bprm->cap_post_exec_permitted = cap_intersect( |
376 | bprm->cap_post_exec_permitted, | |
377 | current->cap_permitted); | |
1da177e4 LT |
378 | } |
379 | } | |
380 | } | |
381 | ||
382 | current->suid = current->euid = current->fsuid = bprm->e_uid; | |
383 | current->sgid = current->egid = current->fsgid = bprm->e_gid; | |
384 | ||
385 | /* For init, we want to retain the capabilities set | |
386 | * in the init_task struct. Thus we skip the usual | |
387 | * capability rules */ | |
b460cbc5 | 388 | if (!is_global_init(current)) { |
5459c164 | 389 | current->cap_permitted = bprm->cap_post_exec_permitted; |
e338d263 | 390 | if (bprm->cap_effective) |
5459c164 | 391 | current->cap_effective = bprm->cap_post_exec_permitted; |
e338d263 AM |
392 | else |
393 | cap_clear(current->cap_effective); | |
1da177e4 LT |
394 | } |
395 | ||
396 | /* AUD: Audit candidate if current->cap_effective is set */ | |
397 | ||
3898b1b4 | 398 | current->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); |
1da177e4 LT |
399 | } |
400 | ||
401 | int cap_bprm_secureexec (struct linux_binprm *bprm) | |
402 | { | |
b5376771 SH |
403 | if (current->uid != 0) { |
404 | if (bprm->cap_effective) | |
405 | return 1; | |
5459c164 | 406 | if (!cap_isclear(bprm->cap_post_exec_permitted)) |
b5376771 SH |
407 | return 1; |
408 | } | |
409 | ||
1da177e4 LT |
410 | return (current->euid != current->uid || |
411 | current->egid != current->gid); | |
412 | } | |
413 | ||
8f0cfa52 DH |
414 | int cap_inode_setxattr(struct dentry *dentry, const char *name, |
415 | const void *value, size_t size, int flags) | |
1da177e4 | 416 | { |
b5376771 SH |
417 | if (!strcmp(name, XATTR_NAME_CAPS)) { |
418 | if (!capable(CAP_SETFCAP)) | |
419 | return -EPERM; | |
420 | return 0; | |
421 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
1da177e4 LT |
422 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
423 | !capable(CAP_SYS_ADMIN)) | |
424 | return -EPERM; | |
425 | return 0; | |
426 | } | |
427 | ||
8f0cfa52 | 428 | int cap_inode_removexattr(struct dentry *dentry, const char *name) |
1da177e4 | 429 | { |
b5376771 SH |
430 | if (!strcmp(name, XATTR_NAME_CAPS)) { |
431 | if (!capable(CAP_SETFCAP)) | |
432 | return -EPERM; | |
433 | return 0; | |
434 | } else if (!strncmp(name, XATTR_SECURITY_PREFIX, | |
1da177e4 LT |
435 | sizeof(XATTR_SECURITY_PREFIX) - 1) && |
436 | !capable(CAP_SYS_ADMIN)) | |
437 | return -EPERM; | |
438 | return 0; | |
439 | } | |
440 | ||
441 | /* moved from kernel/sys.c. */ | |
442 | /* | |
443 | * cap_emulate_setxuid() fixes the effective / permitted capabilities of | |
444 | * a process after a call to setuid, setreuid, or setresuid. | |
445 | * | |
446 | * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of | |
447 | * {r,e,s}uid != 0, the permitted and effective capabilities are | |
448 | * cleared. | |
449 | * | |
450 | * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective | |
451 | * capabilities of the process are cleared. | |
452 | * | |
453 | * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective | |
454 | * capabilities are set to the permitted capabilities. | |
455 | * | |
456 | * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should | |
457 | * never happen. | |
458 | * | |
459 | * -astor | |
460 | * | |
461 | * cevans - New behaviour, Oct '99 | |
462 | * A process may, via prctl(), elect to keep its capabilities when it | |
463 | * calls setuid() and switches away from uid==0. Both permitted and | |
464 | * effective sets will be retained. | |
465 | * Without this change, it was impossible for a daemon to drop only some | |
466 | * of its privilege. The call to setuid(!=0) would drop all privileges! | |
467 | * Keeping uid 0 is not an option because uid 0 owns too many vital | |
468 | * files.. | |
469 | * Thanks to Olaf Kirch and Peter Benie for spotting this. | |
470 | */ | |
471 | static inline void cap_emulate_setxuid (int old_ruid, int old_euid, | |
472 | int old_suid) | |
473 | { | |
474 | if ((old_ruid == 0 || old_euid == 0 || old_suid == 0) && | |
475 | (current->uid != 0 && current->euid != 0 && current->suid != 0) && | |
3898b1b4 | 476 | !issecure(SECURE_KEEP_CAPS)) { |
1da177e4 LT |
477 | cap_clear (current->cap_permitted); |
478 | cap_clear (current->cap_effective); | |
479 | } | |
480 | if (old_euid == 0 && current->euid != 0) { | |
481 | cap_clear (current->cap_effective); | |
482 | } | |
483 | if (old_euid != 0 && current->euid == 0) { | |
484 | current->cap_effective = current->cap_permitted; | |
485 | } | |
486 | } | |
487 | ||
488 | int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, | |
489 | int flags) | |
490 | { | |
491 | switch (flags) { | |
492 | case LSM_SETID_RE: | |
493 | case LSM_SETID_ID: | |
494 | case LSM_SETID_RES: | |
495 | /* Copied from kernel/sys.c:setreuid/setuid/setresuid. */ | |
496 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
497 | cap_emulate_setxuid (old_ruid, old_euid, old_suid); | |
498 | } | |
499 | break; | |
500 | case LSM_SETID_FS: | |
501 | { | |
502 | uid_t old_fsuid = old_ruid; | |
503 | ||
504 | /* Copied from kernel/sys.c:setfsuid. */ | |
505 | ||
506 | /* | |
507 | * FIXME - is fsuser used for all CAP_FS_MASK capabilities? | |
508 | * if not, we might be a bit too harsh here. | |
509 | */ | |
510 | ||
511 | if (!issecure (SECURE_NO_SETUID_FIXUP)) { | |
512 | if (old_fsuid == 0 && current->fsuid != 0) { | |
e338d263 AM |
513 | current->cap_effective = |
514 | cap_drop_fs_set( | |
515 | current->cap_effective); | |
1da177e4 LT |
516 | } |
517 | if (old_fsuid != 0 && current->fsuid == 0) { | |
e338d263 AM |
518 | current->cap_effective = |
519 | cap_raise_fs_set( | |
520 | current->cap_effective, | |
521 | current->cap_permitted); | |
1da177e4 LT |
522 | } |
523 | } | |
524 | break; | |
525 | } | |
526 | default: | |
527 | return -EINVAL; | |
528 | } | |
529 | ||
530 | return 0; | |
531 | } | |
532 | ||
b5376771 SH |
533 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES |
534 | /* | |
535 | * Rationale: code calling task_setscheduler, task_setioprio, and | |
536 | * task_setnice, assumes that | |
537 | * . if capable(cap_sys_nice), then those actions should be allowed | |
538 | * . if not capable(cap_sys_nice), but acting on your own processes, | |
539 | * then those actions should be allowed | |
540 | * This is insufficient now since you can call code without suid, but | |
541 | * yet with increased caps. | |
542 | * So we check for increased caps on the target process. | |
543 | */ | |
de45e806 | 544 | static int cap_safe_nice(struct task_struct *p) |
b5376771 SH |
545 | { |
546 | if (!cap_issubset(p->cap_permitted, current->cap_permitted) && | |
5cd9c58f | 547 | !capable(CAP_SYS_NICE)) |
b5376771 SH |
548 | return -EPERM; |
549 | return 0; | |
550 | } | |
551 | ||
552 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
553 | struct sched_param *lp) | |
554 | { | |
555 | return cap_safe_nice(p); | |
556 | } | |
557 | ||
558 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
559 | { | |
560 | return cap_safe_nice(p); | |
561 | } | |
562 | ||
563 | int cap_task_setnice (struct task_struct *p, int nice) | |
564 | { | |
565 | return cap_safe_nice(p); | |
566 | } | |
567 | ||
3b7391de SH |
568 | /* |
569 | * called from kernel/sys.c for prctl(PR_CABSET_DROP) | |
570 | * done without task_capability_lock() because it introduces | |
571 | * no new races - i.e. only another task doing capget() on | |
572 | * this task could get inconsistent info. There can be no | |
573 | * racing writer bc a task can only change its own caps. | |
574 | */ | |
3898b1b4 | 575 | static long cap_prctl_drop(unsigned long cap) |
3b7391de SH |
576 | { |
577 | if (!capable(CAP_SETPCAP)) | |
578 | return -EPERM; | |
579 | if (!cap_valid(cap)) | |
580 | return -EINVAL; | |
581 | cap_lower(current->cap_bset, cap); | |
582 | return 0; | |
583 | } | |
3898b1b4 | 584 | |
b5376771 SH |
585 | #else |
586 | int cap_task_setscheduler (struct task_struct *p, int policy, | |
587 | struct sched_param *lp) | |
588 | { | |
589 | return 0; | |
590 | } | |
591 | int cap_task_setioprio (struct task_struct *p, int ioprio) | |
592 | { | |
593 | return 0; | |
594 | } | |
595 | int cap_task_setnice (struct task_struct *p, int nice) | |
596 | { | |
597 | return 0; | |
598 | } | |
b5376771 SH |
599 | #endif |
600 | ||
3898b1b4 AM |
601 | int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, |
602 | unsigned long arg4, unsigned long arg5, long *rc_p) | |
603 | { | |
604 | long error = 0; | |
605 | ||
606 | switch (option) { | |
607 | case PR_CAPBSET_READ: | |
608 | if (!cap_valid(arg2)) | |
609 | error = -EINVAL; | |
610 | else | |
611 | error = !!cap_raised(current->cap_bset, arg2); | |
612 | break; | |
613 | #ifdef CONFIG_SECURITY_FILE_CAPABILITIES | |
614 | case PR_CAPBSET_DROP: | |
615 | error = cap_prctl_drop(arg2); | |
616 | break; | |
617 | ||
618 | /* | |
619 | * The next four prctl's remain to assist with transitioning a | |
620 | * system from legacy UID=0 based privilege (when filesystem | |
621 | * capabilities are not in use) to a system using filesystem | |
622 | * capabilities only - as the POSIX.1e draft intended. | |
623 | * | |
624 | * Note: | |
625 | * | |
626 | * PR_SET_SECUREBITS = | |
627 | * issecure_mask(SECURE_KEEP_CAPS_LOCKED) | |
628 | * | issecure_mask(SECURE_NOROOT) | |
629 | * | issecure_mask(SECURE_NOROOT_LOCKED) | |
630 | * | issecure_mask(SECURE_NO_SETUID_FIXUP) | |
631 | * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED) | |
632 | * | |
633 | * will ensure that the current process and all of its | |
634 | * children will be locked into a pure | |
635 | * capability-based-privilege environment. | |
636 | */ | |
637 | case PR_SET_SECUREBITS: | |
638 | if ((((current->securebits & SECURE_ALL_LOCKS) >> 1) | |
639 | & (current->securebits ^ arg2)) /*[1]*/ | |
640 | || ((current->securebits & SECURE_ALL_LOCKS | |
641 | & ~arg2)) /*[2]*/ | |
642 | || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ | |
643 | || (cap_capable(current, CAP_SETPCAP) != 0)) { /*[4]*/ | |
644 | /* | |
645 | * [1] no changing of bits that are locked | |
646 | * [2] no unlocking of locks | |
647 | * [3] no setting of unsupported bits | |
648 | * [4] doing anything requires privilege (go read about | |
649 | * the "sendmail capabilities bug") | |
650 | */ | |
651 | error = -EPERM; /* cannot change a locked bit */ | |
652 | } else { | |
653 | current->securebits = arg2; | |
654 | } | |
655 | break; | |
656 | case PR_GET_SECUREBITS: | |
657 | error = current->securebits; | |
658 | break; | |
659 | ||
660 | #endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ | |
661 | ||
662 | case PR_GET_KEEPCAPS: | |
663 | if (issecure(SECURE_KEEP_CAPS)) | |
664 | error = 1; | |
665 | break; | |
666 | case PR_SET_KEEPCAPS: | |
667 | if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ | |
668 | error = -EINVAL; | |
669 | else if (issecure(SECURE_KEEP_CAPS_LOCKED)) | |
670 | error = -EPERM; | |
671 | else if (arg2) | |
672 | current->securebits |= issecure_mask(SECURE_KEEP_CAPS); | |
673 | else | |
674 | current->securebits &= | |
675 | ~issecure_mask(SECURE_KEEP_CAPS); | |
676 | break; | |
677 | ||
678 | default: | |
679 | /* No functionality available - continue with default */ | |
680 | return 0; | |
681 | } | |
682 | ||
683 | /* Functionality provided */ | |
684 | *rc_p = error; | |
685 | return 1; | |
686 | } | |
687 | ||
1da177e4 LT |
688 | void cap_task_reparent_to_init (struct task_struct *p) |
689 | { | |
e338d263 AM |
690 | cap_set_init_eff(p->cap_effective); |
691 | cap_clear(p->cap_inheritable); | |
692 | cap_set_full(p->cap_permitted); | |
3898b1b4 | 693 | p->securebits = SECUREBITS_DEFAULT; |
1da177e4 LT |
694 | return; |
695 | } | |
696 | ||
697 | int cap_syslog (int type) | |
698 | { | |
699 | if ((type != 3 && type != 10) && !capable(CAP_SYS_ADMIN)) | |
700 | return -EPERM; | |
701 | return 0; | |
702 | } | |
703 | ||
34b4e4aa | 704 | int cap_vm_enough_memory(struct mm_struct *mm, long pages) |
1da177e4 LT |
705 | { |
706 | int cap_sys_admin = 0; | |
707 | ||
708 | if (cap_capable(current, CAP_SYS_ADMIN) == 0) | |
709 | cap_sys_admin = 1; | |
34b4e4aa | 710 | return __vm_enough_memory(mm, pages, cap_sys_admin); |
1da177e4 LT |
711 | } |
712 |