1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * linux/kernel/capability.c 3 * linux/kernel/capability.c
4 * 4 *
5 * Copyright (C) 1997 Andrew Main <zefram@fys 5 * Copyright (C) 1997 Andrew Main <zefram@fysh.org>
6 * 6 *
7 * Integrated into 2.1.97+, Andrew G. Morgan 7 * Integrated into 2.1.97+, Andrew G. Morgan <morgan@kernel.org>
8 * 30 May 2002: Cleanup, Robert M. Love <rml@t 8 * 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net>
9 */ 9 */
10 10
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 12
13 #include <linux/audit.h> 13 #include <linux/audit.h>
14 #include <linux/capability.h> 14 #include <linux/capability.h>
15 #include <linux/mm.h> 15 #include <linux/mm.h>
16 #include <linux/export.h> 16 #include <linux/export.h>
17 #include <linux/security.h> 17 #include <linux/security.h>
18 #include <linux/syscalls.h> 18 #include <linux/syscalls.h>
19 #include <linux/pid_namespace.h> 19 #include <linux/pid_namespace.h>
20 #include <linux/user_namespace.h> 20 #include <linux/user_namespace.h>
21 #include <linux/uaccess.h> 21 #include <linux/uaccess.h>
22 22
>> 23 /*
>> 24 * Leveraged for setting/resetting capabilities
>> 25 */
>> 26
>> 27 const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET;
>> 28 EXPORT_SYMBOL(__cap_empty_set);
>> 29
23 int file_caps_enabled = 1; 30 int file_caps_enabled = 1;
24 31
25 static int __init file_caps_disable(char *str) 32 static int __init file_caps_disable(char *str)
26 { 33 {
27 file_caps_enabled = 0; 34 file_caps_enabled = 0;
28 return 1; 35 return 1;
29 } 36 }
30 __setup("no_file_caps", file_caps_disable); 37 __setup("no_file_caps", file_caps_disable);
31 38
32 #ifdef CONFIG_MULTIUSER 39 #ifdef CONFIG_MULTIUSER
33 /* 40 /*
34 * More recent versions of libcap are availabl 41 * More recent versions of libcap are available from:
35 * 42 *
36 * http://www.kernel.org/pub/linux/libs/secu 43 * http://www.kernel.org/pub/linux/libs/security/linux-privs/
37 */ 44 */
38 45
39 static void warn_legacy_capability_use(void) 46 static void warn_legacy_capability_use(void)
40 { 47 {
41 char name[sizeof(current->comm)]; 48 char name[sizeof(current->comm)];
42 49
43 pr_info_once("warning: `%s' uses 32-bi 50 pr_info_once("warning: `%s' uses 32-bit capabilities (legacy support in use)\n",
44 get_task_comm(name, curre 51 get_task_comm(name, current));
45 } 52 }
46 53
47 /* 54 /*
48 * Version 2 capabilities worked fine, but the 55 * Version 2 capabilities worked fine, but the linux/capability.h file
49 * that accompanied their introduction encoura 56 * that accompanied their introduction encouraged their use without
50 * the necessary user-space source code change 57 * the necessary user-space source code changes. As such, we have
51 * created a version 3 with equivalent functio 58 * created a version 3 with equivalent functionality to version 2, but
52 * with a header change to protect legacy sour 59 * with a header change to protect legacy source code from using
53 * version 2 when it wanted to use version 1. 60 * version 2 when it wanted to use version 1. If your system has code
54 * that trips the following warning, it is usi 61 * that trips the following warning, it is using version 2 specific
55 * capabilities and may be doing so insecurely 62 * capabilities and may be doing so insecurely.
56 * 63 *
57 * The remedy is to either upgrade your versio 64 * The remedy is to either upgrade your version of libcap (to 2.10+,
58 * if the application is linked against it), o 65 * if the application is linked against it), or recompile your
59 * application with modern kernel headers and 66 * application with modern kernel headers and this warning will go
60 * away. 67 * away.
61 */ 68 */
62 69
63 static void warn_deprecated_v2(void) 70 static void warn_deprecated_v2(void)
64 { 71 {
65 char name[sizeof(current->comm)]; 72 char name[sizeof(current->comm)];
66 73
67 pr_info_once("warning: `%s' uses depre 74 pr_info_once("warning: `%s' uses deprecated v2 capabilities in a way that may be insecure\n",
68 get_task_comm(name, curre 75 get_task_comm(name, current));
69 } 76 }
70 77
71 /* 78 /*
72 * Version check. Return the number of u32s in 79 * Version check. Return the number of u32s in each capability flag
73 * array, or a negative value on error. 80 * array, or a negative value on error.
74 */ 81 */
75 static int cap_validate_magic(cap_user_header_ 82 static int cap_validate_magic(cap_user_header_t header, unsigned *tocopy)
76 { 83 {
77 __u32 version; 84 __u32 version;
78 85
79 if (get_user(version, &header->version 86 if (get_user(version, &header->version))
80 return -EFAULT; 87 return -EFAULT;
81 88
82 switch (version) { 89 switch (version) {
83 case _LINUX_CAPABILITY_VERSION_1: 90 case _LINUX_CAPABILITY_VERSION_1:
84 warn_legacy_capability_use(); 91 warn_legacy_capability_use();
85 *tocopy = _LINUX_CAPABILITY_U3 92 *tocopy = _LINUX_CAPABILITY_U32S_1;
86 break; 93 break;
87 case _LINUX_CAPABILITY_VERSION_2: 94 case _LINUX_CAPABILITY_VERSION_2:
88 warn_deprecated_v2(); 95 warn_deprecated_v2();
89 fallthrough; /* v3 is other !! 96 /* fall through - v3 is otherwise equivalent to v2. */
90 case _LINUX_CAPABILITY_VERSION_3: 97 case _LINUX_CAPABILITY_VERSION_3:
91 *tocopy = _LINUX_CAPABILITY_U3 98 *tocopy = _LINUX_CAPABILITY_U32S_3;
92 break; 99 break;
93 default: 100 default:
94 if (put_user((u32)_KERNEL_CAPA 101 if (put_user((u32)_KERNEL_CAPABILITY_VERSION, &header->version))
95 return -EFAULT; 102 return -EFAULT;
96 return -EINVAL; 103 return -EINVAL;
97 } 104 }
98 105
99 return 0; 106 return 0;
100 } 107 }
101 108
102 /* 109 /*
103 * The only thing that can change the capabili 110 * The only thing that can change the capabilities of the current
104 * process is the current process. As such, we 111 * process is the current process. As such, we can't be in this code
105 * at the same time as we are in the process o 112 * at the same time as we are in the process of setting capabilities
106 * in this process. The net result is that we 113 * in this process. The net result is that we can limit our use of
107 * locks to when we are reading the caps of an 114 * locks to when we are reading the caps of another process.
108 */ 115 */
109 static inline int cap_get_target_pid(pid_t pid 116 static inline int cap_get_target_pid(pid_t pid, kernel_cap_t *pEp,
110 kernel_ca 117 kernel_cap_t *pIp, kernel_cap_t *pPp)
111 { 118 {
112 int ret; 119 int ret;
113 120
114 if (pid && (pid != task_pid_vnr(curren 121 if (pid && (pid != task_pid_vnr(current))) {
115 const struct task_struct *targ !! 122 struct task_struct *target;
116 123
117 rcu_read_lock(); 124 rcu_read_lock();
118 125
119 target = find_task_by_vpid(pid 126 target = find_task_by_vpid(pid);
120 if (!target) 127 if (!target)
121 ret = -ESRCH; 128 ret = -ESRCH;
122 else 129 else
123 ret = security_capget( 130 ret = security_capget(target, pEp, pIp, pPp);
124 131
125 rcu_read_unlock(); 132 rcu_read_unlock();
126 } else 133 } else
127 ret = security_capget(current, 134 ret = security_capget(current, pEp, pIp, pPp);
128 135
129 return ret; 136 return ret;
130 } 137 }
131 138
132 /** 139 /**
133 * sys_capget - get the capabilities of a give 140 * sys_capget - get the capabilities of a given process.
134 * @header: pointer to struct that contains ca 141 * @header: pointer to struct that contains capability version and
135 * target pid data 142 * target pid data
136 * @dataptr: pointer to struct that contains t 143 * @dataptr: pointer to struct that contains the effective, permitted,
137 * and inheritable capabilities that are 144 * and inheritable capabilities that are returned
138 * 145 *
139 * Returns 0 on success and < 0 on error. 146 * Returns 0 on success and < 0 on error.
140 */ 147 */
141 SYSCALL_DEFINE2(capget, cap_user_header_t, hea 148 SYSCALL_DEFINE2(capget, cap_user_header_t, header, cap_user_data_t, dataptr)
142 { 149 {
143 int ret = 0; 150 int ret = 0;
144 pid_t pid; 151 pid_t pid;
145 unsigned tocopy; 152 unsigned tocopy;
146 kernel_cap_t pE, pI, pP; 153 kernel_cap_t pE, pI, pP;
147 struct __user_cap_data_struct kdata[2] <<
148 154
149 ret = cap_validate_magic(header, &toco 155 ret = cap_validate_magic(header, &tocopy);
150 if ((dataptr == NULL) || (ret != 0)) 156 if ((dataptr == NULL) || (ret != 0))
151 return ((dataptr == NULL) && ( 157 return ((dataptr == NULL) && (ret == -EINVAL)) ? 0 : ret;
152 158
153 if (get_user(pid, &header->pid)) 159 if (get_user(pid, &header->pid))
154 return -EFAULT; 160 return -EFAULT;
155 161
156 if (pid < 0) 162 if (pid < 0)
157 return -EINVAL; 163 return -EINVAL;
158 164
159 ret = cap_get_target_pid(pid, &pE, &pI 165 ret = cap_get_target_pid(pid, &pE, &pI, &pP);
160 if (ret) !! 166 if (!ret) {
161 return ret; !! 167 struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S];
162 !! 168 unsigned i;
163 /* !! 169
164 * Annoying legacy format with 64-bit !! 170 for (i = 0; i < tocopy; i++) {
165 * as two sets of 32-bit fields, so we !! 171 kdata[i].effective = pE.cap[i];
166 * capability values up. !! 172 kdata[i].permitted = pP.cap[i];
167 */ !! 173 kdata[i].inheritable = pI.cap[i];
168 kdata[0].effective = pE.val; kdata[1 !! 174 }
169 kdata[0].permitted = pP.val; kdata[1 !! 175
170 kdata[0].inheritable = pI.val; kdata[1 !! 176 /*
171 !! 177 * Note, in the case, tocopy < _KERNEL_CAPABILITY_U32S,
172 /* !! 178 * we silently drop the upper capabilities here. This
173 * Note, in the case, tocopy < _KERNEL !! 179 * has the effect of making older libcap
174 * we silently drop the upper capabili !! 180 * implementations implicitly drop upper capability
175 * has the effect of making older libc !! 181 * bits when they perform a: capget/modify/capset
176 * implementations implicitly drop upp !! 182 * sequence.
177 * bits when they perform a: capget/mo !! 183 *
178 * sequence. !! 184 * This behavior is considered fail-safe
179 * !! 185 * behavior. Upgrading the application to a newer
180 * This behavior is considered fail-sa !! 186 * version of libcap will enable access to the newer
181 * behavior. Upgrading the application !! 187 * capabilities.
182 * version of libcap will enable acces !! 188 *
183 * capabilities. !! 189 * An alternative would be to return an error here
184 * !! 190 * (-ERANGE), but that causes legacy applications to
185 * An alternative would be to return a !! 191 * unexpectedly fail; the capget/modify/capset aborts
186 * (-ERANGE), but that causes legacy a !! 192 * before modification is attempted and the application
187 * unexpectedly fail; the capget/modif !! 193 * fails.
188 * before modification is attempted an !! 194 */
189 * fails. !! 195 if (copy_to_user(dataptr, kdata, tocopy
190 */ !! 196 * sizeof(struct __user_cap_data_struct))) {
191 if (copy_to_user(dataptr, kdata, tocop !! 197 return -EFAULT;
192 return -EFAULT; !! 198 }
193 !! 199 }
194 return 0; <<
195 } <<
196 200
197 static kernel_cap_t mk_kernel_cap(u32 low, u32 !! 201 return ret;
198 { <<
199 return (kernel_cap_t) { (low | ((u64)h <<
200 } 202 }
201 203
202 /** 204 /**
203 * sys_capset - set capabilities for a process 205 * sys_capset - set capabilities for a process or (*) a group of processes
204 * @header: pointer to struct that contains ca 206 * @header: pointer to struct that contains capability version and
205 * target pid data 207 * target pid data
206 * @data: pointer to struct that contains the 208 * @data: pointer to struct that contains the effective, permitted,
207 * and inheritable capabilities 209 * and inheritable capabilities
208 * 210 *
209 * Set capabilities for the current process on 211 * Set capabilities for the current process only. The ability to any other
210 * process(es) has been deprecated and removed 212 * process(es) has been deprecated and removed.
211 * 213 *
212 * The restrictions on setting capabilities ar 214 * The restrictions on setting capabilities are specified as:
213 * 215 *
214 * I: any raised capabilities must be a subset 216 * I: any raised capabilities must be a subset of the old permitted
215 * P: any raised capabilities must be a subset 217 * P: any raised capabilities must be a subset of the old permitted
216 * E: must be set to a subset of new permitted 218 * E: must be set to a subset of new permitted
217 * 219 *
218 * Returns 0 on success and < 0 on error. 220 * Returns 0 on success and < 0 on error.
219 */ 221 */
220 SYSCALL_DEFINE2(capset, cap_user_header_t, hea 222 SYSCALL_DEFINE2(capset, cap_user_header_t, header, const cap_user_data_t, data)
221 { 223 {
222 struct __user_cap_data_struct kdata[2] !! 224 struct __user_cap_data_struct kdata[_KERNEL_CAPABILITY_U32S];
223 unsigned tocopy, copybytes; !! 225 unsigned i, tocopy, copybytes;
224 kernel_cap_t inheritable, permitted, e 226 kernel_cap_t inheritable, permitted, effective;
225 struct cred *new; 227 struct cred *new;
226 int ret; 228 int ret;
227 pid_t pid; 229 pid_t pid;
228 230
229 ret = cap_validate_magic(header, &toco 231 ret = cap_validate_magic(header, &tocopy);
230 if (ret != 0) 232 if (ret != 0)
231 return ret; 233 return ret;
232 234
233 if (get_user(pid, &header->pid)) 235 if (get_user(pid, &header->pid))
234 return -EFAULT; 236 return -EFAULT;
235 237
236 /* may only affect current now */ 238 /* may only affect current now */
237 if (pid != 0 && pid != task_pid_vnr(cu 239 if (pid != 0 && pid != task_pid_vnr(current))
238 return -EPERM; 240 return -EPERM;
239 241
240 copybytes = tocopy * sizeof(struct __u 242 copybytes = tocopy * sizeof(struct __user_cap_data_struct);
241 if (copybytes > sizeof(kdata)) 243 if (copybytes > sizeof(kdata))
242 return -EFAULT; 244 return -EFAULT;
243 245
244 if (copy_from_user(&kdata, data, copyb 246 if (copy_from_user(&kdata, data, copybytes))
245 return -EFAULT; 247 return -EFAULT;
246 248
247 effective = mk_kernel_cap(kdata[0].e !! 249 for (i = 0; i < tocopy; i++) {
248 permitted = mk_kernel_cap(kdata[0].p !! 250 effective.cap[i] = kdata[i].effective;
249 inheritable = mk_kernel_cap(kdata[0].i !! 251 permitted.cap[i] = kdata[i].permitted;
>> 252 inheritable.cap[i] = kdata[i].inheritable;
>> 253 }
>> 254 while (i < _KERNEL_CAPABILITY_U32S) {
>> 255 effective.cap[i] = 0;
>> 256 permitted.cap[i] = 0;
>> 257 inheritable.cap[i] = 0;
>> 258 i++;
>> 259 }
>> 260
>> 261 effective.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
>> 262 permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
>> 263 inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK;
250 264
251 new = prepare_creds(); 265 new = prepare_creds();
252 if (!new) 266 if (!new)
253 return -ENOMEM; 267 return -ENOMEM;
254 268
255 ret = security_capset(new, current_cre 269 ret = security_capset(new, current_cred(),
256 &effective, &inh 270 &effective, &inheritable, &permitted);
257 if (ret < 0) 271 if (ret < 0)
258 goto error; 272 goto error;
259 273
260 audit_log_capset(new, current_cred()); 274 audit_log_capset(new, current_cred());
261 275
262 return commit_creds(new); 276 return commit_creds(new);
263 277
264 error: 278 error:
265 abort_creds(new); 279 abort_creds(new);
266 return ret; 280 return ret;
267 } 281 }
268 282
269 /** 283 /**
270 * has_ns_capability - Does a task have a capa 284 * has_ns_capability - Does a task have a capability in a specific user ns
271 * @t: The task in question 285 * @t: The task in question
272 * @ns: target user namespace 286 * @ns: target user namespace
273 * @cap: The capability to be tested for 287 * @cap: The capability to be tested for
274 * 288 *
275 * Return true if the specified task has the g 289 * Return true if the specified task has the given superior capability
276 * currently in effect to the specified user n 290 * currently in effect to the specified user namespace, false if not.
277 * 291 *
278 * Note that this does not set PF_SUPERPRIV on 292 * Note that this does not set PF_SUPERPRIV on the task.
279 */ 293 */
280 bool has_ns_capability(struct task_struct *t, 294 bool has_ns_capability(struct task_struct *t,
281 struct user_namespace * 295 struct user_namespace *ns, int cap)
282 { 296 {
283 int ret; 297 int ret;
284 298
285 rcu_read_lock(); 299 rcu_read_lock();
286 ret = security_capable(__task_cred(t), 300 ret = security_capable(__task_cred(t), ns, cap, CAP_OPT_NONE);
287 rcu_read_unlock(); 301 rcu_read_unlock();
288 302
289 return (ret == 0); 303 return (ret == 0);
290 } 304 }
291 305
292 /** 306 /**
293 * has_capability - Does a task have a capabil 307 * has_capability - Does a task have a capability in init_user_ns
294 * @t: The task in question 308 * @t: The task in question
295 * @cap: The capability to be tested for 309 * @cap: The capability to be tested for
296 * 310 *
297 * Return true if the specified task has the g 311 * Return true if the specified task has the given superior capability
298 * currently in effect to the initial user nam 312 * currently in effect to the initial user namespace, false if not.
299 * 313 *
300 * Note that this does not set PF_SUPERPRIV on 314 * Note that this does not set PF_SUPERPRIV on the task.
301 */ 315 */
302 bool has_capability(struct task_struct *t, int 316 bool has_capability(struct task_struct *t, int cap)
303 { 317 {
304 return has_ns_capability(t, &init_user 318 return has_ns_capability(t, &init_user_ns, cap);
305 } 319 }
306 EXPORT_SYMBOL(has_capability); 320 EXPORT_SYMBOL(has_capability);
307 321
308 /** 322 /**
309 * has_ns_capability_noaudit - Does a task hav 323 * has_ns_capability_noaudit - Does a task have a capability (unaudited)
310 * in a specific user ns. 324 * in a specific user ns.
311 * @t: The task in question 325 * @t: The task in question
312 * @ns: target user namespace 326 * @ns: target user namespace
313 * @cap: The capability to be tested for 327 * @cap: The capability to be tested for
314 * 328 *
315 * Return true if the specified task has the g 329 * Return true if the specified task has the given superior capability
316 * currently in effect to the specified user n 330 * currently in effect to the specified user namespace, false if not.
317 * Do not write an audit message for the check 331 * Do not write an audit message for the check.
318 * 332 *
319 * Note that this does not set PF_SUPERPRIV on 333 * Note that this does not set PF_SUPERPRIV on the task.
320 */ 334 */
321 bool has_ns_capability_noaudit(struct task_str 335 bool has_ns_capability_noaudit(struct task_struct *t,
322 struct user_nam 336 struct user_namespace *ns, int cap)
323 { 337 {
324 int ret; 338 int ret;
325 339
326 rcu_read_lock(); 340 rcu_read_lock();
327 ret = security_capable(__task_cred(t), 341 ret = security_capable(__task_cred(t), ns, cap, CAP_OPT_NOAUDIT);
328 rcu_read_unlock(); 342 rcu_read_unlock();
329 343
330 return (ret == 0); 344 return (ret == 0);
331 } 345 }
332 346
333 /** 347 /**
334 * has_capability_noaudit - Does a task have a 348 * has_capability_noaudit - Does a task have a capability (unaudited) in the
335 * initial user ns 349 * initial user ns
336 * @t: The task in question 350 * @t: The task in question
337 * @cap: The capability to be tested for 351 * @cap: The capability to be tested for
338 * 352 *
339 * Return true if the specified task has the g 353 * Return true if the specified task has the given superior capability
340 * currently in effect to init_user_ns, false 354 * currently in effect to init_user_ns, false if not. Don't write an
341 * audit message for the check. 355 * audit message for the check.
342 * 356 *
343 * Note that this does not set PF_SUPERPRIV on 357 * Note that this does not set PF_SUPERPRIV on the task.
344 */ 358 */
345 bool has_capability_noaudit(struct task_struct 359 bool has_capability_noaudit(struct task_struct *t, int cap)
346 { 360 {
347 return has_ns_capability_noaudit(t, &i 361 return has_ns_capability_noaudit(t, &init_user_ns, cap);
348 } 362 }
349 EXPORT_SYMBOL(has_capability_noaudit); <<
350 363
351 static bool ns_capable_common(struct user_name 364 static bool ns_capable_common(struct user_namespace *ns,
352 int cap, 365 int cap,
353 unsigned int opt 366 unsigned int opts)
354 { 367 {
355 int capable; 368 int capable;
356 369
357 if (unlikely(!cap_valid(cap))) { 370 if (unlikely(!cap_valid(cap))) {
358 pr_crit("capable() called with 371 pr_crit("capable() called with invalid cap=%u\n", cap);
359 BUG(); 372 BUG();
360 } 373 }
361 374
362 capable = security_capable(current_cre 375 capable = security_capable(current_cred(), ns, cap, opts);
363 if (capable == 0) { 376 if (capable == 0) {
364 current->flags |= PF_SUPERPRIV 377 current->flags |= PF_SUPERPRIV;
365 return true; 378 return true;
366 } 379 }
367 return false; 380 return false;
368 } 381 }
369 382
370 /** 383 /**
371 * ns_capable - Determine if the current task 384 * ns_capable - Determine if the current task has a superior capability in effect
372 * @ns: The usernamespace we want the capabil 385 * @ns: The usernamespace we want the capability in
373 * @cap: The capability to be tested for 386 * @cap: The capability to be tested for
374 * 387 *
375 * Return true if the current task has the giv 388 * Return true if the current task has the given superior capability currently
376 * available for use, false if not. 389 * available for use, false if not.
377 * 390 *
378 * This sets PF_SUPERPRIV on the task if the c 391 * This sets PF_SUPERPRIV on the task if the capability is available on the
379 * assumption that it's about to be used. 392 * assumption that it's about to be used.
380 */ 393 */
381 bool ns_capable(struct user_namespace *ns, int 394 bool ns_capable(struct user_namespace *ns, int cap)
382 { 395 {
383 return ns_capable_common(ns, cap, CAP_ 396 return ns_capable_common(ns, cap, CAP_OPT_NONE);
384 } 397 }
385 EXPORT_SYMBOL(ns_capable); 398 EXPORT_SYMBOL(ns_capable);
386 399
387 /** 400 /**
388 * ns_capable_noaudit - Determine if the curre 401 * ns_capable_noaudit - Determine if the current task has a superior capability
389 * (unaudited) in effect 402 * (unaudited) in effect
390 * @ns: The usernamespace we want the capabil 403 * @ns: The usernamespace we want the capability in
391 * @cap: The capability to be tested for 404 * @cap: The capability to be tested for
392 * 405 *
393 * Return true if the current task has the giv 406 * Return true if the current task has the given superior capability currently
394 * available for use, false if not. 407 * available for use, false if not.
395 * 408 *
396 * This sets PF_SUPERPRIV on the task if the c 409 * This sets PF_SUPERPRIV on the task if the capability is available on the
397 * assumption that it's about to be used. 410 * assumption that it's about to be used.
398 */ 411 */
399 bool ns_capable_noaudit(struct user_namespace 412 bool ns_capable_noaudit(struct user_namespace *ns, int cap)
400 { 413 {
401 return ns_capable_common(ns, cap, CAP_ 414 return ns_capable_common(ns, cap, CAP_OPT_NOAUDIT);
402 } 415 }
403 EXPORT_SYMBOL(ns_capable_noaudit); 416 EXPORT_SYMBOL(ns_capable_noaudit);
404 417
405 /** 418 /**
406 * ns_capable_setid - Determine if the current 419 * ns_capable_setid - Determine if the current task has a superior capability
407 * in effect, while signalling that this check 420 * in effect, while signalling that this check is being done from within a
408 * setid or setgroups syscall. !! 421 * setid syscall.
409 * @ns: The usernamespace we want the capabil 422 * @ns: The usernamespace we want the capability in
410 * @cap: The capability to be tested for 423 * @cap: The capability to be tested for
411 * 424 *
412 * Return true if the current task has the giv 425 * Return true if the current task has the given superior capability currently
413 * available for use, false if not. 426 * available for use, false if not.
414 * 427 *
415 * This sets PF_SUPERPRIV on the task if the c 428 * This sets PF_SUPERPRIV on the task if the capability is available on the
416 * assumption that it's about to be used. 429 * assumption that it's about to be used.
417 */ 430 */
418 bool ns_capable_setid(struct user_namespace *n 431 bool ns_capable_setid(struct user_namespace *ns, int cap)
419 { 432 {
420 return ns_capable_common(ns, cap, CAP_ 433 return ns_capable_common(ns, cap, CAP_OPT_INSETID);
421 } 434 }
422 EXPORT_SYMBOL(ns_capable_setid); 435 EXPORT_SYMBOL(ns_capable_setid);
423 436
424 /** 437 /**
425 * capable - Determine if the current task has 438 * capable - Determine if the current task has a superior capability in effect
426 * @cap: The capability to be tested for 439 * @cap: The capability to be tested for
427 * 440 *
428 * Return true if the current task has the giv 441 * Return true if the current task has the given superior capability currently
429 * available for use, false if not. 442 * available for use, false if not.
430 * 443 *
431 * This sets PF_SUPERPRIV on the task if the c 444 * This sets PF_SUPERPRIV on the task if the capability is available on the
432 * assumption that it's about to be used. 445 * assumption that it's about to be used.
433 */ 446 */
434 bool capable(int cap) 447 bool capable(int cap)
435 { 448 {
436 return ns_capable(&init_user_ns, cap); 449 return ns_capable(&init_user_ns, cap);
437 } 450 }
438 EXPORT_SYMBOL(capable); 451 EXPORT_SYMBOL(capable);
439 #endif /* CONFIG_MULTIUSER */ 452 #endif /* CONFIG_MULTIUSER */
440 453
441 /** 454 /**
442 * file_ns_capable - Determine if the file's o 455 * file_ns_capable - Determine if the file's opener had a capability in effect
443 * @file: The file we want to check 456 * @file: The file we want to check
444 * @ns: The usernamespace we want the capabil 457 * @ns: The usernamespace we want the capability in
445 * @cap: The capability to be tested for 458 * @cap: The capability to be tested for
446 * 459 *
447 * Return true if task that opened the file ha 460 * Return true if task that opened the file had a capability in effect
448 * when the file was opened. 461 * when the file was opened.
449 * 462 *
450 * This does not set PF_SUPERPRIV because the 463 * This does not set PF_SUPERPRIV because the caller may not
451 * actually be privileged. 464 * actually be privileged.
452 */ 465 */
453 bool file_ns_capable(const struct file *file, 466 bool file_ns_capable(const struct file *file, struct user_namespace *ns,
454 int cap) 467 int cap)
455 { 468 {
456 469
457 if (WARN_ON_ONCE(!cap_valid(cap))) 470 if (WARN_ON_ONCE(!cap_valid(cap)))
458 return false; 471 return false;
459 472
460 if (security_capable(file->f_cred, ns, 473 if (security_capable(file->f_cred, ns, cap, CAP_OPT_NONE) == 0)
461 return true; 474 return true;
462 475
463 return false; 476 return false;
464 } 477 }
465 EXPORT_SYMBOL(file_ns_capable); 478 EXPORT_SYMBOL(file_ns_capable);
466 479
467 /** 480 /**
468 * privileged_wrt_inode_uidgid - Do capabiliti 481 * privileged_wrt_inode_uidgid - Do capabilities in the namespace work over the inode?
469 * @ns: The user namespace in question 482 * @ns: The user namespace in question
470 * @idmap: idmap of the mount @inode was found <<
471 * @inode: The inode in question 483 * @inode: The inode in question
472 * 484 *
473 * Return true if the inode uid and gid are wi 485 * Return true if the inode uid and gid are within the namespace.
474 */ 486 */
475 bool privileged_wrt_inode_uidgid(struct user_n !! 487 bool privileged_wrt_inode_uidgid(struct user_namespace *ns, const struct inode *inode)
476 struct mnt_id <<
477 const struct <<
478 { 488 {
479 return vfsuid_has_mapping(ns, i_uid_in !! 489 return kuid_has_mapping(ns, inode->i_uid) &&
480 vfsgid_has_mapping(ns, i_gid_in !! 490 kgid_has_mapping(ns, inode->i_gid);
481 } 491 }
482 492
483 /** 493 /**
484 * capable_wrt_inode_uidgid - Check nsown_capa 494 * capable_wrt_inode_uidgid - Check nsown_capable and uid and gid mapped
485 * @idmap: idmap of the mount @inode was found <<
486 * @inode: The inode in question 495 * @inode: The inode in question
487 * @cap: The capability in question 496 * @cap: The capability in question
488 * 497 *
489 * Return true if the current task has the giv 498 * Return true if the current task has the given capability targeted at
490 * its own user namespace and that the given i 499 * its own user namespace and that the given inode's uid and gid are
491 * mapped into the current user namespace. 500 * mapped into the current user namespace.
492 */ 501 */
493 bool capable_wrt_inode_uidgid(struct mnt_idmap !! 502 bool capable_wrt_inode_uidgid(const struct inode *inode, int cap)
494 const struct ino <<
495 { 503 {
496 struct user_namespace *ns = current_us 504 struct user_namespace *ns = current_user_ns();
497 505
498 return ns_capable(ns, cap) && !! 506 return ns_capable(ns, cap) && privileged_wrt_inode_uidgid(ns, inode);
499 privileged_wrt_inode_uidgid(ns, <<
500 } 507 }
501 EXPORT_SYMBOL(capable_wrt_inode_uidgid); 508 EXPORT_SYMBOL(capable_wrt_inode_uidgid);
502 509
503 /** 510 /**
504 * ptracer_capable - Determine if the ptracer 511 * ptracer_capable - Determine if the ptracer holds CAP_SYS_PTRACE in the namespace
505 * @tsk: The task that may be ptraced 512 * @tsk: The task that may be ptraced
506 * @ns: The user namespace to search for CAP_S 513 * @ns: The user namespace to search for CAP_SYS_PTRACE in
507 * 514 *
508 * Return true if the task that is ptracing th 515 * Return true if the task that is ptracing the current task had CAP_SYS_PTRACE
509 * in the specified user namespace. 516 * in the specified user namespace.
510 */ 517 */
511 bool ptracer_capable(struct task_struct *tsk, 518 bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns)
512 { 519 {
513 int ret = 0; /* An absent tracer adds 520 int ret = 0; /* An absent tracer adds no restrictions */
514 const struct cred *cred; 521 const struct cred *cred;
515 522
516 rcu_read_lock(); 523 rcu_read_lock();
517 cred = rcu_dereference(tsk->ptracer_cr 524 cred = rcu_dereference(tsk->ptracer_cred);
518 if (cred) 525 if (cred)
519 ret = security_capable(cred, n 526 ret = security_capable(cred, ns, CAP_SYS_PTRACE,
520 CAP_OPT 527 CAP_OPT_NOAUDIT);
521 rcu_read_unlock(); 528 rcu_read_unlock();
522 return (ret == 0); 529 return (ret == 0);
523 } 530 }
524 531
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