Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/kernel/capability.c |
| 3 | * |
| 4 | * Copyright (C) 1997 Andrew Main <zefram@fysh.org> |
| 5 | * |
Andrew Morgan | 72c2d58 | 2007-10-18 03:05:59 -0700 | [diff] [blame] | 6 | * Integrated into 2.1.97+, Andrew G. Morgan <morgan@kernel.org> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net> |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 8 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 10 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/mm.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/security.h> |
| 14 | #include <linux/syscalls.h> |
Serge E. Hallyn | b460cbc | 2007-10-18 23:39:52 -0700 | [diff] [blame] | 15 | #include <linux/pid_namespace.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <asm/uaccess.h> |
| 17 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | /* |
| 19 | * This lock protects task->cap_* for all tasks including current. |
| 20 | * Locking rule: acquire this prior to tasklist_lock. |
| 21 | */ |
| 22 | static DEFINE_SPINLOCK(task_capability_lock); |
| 23 | |
| 24 | /* |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 25 | * Leveraged for setting/resetting capabilities |
| 26 | */ |
| 27 | |
| 28 | const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET; |
| 29 | const kernel_cap_t __cap_full_set = CAP_FULL_SET; |
| 30 | const kernel_cap_t __cap_init_eff_set = CAP_INIT_EFF_SET; |
| 31 | |
| 32 | EXPORT_SYMBOL(__cap_empty_set); |
| 33 | EXPORT_SYMBOL(__cap_full_set); |
| 34 | EXPORT_SYMBOL(__cap_init_eff_set); |
| 35 | |
| 36 | /* |
| 37 | * More recent versions of libcap are available from: |
| 38 | * |
| 39 | * http://www.kernel.org/pub/linux/libs/security/linux-privs/ |
| 40 | */ |
| 41 | |
| 42 | static void warn_legacy_capability_use(void) |
| 43 | { |
| 44 | static int warned; |
| 45 | if (!warned) { |
| 46 | char name[sizeof(current->comm)]; |
| 47 | |
| 48 | printk(KERN_INFO "warning: `%s' uses 32-bit capabilities" |
| 49 | " (legacy support in use)\n", |
| 50 | get_task_comm(name, current)); |
| 51 | warned = 1; |
| 52 | } |
| 53 | } |
| 54 | |
| 55 | /* |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 56 | * Version 2 capabilities worked fine, but the linux/capability.h file |
| 57 | * that accompanied their introduction encouraged their use without |
| 58 | * the necessary user-space source code changes. As such, we have |
| 59 | * created a version 3 with equivalent functionality to version 2, but |
| 60 | * with a header change to protect legacy source code from using |
| 61 | * version 2 when it wanted to use version 1. If your system has code |
| 62 | * that trips the following warning, it is using version 2 specific |
| 63 | * capabilities and may be doing so insecurely. |
| 64 | * |
| 65 | * The remedy is to either upgrade your version of libcap (to 2.10+, |
| 66 | * if the application is linked against it), or recompile your |
| 67 | * application with modern kernel headers and this warning will go |
| 68 | * away. |
| 69 | */ |
| 70 | |
| 71 | static void warn_deprecated_v2(void) |
| 72 | { |
| 73 | static int warned; |
| 74 | |
| 75 | if (!warned) { |
| 76 | char name[sizeof(current->comm)]; |
| 77 | |
| 78 | printk(KERN_INFO "warning: `%s' uses deprecated v2" |
| 79 | " capabilities in a way that may be insecure.\n", |
| 80 | get_task_comm(name, current)); |
| 81 | warned = 1; |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | /* |
| 86 | * Version check. Return the number of u32s in each capability flag |
| 87 | * array, or a negative value on error. |
| 88 | */ |
| 89 | static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy) |
| 90 | { |
| 91 | __u32 version; |
| 92 | |
| 93 | if (get_user(version, &header->version)) |
| 94 | return -EFAULT; |
| 95 | |
| 96 | switch (version) { |
| 97 | case _LINUX_CAPABILITY_VERSION_1: |
| 98 | warn_legacy_capability_use(); |
| 99 | *tocopy = _LINUX_CAPABILITY_U32S_1; |
| 100 | break; |
| 101 | case _LINUX_CAPABILITY_VERSION_2: |
| 102 | warn_deprecated_v2(); |
| 103 | /* |
| 104 | * fall through - v3 is otherwise equivalent to v2. |
| 105 | */ |
| 106 | case _LINUX_CAPABILITY_VERSION_3: |
| 107 | *tocopy = _LINUX_CAPABILITY_U32S_3; |
| 108 | break; |
| 109 | default: |
| 110 | if (put_user((u32)_KERNEL_CAPABILITY_VERSION, &header->version)) |
| 111 | return -EFAULT; |
| 112 | return -EINVAL; |
| 113 | } |
| 114 | |
| 115 | return 0; |
| 116 | } |
| 117 | |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 118 | #ifndef CONFIG_SECURITY_FILE_CAPABILITIES |
| 119 | |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 120 | /* |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 121 | * Without filesystem capability support, we nominally support one process |
| 122 | * setting the capabilities of another |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | */ |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 124 | static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, |
| 125 | kernel_cap_t *pIp, kernel_cap_t *pPp) |
| 126 | { |
| 127 | struct task_struct *target; |
| 128 | int ret; |
| 129 | |
| 130 | spin_lock(&task_capability_lock); |
| 131 | read_lock(&tasklist_lock); |
| 132 | |
| 133 | if (pid && pid != task_pid_vnr(current)) { |
| 134 | target = find_task_by_vpid(pid); |
| 135 | if (!target) { |
| 136 | ret = -ESRCH; |
| 137 | goto out; |
| 138 | } |
| 139 | } else |
| 140 | target = current; |
| 141 | |
| 142 | ret = security_capget(target, pEp, pIp, pPp); |
| 143 | |
| 144 | out: |
| 145 | read_unlock(&tasklist_lock); |
| 146 | spin_unlock(&task_capability_lock); |
| 147 | |
| 148 | return ret; |
| 149 | } |
| 150 | |
| 151 | /* |
| 152 | * cap_set_pg - set capabilities for all processes in a given process |
| 153 | * group. We call this holding task_capability_lock and tasklist_lock. |
| 154 | */ |
| 155 | static inline int cap_set_pg(int pgrp_nr, kernel_cap_t *effective, |
| 156 | kernel_cap_t *inheritable, |
| 157 | kernel_cap_t *permitted) |
| 158 | { |
| 159 | struct task_struct *g, *target; |
| 160 | int ret = -EPERM; |
| 161 | int found = 0; |
| 162 | struct pid *pgrp; |
| 163 | |
| 164 | spin_lock(&task_capability_lock); |
| 165 | read_lock(&tasklist_lock); |
| 166 | |
| 167 | pgrp = find_vpid(pgrp_nr); |
| 168 | do_each_pid_task(pgrp, PIDTYPE_PGID, g) { |
| 169 | target = g; |
| 170 | while_each_thread(g, target) { |
| 171 | if (!security_capset_check(target, effective, |
| 172 | inheritable, permitted)) { |
| 173 | security_capset_set(target, effective, |
| 174 | inheritable, permitted); |
| 175 | ret = 0; |
| 176 | } |
| 177 | found = 1; |
| 178 | } |
| 179 | } while_each_pid_task(pgrp, PIDTYPE_PGID, g); |
| 180 | |
| 181 | read_unlock(&tasklist_lock); |
| 182 | spin_unlock(&task_capability_lock); |
| 183 | |
| 184 | if (!found) |
| 185 | ret = 0; |
| 186 | return ret; |
| 187 | } |
| 188 | |
| 189 | /* |
| 190 | * cap_set_all - set capabilities for all processes other than init |
| 191 | * and self. We call this holding task_capability_lock and tasklist_lock. |
| 192 | */ |
| 193 | static inline int cap_set_all(kernel_cap_t *effective, |
| 194 | kernel_cap_t *inheritable, |
| 195 | kernel_cap_t *permitted) |
| 196 | { |
| 197 | struct task_struct *g, *target; |
| 198 | int ret = -EPERM; |
| 199 | int found = 0; |
| 200 | |
| 201 | spin_lock(&task_capability_lock); |
| 202 | read_lock(&tasklist_lock); |
| 203 | |
| 204 | do_each_thread(g, target) { |
| 205 | if (target == current |
| 206 | || is_container_init(target->group_leader)) |
| 207 | continue; |
| 208 | found = 1; |
| 209 | if (security_capset_check(target, effective, inheritable, |
| 210 | permitted)) |
| 211 | continue; |
| 212 | ret = 0; |
| 213 | security_capset_set(target, effective, inheritable, permitted); |
| 214 | } while_each_thread(g, target); |
| 215 | |
| 216 | read_unlock(&tasklist_lock); |
| 217 | spin_unlock(&task_capability_lock); |
| 218 | |
| 219 | if (!found) |
| 220 | ret = 0; |
| 221 | |
| 222 | return ret; |
| 223 | } |
| 224 | |
| 225 | /* |
| 226 | * Given the target pid does not refer to the current process we |
| 227 | * need more elaborate support... (This support is not present when |
| 228 | * filesystem capabilities are configured.) |
| 229 | */ |
| 230 | static inline int do_sys_capset_other_tasks(pid_t pid, kernel_cap_t *effective, |
| 231 | kernel_cap_t *inheritable, |
| 232 | kernel_cap_t *permitted) |
| 233 | { |
| 234 | struct task_struct *target; |
| 235 | int ret; |
| 236 | |
| 237 | if (!capable(CAP_SETPCAP)) |
| 238 | return -EPERM; |
| 239 | |
| 240 | if (pid == -1) /* all procs other than current and init */ |
| 241 | return cap_set_all(effective, inheritable, permitted); |
| 242 | |
| 243 | else if (pid < 0) /* all procs in process group */ |
| 244 | return cap_set_pg(-pid, effective, inheritable, permitted); |
| 245 | |
| 246 | /* target != current */ |
| 247 | spin_lock(&task_capability_lock); |
| 248 | read_lock(&tasklist_lock); |
| 249 | |
| 250 | target = find_task_by_vpid(pid); |
| 251 | if (!target) |
| 252 | ret = -ESRCH; |
| 253 | else { |
| 254 | ret = security_capset_check(target, effective, inheritable, |
| 255 | permitted); |
| 256 | |
| 257 | /* having verified that the proposed changes are legal, |
| 258 | we now put them into effect. */ |
| 259 | if (!ret) |
| 260 | security_capset_set(target, effective, inheritable, |
| 261 | permitted); |
| 262 | } |
| 263 | |
| 264 | read_unlock(&tasklist_lock); |
| 265 | spin_unlock(&task_capability_lock); |
| 266 | |
| 267 | return ret; |
| 268 | } |
| 269 | |
| 270 | #else /* ie., def CONFIG_SECURITY_FILE_CAPABILITIES */ |
| 271 | |
| 272 | /* |
| 273 | * If we have configured with filesystem capability support, then the |
| 274 | * only thing that can change the capabilities of the current process |
| 275 | * is the current process. As such, we can't be in this code at the |
| 276 | * same time as we are in the process of setting capabilities in this |
| 277 | * process. The net result is that we can limit our use of locks to |
| 278 | * when we are reading the caps of another process. |
| 279 | */ |
| 280 | static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp, |
| 281 | kernel_cap_t *pIp, kernel_cap_t *pPp) |
| 282 | { |
| 283 | int ret; |
| 284 | |
| 285 | if (pid && (pid != task_pid_vnr(current))) { |
| 286 | struct task_struct *target; |
| 287 | |
| 288 | spin_lock(&task_capability_lock); |
| 289 | read_lock(&tasklist_lock); |
| 290 | |
| 291 | target = find_task_by_vpid(pid); |
| 292 | if (!target) |
| 293 | ret = -ESRCH; |
| 294 | else |
| 295 | ret = security_capget(target, pEp, pIp, pPp); |
| 296 | |
| 297 | read_unlock(&tasklist_lock); |
| 298 | spin_unlock(&task_capability_lock); |
| 299 | } else |
| 300 | ret = security_capget(current, pEp, pIp, pPp); |
| 301 | |
| 302 | return ret; |
| 303 | } |
| 304 | |
| 305 | /* |
| 306 | * With filesystem capability support configured, the kernel does not |
| 307 | * permit the changing of capabilities in one process by another |
| 308 | * process. (CAP_SETPCAP has much less broad semantics when configured |
| 309 | * this way.) |
| 310 | */ |
| 311 | static inline int do_sys_capset_other_tasks(pid_t pid, |
| 312 | kernel_cap_t *effective, |
| 313 | kernel_cap_t *inheritable, |
| 314 | kernel_cap_t *permitted) |
| 315 | { |
| 316 | return -EPERM; |
| 317 | } |
| 318 | |
| 319 | #endif /* ie., ndef CONFIG_SECURITY_FILE_CAPABILITIES */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | |
Andrew G. Morgan | 086f731 | 2008-07-04 09:59:58 -0700 | [diff] [blame] | 321 | /* |
| 322 | * Atomically modify the effective capabilities returning the original |
| 323 | * value. No permission check is performed here - it is assumed that the |
| 324 | * caller is permitted to set the desired effective capabilities. |
| 325 | */ |
| 326 | kernel_cap_t cap_set_effective(const kernel_cap_t pE_new) |
| 327 | { |
| 328 | kernel_cap_t pE_old; |
| 329 | |
| 330 | spin_lock(&task_capability_lock); |
| 331 | |
| 332 | pE_old = current->cap_effective; |
| 333 | current->cap_effective = pE_new; |
| 334 | |
| 335 | spin_unlock(&task_capability_lock); |
| 336 | |
| 337 | return pE_old; |
| 338 | } |
| 339 | |
| 340 | EXPORT_SYMBOL(cap_set_effective); |
| 341 | |
Randy Dunlap | 207a7ba | 2005-07-27 11:45:10 -0700 | [diff] [blame] | 342 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | * sys_capget - get the capabilities of a given process. |
Randy Dunlap | 207a7ba | 2005-07-27 11:45:10 -0700 | [diff] [blame] | 344 | * @header: pointer to struct that contains capability version and |
| 345 | * target pid data |
| 346 | * @dataptr: pointer to struct that contains the effective, permitted, |
| 347 | * and inheritable capabilities that are returned |
| 348 | * |
| 349 | * Returns 0 on success and < 0 on error. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | */ |
| 351 | asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr) |
| 352 | { |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 353 | int ret = 0; |
| 354 | pid_t pid; |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 355 | unsigned tocopy; |
| 356 | kernel_cap_t pE, pI, pP; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 357 | |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 358 | ret = cap_validate_magic(header, &tocopy); |
| 359 | if (ret != 0) |
| 360 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 361 | |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 362 | if (get_user(pid, &header->pid)) |
| 363 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 364 | |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 365 | if (pid < 0) |
| 366 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 367 | |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 368 | ret = cap_get_target_pid(pid, &pE, &pI, &pP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 370 | if (!ret) { |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 371 | struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S]; |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 372 | unsigned i; |
| 373 | |
| 374 | for (i = 0; i < tocopy; i++) { |
| 375 | kdata[i].effective = pE.cap[i]; |
| 376 | kdata[i].permitted = pP.cap[i]; |
| 377 | kdata[i].inheritable = pI.cap[i]; |
| 378 | } |
| 379 | |
| 380 | /* |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 381 | * Note, in the case, tocopy < _KERNEL_CAPABILITY_U32S, |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 382 | * we silently drop the upper capabilities here. This |
| 383 | * has the effect of making older libcap |
| 384 | * implementations implicitly drop upper capability |
| 385 | * bits when they perform a: capget/modify/capset |
| 386 | * sequence. |
| 387 | * |
| 388 | * This behavior is considered fail-safe |
| 389 | * behavior. Upgrading the application to a newer |
| 390 | * version of libcap will enable access to the newer |
| 391 | * capabilities. |
| 392 | * |
| 393 | * An alternative would be to return an error here |
| 394 | * (-ERANGE), but that causes legacy applications to |
| 395 | * unexpectidly fail; the capget/modify/capset aborts |
| 396 | * before modification is attempted and the application |
| 397 | * fails. |
| 398 | */ |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 399 | if (copy_to_user(dataptr, kdata, tocopy |
| 400 | * sizeof(struct __user_cap_data_struct))) { |
| 401 | return -EFAULT; |
| 402 | } |
| 403 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 405 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | } |
| 407 | |
Randy Dunlap | 207a7ba | 2005-07-27 11:45:10 -0700 | [diff] [blame] | 408 | /** |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 409 | * sys_capset - set capabilities for a process or (*) a group of processes |
Randy Dunlap | 207a7ba | 2005-07-27 11:45:10 -0700 | [diff] [blame] | 410 | * @header: pointer to struct that contains capability version and |
| 411 | * target pid data |
| 412 | * @data: pointer to struct that contains the effective, permitted, |
| 413 | * and inheritable capabilities |
| 414 | * |
| 415 | * Set capabilities for a given process, all processes, or all |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 416 | * processes in a given process group. |
| 417 | * |
| 418 | * The restrictions on setting capabilities are specified as: |
| 419 | * |
| 420 | * [pid is for the 'target' task. 'current' is the calling task.] |
| 421 | * |
| 422 | * I: any raised capabilities must be a subset of the (old current) permitted |
| 423 | * P: any raised capabilities must be a subset of the (old current) permitted |
| 424 | * E: must be set to a subset of (new target) permitted |
Randy Dunlap | 207a7ba | 2005-07-27 11:45:10 -0700 | [diff] [blame] | 425 | * |
| 426 | * Returns 0 on success and < 0 on error. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | */ |
| 428 | asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data) |
| 429 | { |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 430 | struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S]; |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 431 | unsigned i, tocopy; |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 432 | kernel_cap_t inheritable, permitted, effective; |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 433 | int ret; |
| 434 | pid_t pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 435 | |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 436 | ret = cap_validate_magic(header, &tocopy); |
| 437 | if (ret != 0) |
| 438 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 440 | if (get_user(pid, &header->pid)) |
| 441 | return -EFAULT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 443 | if (copy_from_user(&kdata, data, tocopy |
| 444 | * sizeof(struct __user_cap_data_struct))) { |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 445 | return -EFAULT; |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 446 | } |
| 447 | |
| 448 | for (i = 0; i < tocopy; i++) { |
| 449 | effective.cap[i] = kdata[i].effective; |
| 450 | permitted.cap[i] = kdata[i].permitted; |
| 451 | inheritable.cap[i] = kdata[i].inheritable; |
| 452 | } |
Andrew G. Morgan | ca05a99 | 2008-05-27 22:05:17 -0700 | [diff] [blame] | 453 | while (i < _KERNEL_CAPABILITY_U32S) { |
Andrew Morgan | e338d26 | 2008-02-04 22:29:42 -0800 | [diff] [blame] | 454 | effective.cap[i] = 0; |
| 455 | permitted.cap[i] = 0; |
| 456 | inheritable.cap[i] = 0; |
| 457 | i++; |
| 458 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 460 | if (pid && (pid != task_pid_vnr(current))) |
| 461 | ret = do_sys_capset_other_tasks(pid, &effective, &inheritable, |
| 462 | &permitted); |
| 463 | else { |
| 464 | /* |
| 465 | * This lock is required even when filesystem |
| 466 | * capability support is configured - it protects the |
| 467 | * sys_capget() call from returning incorrect data in |
| 468 | * the case that the targeted process is not the |
| 469 | * current one. |
| 470 | */ |
| 471 | spin_lock(&task_capability_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 473 | ret = security_capset_check(current, &effective, &inheritable, |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 474 | &permitted); |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 475 | /* |
| 476 | * Having verified that the proposed changes are |
| 477 | * legal, we now put them into effect. |
| 478 | */ |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 479 | if (!ret) |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 480 | security_capset_set(current, &effective, &inheritable, |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 481 | &permitted); |
Andrew G. Morgan | ab763c7 | 2008-07-23 21:28:25 -0700 | [diff] [blame] | 482 | spin_unlock(&task_capability_lock); |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 483 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 484 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 485 | |
Daniel Walker | 314f70f | 2007-10-18 03:06:08 -0700 | [diff] [blame] | 486 | return ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | } |
Chris Wright | 12b5989 | 2006-03-25 03:07:41 -0800 | [diff] [blame] | 488 | |
| 489 | int __capable(struct task_struct *t, int cap) |
| 490 | { |
| 491 | if (security_capable(t, cap) == 0) { |
| 492 | t->flags |= PF_SUPERPRIV; |
| 493 | return 1; |
| 494 | } |
| 495 | return 0; |
| 496 | } |
Chris Wright | 12b5989 | 2006-03-25 03:07:41 -0800 | [diff] [blame] | 497 | |
| 498 | int capable(int cap) |
| 499 | { |
| 500 | return __capable(current, cap); |
| 501 | } |
| 502 | EXPORT_SYMBOL(capable); |