xref: /openbmc/linux/security/smack/smack_lsm.c (revision 99b7e93c)
1 /*
2  *  Simplified MAC Kernel (smack) security module
3  *
4  *  This file contains the smack hook function implementations.
5  *
6  *  Authors:
7  *	Casey Schaufler <casey@schaufler-ca.com>
8  *	Jarkko Sakkinen <jarkko.sakkinen@intel.com>
9  *
10  *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
11  *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
12  *                Paul Moore <paul@paul-moore.com>
13  *  Copyright (C) 2010 Nokia Corporation
14  *  Copyright (C) 2011 Intel Corporation.
15  *
16  *	This program is free software; you can redistribute it and/or modify
17  *	it under the terms of the GNU General Public License version 2,
18  *      as published by the Free Software Foundation.
19  */
20 
21 #include <linux/xattr.h>
22 #include <linux/pagemap.h>
23 #include <linux/mount.h>
24 #include <linux/stat.h>
25 #include <linux/kd.h>
26 #include <asm/ioctls.h>
27 #include <linux/ip.h>
28 #include <linux/tcp.h>
29 #include <linux/udp.h>
30 #include <linux/dccp.h>
31 #include <linux/slab.h>
32 #include <linux/mutex.h>
33 #include <linux/pipe_fs_i.h>
34 #include <net/cipso_ipv4.h>
35 #include <net/ip.h>
36 #include <net/ipv6.h>
37 #include <linux/audit.h>
38 #include <linux/magic.h>
39 #include <linux/dcache.h>
40 #include <linux/personality.h>
41 #include <linux/msg.h>
42 #include <linux/shm.h>
43 #include <linux/binfmts.h>
44 #include "smack.h"
45 
46 #define TRANS_TRUE	"TRUE"
47 #define TRANS_TRUE_SIZE	4
48 
49 #define SMK_CONNECTING	0
50 #define SMK_RECEIVING	1
51 #define SMK_SENDING	2
52 
53 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
54 LIST_HEAD(smk_ipv6_port_list);
55 #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
56 static struct kmem_cache *smack_inode_cache;
57 int smack_enabled;
58 
59 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
60 static char *smk_bu_mess[] = {
61 	"Bringup Error",	/* Unused */
62 	"Bringup",		/* SMACK_BRINGUP_ALLOW */
63 	"Unconfined Subject",	/* SMACK_UNCONFINED_SUBJECT */
64 	"Unconfined Object",	/* SMACK_UNCONFINED_OBJECT */
65 };
66 
67 static void smk_bu_mode(int mode, char *s)
68 {
69 	int i = 0;
70 
71 	if (mode & MAY_READ)
72 		s[i++] = 'r';
73 	if (mode & MAY_WRITE)
74 		s[i++] = 'w';
75 	if (mode & MAY_EXEC)
76 		s[i++] = 'x';
77 	if (mode & MAY_APPEND)
78 		s[i++] = 'a';
79 	if (mode & MAY_TRANSMUTE)
80 		s[i++] = 't';
81 	if (mode & MAY_LOCK)
82 		s[i++] = 'l';
83 	if (i == 0)
84 		s[i++] = '-';
85 	s[i] = '\0';
86 }
87 #endif
88 
89 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
90 static int smk_bu_note(char *note, struct smack_known *sskp,
91 		       struct smack_known *oskp, int mode, int rc)
92 {
93 	char acc[SMK_NUM_ACCESS_TYPE + 1];
94 
95 	if (rc <= 0)
96 		return rc;
97 	if (rc > SMACK_UNCONFINED_OBJECT)
98 		rc = 0;
99 
100 	smk_bu_mode(mode, acc);
101 	pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
102 		sskp->smk_known, oskp->smk_known, acc, note);
103 	return 0;
104 }
105 #else
106 #define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
107 #endif
108 
109 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
110 static int smk_bu_current(char *note, struct smack_known *oskp,
111 			  int mode, int rc)
112 {
113 	struct task_smack *tsp = current_security();
114 	char acc[SMK_NUM_ACCESS_TYPE + 1];
115 
116 	if (rc <= 0)
117 		return rc;
118 	if (rc > SMACK_UNCONFINED_OBJECT)
119 		rc = 0;
120 
121 	smk_bu_mode(mode, acc);
122 	pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
123 		tsp->smk_task->smk_known, oskp->smk_known,
124 		acc, current->comm, note);
125 	return 0;
126 }
127 #else
128 #define smk_bu_current(note, oskp, mode, RC) (RC)
129 #endif
130 
131 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
132 static int smk_bu_task(struct task_struct *otp, int mode, int rc)
133 {
134 	struct task_smack *tsp = current_security();
135 	struct smack_known *smk_task = smk_of_task_struct(otp);
136 	char acc[SMK_NUM_ACCESS_TYPE + 1];
137 
138 	if (rc <= 0)
139 		return rc;
140 	if (rc > SMACK_UNCONFINED_OBJECT)
141 		rc = 0;
142 
143 	smk_bu_mode(mode, acc);
144 	pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
145 		tsp->smk_task->smk_known, smk_task->smk_known, acc,
146 		current->comm, otp->comm);
147 	return 0;
148 }
149 #else
150 #define smk_bu_task(otp, mode, RC) (RC)
151 #endif
152 
153 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
154 static int smk_bu_inode(struct inode *inode, int mode, int rc)
155 {
156 	struct task_smack *tsp = current_security();
157 	struct inode_smack *isp = inode->i_security;
158 	char acc[SMK_NUM_ACCESS_TYPE + 1];
159 
160 	if (isp->smk_flags & SMK_INODE_IMPURE)
161 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
162 			inode->i_sb->s_id, inode->i_ino, current->comm);
163 
164 	if (rc <= 0)
165 		return rc;
166 	if (rc > SMACK_UNCONFINED_OBJECT)
167 		rc = 0;
168 	if (rc == SMACK_UNCONFINED_SUBJECT &&
169 	    (mode & (MAY_WRITE | MAY_APPEND)))
170 		isp->smk_flags |= SMK_INODE_IMPURE;
171 
172 	smk_bu_mode(mode, acc);
173 
174 	pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
175 		tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
176 		inode->i_sb->s_id, inode->i_ino, current->comm);
177 	return 0;
178 }
179 #else
180 #define smk_bu_inode(inode, mode, RC) (RC)
181 #endif
182 
183 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
184 static int smk_bu_file(struct file *file, int mode, int rc)
185 {
186 	struct task_smack *tsp = current_security();
187 	struct smack_known *sskp = tsp->smk_task;
188 	struct inode *inode = file_inode(file);
189 	struct inode_smack *isp = inode->i_security;
190 	char acc[SMK_NUM_ACCESS_TYPE + 1];
191 
192 	if (isp->smk_flags & SMK_INODE_IMPURE)
193 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
194 			inode->i_sb->s_id, inode->i_ino, current->comm);
195 
196 	if (rc <= 0)
197 		return rc;
198 	if (rc > SMACK_UNCONFINED_OBJECT)
199 		rc = 0;
200 
201 	smk_bu_mode(mode, acc);
202 	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
203 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
204 		inode->i_sb->s_id, inode->i_ino, file,
205 		current->comm);
206 	return 0;
207 }
208 #else
209 #define smk_bu_file(file, mode, RC) (RC)
210 #endif
211 
212 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
213 static int smk_bu_credfile(const struct cred *cred, struct file *file,
214 				int mode, int rc)
215 {
216 	struct task_smack *tsp = cred->security;
217 	struct smack_known *sskp = tsp->smk_task;
218 	struct inode *inode = file->f_inode;
219 	struct inode_smack *isp = inode->i_security;
220 	char acc[SMK_NUM_ACCESS_TYPE + 1];
221 
222 	if (isp->smk_flags & SMK_INODE_IMPURE)
223 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
224 			inode->i_sb->s_id, inode->i_ino, current->comm);
225 
226 	if (rc <= 0)
227 		return rc;
228 	if (rc > SMACK_UNCONFINED_OBJECT)
229 		rc = 0;
230 
231 	smk_bu_mode(mode, acc);
232 	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
233 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
234 		inode->i_sb->s_id, inode->i_ino, file,
235 		current->comm);
236 	return 0;
237 }
238 #else
239 #define smk_bu_credfile(cred, file, mode, RC) (RC)
240 #endif
241 
242 /**
243  * smk_fetch - Fetch the smack label from a file.
244  * @name: type of the label (attribute)
245  * @ip: a pointer to the inode
246  * @dp: a pointer to the dentry
247  *
248  * Returns a pointer to the master list entry for the Smack label
249  * or NULL if there was no label to fetch.
250  */
251 static struct smack_known *smk_fetch(const char *name, struct inode *ip,
252 					struct dentry *dp)
253 {
254 	int rc;
255 	char *buffer;
256 	struct smack_known *skp = NULL;
257 
258 	if (ip->i_op->getxattr == NULL)
259 		return NULL;
260 
261 	buffer = kzalloc(SMK_LONGLABEL, GFP_KERNEL);
262 	if (buffer == NULL)
263 		return NULL;
264 
265 	rc = ip->i_op->getxattr(dp, name, buffer, SMK_LONGLABEL);
266 	if (rc > 0)
267 		skp = smk_import_entry(buffer, rc);
268 
269 	kfree(buffer);
270 
271 	return skp;
272 }
273 
274 /**
275  * new_inode_smack - allocate an inode security blob
276  * @skp: a pointer to the Smack label entry to use in the blob
277  *
278  * Returns the new blob or NULL if there's no memory available
279  */
280 struct inode_smack *new_inode_smack(struct smack_known *skp)
281 {
282 	struct inode_smack *isp;
283 
284 	isp = kmem_cache_zalloc(smack_inode_cache, GFP_NOFS);
285 	if (isp == NULL)
286 		return NULL;
287 
288 	isp->smk_inode = skp;
289 	isp->smk_flags = 0;
290 	mutex_init(&isp->smk_lock);
291 
292 	return isp;
293 }
294 
295 /**
296  * new_task_smack - allocate a task security blob
297  * @task: a pointer to the Smack label for the running task
298  * @forked: a pointer to the Smack label for the forked task
299  * @gfp: type of the memory for the allocation
300  *
301  * Returns the new blob or NULL if there's no memory available
302  */
303 static struct task_smack *new_task_smack(struct smack_known *task,
304 					struct smack_known *forked, gfp_t gfp)
305 {
306 	struct task_smack *tsp;
307 
308 	tsp = kzalloc(sizeof(struct task_smack), gfp);
309 	if (tsp == NULL)
310 		return NULL;
311 
312 	tsp->smk_task = task;
313 	tsp->smk_forked = forked;
314 	INIT_LIST_HEAD(&tsp->smk_rules);
315 	mutex_init(&tsp->smk_rules_lock);
316 
317 	return tsp;
318 }
319 
320 /**
321  * smk_copy_rules - copy a rule set
322  * @nhead: new rules header pointer
323  * @ohead: old rules header pointer
324  * @gfp: type of the memory for the allocation
325  *
326  * Returns 0 on success, -ENOMEM on error
327  */
328 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
329 				gfp_t gfp)
330 {
331 	struct smack_rule *nrp;
332 	struct smack_rule *orp;
333 	int rc = 0;
334 
335 	INIT_LIST_HEAD(nhead);
336 
337 	list_for_each_entry_rcu(orp, ohead, list) {
338 		nrp = kzalloc(sizeof(struct smack_rule), gfp);
339 		if (nrp == NULL) {
340 			rc = -ENOMEM;
341 			break;
342 		}
343 		*nrp = *orp;
344 		list_add_rcu(&nrp->list, nhead);
345 	}
346 	return rc;
347 }
348 
349 /**
350  * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
351  * @mode - input mode in form of PTRACE_MODE_*
352  *
353  * Returns a converted MAY_* mode usable by smack rules
354  */
355 static inline unsigned int smk_ptrace_mode(unsigned int mode)
356 {
357 	switch (mode) {
358 	case PTRACE_MODE_READ:
359 		return MAY_READ;
360 	case PTRACE_MODE_ATTACH:
361 		return MAY_READWRITE;
362 	}
363 
364 	return 0;
365 }
366 
367 /**
368  * smk_ptrace_rule_check - helper for ptrace access
369  * @tracer: tracer process
370  * @tracee_known: label entry of the process that's about to be traced
371  * @mode: ptrace attachment mode (PTRACE_MODE_*)
372  * @func: name of the function that called us, used for audit
373  *
374  * Returns 0 on access granted, -error on error
375  */
376 static int smk_ptrace_rule_check(struct task_struct *tracer,
377 				 struct smack_known *tracee_known,
378 				 unsigned int mode, const char *func)
379 {
380 	int rc;
381 	struct smk_audit_info ad, *saip = NULL;
382 	struct task_smack *tsp;
383 	struct smack_known *tracer_known;
384 
385 	if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
386 		smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
387 		smk_ad_setfield_u_tsk(&ad, tracer);
388 		saip = &ad;
389 	}
390 
391 	rcu_read_lock();
392 	tsp = __task_cred(tracer)->security;
393 	tracer_known = smk_of_task(tsp);
394 
395 	if ((mode & PTRACE_MODE_ATTACH) &&
396 	    (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
397 	     smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
398 		if (tracer_known->smk_known == tracee_known->smk_known)
399 			rc = 0;
400 		else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
401 			rc = -EACCES;
402 		else if (capable(CAP_SYS_PTRACE))
403 			rc = 0;
404 		else
405 			rc = -EACCES;
406 
407 		if (saip)
408 			smack_log(tracer_known->smk_known,
409 				  tracee_known->smk_known,
410 				  0, rc, saip);
411 
412 		rcu_read_unlock();
413 		return rc;
414 	}
415 
416 	/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
417 	rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
418 
419 	rcu_read_unlock();
420 	return rc;
421 }
422 
423 /*
424  * LSM hooks.
425  * We he, that is fun!
426  */
427 
428 /**
429  * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
430  * @ctp: child task pointer
431  * @mode: ptrace attachment mode (PTRACE_MODE_*)
432  *
433  * Returns 0 if access is OK, an error code otherwise
434  *
435  * Do the capability checks.
436  */
437 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
438 {
439 	int rc;
440 	struct smack_known *skp;
441 
442 	rc = cap_ptrace_access_check(ctp, mode);
443 	if (rc != 0)
444 		return rc;
445 
446 	skp = smk_of_task_struct(ctp);
447 
448 	rc = smk_ptrace_rule_check(current, skp, mode, __func__);
449 	return rc;
450 }
451 
452 /**
453  * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
454  * @ptp: parent task pointer
455  *
456  * Returns 0 if access is OK, an error code otherwise
457  *
458  * Do the capability checks, and require PTRACE_MODE_ATTACH.
459  */
460 static int smack_ptrace_traceme(struct task_struct *ptp)
461 {
462 	int rc;
463 	struct smack_known *skp;
464 
465 	rc = cap_ptrace_traceme(ptp);
466 	if (rc != 0)
467 		return rc;
468 
469 	skp = smk_of_task(current_security());
470 
471 	rc = smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
472 	return rc;
473 }
474 
475 /**
476  * smack_syslog - Smack approval on syslog
477  * @type: message type
478  *
479  * Returns 0 on success, error code otherwise.
480  */
481 static int smack_syslog(int typefrom_file)
482 {
483 	int rc = 0;
484 	struct smack_known *skp = smk_of_current();
485 
486 	if (smack_privileged(CAP_MAC_OVERRIDE))
487 		return 0;
488 
489 	if (smack_syslog_label != NULL && smack_syslog_label != skp)
490 		rc = -EACCES;
491 
492 	return rc;
493 }
494 
495 
496 /*
497  * Superblock Hooks.
498  */
499 
500 /**
501  * smack_sb_alloc_security - allocate a superblock blob
502  * @sb: the superblock getting the blob
503  *
504  * Returns 0 on success or -ENOMEM on error.
505  */
506 static int smack_sb_alloc_security(struct super_block *sb)
507 {
508 	struct superblock_smack *sbsp;
509 
510 	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
511 
512 	if (sbsp == NULL)
513 		return -ENOMEM;
514 
515 	sbsp->smk_root = &smack_known_floor;
516 	sbsp->smk_default = &smack_known_floor;
517 	sbsp->smk_floor = &smack_known_floor;
518 	sbsp->smk_hat = &smack_known_hat;
519 	/*
520 	 * smk_initialized will be zero from kzalloc.
521 	 */
522 	sb->s_security = sbsp;
523 
524 	return 0;
525 }
526 
527 /**
528  * smack_sb_free_security - free a superblock blob
529  * @sb: the superblock getting the blob
530  *
531  */
532 static void smack_sb_free_security(struct super_block *sb)
533 {
534 	kfree(sb->s_security);
535 	sb->s_security = NULL;
536 }
537 
538 /**
539  * smack_sb_copy_data - copy mount options data for processing
540  * @orig: where to start
541  * @smackopts: mount options string
542  *
543  * Returns 0 on success or -ENOMEM on error.
544  *
545  * Copy the Smack specific mount options out of the mount
546  * options list.
547  */
548 static int smack_sb_copy_data(char *orig, char *smackopts)
549 {
550 	char *cp, *commap, *otheropts, *dp;
551 
552 	otheropts = (char *)get_zeroed_page(GFP_KERNEL);
553 	if (otheropts == NULL)
554 		return -ENOMEM;
555 
556 	for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
557 		if (strstr(cp, SMK_FSDEFAULT) == cp)
558 			dp = smackopts;
559 		else if (strstr(cp, SMK_FSFLOOR) == cp)
560 			dp = smackopts;
561 		else if (strstr(cp, SMK_FSHAT) == cp)
562 			dp = smackopts;
563 		else if (strstr(cp, SMK_FSROOT) == cp)
564 			dp = smackopts;
565 		else if (strstr(cp, SMK_FSTRANS) == cp)
566 			dp = smackopts;
567 		else
568 			dp = otheropts;
569 
570 		commap = strchr(cp, ',');
571 		if (commap != NULL)
572 			*commap = '\0';
573 
574 		if (*dp != '\0')
575 			strcat(dp, ",");
576 		strcat(dp, cp);
577 	}
578 
579 	strcpy(orig, otheropts);
580 	free_page((unsigned long)otheropts);
581 
582 	return 0;
583 }
584 
585 /**
586  * smack_sb_kern_mount - Smack specific mount processing
587  * @sb: the file system superblock
588  * @flags: the mount flags
589  * @data: the smack mount options
590  *
591  * Returns 0 on success, an error code on failure
592  */
593 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
594 {
595 	struct dentry *root = sb->s_root;
596 	struct inode *inode = d_backing_inode(root);
597 	struct superblock_smack *sp = sb->s_security;
598 	struct inode_smack *isp;
599 	struct smack_known *skp;
600 	char *op;
601 	char *commap;
602 	int transmute = 0;
603 	int specified = 0;
604 
605 	if (sp->smk_initialized)
606 		return 0;
607 
608 	sp->smk_initialized = 1;
609 
610 	for (op = data; op != NULL; op = commap) {
611 		commap = strchr(op, ',');
612 		if (commap != NULL)
613 			*commap++ = '\0';
614 
615 		if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
616 			op += strlen(SMK_FSHAT);
617 			skp = smk_import_entry(op, 0);
618 			if (skp != NULL) {
619 				sp->smk_hat = skp;
620 				specified = 1;
621 			}
622 		} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
623 			op += strlen(SMK_FSFLOOR);
624 			skp = smk_import_entry(op, 0);
625 			if (skp != NULL) {
626 				sp->smk_floor = skp;
627 				specified = 1;
628 			}
629 		} else if (strncmp(op, SMK_FSDEFAULT,
630 				   strlen(SMK_FSDEFAULT)) == 0) {
631 			op += strlen(SMK_FSDEFAULT);
632 			skp = smk_import_entry(op, 0);
633 			if (skp != NULL) {
634 				sp->smk_default = skp;
635 				specified = 1;
636 			}
637 		} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
638 			op += strlen(SMK_FSROOT);
639 			skp = smk_import_entry(op, 0);
640 			if (skp != NULL) {
641 				sp->smk_root = skp;
642 				specified = 1;
643 			}
644 		} else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
645 			op += strlen(SMK_FSTRANS);
646 			skp = smk_import_entry(op, 0);
647 			if (skp != NULL) {
648 				sp->smk_root = skp;
649 				transmute = 1;
650 				specified = 1;
651 			}
652 		}
653 	}
654 
655 	if (!smack_privileged(CAP_MAC_ADMIN)) {
656 		/*
657 		 * Unprivileged mounts don't get to specify Smack values.
658 		 */
659 		if (specified)
660 			return -EPERM;
661 		/*
662 		 * Unprivileged mounts get root and default from the caller.
663 		 */
664 		skp = smk_of_current();
665 		sp->smk_root = skp;
666 		sp->smk_default = skp;
667 	}
668 	/*
669 	 * Initialize the root inode.
670 	 */
671 	isp = inode->i_security;
672 	if (isp == NULL) {
673 		isp = new_inode_smack(sp->smk_root);
674 		if (isp == NULL)
675 			return -ENOMEM;
676 		inode->i_security = isp;
677 	} else
678 		isp->smk_inode = sp->smk_root;
679 
680 	if (transmute)
681 		isp->smk_flags |= SMK_INODE_TRANSMUTE;
682 
683 	return 0;
684 }
685 
686 /**
687  * smack_sb_statfs - Smack check on statfs
688  * @dentry: identifies the file system in question
689  *
690  * Returns 0 if current can read the floor of the filesystem,
691  * and error code otherwise
692  */
693 static int smack_sb_statfs(struct dentry *dentry)
694 {
695 	struct superblock_smack *sbp = dentry->d_sb->s_security;
696 	int rc;
697 	struct smk_audit_info ad;
698 
699 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
700 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
701 
702 	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
703 	rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
704 	return rc;
705 }
706 
707 /*
708  * BPRM hooks
709  */
710 
711 /**
712  * smack_bprm_set_creds - set creds for exec
713  * @bprm: the exec information
714  *
715  * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
716  */
717 static int smack_bprm_set_creds(struct linux_binprm *bprm)
718 {
719 	struct inode *inode = file_inode(bprm->file);
720 	struct task_smack *bsp = bprm->cred->security;
721 	struct inode_smack *isp;
722 	int rc;
723 
724 	rc = cap_bprm_set_creds(bprm);
725 	if (rc != 0)
726 		return rc;
727 
728 	if (bprm->cred_prepared)
729 		return 0;
730 
731 	isp = inode->i_security;
732 	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
733 		return 0;
734 
735 	if (bprm->unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
736 		struct task_struct *tracer;
737 		rc = 0;
738 
739 		rcu_read_lock();
740 		tracer = ptrace_parent(current);
741 		if (likely(tracer != NULL))
742 			rc = smk_ptrace_rule_check(tracer,
743 						   isp->smk_task,
744 						   PTRACE_MODE_ATTACH,
745 						   __func__);
746 		rcu_read_unlock();
747 
748 		if (rc != 0)
749 			return rc;
750 	} else if (bprm->unsafe)
751 		return -EPERM;
752 
753 	bsp->smk_task = isp->smk_task;
754 	bprm->per_clear |= PER_CLEAR_ON_SETID;
755 
756 	return 0;
757 }
758 
759 /**
760  * smack_bprm_committing_creds - Prepare to install the new credentials
761  * from bprm.
762  *
763  * @bprm: binprm for exec
764  */
765 static void smack_bprm_committing_creds(struct linux_binprm *bprm)
766 {
767 	struct task_smack *bsp = bprm->cred->security;
768 
769 	if (bsp->smk_task != bsp->smk_forked)
770 		current->pdeath_signal = 0;
771 }
772 
773 /**
774  * smack_bprm_secureexec - Return the decision to use secureexec.
775  * @bprm: binprm for exec
776  *
777  * Returns 0 on success.
778  */
779 static int smack_bprm_secureexec(struct linux_binprm *bprm)
780 {
781 	struct task_smack *tsp = current_security();
782 	int ret = cap_bprm_secureexec(bprm);
783 
784 	if (!ret && (tsp->smk_task != tsp->smk_forked))
785 		ret = 1;
786 
787 	return ret;
788 }
789 
790 /*
791  * Inode hooks
792  */
793 
794 /**
795  * smack_inode_alloc_security - allocate an inode blob
796  * @inode: the inode in need of a blob
797  *
798  * Returns 0 if it gets a blob, -ENOMEM otherwise
799  */
800 static int smack_inode_alloc_security(struct inode *inode)
801 {
802 	struct smack_known *skp = smk_of_current();
803 
804 	inode->i_security = new_inode_smack(skp);
805 	if (inode->i_security == NULL)
806 		return -ENOMEM;
807 	return 0;
808 }
809 
810 /**
811  * smack_inode_free_security - free an inode blob
812  * @inode: the inode with a blob
813  *
814  * Clears the blob pointer in inode
815  */
816 static void smack_inode_free_security(struct inode *inode)
817 {
818 	kmem_cache_free(smack_inode_cache, inode->i_security);
819 	inode->i_security = NULL;
820 }
821 
822 /**
823  * smack_inode_init_security - copy out the smack from an inode
824  * @inode: the newly created inode
825  * @dir: containing directory object
826  * @qstr: unused
827  * @name: where to put the attribute name
828  * @value: where to put the attribute value
829  * @len: where to put the length of the attribute
830  *
831  * Returns 0 if it all works out, -ENOMEM if there's no memory
832  */
833 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
834 				     const struct qstr *qstr, const char **name,
835 				     void **value, size_t *len)
836 {
837 	struct inode_smack *issp = inode->i_security;
838 	struct smack_known *skp = smk_of_current();
839 	struct smack_known *isp = smk_of_inode(inode);
840 	struct smack_known *dsp = smk_of_inode(dir);
841 	int may;
842 
843 	if (name)
844 		*name = XATTR_SMACK_SUFFIX;
845 
846 	if (value && len) {
847 		rcu_read_lock();
848 		may = smk_access_entry(skp->smk_known, dsp->smk_known,
849 				       &skp->smk_rules);
850 		rcu_read_unlock();
851 
852 		/*
853 		 * If the access rule allows transmutation and
854 		 * the directory requests transmutation then
855 		 * by all means transmute.
856 		 * Mark the inode as changed.
857 		 */
858 		if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
859 		    smk_inode_transmutable(dir)) {
860 			isp = dsp;
861 			issp->smk_flags |= SMK_INODE_CHANGED;
862 		}
863 
864 		*value = kstrdup(isp->smk_known, GFP_NOFS);
865 		if (*value == NULL)
866 			return -ENOMEM;
867 
868 		*len = strlen(isp->smk_known);
869 	}
870 
871 	return 0;
872 }
873 
874 /**
875  * smack_inode_link - Smack check on link
876  * @old_dentry: the existing object
877  * @dir: unused
878  * @new_dentry: the new object
879  *
880  * Returns 0 if access is permitted, an error code otherwise
881  */
882 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
883 			    struct dentry *new_dentry)
884 {
885 	struct smack_known *isp;
886 	struct smk_audit_info ad;
887 	int rc;
888 
889 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
890 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
891 
892 	isp = smk_of_inode(d_backing_inode(old_dentry));
893 	rc = smk_curacc(isp, MAY_WRITE, &ad);
894 	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
895 
896 	if (rc == 0 && d_is_positive(new_dentry)) {
897 		isp = smk_of_inode(d_backing_inode(new_dentry));
898 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
899 		rc = smk_curacc(isp, MAY_WRITE, &ad);
900 		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
901 	}
902 
903 	return rc;
904 }
905 
906 /**
907  * smack_inode_unlink - Smack check on inode deletion
908  * @dir: containing directory object
909  * @dentry: file to unlink
910  *
911  * Returns 0 if current can write the containing directory
912  * and the object, error code otherwise
913  */
914 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
915 {
916 	struct inode *ip = d_backing_inode(dentry);
917 	struct smk_audit_info ad;
918 	int rc;
919 
920 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
921 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
922 
923 	/*
924 	 * You need write access to the thing you're unlinking
925 	 */
926 	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
927 	rc = smk_bu_inode(ip, MAY_WRITE, rc);
928 	if (rc == 0) {
929 		/*
930 		 * You also need write access to the containing directory
931 		 */
932 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
933 		smk_ad_setfield_u_fs_inode(&ad, dir);
934 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
935 		rc = smk_bu_inode(dir, MAY_WRITE, rc);
936 	}
937 	return rc;
938 }
939 
940 /**
941  * smack_inode_rmdir - Smack check on directory deletion
942  * @dir: containing directory object
943  * @dentry: directory to unlink
944  *
945  * Returns 0 if current can write the containing directory
946  * and the directory, error code otherwise
947  */
948 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
949 {
950 	struct smk_audit_info ad;
951 	int rc;
952 
953 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
954 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
955 
956 	/*
957 	 * You need write access to the thing you're removing
958 	 */
959 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
960 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
961 	if (rc == 0) {
962 		/*
963 		 * You also need write access to the containing directory
964 		 */
965 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
966 		smk_ad_setfield_u_fs_inode(&ad, dir);
967 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
968 		rc = smk_bu_inode(dir, MAY_WRITE, rc);
969 	}
970 
971 	return rc;
972 }
973 
974 /**
975  * smack_inode_rename - Smack check on rename
976  * @old_inode: unused
977  * @old_dentry: the old object
978  * @new_inode: unused
979  * @new_dentry: the new object
980  *
981  * Read and write access is required on both the old and
982  * new directories.
983  *
984  * Returns 0 if access is permitted, an error code otherwise
985  */
986 static int smack_inode_rename(struct inode *old_inode,
987 			      struct dentry *old_dentry,
988 			      struct inode *new_inode,
989 			      struct dentry *new_dentry)
990 {
991 	int rc;
992 	struct smack_known *isp;
993 	struct smk_audit_info ad;
994 
995 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
996 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
997 
998 	isp = smk_of_inode(d_backing_inode(old_dentry));
999 	rc = smk_curacc(isp, MAY_READWRITE, &ad);
1000 	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
1001 
1002 	if (rc == 0 && d_is_positive(new_dentry)) {
1003 		isp = smk_of_inode(d_backing_inode(new_dentry));
1004 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1005 		rc = smk_curacc(isp, MAY_READWRITE, &ad);
1006 		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
1007 	}
1008 	return rc;
1009 }
1010 
1011 /**
1012  * smack_inode_permission - Smack version of permission()
1013  * @inode: the inode in question
1014  * @mask: the access requested
1015  *
1016  * This is the important Smack hook.
1017  *
1018  * Returns 0 if access is permitted, -EACCES otherwise
1019  */
1020 static int smack_inode_permission(struct inode *inode, int mask)
1021 {
1022 	struct smk_audit_info ad;
1023 	int no_block = mask & MAY_NOT_BLOCK;
1024 	int rc;
1025 
1026 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
1027 	/*
1028 	 * No permission to check. Existence test. Yup, it's there.
1029 	 */
1030 	if (mask == 0)
1031 		return 0;
1032 
1033 	/* May be droppable after audit */
1034 	if (no_block)
1035 		return -ECHILD;
1036 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1037 	smk_ad_setfield_u_fs_inode(&ad, inode);
1038 	rc = smk_curacc(smk_of_inode(inode), mask, &ad);
1039 	rc = smk_bu_inode(inode, mask, rc);
1040 	return rc;
1041 }
1042 
1043 /**
1044  * smack_inode_setattr - Smack check for setting attributes
1045  * @dentry: the object
1046  * @iattr: for the force flag
1047  *
1048  * Returns 0 if access is permitted, an error code otherwise
1049  */
1050 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
1051 {
1052 	struct smk_audit_info ad;
1053 	int rc;
1054 
1055 	/*
1056 	 * Need to allow for clearing the setuid bit.
1057 	 */
1058 	if (iattr->ia_valid & ATTR_FORCE)
1059 		return 0;
1060 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1061 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1062 
1063 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1064 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1065 	return rc;
1066 }
1067 
1068 /**
1069  * smack_inode_getattr - Smack check for getting attributes
1070  * @mnt: vfsmount of the object
1071  * @dentry: the object
1072  *
1073  * Returns 0 if access is permitted, an error code otherwise
1074  */
1075 static int smack_inode_getattr(const struct path *path)
1076 {
1077 	struct smk_audit_info ad;
1078 	struct inode *inode = d_backing_inode(path->dentry);
1079 	int rc;
1080 
1081 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1082 	smk_ad_setfield_u_fs_path(&ad, *path);
1083 	rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1084 	rc = smk_bu_inode(inode, MAY_READ, rc);
1085 	return rc;
1086 }
1087 
1088 /**
1089  * smack_inode_setxattr - Smack check for setting xattrs
1090  * @dentry: the object
1091  * @name: name of the attribute
1092  * @value: value of the attribute
1093  * @size: size of the value
1094  * @flags: unused
1095  *
1096  * This protects the Smack attribute explicitly.
1097  *
1098  * Returns 0 if access is permitted, an error code otherwise
1099  */
1100 static int smack_inode_setxattr(struct dentry *dentry, const char *name,
1101 				const void *value, size_t size, int flags)
1102 {
1103 	struct smk_audit_info ad;
1104 	struct smack_known *skp;
1105 	int check_priv = 0;
1106 	int check_import = 0;
1107 	int check_star = 0;
1108 	int rc = 0;
1109 
1110 	/*
1111 	 * Check label validity here so import won't fail in post_setxattr
1112 	 */
1113 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1114 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1115 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
1116 		check_priv = 1;
1117 		check_import = 1;
1118 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1119 		   strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1120 		check_priv = 1;
1121 		check_import = 1;
1122 		check_star = 1;
1123 	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1124 		check_priv = 1;
1125 		if (size != TRANS_TRUE_SIZE ||
1126 		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
1127 			rc = -EINVAL;
1128 	} else
1129 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
1130 
1131 	if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
1132 		rc = -EPERM;
1133 
1134 	if (rc == 0 && check_import) {
1135 		skp = size ? smk_import_entry(value, size) : NULL;
1136 		if (skp == NULL || (check_star &&
1137 		    (skp == &smack_known_star || skp == &smack_known_web)))
1138 			rc = -EINVAL;
1139 	}
1140 
1141 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1142 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1143 
1144 	if (rc == 0) {
1145 		rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1146 		rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1147 	}
1148 
1149 	return rc;
1150 }
1151 
1152 /**
1153  * smack_inode_post_setxattr - Apply the Smack update approved above
1154  * @dentry: object
1155  * @name: attribute name
1156  * @value: attribute value
1157  * @size: attribute size
1158  * @flags: unused
1159  *
1160  * Set the pointer in the inode blob to the entry found
1161  * in the master label list.
1162  */
1163 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
1164 				      const void *value, size_t size, int flags)
1165 {
1166 	struct smack_known *skp;
1167 	struct inode_smack *isp = d_backing_inode(dentry)->i_security;
1168 
1169 	if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1170 		isp->smk_flags |= SMK_INODE_TRANSMUTE;
1171 		return;
1172 	}
1173 
1174 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1175 		skp = smk_import_entry(value, size);
1176 		if (skp != NULL)
1177 			isp->smk_inode = skp;
1178 		else
1179 			isp->smk_inode = &smack_known_invalid;
1180 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1181 		skp = smk_import_entry(value, size);
1182 		if (skp != NULL)
1183 			isp->smk_task = skp;
1184 		else
1185 			isp->smk_task = &smack_known_invalid;
1186 	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1187 		skp = smk_import_entry(value, size);
1188 		if (skp != NULL)
1189 			isp->smk_mmap = skp;
1190 		else
1191 			isp->smk_mmap = &smack_known_invalid;
1192 	}
1193 
1194 	return;
1195 }
1196 
1197 /**
1198  * smack_inode_getxattr - Smack check on getxattr
1199  * @dentry: the object
1200  * @name: unused
1201  *
1202  * Returns 0 if access is permitted, an error code otherwise
1203  */
1204 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1205 {
1206 	struct smk_audit_info ad;
1207 	int rc;
1208 
1209 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1210 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1211 
1212 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1213 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1214 	return rc;
1215 }
1216 
1217 /**
1218  * smack_inode_removexattr - Smack check on removexattr
1219  * @dentry: the object
1220  * @name: name of the attribute
1221  *
1222  * Removing the Smack attribute requires CAP_MAC_ADMIN
1223  *
1224  * Returns 0 if access is permitted, an error code otherwise
1225  */
1226 static int smack_inode_removexattr(struct dentry *dentry, const char *name)
1227 {
1228 	struct inode_smack *isp;
1229 	struct smk_audit_info ad;
1230 	int rc = 0;
1231 
1232 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1233 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1234 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1235 	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1236 	    strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
1237 	    strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1238 		if (!smack_privileged(CAP_MAC_ADMIN))
1239 			rc = -EPERM;
1240 	} else
1241 		rc = cap_inode_removexattr(dentry, name);
1242 
1243 	if (rc != 0)
1244 		return rc;
1245 
1246 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1247 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1248 
1249 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1250 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1251 	if (rc != 0)
1252 		return rc;
1253 
1254 	isp = d_backing_inode(dentry)->i_security;
1255 	/*
1256 	 * Don't do anything special for these.
1257 	 *	XATTR_NAME_SMACKIPIN
1258 	 *	XATTR_NAME_SMACKIPOUT
1259 	 *	XATTR_NAME_SMACKEXEC
1260 	 */
1261 	if (strcmp(name, XATTR_NAME_SMACK) == 0)
1262 		isp->smk_task = NULL;
1263 	else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1264 		isp->smk_mmap = NULL;
1265 	else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
1266 		isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1267 
1268 	return 0;
1269 }
1270 
1271 /**
1272  * smack_inode_getsecurity - get smack xattrs
1273  * @inode: the object
1274  * @name: attribute name
1275  * @buffer: where to put the result
1276  * @alloc: unused
1277  *
1278  * Returns the size of the attribute or an error code
1279  */
1280 static int smack_inode_getsecurity(const struct inode *inode,
1281 				   const char *name, void **buffer,
1282 				   bool alloc)
1283 {
1284 	struct socket_smack *ssp;
1285 	struct socket *sock;
1286 	struct super_block *sbp;
1287 	struct inode *ip = (struct inode *)inode;
1288 	struct smack_known *isp;
1289 	int ilen;
1290 	int rc = 0;
1291 
1292 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1293 		isp = smk_of_inode(inode);
1294 		ilen = strlen(isp->smk_known);
1295 		*buffer = isp->smk_known;
1296 		return ilen;
1297 	}
1298 
1299 	/*
1300 	 * The rest of the Smack xattrs are only on sockets.
1301 	 */
1302 	sbp = ip->i_sb;
1303 	if (sbp->s_magic != SOCKFS_MAGIC)
1304 		return -EOPNOTSUPP;
1305 
1306 	sock = SOCKET_I(ip);
1307 	if (sock == NULL || sock->sk == NULL)
1308 		return -EOPNOTSUPP;
1309 
1310 	ssp = sock->sk->sk_security;
1311 
1312 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1313 		isp = ssp->smk_in;
1314 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1315 		isp = ssp->smk_out;
1316 	else
1317 		return -EOPNOTSUPP;
1318 
1319 	ilen = strlen(isp->smk_known);
1320 	if (rc == 0) {
1321 		*buffer = isp->smk_known;
1322 		rc = ilen;
1323 	}
1324 
1325 	return rc;
1326 }
1327 
1328 
1329 /**
1330  * smack_inode_listsecurity - list the Smack attributes
1331  * @inode: the object
1332  * @buffer: where they go
1333  * @buffer_size: size of buffer
1334  *
1335  * Returns 0 on success, -EINVAL otherwise
1336  */
1337 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1338 				    size_t buffer_size)
1339 {
1340 	int len = sizeof(XATTR_NAME_SMACK);
1341 
1342 	if (buffer != NULL && len <= buffer_size)
1343 		memcpy(buffer, XATTR_NAME_SMACK, len);
1344 
1345 	return len;
1346 }
1347 
1348 /**
1349  * smack_inode_getsecid - Extract inode's security id
1350  * @inode: inode to extract the info from
1351  * @secid: where result will be saved
1352  */
1353 static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
1354 {
1355 	struct inode_smack *isp = inode->i_security;
1356 
1357 	*secid = isp->smk_inode->smk_secid;
1358 }
1359 
1360 /*
1361  * File Hooks
1362  */
1363 
1364 /**
1365  * smack_file_permission - Smack check on file operations
1366  * @file: unused
1367  * @mask: unused
1368  *
1369  * Returns 0
1370  *
1371  * Should access checks be done on each read or write?
1372  * UNICOS and SELinux say yes.
1373  * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1374  *
1375  * I'll say no for now. Smack does not do the frequent
1376  * label changing that SELinux does.
1377  */
1378 static int smack_file_permission(struct file *file, int mask)
1379 {
1380 	return 0;
1381 }
1382 
1383 /**
1384  * smack_file_alloc_security - assign a file security blob
1385  * @file: the object
1386  *
1387  * The security blob for a file is a pointer to the master
1388  * label list, so no allocation is done.
1389  *
1390  * f_security is the owner security information. It
1391  * isn't used on file access checks, it's for send_sigio.
1392  *
1393  * Returns 0
1394  */
1395 static int smack_file_alloc_security(struct file *file)
1396 {
1397 	struct smack_known *skp = smk_of_current();
1398 
1399 	file->f_security = skp;
1400 	return 0;
1401 }
1402 
1403 /**
1404  * smack_file_free_security - clear a file security blob
1405  * @file: the object
1406  *
1407  * The security blob for a file is a pointer to the master
1408  * label list, so no memory is freed.
1409  */
1410 static void smack_file_free_security(struct file *file)
1411 {
1412 	file->f_security = NULL;
1413 }
1414 
1415 /**
1416  * smack_file_ioctl - Smack check on ioctls
1417  * @file: the object
1418  * @cmd: what to do
1419  * @arg: unused
1420  *
1421  * Relies heavily on the correct use of the ioctl command conventions.
1422  *
1423  * Returns 0 if allowed, error code otherwise
1424  */
1425 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1426 			    unsigned long arg)
1427 {
1428 	int rc = 0;
1429 	struct smk_audit_info ad;
1430 	struct inode *inode = file_inode(file);
1431 
1432 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1433 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1434 
1435 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
1436 		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1437 		rc = smk_bu_file(file, MAY_WRITE, rc);
1438 	}
1439 
1440 	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
1441 		rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1442 		rc = smk_bu_file(file, MAY_READ, rc);
1443 	}
1444 
1445 	return rc;
1446 }
1447 
1448 /**
1449  * smack_file_lock - Smack check on file locking
1450  * @file: the object
1451  * @cmd: unused
1452  *
1453  * Returns 0 if current has lock access, error code otherwise
1454  */
1455 static int smack_file_lock(struct file *file, unsigned int cmd)
1456 {
1457 	struct smk_audit_info ad;
1458 	int rc;
1459 	struct inode *inode = file_inode(file);
1460 
1461 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1462 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1463 	rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1464 	rc = smk_bu_file(file, MAY_LOCK, rc);
1465 	return rc;
1466 }
1467 
1468 /**
1469  * smack_file_fcntl - Smack check on fcntl
1470  * @file: the object
1471  * @cmd: what action to check
1472  * @arg: unused
1473  *
1474  * Generally these operations are harmless.
1475  * File locking operations present an obvious mechanism
1476  * for passing information, so they require write access.
1477  *
1478  * Returns 0 if current has access, error code otherwise
1479  */
1480 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1481 			    unsigned long arg)
1482 {
1483 	struct smk_audit_info ad;
1484 	int rc = 0;
1485 	struct inode *inode = file_inode(file);
1486 
1487 	switch (cmd) {
1488 	case F_GETLK:
1489 		break;
1490 	case F_SETLK:
1491 	case F_SETLKW:
1492 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1493 		smk_ad_setfield_u_fs_path(&ad, file->f_path);
1494 		rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1495 		rc = smk_bu_file(file, MAY_LOCK, rc);
1496 		break;
1497 	case F_SETOWN:
1498 	case F_SETSIG:
1499 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1500 		smk_ad_setfield_u_fs_path(&ad, file->f_path);
1501 		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1502 		rc = smk_bu_file(file, MAY_WRITE, rc);
1503 		break;
1504 	default:
1505 		break;
1506 	}
1507 
1508 	return rc;
1509 }
1510 
1511 /**
1512  * smack_mmap_file :
1513  * Check permissions for a mmap operation.  The @file may be NULL, e.g.
1514  * if mapping anonymous memory.
1515  * @file contains the file structure for file to map (may be NULL).
1516  * @reqprot contains the protection requested by the application.
1517  * @prot contains the protection that will be applied by the kernel.
1518  * @flags contains the operational flags.
1519  * Return 0 if permission is granted.
1520  */
1521 static int smack_mmap_file(struct file *file,
1522 			   unsigned long reqprot, unsigned long prot,
1523 			   unsigned long flags)
1524 {
1525 	struct smack_known *skp;
1526 	struct smack_known *mkp;
1527 	struct smack_rule *srp;
1528 	struct task_smack *tsp;
1529 	struct smack_known *okp;
1530 	struct inode_smack *isp;
1531 	int may;
1532 	int mmay;
1533 	int tmay;
1534 	int rc;
1535 
1536 	if (file == NULL)
1537 		return 0;
1538 
1539 	isp = file_inode(file)->i_security;
1540 	if (isp->smk_mmap == NULL)
1541 		return 0;
1542 	mkp = isp->smk_mmap;
1543 
1544 	tsp = current_security();
1545 	skp = smk_of_current();
1546 	rc = 0;
1547 
1548 	rcu_read_lock();
1549 	/*
1550 	 * For each Smack rule associated with the subject
1551 	 * label verify that the SMACK64MMAP also has access
1552 	 * to that rule's object label.
1553 	 */
1554 	list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1555 		okp = srp->smk_object;
1556 		/*
1557 		 * Matching labels always allows access.
1558 		 */
1559 		if (mkp->smk_known == okp->smk_known)
1560 			continue;
1561 		/*
1562 		 * If there is a matching local rule take
1563 		 * that into account as well.
1564 		 */
1565 		may = smk_access_entry(srp->smk_subject->smk_known,
1566 				       okp->smk_known,
1567 				       &tsp->smk_rules);
1568 		if (may == -ENOENT)
1569 			may = srp->smk_access;
1570 		else
1571 			may &= srp->smk_access;
1572 		/*
1573 		 * If may is zero the SMACK64MMAP subject can't
1574 		 * possibly have less access.
1575 		 */
1576 		if (may == 0)
1577 			continue;
1578 
1579 		/*
1580 		 * Fetch the global list entry.
1581 		 * If there isn't one a SMACK64MMAP subject
1582 		 * can't have as much access as current.
1583 		 */
1584 		mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1585 					&mkp->smk_rules);
1586 		if (mmay == -ENOENT) {
1587 			rc = -EACCES;
1588 			break;
1589 		}
1590 		/*
1591 		 * If there is a local entry it modifies the
1592 		 * potential access, too.
1593 		 */
1594 		tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1595 					&tsp->smk_rules);
1596 		if (tmay != -ENOENT)
1597 			mmay &= tmay;
1598 
1599 		/*
1600 		 * If there is any access available to current that is
1601 		 * not available to a SMACK64MMAP subject
1602 		 * deny access.
1603 		 */
1604 		if ((may | mmay) != mmay) {
1605 			rc = -EACCES;
1606 			break;
1607 		}
1608 	}
1609 
1610 	rcu_read_unlock();
1611 
1612 	return rc;
1613 }
1614 
1615 /**
1616  * smack_file_set_fowner - set the file security blob value
1617  * @file: object in question
1618  *
1619  */
1620 static void smack_file_set_fowner(struct file *file)
1621 {
1622 	file->f_security = smk_of_current();
1623 }
1624 
1625 /**
1626  * smack_file_send_sigiotask - Smack on sigio
1627  * @tsk: The target task
1628  * @fown: the object the signal come from
1629  * @signum: unused
1630  *
1631  * Allow a privileged task to get signals even if it shouldn't
1632  *
1633  * Returns 0 if a subject with the object's smack could
1634  * write to the task, an error code otherwise.
1635  */
1636 static int smack_file_send_sigiotask(struct task_struct *tsk,
1637 				     struct fown_struct *fown, int signum)
1638 {
1639 	struct smack_known *skp;
1640 	struct smack_known *tkp = smk_of_task(tsk->cred->security);
1641 	struct file *file;
1642 	int rc;
1643 	struct smk_audit_info ad;
1644 
1645 	/*
1646 	 * struct fown_struct is never outside the context of a struct file
1647 	 */
1648 	file = container_of(fown, struct file, f_owner);
1649 
1650 	/* we don't log here as rc can be overriden */
1651 	skp = file->f_security;
1652 	rc = smk_access(skp, tkp, MAY_WRITE, NULL);
1653 	rc = smk_bu_note("sigiotask", skp, tkp, MAY_WRITE, rc);
1654 	if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1655 		rc = 0;
1656 
1657 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1658 	smk_ad_setfield_u_tsk(&ad, tsk);
1659 	smack_log(skp->smk_known, tkp->smk_known, MAY_WRITE, rc, &ad);
1660 	return rc;
1661 }
1662 
1663 /**
1664  * smack_file_receive - Smack file receive check
1665  * @file: the object
1666  *
1667  * Returns 0 if current has access, error code otherwise
1668  */
1669 static int smack_file_receive(struct file *file)
1670 {
1671 	int rc;
1672 	int may = 0;
1673 	struct smk_audit_info ad;
1674 	struct inode *inode = file_inode(file);
1675 
1676 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1677 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1678 	/*
1679 	 * This code relies on bitmasks.
1680 	 */
1681 	if (file->f_mode & FMODE_READ)
1682 		may = MAY_READ;
1683 	if (file->f_mode & FMODE_WRITE)
1684 		may |= MAY_WRITE;
1685 
1686 	rc = smk_curacc(smk_of_inode(inode), may, &ad);
1687 	rc = smk_bu_file(file, may, rc);
1688 	return rc;
1689 }
1690 
1691 /**
1692  * smack_file_open - Smack dentry open processing
1693  * @file: the object
1694  * @cred: task credential
1695  *
1696  * Set the security blob in the file structure.
1697  * Allow the open only if the task has read access. There are
1698  * many read operations (e.g. fstat) that you can do with an
1699  * fd even if you have the file open write-only.
1700  *
1701  * Returns 0
1702  */
1703 static int smack_file_open(struct file *file, const struct cred *cred)
1704 {
1705 	struct task_smack *tsp = cred->security;
1706 	struct inode *inode = file_inode(file);
1707 	struct smk_audit_info ad;
1708 	int rc;
1709 
1710 	if (smack_privileged(CAP_MAC_OVERRIDE))
1711 		return 0;
1712 
1713 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1714 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1715 	rc = smk_access(tsp->smk_task, smk_of_inode(inode), MAY_READ, &ad);
1716 	rc = smk_bu_credfile(cred, file, MAY_READ, rc);
1717 
1718 	return rc;
1719 }
1720 
1721 /*
1722  * Task hooks
1723  */
1724 
1725 /**
1726  * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1727  * @new: the new credentials
1728  * @gfp: the atomicity of any memory allocations
1729  *
1730  * Prepare a blank set of credentials for modification.  This must allocate all
1731  * the memory the LSM module might require such that cred_transfer() can
1732  * complete without error.
1733  */
1734 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1735 {
1736 	struct task_smack *tsp;
1737 
1738 	tsp = new_task_smack(NULL, NULL, gfp);
1739 	if (tsp == NULL)
1740 		return -ENOMEM;
1741 
1742 	cred->security = tsp;
1743 
1744 	return 0;
1745 }
1746 
1747 
1748 /**
1749  * smack_cred_free - "free" task-level security credentials
1750  * @cred: the credentials in question
1751  *
1752  */
1753 static void smack_cred_free(struct cred *cred)
1754 {
1755 	struct task_smack *tsp = cred->security;
1756 	struct smack_rule *rp;
1757 	struct list_head *l;
1758 	struct list_head *n;
1759 
1760 	if (tsp == NULL)
1761 		return;
1762 	cred->security = NULL;
1763 
1764 	list_for_each_safe(l, n, &tsp->smk_rules) {
1765 		rp = list_entry(l, struct smack_rule, list);
1766 		list_del(&rp->list);
1767 		kfree(rp);
1768 	}
1769 	kfree(tsp);
1770 }
1771 
1772 /**
1773  * smack_cred_prepare - prepare new set of credentials for modification
1774  * @new: the new credentials
1775  * @old: the original credentials
1776  * @gfp: the atomicity of any memory allocations
1777  *
1778  * Prepare a new set of credentials for modification.
1779  */
1780 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1781 			      gfp_t gfp)
1782 {
1783 	struct task_smack *old_tsp = old->security;
1784 	struct task_smack *new_tsp;
1785 	int rc;
1786 
1787 	new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1788 	if (new_tsp == NULL)
1789 		return -ENOMEM;
1790 
1791 	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1792 	if (rc != 0)
1793 		return rc;
1794 
1795 	new->security = new_tsp;
1796 	return 0;
1797 }
1798 
1799 /**
1800  * smack_cred_transfer - Transfer the old credentials to the new credentials
1801  * @new: the new credentials
1802  * @old: the original credentials
1803  *
1804  * Fill in a set of blank credentials from another set of credentials.
1805  */
1806 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1807 {
1808 	struct task_smack *old_tsp = old->security;
1809 	struct task_smack *new_tsp = new->security;
1810 
1811 	new_tsp->smk_task = old_tsp->smk_task;
1812 	new_tsp->smk_forked = old_tsp->smk_task;
1813 	mutex_init(&new_tsp->smk_rules_lock);
1814 	INIT_LIST_HEAD(&new_tsp->smk_rules);
1815 
1816 
1817 	/* cbs copy rule list */
1818 }
1819 
1820 /**
1821  * smack_kernel_act_as - Set the subjective context in a set of credentials
1822  * @new: points to the set of credentials to be modified.
1823  * @secid: specifies the security ID to be set
1824  *
1825  * Set the security data for a kernel service.
1826  */
1827 static int smack_kernel_act_as(struct cred *new, u32 secid)
1828 {
1829 	struct task_smack *new_tsp = new->security;
1830 	struct smack_known *skp = smack_from_secid(secid);
1831 
1832 	if (skp == NULL)
1833 		return -EINVAL;
1834 
1835 	new_tsp->smk_task = skp;
1836 	return 0;
1837 }
1838 
1839 /**
1840  * smack_kernel_create_files_as - Set the file creation label in a set of creds
1841  * @new: points to the set of credentials to be modified
1842  * @inode: points to the inode to use as a reference
1843  *
1844  * Set the file creation context in a set of credentials to the same
1845  * as the objective context of the specified inode
1846  */
1847 static int smack_kernel_create_files_as(struct cred *new,
1848 					struct inode *inode)
1849 {
1850 	struct inode_smack *isp = inode->i_security;
1851 	struct task_smack *tsp = new->security;
1852 
1853 	tsp->smk_forked = isp->smk_inode;
1854 	tsp->smk_task = tsp->smk_forked;
1855 	return 0;
1856 }
1857 
1858 /**
1859  * smk_curacc_on_task - helper to log task related access
1860  * @p: the task object
1861  * @access: the access requested
1862  * @caller: name of the calling function for audit
1863  *
1864  * Return 0 if access is permitted
1865  */
1866 static int smk_curacc_on_task(struct task_struct *p, int access,
1867 				const char *caller)
1868 {
1869 	struct smk_audit_info ad;
1870 	struct smack_known *skp = smk_of_task_struct(p);
1871 	int rc;
1872 
1873 	smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
1874 	smk_ad_setfield_u_tsk(&ad, p);
1875 	rc = smk_curacc(skp, access, &ad);
1876 	rc = smk_bu_task(p, access, rc);
1877 	return rc;
1878 }
1879 
1880 /**
1881  * smack_task_setpgid - Smack check on setting pgid
1882  * @p: the task object
1883  * @pgid: unused
1884  *
1885  * Return 0 if write access is permitted
1886  */
1887 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1888 {
1889 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
1890 }
1891 
1892 /**
1893  * smack_task_getpgid - Smack access check for getpgid
1894  * @p: the object task
1895  *
1896  * Returns 0 if current can read the object task, error code otherwise
1897  */
1898 static int smack_task_getpgid(struct task_struct *p)
1899 {
1900 	return smk_curacc_on_task(p, MAY_READ, __func__);
1901 }
1902 
1903 /**
1904  * smack_task_getsid - Smack access check for getsid
1905  * @p: the object task
1906  *
1907  * Returns 0 if current can read the object task, error code otherwise
1908  */
1909 static int smack_task_getsid(struct task_struct *p)
1910 {
1911 	return smk_curacc_on_task(p, MAY_READ, __func__);
1912 }
1913 
1914 /**
1915  * smack_task_getsecid - get the secid of the task
1916  * @p: the object task
1917  * @secid: where to put the result
1918  *
1919  * Sets the secid to contain a u32 version of the smack label.
1920  */
1921 static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1922 {
1923 	struct smack_known *skp = smk_of_task_struct(p);
1924 
1925 	*secid = skp->smk_secid;
1926 }
1927 
1928 /**
1929  * smack_task_setnice - Smack check on setting nice
1930  * @p: the task object
1931  * @nice: unused
1932  *
1933  * Return 0 if write access is permitted
1934  */
1935 static int smack_task_setnice(struct task_struct *p, int nice)
1936 {
1937 	int rc;
1938 
1939 	rc = cap_task_setnice(p, nice);
1940 	if (rc == 0)
1941 		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1942 	return rc;
1943 }
1944 
1945 /**
1946  * smack_task_setioprio - Smack check on setting ioprio
1947  * @p: the task object
1948  * @ioprio: unused
1949  *
1950  * Return 0 if write access is permitted
1951  */
1952 static int smack_task_setioprio(struct task_struct *p, int ioprio)
1953 {
1954 	int rc;
1955 
1956 	rc = cap_task_setioprio(p, ioprio);
1957 	if (rc == 0)
1958 		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1959 	return rc;
1960 }
1961 
1962 /**
1963  * smack_task_getioprio - Smack check on reading ioprio
1964  * @p: the task object
1965  *
1966  * Return 0 if read access is permitted
1967  */
1968 static int smack_task_getioprio(struct task_struct *p)
1969 {
1970 	return smk_curacc_on_task(p, MAY_READ, __func__);
1971 }
1972 
1973 /**
1974  * smack_task_setscheduler - Smack check on setting scheduler
1975  * @p: the task object
1976  * @policy: unused
1977  * @lp: unused
1978  *
1979  * Return 0 if read access is permitted
1980  */
1981 static int smack_task_setscheduler(struct task_struct *p)
1982 {
1983 	int rc;
1984 
1985 	rc = cap_task_setscheduler(p);
1986 	if (rc == 0)
1987 		rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
1988 	return rc;
1989 }
1990 
1991 /**
1992  * smack_task_getscheduler - Smack check on reading scheduler
1993  * @p: the task object
1994  *
1995  * Return 0 if read access is permitted
1996  */
1997 static int smack_task_getscheduler(struct task_struct *p)
1998 {
1999 	return smk_curacc_on_task(p, MAY_READ, __func__);
2000 }
2001 
2002 /**
2003  * smack_task_movememory - Smack check on moving memory
2004  * @p: the task object
2005  *
2006  * Return 0 if write access is permitted
2007  */
2008 static int smack_task_movememory(struct task_struct *p)
2009 {
2010 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2011 }
2012 
2013 /**
2014  * smack_task_kill - Smack check on signal delivery
2015  * @p: the task object
2016  * @info: unused
2017  * @sig: unused
2018  * @secid: identifies the smack to use in lieu of current's
2019  *
2020  * Return 0 if write access is permitted
2021  *
2022  * The secid behavior is an artifact of an SELinux hack
2023  * in the USB code. Someday it may go away.
2024  */
2025 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
2026 			   int sig, u32 secid)
2027 {
2028 	struct smk_audit_info ad;
2029 	struct smack_known *skp;
2030 	struct smack_known *tkp = smk_of_task_struct(p);
2031 	int rc;
2032 
2033 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
2034 	smk_ad_setfield_u_tsk(&ad, p);
2035 	/*
2036 	 * Sending a signal requires that the sender
2037 	 * can write the receiver.
2038 	 */
2039 	if (secid == 0) {
2040 		rc = smk_curacc(tkp, MAY_WRITE, &ad);
2041 		rc = smk_bu_task(p, MAY_WRITE, rc);
2042 		return rc;
2043 	}
2044 	/*
2045 	 * If the secid isn't 0 we're dealing with some USB IO
2046 	 * specific behavior. This is not clean. For one thing
2047 	 * we can't take privilege into account.
2048 	 */
2049 	skp = smack_from_secid(secid);
2050 	rc = smk_access(skp, tkp, MAY_WRITE, &ad);
2051 	rc = smk_bu_note("USB signal", skp, tkp, MAY_WRITE, rc);
2052 	return rc;
2053 }
2054 
2055 /**
2056  * smack_task_wait - Smack access check for waiting
2057  * @p: task to wait for
2058  *
2059  * Returns 0
2060  */
2061 static int smack_task_wait(struct task_struct *p)
2062 {
2063 	/*
2064 	 * Allow the operation to succeed.
2065 	 * Zombies are bad.
2066 	 * In userless environments (e.g. phones) programs
2067 	 * get marked with SMACK64EXEC and even if the parent
2068 	 * and child shouldn't be talking the parent still
2069 	 * may expect to know when the child exits.
2070 	 */
2071 	return 0;
2072 }
2073 
2074 /**
2075  * smack_task_to_inode - copy task smack into the inode blob
2076  * @p: task to copy from
2077  * @inode: inode to copy to
2078  *
2079  * Sets the smack pointer in the inode security blob
2080  */
2081 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
2082 {
2083 	struct inode_smack *isp = inode->i_security;
2084 	struct smack_known *skp = smk_of_task_struct(p);
2085 
2086 	isp->smk_inode = skp;
2087 }
2088 
2089 /*
2090  * Socket hooks.
2091  */
2092 
2093 /**
2094  * smack_sk_alloc_security - Allocate a socket blob
2095  * @sk: the socket
2096  * @family: unused
2097  * @gfp_flags: memory allocation flags
2098  *
2099  * Assign Smack pointers to current
2100  *
2101  * Returns 0 on success, -ENOMEM is there's no memory
2102  */
2103 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
2104 {
2105 	struct smack_known *skp = smk_of_current();
2106 	struct socket_smack *ssp;
2107 
2108 	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
2109 	if (ssp == NULL)
2110 		return -ENOMEM;
2111 
2112 	ssp->smk_in = skp;
2113 	ssp->smk_out = skp;
2114 	ssp->smk_packet = NULL;
2115 
2116 	sk->sk_security = ssp;
2117 
2118 	return 0;
2119 }
2120 
2121 /**
2122  * smack_sk_free_security - Free a socket blob
2123  * @sk: the socket
2124  *
2125  * Clears the blob pointer
2126  */
2127 static void smack_sk_free_security(struct sock *sk)
2128 {
2129 	kfree(sk->sk_security);
2130 }
2131 
2132 /**
2133 * smack_host_label - check host based restrictions
2134 * @sip: the object end
2135 *
2136 * looks for host based access restrictions
2137 *
2138 * This version will only be appropriate for really small sets of single label
2139 * hosts.  The caller is responsible for ensuring that the RCU read lock is
2140 * taken before calling this function.
2141 *
2142 * Returns the label of the far end or NULL if it's not special.
2143 */
2144 static struct smack_known *smack_host_label(struct sockaddr_in *sip)
2145 {
2146 	struct smk_netlbladdr *snp;
2147 	struct in_addr *siap = &sip->sin_addr;
2148 
2149 	if (siap->s_addr == 0)
2150 		return NULL;
2151 
2152 	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
2153 		/*
2154 		* we break after finding the first match because
2155 		* the list is sorted from longest to shortest mask
2156 		* so we have found the most specific match
2157 		*/
2158 		if ((&snp->smk_host.sin_addr)->s_addr ==
2159 		    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
2160 			/* we have found the special CIPSO option */
2161 			if (snp->smk_label == &smack_cipso_option)
2162 				return NULL;
2163 			return snp->smk_label;
2164 		}
2165 
2166 	return NULL;
2167 }
2168 
2169 /**
2170  * smack_netlabel - Set the secattr on a socket
2171  * @sk: the socket
2172  * @labeled: socket label scheme
2173  *
2174  * Convert the outbound smack value (smk_out) to a
2175  * secattr and attach it to the socket.
2176  *
2177  * Returns 0 on success or an error code
2178  */
2179 static int smack_netlabel(struct sock *sk, int labeled)
2180 {
2181 	struct smack_known *skp;
2182 	struct socket_smack *ssp = sk->sk_security;
2183 	int rc = 0;
2184 
2185 	/*
2186 	 * Usually the netlabel code will handle changing the
2187 	 * packet labeling based on the label.
2188 	 * The case of a single label host is different, because
2189 	 * a single label host should never get a labeled packet
2190 	 * even though the label is usually associated with a packet
2191 	 * label.
2192 	 */
2193 	local_bh_disable();
2194 	bh_lock_sock_nested(sk);
2195 
2196 	if (ssp->smk_out == smack_net_ambient ||
2197 	    labeled == SMACK_UNLABELED_SOCKET)
2198 		netlbl_sock_delattr(sk);
2199 	else {
2200 		skp = ssp->smk_out;
2201 		rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2202 	}
2203 
2204 	bh_unlock_sock(sk);
2205 	local_bh_enable();
2206 
2207 	return rc;
2208 }
2209 
2210 /**
2211  * smack_netlbel_send - Set the secattr on a socket and perform access checks
2212  * @sk: the socket
2213  * @sap: the destination address
2214  *
2215  * Set the correct secattr for the given socket based on the destination
2216  * address and perform any outbound access checks needed.
2217  *
2218  * Returns 0 on success or an error code.
2219  *
2220  */
2221 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
2222 {
2223 	struct smack_known *skp;
2224 	int rc;
2225 	int sk_lbl;
2226 	struct smack_known *hkp;
2227 	struct socket_smack *ssp = sk->sk_security;
2228 	struct smk_audit_info ad;
2229 
2230 	rcu_read_lock();
2231 	hkp = smack_host_label(sap);
2232 	if (hkp != NULL) {
2233 #ifdef CONFIG_AUDIT
2234 		struct lsm_network_audit net;
2235 
2236 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2237 		ad.a.u.net->family = sap->sin_family;
2238 		ad.a.u.net->dport = sap->sin_port;
2239 		ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
2240 #endif
2241 		sk_lbl = SMACK_UNLABELED_SOCKET;
2242 		skp = ssp->smk_out;
2243 		rc = smk_access(skp, hkp, MAY_WRITE, &ad);
2244 		rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2245 	} else {
2246 		sk_lbl = SMACK_CIPSO_SOCKET;
2247 		rc = 0;
2248 	}
2249 	rcu_read_unlock();
2250 	if (rc != 0)
2251 		return rc;
2252 
2253 	return smack_netlabel(sk, sk_lbl);
2254 }
2255 
2256 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2257 /**
2258  * smk_ipv6_port_label - Smack port access table management
2259  * @sock: socket
2260  * @address: address
2261  *
2262  * Create or update the port list entry
2263  */
2264 static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
2265 {
2266 	struct sock *sk = sock->sk;
2267 	struct sockaddr_in6 *addr6;
2268 	struct socket_smack *ssp = sock->sk->sk_security;
2269 	struct smk_port_label *spp;
2270 	unsigned short port = 0;
2271 
2272 	if (address == NULL) {
2273 		/*
2274 		 * This operation is changing the Smack information
2275 		 * on the bound socket. Take the changes to the port
2276 		 * as well.
2277 		 */
2278 		list_for_each_entry(spp, &smk_ipv6_port_list, list) {
2279 			if (sk != spp->smk_sock)
2280 				continue;
2281 			spp->smk_in = ssp->smk_in;
2282 			spp->smk_out = ssp->smk_out;
2283 			return;
2284 		}
2285 		/*
2286 		 * A NULL address is only used for updating existing
2287 		 * bound entries. If there isn't one, it's OK.
2288 		 */
2289 		return;
2290 	}
2291 
2292 	addr6 = (struct sockaddr_in6 *)address;
2293 	port = ntohs(addr6->sin6_port);
2294 	/*
2295 	 * This is a special case that is safely ignored.
2296 	 */
2297 	if (port == 0)
2298 		return;
2299 
2300 	/*
2301 	 * Look for an existing port list entry.
2302 	 * This is an indication that a port is getting reused.
2303 	 */
2304 	list_for_each_entry(spp, &smk_ipv6_port_list, list) {
2305 		if (spp->smk_port != port)
2306 			continue;
2307 		spp->smk_port = port;
2308 		spp->smk_sock = sk;
2309 		spp->smk_in = ssp->smk_in;
2310 		spp->smk_out = ssp->smk_out;
2311 		return;
2312 	}
2313 
2314 	/*
2315 	 * A new port entry is required.
2316 	 */
2317 	spp = kzalloc(sizeof(*spp), GFP_KERNEL);
2318 	if (spp == NULL)
2319 		return;
2320 
2321 	spp->smk_port = port;
2322 	spp->smk_sock = sk;
2323 	spp->smk_in = ssp->smk_in;
2324 	spp->smk_out = ssp->smk_out;
2325 
2326 	list_add(&spp->list, &smk_ipv6_port_list);
2327 	return;
2328 }
2329 
2330 /**
2331  * smk_ipv6_port_check - check Smack port access
2332  * @sock: socket
2333  * @address: address
2334  *
2335  * Create or update the port list entry
2336  */
2337 static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2338 				int act)
2339 {
2340 	__be16 *bep;
2341 	__be32 *be32p;
2342 	struct smk_port_label *spp;
2343 	struct socket_smack *ssp = sk->sk_security;
2344 	struct smack_known *skp;
2345 	unsigned short port = 0;
2346 	struct smack_known *object;
2347 	struct smk_audit_info ad;
2348 	int rc;
2349 #ifdef CONFIG_AUDIT
2350 	struct lsm_network_audit net;
2351 #endif
2352 
2353 	if (act == SMK_RECEIVING) {
2354 		skp = smack_net_ambient;
2355 		object = ssp->smk_in;
2356 	} else {
2357 		skp = ssp->smk_out;
2358 		object = smack_net_ambient;
2359 	}
2360 
2361 	/*
2362 	 * Get the IP address and port from the address.
2363 	 */
2364 	port = ntohs(address->sin6_port);
2365 	bep = (__be16 *)(&address->sin6_addr);
2366 	be32p = (__be32 *)(&address->sin6_addr);
2367 
2368 	/*
2369 	 * It's remote, so port lookup does no good.
2370 	 */
2371 	if (be32p[0] || be32p[1] || be32p[2] || bep[6] || ntohs(bep[7]) != 1)
2372 		goto auditout;
2373 
2374 	/*
2375 	 * It's local so the send check has to have passed.
2376 	 */
2377 	if (act == SMK_RECEIVING) {
2378 		skp = &smack_known_web;
2379 		goto auditout;
2380 	}
2381 
2382 	list_for_each_entry(spp, &smk_ipv6_port_list, list) {
2383 		if (spp->smk_port != port)
2384 			continue;
2385 		object = spp->smk_in;
2386 		if (act == SMK_CONNECTING)
2387 			ssp->smk_packet = spp->smk_out;
2388 		break;
2389 	}
2390 
2391 auditout:
2392 
2393 #ifdef CONFIG_AUDIT
2394 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2395 	ad.a.u.net->family = sk->sk_family;
2396 	ad.a.u.net->dport = port;
2397 	if (act == SMK_RECEIVING)
2398 		ad.a.u.net->v6info.saddr = address->sin6_addr;
2399 	else
2400 		ad.a.u.net->v6info.daddr = address->sin6_addr;
2401 #endif
2402 	rc = smk_access(skp, object, MAY_WRITE, &ad);
2403 	rc = smk_bu_note("IPv6 port check", skp, object, MAY_WRITE, rc);
2404 	return rc;
2405 }
2406 #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2407 
2408 /**
2409  * smack_inode_setsecurity - set smack xattrs
2410  * @inode: the object
2411  * @name: attribute name
2412  * @value: attribute value
2413  * @size: size of the attribute
2414  * @flags: unused
2415  *
2416  * Sets the named attribute in the appropriate blob
2417  *
2418  * Returns 0 on success, or an error code
2419  */
2420 static int smack_inode_setsecurity(struct inode *inode, const char *name,
2421 				   const void *value, size_t size, int flags)
2422 {
2423 	struct smack_known *skp;
2424 	struct inode_smack *nsp = inode->i_security;
2425 	struct socket_smack *ssp;
2426 	struct socket *sock;
2427 	int rc = 0;
2428 
2429 	if (value == NULL || size > SMK_LONGLABEL || size == 0)
2430 		return -EINVAL;
2431 
2432 	skp = smk_import_entry(value, size);
2433 	if (skp == NULL)
2434 		return -EINVAL;
2435 
2436 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2437 		nsp->smk_inode = skp;
2438 		nsp->smk_flags |= SMK_INODE_INSTANT;
2439 		return 0;
2440 	}
2441 	/*
2442 	 * The rest of the Smack xattrs are only on sockets.
2443 	 */
2444 	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2445 		return -EOPNOTSUPP;
2446 
2447 	sock = SOCKET_I(inode);
2448 	if (sock == NULL || sock->sk == NULL)
2449 		return -EOPNOTSUPP;
2450 
2451 	ssp = sock->sk->sk_security;
2452 
2453 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2454 		ssp->smk_in = skp;
2455 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2456 		ssp->smk_out = skp;
2457 		if (sock->sk->sk_family == PF_INET) {
2458 			rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2459 			if (rc != 0)
2460 				printk(KERN_WARNING
2461 					"Smack: \"%s\" netlbl error %d.\n",
2462 					__func__, -rc);
2463 		}
2464 	} else
2465 		return -EOPNOTSUPP;
2466 
2467 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2468 	if (sock->sk->sk_family == PF_INET6)
2469 		smk_ipv6_port_label(sock, NULL);
2470 #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2471 
2472 	return 0;
2473 }
2474 
2475 /**
2476  * smack_socket_post_create - finish socket setup
2477  * @sock: the socket
2478  * @family: protocol family
2479  * @type: unused
2480  * @protocol: unused
2481  * @kern: unused
2482  *
2483  * Sets the netlabel information on the socket
2484  *
2485  * Returns 0 on success, and error code otherwise
2486  */
2487 static int smack_socket_post_create(struct socket *sock, int family,
2488 				    int type, int protocol, int kern)
2489 {
2490 	struct socket_smack *ssp;
2491 
2492 	if (sock->sk == NULL)
2493 		return 0;
2494 
2495 	/*
2496 	 * Sockets created by kernel threads receive web label.
2497 	 */
2498 	if (unlikely(current->flags & PF_KTHREAD)) {
2499 		ssp = sock->sk->sk_security;
2500 		ssp->smk_in = &smack_known_web;
2501 		ssp->smk_out = &smack_known_web;
2502 	}
2503 
2504 	if (family != PF_INET)
2505 		return 0;
2506 	/*
2507 	 * Set the outbound netlbl.
2508 	 */
2509 	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
2510 }
2511 
2512 #ifndef CONFIG_SECURITY_SMACK_NETFILTER
2513 /**
2514  * smack_socket_bind - record port binding information.
2515  * @sock: the socket
2516  * @address: the port address
2517  * @addrlen: size of the address
2518  *
2519  * Records the label bound to a port.
2520  *
2521  * Returns 0
2522  */
2523 static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
2524 				int addrlen)
2525 {
2526 #if IS_ENABLED(CONFIG_IPV6)
2527 	if (sock->sk != NULL && sock->sk->sk_family == PF_INET6)
2528 		smk_ipv6_port_label(sock, address);
2529 #endif
2530 
2531 	return 0;
2532 }
2533 #endif /* !CONFIG_SECURITY_SMACK_NETFILTER */
2534 
2535 /**
2536  * smack_socket_connect - connect access check
2537  * @sock: the socket
2538  * @sap: the other end
2539  * @addrlen: size of sap
2540  *
2541  * Verifies that a connection may be possible
2542  *
2543  * Returns 0 on success, and error code otherwise
2544  */
2545 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2546 				int addrlen)
2547 {
2548 	int rc = 0;
2549 
2550 	if (sock->sk == NULL)
2551 		return 0;
2552 
2553 	switch (sock->sk->sk_family) {
2554 	case PF_INET:
2555 		if (addrlen < sizeof(struct sockaddr_in))
2556 			return -EINVAL;
2557 		rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2558 		break;
2559 	case PF_INET6:
2560 		if (addrlen < sizeof(struct sockaddr_in6))
2561 			return -EINVAL;
2562 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
2563 		rc = smk_ipv6_port_check(sock->sk, (struct sockaddr_in6 *)sap,
2564 						SMK_CONNECTING);
2565 #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
2566 		break;
2567 	}
2568 	return rc;
2569 }
2570 
2571 /**
2572  * smack_flags_to_may - convert S_ to MAY_ values
2573  * @flags: the S_ value
2574  *
2575  * Returns the equivalent MAY_ value
2576  */
2577 static int smack_flags_to_may(int flags)
2578 {
2579 	int may = 0;
2580 
2581 	if (flags & S_IRUGO)
2582 		may |= MAY_READ;
2583 	if (flags & S_IWUGO)
2584 		may |= MAY_WRITE;
2585 	if (flags & S_IXUGO)
2586 		may |= MAY_EXEC;
2587 
2588 	return may;
2589 }
2590 
2591 /**
2592  * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2593  * @msg: the object
2594  *
2595  * Returns 0
2596  */
2597 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2598 {
2599 	struct smack_known *skp = smk_of_current();
2600 
2601 	msg->security = skp;
2602 	return 0;
2603 }
2604 
2605 /**
2606  * smack_msg_msg_free_security - Clear the security blob for msg_msg
2607  * @msg: the object
2608  *
2609  * Clears the blob pointer
2610  */
2611 static void smack_msg_msg_free_security(struct msg_msg *msg)
2612 {
2613 	msg->security = NULL;
2614 }
2615 
2616 /**
2617  * smack_of_shm - the smack pointer for the shm
2618  * @shp: the object
2619  *
2620  * Returns a pointer to the smack value
2621  */
2622 static struct smack_known *smack_of_shm(struct shmid_kernel *shp)
2623 {
2624 	return (struct smack_known *)shp->shm_perm.security;
2625 }
2626 
2627 /**
2628  * smack_shm_alloc_security - Set the security blob for shm
2629  * @shp: the object
2630  *
2631  * Returns 0
2632  */
2633 static int smack_shm_alloc_security(struct shmid_kernel *shp)
2634 {
2635 	struct kern_ipc_perm *isp = &shp->shm_perm;
2636 	struct smack_known *skp = smk_of_current();
2637 
2638 	isp->security = skp;
2639 	return 0;
2640 }
2641 
2642 /**
2643  * smack_shm_free_security - Clear the security blob for shm
2644  * @shp: the object
2645  *
2646  * Clears the blob pointer
2647  */
2648 static void smack_shm_free_security(struct shmid_kernel *shp)
2649 {
2650 	struct kern_ipc_perm *isp = &shp->shm_perm;
2651 
2652 	isp->security = NULL;
2653 }
2654 
2655 /**
2656  * smk_curacc_shm : check if current has access on shm
2657  * @shp : the object
2658  * @access : access requested
2659  *
2660  * Returns 0 if current has the requested access, error code otherwise
2661  */
2662 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2663 {
2664 	struct smack_known *ssp = smack_of_shm(shp);
2665 	struct smk_audit_info ad;
2666 	int rc;
2667 
2668 #ifdef CONFIG_AUDIT
2669 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2670 	ad.a.u.ipc_id = shp->shm_perm.id;
2671 #endif
2672 	rc = smk_curacc(ssp, access, &ad);
2673 	rc = smk_bu_current("shm", ssp, access, rc);
2674 	return rc;
2675 }
2676 
2677 /**
2678  * smack_shm_associate - Smack access check for shm
2679  * @shp: the object
2680  * @shmflg: access requested
2681  *
2682  * Returns 0 if current has the requested access, error code otherwise
2683  */
2684 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2685 {
2686 	int may;
2687 
2688 	may = smack_flags_to_may(shmflg);
2689 	return smk_curacc_shm(shp, may);
2690 }
2691 
2692 /**
2693  * smack_shm_shmctl - Smack access check for shm
2694  * @shp: the object
2695  * @cmd: what it wants to do
2696  *
2697  * Returns 0 if current has the requested access, error code otherwise
2698  */
2699 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2700 {
2701 	int may;
2702 
2703 	switch (cmd) {
2704 	case IPC_STAT:
2705 	case SHM_STAT:
2706 		may = MAY_READ;
2707 		break;
2708 	case IPC_SET:
2709 	case SHM_LOCK:
2710 	case SHM_UNLOCK:
2711 	case IPC_RMID:
2712 		may = MAY_READWRITE;
2713 		break;
2714 	case IPC_INFO:
2715 	case SHM_INFO:
2716 		/*
2717 		 * System level information.
2718 		 */
2719 		return 0;
2720 	default:
2721 		return -EINVAL;
2722 	}
2723 	return smk_curacc_shm(shp, may);
2724 }
2725 
2726 /**
2727  * smack_shm_shmat - Smack access for shmat
2728  * @shp: the object
2729  * @shmaddr: unused
2730  * @shmflg: access requested
2731  *
2732  * Returns 0 if current has the requested access, error code otherwise
2733  */
2734 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2735 			   int shmflg)
2736 {
2737 	int may;
2738 
2739 	may = smack_flags_to_may(shmflg);
2740 	return smk_curacc_shm(shp, may);
2741 }
2742 
2743 /**
2744  * smack_of_sem - the smack pointer for the sem
2745  * @sma: the object
2746  *
2747  * Returns a pointer to the smack value
2748  */
2749 static struct smack_known *smack_of_sem(struct sem_array *sma)
2750 {
2751 	return (struct smack_known *)sma->sem_perm.security;
2752 }
2753 
2754 /**
2755  * smack_sem_alloc_security - Set the security blob for sem
2756  * @sma: the object
2757  *
2758  * Returns 0
2759  */
2760 static int smack_sem_alloc_security(struct sem_array *sma)
2761 {
2762 	struct kern_ipc_perm *isp = &sma->sem_perm;
2763 	struct smack_known *skp = smk_of_current();
2764 
2765 	isp->security = skp;
2766 	return 0;
2767 }
2768 
2769 /**
2770  * smack_sem_free_security - Clear the security blob for sem
2771  * @sma: the object
2772  *
2773  * Clears the blob pointer
2774  */
2775 static void smack_sem_free_security(struct sem_array *sma)
2776 {
2777 	struct kern_ipc_perm *isp = &sma->sem_perm;
2778 
2779 	isp->security = NULL;
2780 }
2781 
2782 /**
2783  * smk_curacc_sem : check if current has access on sem
2784  * @sma : the object
2785  * @access : access requested
2786  *
2787  * Returns 0 if current has the requested access, error code otherwise
2788  */
2789 static int smk_curacc_sem(struct sem_array *sma, int access)
2790 {
2791 	struct smack_known *ssp = smack_of_sem(sma);
2792 	struct smk_audit_info ad;
2793 	int rc;
2794 
2795 #ifdef CONFIG_AUDIT
2796 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2797 	ad.a.u.ipc_id = sma->sem_perm.id;
2798 #endif
2799 	rc = smk_curacc(ssp, access, &ad);
2800 	rc = smk_bu_current("sem", ssp, access, rc);
2801 	return rc;
2802 }
2803 
2804 /**
2805  * smack_sem_associate - Smack access check for sem
2806  * @sma: the object
2807  * @semflg: access requested
2808  *
2809  * Returns 0 if current has the requested access, error code otherwise
2810  */
2811 static int smack_sem_associate(struct sem_array *sma, int semflg)
2812 {
2813 	int may;
2814 
2815 	may = smack_flags_to_may(semflg);
2816 	return smk_curacc_sem(sma, may);
2817 }
2818 
2819 /**
2820  * smack_sem_shmctl - Smack access check for sem
2821  * @sma: the object
2822  * @cmd: what it wants to do
2823  *
2824  * Returns 0 if current has the requested access, error code otherwise
2825  */
2826 static int smack_sem_semctl(struct sem_array *sma, int cmd)
2827 {
2828 	int may;
2829 
2830 	switch (cmd) {
2831 	case GETPID:
2832 	case GETNCNT:
2833 	case GETZCNT:
2834 	case GETVAL:
2835 	case GETALL:
2836 	case IPC_STAT:
2837 	case SEM_STAT:
2838 		may = MAY_READ;
2839 		break;
2840 	case SETVAL:
2841 	case SETALL:
2842 	case IPC_RMID:
2843 	case IPC_SET:
2844 		may = MAY_READWRITE;
2845 		break;
2846 	case IPC_INFO:
2847 	case SEM_INFO:
2848 		/*
2849 		 * System level information
2850 		 */
2851 		return 0;
2852 	default:
2853 		return -EINVAL;
2854 	}
2855 
2856 	return smk_curacc_sem(sma, may);
2857 }
2858 
2859 /**
2860  * smack_sem_semop - Smack checks of semaphore operations
2861  * @sma: the object
2862  * @sops: unused
2863  * @nsops: unused
2864  * @alter: unused
2865  *
2866  * Treated as read and write in all cases.
2867  *
2868  * Returns 0 if access is allowed, error code otherwise
2869  */
2870 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2871 			   unsigned nsops, int alter)
2872 {
2873 	return smk_curacc_sem(sma, MAY_READWRITE);
2874 }
2875 
2876 /**
2877  * smack_msg_alloc_security - Set the security blob for msg
2878  * @msq: the object
2879  *
2880  * Returns 0
2881  */
2882 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2883 {
2884 	struct kern_ipc_perm *kisp = &msq->q_perm;
2885 	struct smack_known *skp = smk_of_current();
2886 
2887 	kisp->security = skp;
2888 	return 0;
2889 }
2890 
2891 /**
2892  * smack_msg_free_security - Clear the security blob for msg
2893  * @msq: the object
2894  *
2895  * Clears the blob pointer
2896  */
2897 static void smack_msg_queue_free_security(struct msg_queue *msq)
2898 {
2899 	struct kern_ipc_perm *kisp = &msq->q_perm;
2900 
2901 	kisp->security = NULL;
2902 }
2903 
2904 /**
2905  * smack_of_msq - the smack pointer for the msq
2906  * @msq: the object
2907  *
2908  * Returns a pointer to the smack label entry
2909  */
2910 static struct smack_known *smack_of_msq(struct msg_queue *msq)
2911 {
2912 	return (struct smack_known *)msq->q_perm.security;
2913 }
2914 
2915 /**
2916  * smk_curacc_msq : helper to check if current has access on msq
2917  * @msq : the msq
2918  * @access : access requested
2919  *
2920  * return 0 if current has access, error otherwise
2921  */
2922 static int smk_curacc_msq(struct msg_queue *msq, int access)
2923 {
2924 	struct smack_known *msp = smack_of_msq(msq);
2925 	struct smk_audit_info ad;
2926 	int rc;
2927 
2928 #ifdef CONFIG_AUDIT
2929 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2930 	ad.a.u.ipc_id = msq->q_perm.id;
2931 #endif
2932 	rc = smk_curacc(msp, access, &ad);
2933 	rc = smk_bu_current("msq", msp, access, rc);
2934 	return rc;
2935 }
2936 
2937 /**
2938  * smack_msg_queue_associate - Smack access check for msg_queue
2939  * @msq: the object
2940  * @msqflg: access requested
2941  *
2942  * Returns 0 if current has the requested access, error code otherwise
2943  */
2944 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2945 {
2946 	int may;
2947 
2948 	may = smack_flags_to_may(msqflg);
2949 	return smk_curacc_msq(msq, may);
2950 }
2951 
2952 /**
2953  * smack_msg_queue_msgctl - Smack access check for msg_queue
2954  * @msq: the object
2955  * @cmd: what it wants to do
2956  *
2957  * Returns 0 if current has the requested access, error code otherwise
2958  */
2959 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2960 {
2961 	int may;
2962 
2963 	switch (cmd) {
2964 	case IPC_STAT:
2965 	case MSG_STAT:
2966 		may = MAY_READ;
2967 		break;
2968 	case IPC_SET:
2969 	case IPC_RMID:
2970 		may = MAY_READWRITE;
2971 		break;
2972 	case IPC_INFO:
2973 	case MSG_INFO:
2974 		/*
2975 		 * System level information
2976 		 */
2977 		return 0;
2978 	default:
2979 		return -EINVAL;
2980 	}
2981 
2982 	return smk_curacc_msq(msq, may);
2983 }
2984 
2985 /**
2986  * smack_msg_queue_msgsnd - Smack access check for msg_queue
2987  * @msq: the object
2988  * @msg: unused
2989  * @msqflg: access requested
2990  *
2991  * Returns 0 if current has the requested access, error code otherwise
2992  */
2993 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2994 				  int msqflg)
2995 {
2996 	int may;
2997 
2998 	may = smack_flags_to_may(msqflg);
2999 	return smk_curacc_msq(msq, may);
3000 }
3001 
3002 /**
3003  * smack_msg_queue_msgsnd - Smack access check for msg_queue
3004  * @msq: the object
3005  * @msg: unused
3006  * @target: unused
3007  * @type: unused
3008  * @mode: unused
3009  *
3010  * Returns 0 if current has read and write access, error code otherwise
3011  */
3012 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
3013 			struct task_struct *target, long type, int mode)
3014 {
3015 	return smk_curacc_msq(msq, MAY_READWRITE);
3016 }
3017 
3018 /**
3019  * smack_ipc_permission - Smack access for ipc_permission()
3020  * @ipp: the object permissions
3021  * @flag: access requested
3022  *
3023  * Returns 0 if current has read and write access, error code otherwise
3024  */
3025 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
3026 {
3027 	struct smack_known *iskp = ipp->security;
3028 	int may = smack_flags_to_may(flag);
3029 	struct smk_audit_info ad;
3030 	int rc;
3031 
3032 #ifdef CONFIG_AUDIT
3033 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3034 	ad.a.u.ipc_id = ipp->id;
3035 #endif
3036 	rc = smk_curacc(iskp, may, &ad);
3037 	rc = smk_bu_current("svipc", iskp, may, rc);
3038 	return rc;
3039 }
3040 
3041 /**
3042  * smack_ipc_getsecid - Extract smack security id
3043  * @ipp: the object permissions
3044  * @secid: where result will be saved
3045  */
3046 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
3047 {
3048 	struct smack_known *iskp = ipp->security;
3049 
3050 	*secid = iskp->smk_secid;
3051 }
3052 
3053 /**
3054  * smack_d_instantiate - Make sure the blob is correct on an inode
3055  * @opt_dentry: dentry where inode will be attached
3056  * @inode: the object
3057  *
3058  * Set the inode's security blob if it hasn't been done already.
3059  */
3060 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
3061 {
3062 	struct super_block *sbp;
3063 	struct superblock_smack *sbsp;
3064 	struct inode_smack *isp;
3065 	struct smack_known *skp;
3066 	struct smack_known *ckp = smk_of_current();
3067 	struct smack_known *final;
3068 	char trattr[TRANS_TRUE_SIZE];
3069 	int transflag = 0;
3070 	int rc;
3071 	struct dentry *dp;
3072 
3073 	if (inode == NULL)
3074 		return;
3075 
3076 	isp = inode->i_security;
3077 
3078 	mutex_lock(&isp->smk_lock);
3079 	/*
3080 	 * If the inode is already instantiated
3081 	 * take the quick way out
3082 	 */
3083 	if (isp->smk_flags & SMK_INODE_INSTANT)
3084 		goto unlockandout;
3085 
3086 	sbp = inode->i_sb;
3087 	sbsp = sbp->s_security;
3088 	/*
3089 	 * We're going to use the superblock default label
3090 	 * if there's no label on the file.
3091 	 */
3092 	final = sbsp->smk_default;
3093 
3094 	/*
3095 	 * If this is the root inode the superblock
3096 	 * may be in the process of initialization.
3097 	 * If that is the case use the root value out
3098 	 * of the superblock.
3099 	 */
3100 	if (opt_dentry->d_parent == opt_dentry) {
3101 		switch (sbp->s_magic) {
3102 		case CGROUP_SUPER_MAGIC:
3103 			/*
3104 			 * The cgroup filesystem is never mounted,
3105 			 * so there's no opportunity to set the mount
3106 			 * options.
3107 			 */
3108 			sbsp->smk_root = &smack_known_star;
3109 			sbsp->smk_default = &smack_known_star;
3110 			isp->smk_inode = sbsp->smk_root;
3111 			break;
3112 		case TMPFS_MAGIC:
3113 			/*
3114 			 * What about shmem/tmpfs anonymous files with dentry
3115 			 * obtained from d_alloc_pseudo()?
3116 			 */
3117 			isp->smk_inode = smk_of_current();
3118 			break;
3119 		default:
3120 			isp->smk_inode = sbsp->smk_root;
3121 			break;
3122 		}
3123 		isp->smk_flags |= SMK_INODE_INSTANT;
3124 		goto unlockandout;
3125 	}
3126 
3127 	/*
3128 	 * This is pretty hackish.
3129 	 * Casey says that we shouldn't have to do
3130 	 * file system specific code, but it does help
3131 	 * with keeping it simple.
3132 	 */
3133 	switch (sbp->s_magic) {
3134 	case SMACK_MAGIC:
3135 	case PIPEFS_MAGIC:
3136 	case SOCKFS_MAGIC:
3137 	case CGROUP_SUPER_MAGIC:
3138 		/*
3139 		 * Casey says that it's a little embarrassing
3140 		 * that the smack file system doesn't do
3141 		 * extended attributes.
3142 		 *
3143 		 * Casey says pipes are easy (?)
3144 		 *
3145 		 * Socket access is controlled by the socket
3146 		 * structures associated with the task involved.
3147 		 *
3148 		 * Cgroupfs is special
3149 		 */
3150 		final = &smack_known_star;
3151 		break;
3152 	case DEVPTS_SUPER_MAGIC:
3153 		/*
3154 		 * devpts seems content with the label of the task.
3155 		 * Programs that change smack have to treat the
3156 		 * pty with respect.
3157 		 */
3158 		final = ckp;
3159 		break;
3160 	case PROC_SUPER_MAGIC:
3161 		/*
3162 		 * Casey says procfs appears not to care.
3163 		 * The superblock default suffices.
3164 		 */
3165 		break;
3166 	case TMPFS_MAGIC:
3167 		/*
3168 		 * Device labels should come from the filesystem,
3169 		 * but watch out, because they're volitile,
3170 		 * getting recreated on every reboot.
3171 		 */
3172 		final = &smack_known_star;
3173 		/*
3174 		 * No break.
3175 		 *
3176 		 * If a smack value has been set we want to use it,
3177 		 * but since tmpfs isn't giving us the opportunity
3178 		 * to set mount options simulate setting the
3179 		 * superblock default.
3180 		 */
3181 	default:
3182 		/*
3183 		 * This isn't an understood special case.
3184 		 * Get the value from the xattr.
3185 		 */
3186 
3187 		/*
3188 		 * UNIX domain sockets use lower level socket data.
3189 		 */
3190 		if (S_ISSOCK(inode->i_mode)) {
3191 			final = &smack_known_star;
3192 			break;
3193 		}
3194 		/*
3195 		 * No xattr support means, alas, no SMACK label.
3196 		 * Use the aforeapplied default.
3197 		 * It would be curious if the label of the task
3198 		 * does not match that assigned.
3199 		 */
3200 		if (inode->i_op->getxattr == NULL)
3201 			break;
3202 		/*
3203 		 * Get the dentry for xattr.
3204 		 */
3205 		dp = dget(opt_dentry);
3206 		skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
3207 		if (skp != NULL)
3208 			final = skp;
3209 
3210 		/*
3211 		 * Transmuting directory
3212 		 */
3213 		if (S_ISDIR(inode->i_mode)) {
3214 			/*
3215 			 * If this is a new directory and the label was
3216 			 * transmuted when the inode was initialized
3217 			 * set the transmute attribute on the directory
3218 			 * and mark the inode.
3219 			 *
3220 			 * If there is a transmute attribute on the
3221 			 * directory mark the inode.
3222 			 */
3223 			if (isp->smk_flags & SMK_INODE_CHANGED) {
3224 				isp->smk_flags &= ~SMK_INODE_CHANGED;
3225 				rc = inode->i_op->setxattr(dp,
3226 					XATTR_NAME_SMACKTRANSMUTE,
3227 					TRANS_TRUE, TRANS_TRUE_SIZE,
3228 					0);
3229 			} else {
3230 				rc = inode->i_op->getxattr(dp,
3231 					XATTR_NAME_SMACKTRANSMUTE, trattr,
3232 					TRANS_TRUE_SIZE);
3233 				if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
3234 						       TRANS_TRUE_SIZE) != 0)
3235 					rc = -EINVAL;
3236 			}
3237 			if (rc >= 0)
3238 				transflag = SMK_INODE_TRANSMUTE;
3239 		}
3240 		/*
3241 		 * Don't let the exec or mmap label be "*" or "@".
3242 		 */
3243 		skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
3244 		if (skp == &smack_known_star || skp == &smack_known_web)
3245 			skp = NULL;
3246 		isp->smk_task = skp;
3247 		skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
3248 		if (skp == &smack_known_star || skp == &smack_known_web)
3249 			skp = NULL;
3250 		isp->smk_mmap = skp;
3251 
3252 		dput(dp);
3253 		break;
3254 	}
3255 
3256 	if (final == NULL)
3257 		isp->smk_inode = ckp;
3258 	else
3259 		isp->smk_inode = final;
3260 
3261 	isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3262 
3263 unlockandout:
3264 	mutex_unlock(&isp->smk_lock);
3265 	return;
3266 }
3267 
3268 /**
3269  * smack_getprocattr - Smack process attribute access
3270  * @p: the object task
3271  * @name: the name of the attribute in /proc/.../attr
3272  * @value: where to put the result
3273  *
3274  * Places a copy of the task Smack into value
3275  *
3276  * Returns the length of the smack label or an error code
3277  */
3278 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
3279 {
3280 	struct smack_known *skp = smk_of_task_struct(p);
3281 	char *cp;
3282 	int slen;
3283 
3284 	if (strcmp(name, "current") != 0)
3285 		return -EINVAL;
3286 
3287 	cp = kstrdup(skp->smk_known, GFP_KERNEL);
3288 	if (cp == NULL)
3289 		return -ENOMEM;
3290 
3291 	slen = strlen(cp);
3292 	*value = cp;
3293 	return slen;
3294 }
3295 
3296 /**
3297  * smack_setprocattr - Smack process attribute setting
3298  * @p: the object task
3299  * @name: the name of the attribute in /proc/.../attr
3300  * @value: the value to set
3301  * @size: the size of the value
3302  *
3303  * Sets the Smack value of the task. Only setting self
3304  * is permitted and only with privilege
3305  *
3306  * Returns the length of the smack label or an error code
3307  */
3308 static int smack_setprocattr(struct task_struct *p, char *name,
3309 			     void *value, size_t size)
3310 {
3311 	struct task_smack *tsp;
3312 	struct cred *new;
3313 	struct smack_known *skp;
3314 
3315 	/*
3316 	 * Changing another process' Smack value is too dangerous
3317 	 * and supports no sane use case.
3318 	 */
3319 	if (p != current)
3320 		return -EPERM;
3321 
3322 	if (!smack_privileged(CAP_MAC_ADMIN))
3323 		return -EPERM;
3324 
3325 	if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3326 		return -EINVAL;
3327 
3328 	if (strcmp(name, "current") != 0)
3329 		return -EINVAL;
3330 
3331 	skp = smk_import_entry(value, size);
3332 	if (skp == NULL)
3333 		return -EINVAL;
3334 
3335 	/*
3336 	 * No process is ever allowed the web ("@") label.
3337 	 */
3338 	if (skp == &smack_known_web)
3339 		return -EPERM;
3340 
3341 	new = prepare_creds();
3342 	if (new == NULL)
3343 		return -ENOMEM;
3344 
3345 	tsp = new->security;
3346 	tsp->smk_task = skp;
3347 
3348 	commit_creds(new);
3349 	return size;
3350 }
3351 
3352 /**
3353  * smack_unix_stream_connect - Smack access on UDS
3354  * @sock: one sock
3355  * @other: the other sock
3356  * @newsk: unused
3357  *
3358  * Return 0 if a subject with the smack of sock could access
3359  * an object with the smack of other, otherwise an error code
3360  */
3361 static int smack_unix_stream_connect(struct sock *sock,
3362 				     struct sock *other, struct sock *newsk)
3363 {
3364 	struct smack_known *skp;
3365 	struct smack_known *okp;
3366 	struct socket_smack *ssp = sock->sk_security;
3367 	struct socket_smack *osp = other->sk_security;
3368 	struct socket_smack *nsp = newsk->sk_security;
3369 	struct smk_audit_info ad;
3370 	int rc = 0;
3371 #ifdef CONFIG_AUDIT
3372 	struct lsm_network_audit net;
3373 #endif
3374 
3375 	if (!smack_privileged(CAP_MAC_OVERRIDE)) {
3376 		skp = ssp->smk_out;
3377 		okp = osp->smk_in;
3378 #ifdef CONFIG_AUDIT
3379 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3380 		smk_ad_setfield_u_net_sk(&ad, other);
3381 #endif
3382 		rc = smk_access(skp, okp, MAY_WRITE, &ad);
3383 		rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
3384 		if (rc == 0) {
3385 			okp = osp->smk_out;
3386 			skp = ssp->smk_in;
3387 			rc = smk_access(okp, skp, MAY_WRITE, &ad);
3388 			rc = smk_bu_note("UDS connect", okp, skp,
3389 						MAY_WRITE, rc);
3390 		}
3391 	}
3392 
3393 	/*
3394 	 * Cross reference the peer labels for SO_PEERSEC.
3395 	 */
3396 	if (rc == 0) {
3397 		nsp->smk_packet = ssp->smk_out;
3398 		ssp->smk_packet = osp->smk_out;
3399 	}
3400 
3401 	return rc;
3402 }
3403 
3404 /**
3405  * smack_unix_may_send - Smack access on UDS
3406  * @sock: one socket
3407  * @other: the other socket
3408  *
3409  * Return 0 if a subject with the smack of sock could access
3410  * an object with the smack of other, otherwise an error code
3411  */
3412 static int smack_unix_may_send(struct socket *sock, struct socket *other)
3413 {
3414 	struct socket_smack *ssp = sock->sk->sk_security;
3415 	struct socket_smack *osp = other->sk->sk_security;
3416 	struct smk_audit_info ad;
3417 	int rc;
3418 
3419 #ifdef CONFIG_AUDIT
3420 	struct lsm_network_audit net;
3421 
3422 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3423 	smk_ad_setfield_u_net_sk(&ad, other->sk);
3424 #endif
3425 
3426 	if (smack_privileged(CAP_MAC_OVERRIDE))
3427 		return 0;
3428 
3429 	rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
3430 	rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
3431 	return rc;
3432 }
3433 
3434 /**
3435  * smack_socket_sendmsg - Smack check based on destination host
3436  * @sock: the socket
3437  * @msg: the message
3438  * @size: the size of the message
3439  *
3440  * Return 0 if the current subject can write to the destination host.
3441  * For IPv4 this is only a question if the destination is a single label host.
3442  * For IPv6 this is a check against the label of the port.
3443  */
3444 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3445 				int size)
3446 {
3447 	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3448 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
3449 	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3450 #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
3451 	int rc = 0;
3452 
3453 	/*
3454 	 * Perfectly reasonable for this to be NULL
3455 	 */
3456 	if (sip == NULL)
3457 		return 0;
3458 
3459 	switch (sip->sin_family) {
3460 	case AF_INET:
3461 		rc = smack_netlabel_send(sock->sk, sip);
3462 		break;
3463 	case AF_INET6:
3464 #if IS_ENABLED(CONFIG_IPV6) && !defined(CONFIG_SECURITY_SMACK_NETFILTER)
3465 		rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3466 #endif /* CONFIG_IPV6 && !CONFIG_SECURITY_SMACK_NETFILTER */
3467 		break;
3468 	}
3469 	return rc;
3470 }
3471 
3472 /**
3473  * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3474  * @sap: netlabel secattr
3475  * @ssp: socket security information
3476  *
3477  * Returns a pointer to a Smack label entry found on the label list.
3478  */
3479 static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
3480 						struct socket_smack *ssp)
3481 {
3482 	struct smack_known *skp;
3483 	int found = 0;
3484 	int acat;
3485 	int kcat;
3486 
3487 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3488 		/*
3489 		 * Looks like a CIPSO packet.
3490 		 * If there are flags but no level netlabel isn't
3491 		 * behaving the way we expect it to.
3492 		 *
3493 		 * Look it up in the label table
3494 		 * Without guidance regarding the smack value
3495 		 * for the packet fall back on the network
3496 		 * ambient value.
3497 		 */
3498 		rcu_read_lock();
3499 		list_for_each_entry(skp, &smack_known_list, list) {
3500 			if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3501 				continue;
3502 			/*
3503 			 * Compare the catsets. Use the netlbl APIs.
3504 			 */
3505 			if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
3506 				if ((skp->smk_netlabel.flags &
3507 				     NETLBL_SECATTR_MLS_CAT) == 0)
3508 					found = 1;
3509 				break;
3510 			}
3511 			for (acat = -1, kcat = -1; acat == kcat; ) {
3512 				acat = netlbl_catmap_walk(sap->attr.mls.cat,
3513 							  acat + 1);
3514 				kcat = netlbl_catmap_walk(
3515 					skp->smk_netlabel.attr.mls.cat,
3516 					kcat + 1);
3517 				if (acat < 0 || kcat < 0)
3518 					break;
3519 			}
3520 			if (acat == kcat) {
3521 				found = 1;
3522 				break;
3523 			}
3524 		}
3525 		rcu_read_unlock();
3526 
3527 		if (found)
3528 			return skp;
3529 
3530 		if (ssp != NULL && ssp->smk_in == &smack_known_star)
3531 			return &smack_known_web;
3532 		return &smack_known_star;
3533 	}
3534 	if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
3535 		/*
3536 		 * Looks like a fallback, which gives us a secid.
3537 		 */
3538 		skp = smack_from_secid(sap->attr.secid);
3539 		/*
3540 		 * This has got to be a bug because it is
3541 		 * impossible to specify a fallback without
3542 		 * specifying the label, which will ensure
3543 		 * it has a secid, and the only way to get a
3544 		 * secid is from a fallback.
3545 		 */
3546 		BUG_ON(skp == NULL);
3547 		return skp;
3548 	}
3549 	/*
3550 	 * Without guidance regarding the smack value
3551 	 * for the packet fall back on the network
3552 	 * ambient value.
3553 	 */
3554 	return smack_net_ambient;
3555 }
3556 
3557 #if IS_ENABLED(CONFIG_IPV6)
3558 static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3559 {
3560 	u8 nexthdr;
3561 	int offset;
3562 	int proto = -EINVAL;
3563 	struct ipv6hdr _ipv6h;
3564 	struct ipv6hdr *ip6;
3565 	__be16 frag_off;
3566 	struct tcphdr _tcph, *th;
3567 	struct udphdr _udph, *uh;
3568 	struct dccp_hdr _dccph, *dh;
3569 
3570 	sip->sin6_port = 0;
3571 
3572 	offset = skb_network_offset(skb);
3573 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3574 	if (ip6 == NULL)
3575 		return -EINVAL;
3576 	sip->sin6_addr = ip6->saddr;
3577 
3578 	nexthdr = ip6->nexthdr;
3579 	offset += sizeof(_ipv6h);
3580 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3581 	if (offset < 0)
3582 		return -EINVAL;
3583 
3584 	proto = nexthdr;
3585 	switch (proto) {
3586 	case IPPROTO_TCP:
3587 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3588 		if (th != NULL)
3589 			sip->sin6_port = th->source;
3590 		break;
3591 	case IPPROTO_UDP:
3592 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3593 		if (uh != NULL)
3594 			sip->sin6_port = uh->source;
3595 		break;
3596 	case IPPROTO_DCCP:
3597 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3598 		if (dh != NULL)
3599 			sip->sin6_port = dh->dccph_sport;
3600 		break;
3601 	}
3602 	return proto;
3603 }
3604 #endif /* CONFIG_IPV6 */
3605 
3606 /**
3607  * smack_socket_sock_rcv_skb - Smack packet delivery access check
3608  * @sk: socket
3609  * @skb: packet
3610  *
3611  * Returns 0 if the packet should be delivered, an error code otherwise
3612  */
3613 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
3614 {
3615 	struct netlbl_lsm_secattr secattr;
3616 	struct socket_smack *ssp = sk->sk_security;
3617 	struct smack_known *skp = NULL;
3618 	int rc = 0;
3619 	struct smk_audit_info ad;
3620 #ifdef CONFIG_AUDIT
3621 	struct lsm_network_audit net;
3622 #endif
3623 #if IS_ENABLED(CONFIG_IPV6)
3624 	struct sockaddr_in6 sadd;
3625 	int proto;
3626 #endif /* CONFIG_IPV6 */
3627 
3628 	switch (sk->sk_family) {
3629 	case PF_INET:
3630 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
3631 		/*
3632 		 * If there is a secmark use it rather than the CIPSO label.
3633 		 * If there is no secmark fall back to CIPSO.
3634 		 * The secmark is assumed to reflect policy better.
3635 		 */
3636 		if (skb && skb->secmark != 0) {
3637 			skp = smack_from_secid(skb->secmark);
3638 			goto access_check;
3639 		}
3640 #endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3641 		/*
3642 		 * Translate what netlabel gave us.
3643 		 */
3644 		netlbl_secattr_init(&secattr);
3645 
3646 		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
3647 		if (rc == 0)
3648 			skp = smack_from_secattr(&secattr, ssp);
3649 		else
3650 			skp = smack_net_ambient;
3651 
3652 		netlbl_secattr_destroy(&secattr);
3653 
3654 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
3655 access_check:
3656 #endif
3657 #ifdef CONFIG_AUDIT
3658 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3659 		ad.a.u.net->family = sk->sk_family;
3660 		ad.a.u.net->netif = skb->skb_iif;
3661 		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3662 #endif
3663 		/*
3664 		 * Receiving a packet requires that the other end
3665 		 * be able to write here. Read access is not required.
3666 		 * This is the simplist possible security model
3667 		 * for networking.
3668 		 */
3669 		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
3670 		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
3671 					MAY_WRITE, rc);
3672 		if (rc != 0)
3673 			netlbl_skbuff_err(skb, rc, 0);
3674 		break;
3675 #if IS_ENABLED(CONFIG_IPV6)
3676 	case PF_INET6:
3677 		proto = smk_skb_to_addr_ipv6(skb, &sadd);
3678 		if (proto != IPPROTO_UDP && proto != IPPROTO_TCP)
3679 			break;
3680 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
3681 		if (skb && skb->secmark != 0)
3682 			skp = smack_from_secid(skb->secmark);
3683 		else
3684 			skp = smack_net_ambient;
3685 #ifdef CONFIG_AUDIT
3686 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3687 		ad.a.u.net->family = sk->sk_family;
3688 		ad.a.u.net->netif = skb->skb_iif;
3689 		ipv6_skb_to_auditdata(skb, &ad.a, NULL);
3690 #endif /* CONFIG_AUDIT */
3691 		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
3692 		rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
3693 					MAY_WRITE, rc);
3694 #else /* CONFIG_SECURITY_SMACK_NETFILTER */
3695 		rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
3696 #endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3697 		break;
3698 #endif /* CONFIG_IPV6 */
3699 	}
3700 
3701 	return rc;
3702 }
3703 
3704 /**
3705  * smack_socket_getpeersec_stream - pull in packet label
3706  * @sock: the socket
3707  * @optval: user's destination
3708  * @optlen: size thereof
3709  * @len: max thereof
3710  *
3711  * returns zero on success, an error code otherwise
3712  */
3713 static int smack_socket_getpeersec_stream(struct socket *sock,
3714 					  char __user *optval,
3715 					  int __user *optlen, unsigned len)
3716 {
3717 	struct socket_smack *ssp;
3718 	char *rcp = "";
3719 	int slen = 1;
3720 	int rc = 0;
3721 
3722 	ssp = sock->sk->sk_security;
3723 	if (ssp->smk_packet != NULL) {
3724 		rcp = ssp->smk_packet->smk_known;
3725 		slen = strlen(rcp) + 1;
3726 	}
3727 
3728 	if (slen > len)
3729 		rc = -ERANGE;
3730 	else if (copy_to_user(optval, rcp, slen) != 0)
3731 		rc = -EFAULT;
3732 
3733 	if (put_user(slen, optlen) != 0)
3734 		rc = -EFAULT;
3735 
3736 	return rc;
3737 }
3738 
3739 
3740 /**
3741  * smack_socket_getpeersec_dgram - pull in packet label
3742  * @sock: the peer socket
3743  * @skb: packet data
3744  * @secid: pointer to where to put the secid of the packet
3745  *
3746  * Sets the netlabel socket state on sk from parent
3747  */
3748 static int smack_socket_getpeersec_dgram(struct socket *sock,
3749 					 struct sk_buff *skb, u32 *secid)
3750 
3751 {
3752 	struct netlbl_lsm_secattr secattr;
3753 	struct socket_smack *ssp = NULL;
3754 	struct smack_known *skp;
3755 	int family = PF_UNSPEC;
3756 	u32 s = 0;	/* 0 is the invalid secid */
3757 	int rc;
3758 
3759 	if (skb != NULL) {
3760 		if (skb->protocol == htons(ETH_P_IP))
3761 			family = PF_INET;
3762 #if IS_ENABLED(CONFIG_IPV6)
3763 		else if (skb->protocol == htons(ETH_P_IPV6))
3764 			family = PF_INET6;
3765 #endif /* CONFIG_IPV6 */
3766 	}
3767 	if (family == PF_UNSPEC && sock != NULL)
3768 		family = sock->sk->sk_family;
3769 
3770 	switch (family) {
3771 	case PF_UNIX:
3772 		ssp = sock->sk->sk_security;
3773 		s = ssp->smk_out->smk_secid;
3774 		break;
3775 	case PF_INET:
3776 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
3777 		s = skb->secmark;
3778 		if (s != 0)
3779 			break;
3780 #endif
3781 		/*
3782 		 * Translate what netlabel gave us.
3783 		 */
3784 		if (sock != NULL && sock->sk != NULL)
3785 			ssp = sock->sk->sk_security;
3786 		netlbl_secattr_init(&secattr);
3787 		rc = netlbl_skbuff_getattr(skb, family, &secattr);
3788 		if (rc == 0) {
3789 			skp = smack_from_secattr(&secattr, ssp);
3790 			s = skp->smk_secid;
3791 		}
3792 		netlbl_secattr_destroy(&secattr);
3793 		break;
3794 #if IS_ENABLED(CONFIG_IPV6)
3795 	case PF_INET6:
3796 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
3797 		s = skb->secmark;
3798 #endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3799 		break;
3800 #endif /* CONFIG_IPV6 */
3801 	}
3802 	*secid = s;
3803 	if (s == 0)
3804 		return -EINVAL;
3805 	return 0;
3806 }
3807 
3808 /**
3809  * smack_sock_graft - Initialize a newly created socket with an existing sock
3810  * @sk: child sock
3811  * @parent: parent socket
3812  *
3813  * Set the smk_{in,out} state of an existing sock based on the process that
3814  * is creating the new socket.
3815  */
3816 static void smack_sock_graft(struct sock *sk, struct socket *parent)
3817 {
3818 	struct socket_smack *ssp;
3819 	struct smack_known *skp = smk_of_current();
3820 
3821 	if (sk == NULL ||
3822 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3823 		return;
3824 
3825 	ssp = sk->sk_security;
3826 	ssp->smk_in = skp;
3827 	ssp->smk_out = skp;
3828 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
3829 }
3830 
3831 /**
3832  * smack_inet_conn_request - Smack access check on connect
3833  * @sk: socket involved
3834  * @skb: packet
3835  * @req: unused
3836  *
3837  * Returns 0 if a task with the packet label could write to
3838  * the socket, otherwise an error code
3839  */
3840 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3841 				   struct request_sock *req)
3842 {
3843 	u16 family = sk->sk_family;
3844 	struct smack_known *skp;
3845 	struct socket_smack *ssp = sk->sk_security;
3846 	struct netlbl_lsm_secattr secattr;
3847 	struct sockaddr_in addr;
3848 	struct iphdr *hdr;
3849 	struct smack_known *hskp;
3850 	int rc;
3851 	struct smk_audit_info ad;
3852 #ifdef CONFIG_AUDIT
3853 	struct lsm_network_audit net;
3854 #endif
3855 
3856 #if IS_ENABLED(CONFIG_IPV6)
3857 	if (family == PF_INET6) {
3858 		/*
3859 		 * Handle mapped IPv4 packets arriving
3860 		 * via IPv6 sockets. Don't set up netlabel
3861 		 * processing on IPv6.
3862 		 */
3863 		if (skb->protocol == htons(ETH_P_IP))
3864 			family = PF_INET;
3865 		else
3866 			return 0;
3867 	}
3868 #endif /* CONFIG_IPV6 */
3869 
3870 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
3871 	/*
3872 	 * If there is a secmark use it rather than the CIPSO label.
3873 	 * If there is no secmark fall back to CIPSO.
3874 	 * The secmark is assumed to reflect policy better.
3875 	 */
3876 	if (skb && skb->secmark != 0) {
3877 		skp = smack_from_secid(skb->secmark);
3878 		goto access_check;
3879 	}
3880 #endif /* CONFIG_SECURITY_SMACK_NETFILTER */
3881 
3882 	netlbl_secattr_init(&secattr);
3883 	rc = netlbl_skbuff_getattr(skb, family, &secattr);
3884 	if (rc == 0)
3885 		skp = smack_from_secattr(&secattr, ssp);
3886 	else
3887 		skp = &smack_known_huh;
3888 	netlbl_secattr_destroy(&secattr);
3889 
3890 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
3891 access_check:
3892 #endif
3893 
3894 #ifdef CONFIG_AUDIT
3895 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3896 	ad.a.u.net->family = family;
3897 	ad.a.u.net->netif = skb->skb_iif;
3898 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3899 #endif
3900 	/*
3901 	 * Receiving a packet requires that the other end be able to write
3902 	 * here. Read access is not required.
3903 	 */
3904 	rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
3905 	rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
3906 	if (rc != 0)
3907 		return rc;
3908 
3909 	/*
3910 	 * Save the peer's label in the request_sock so we can later setup
3911 	 * smk_packet in the child socket so that SO_PEERCRED can report it.
3912 	 */
3913 	req->peer_secid = skp->smk_secid;
3914 
3915 	/*
3916 	 * We need to decide if we want to label the incoming connection here
3917 	 * if we do we only need to label the request_sock and the stack will
3918 	 * propagate the wire-label to the sock when it is created.
3919 	 */
3920 	hdr = ip_hdr(skb);
3921 	addr.sin_addr.s_addr = hdr->saddr;
3922 	rcu_read_lock();
3923 	hskp = smack_host_label(&addr);
3924 	rcu_read_unlock();
3925 
3926 	if (hskp == NULL)
3927 		rc = netlbl_req_setattr(req, &skp->smk_netlabel);
3928 	else
3929 		netlbl_req_delattr(req);
3930 
3931 	return rc;
3932 }
3933 
3934 /**
3935  * smack_inet_csk_clone - Copy the connection information to the new socket
3936  * @sk: the new socket
3937  * @req: the connection's request_sock
3938  *
3939  * Transfer the connection's peer label to the newly created socket.
3940  */
3941 static void smack_inet_csk_clone(struct sock *sk,
3942 				 const struct request_sock *req)
3943 {
3944 	struct socket_smack *ssp = sk->sk_security;
3945 	struct smack_known *skp;
3946 
3947 	if (req->peer_secid != 0) {
3948 		skp = smack_from_secid(req->peer_secid);
3949 		ssp->smk_packet = skp;
3950 	} else
3951 		ssp->smk_packet = NULL;
3952 }
3953 
3954 /*
3955  * Key management security hooks
3956  *
3957  * Casey has not tested key support very heavily.
3958  * The permission check is most likely too restrictive.
3959  * If you care about keys please have a look.
3960  */
3961 #ifdef CONFIG_KEYS
3962 
3963 /**
3964  * smack_key_alloc - Set the key security blob
3965  * @key: object
3966  * @cred: the credentials to use
3967  * @flags: unused
3968  *
3969  * No allocation required
3970  *
3971  * Returns 0
3972  */
3973 static int smack_key_alloc(struct key *key, const struct cred *cred,
3974 			   unsigned long flags)
3975 {
3976 	struct smack_known *skp = smk_of_task(cred->security);
3977 
3978 	key->security = skp;
3979 	return 0;
3980 }
3981 
3982 /**
3983  * smack_key_free - Clear the key security blob
3984  * @key: the object
3985  *
3986  * Clear the blob pointer
3987  */
3988 static void smack_key_free(struct key *key)
3989 {
3990 	key->security = NULL;
3991 }
3992 
3993 /**
3994  * smack_key_permission - Smack access on a key
3995  * @key_ref: gets to the object
3996  * @cred: the credentials to use
3997  * @perm: requested key permissions
3998  *
3999  * Return 0 if the task has read and write to the object,
4000  * an error code otherwise
4001  */
4002 static int smack_key_permission(key_ref_t key_ref,
4003 				const struct cred *cred, unsigned perm)
4004 {
4005 	struct key *keyp;
4006 	struct smk_audit_info ad;
4007 	struct smack_known *tkp = smk_of_task(cred->security);
4008 	int request = 0;
4009 	int rc;
4010 
4011 	keyp = key_ref_to_ptr(key_ref);
4012 	if (keyp == NULL)
4013 		return -EINVAL;
4014 	/*
4015 	 * If the key hasn't been initialized give it access so that
4016 	 * it may do so.
4017 	 */
4018 	if (keyp->security == NULL)
4019 		return 0;
4020 	/*
4021 	 * This should not occur
4022 	 */
4023 	if (tkp == NULL)
4024 		return -EACCES;
4025 #ifdef CONFIG_AUDIT
4026 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4027 	ad.a.u.key_struct.key = keyp->serial;
4028 	ad.a.u.key_struct.key_desc = keyp->description;
4029 #endif
4030 	if (perm & KEY_NEED_READ)
4031 		request = MAY_READ;
4032 	if (perm & (KEY_NEED_WRITE | KEY_NEED_LINK | KEY_NEED_SETATTR))
4033 		request = MAY_WRITE;
4034 	rc = smk_access(tkp, keyp->security, request, &ad);
4035 	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
4036 	return rc;
4037 }
4038 
4039 /*
4040  * smack_key_getsecurity - Smack label tagging the key
4041  * @key points to the key to be queried
4042  * @_buffer points to a pointer that should be set to point to the
4043  * resulting string (if no label or an error occurs).
4044  * Return the length of the string (including terminating NUL) or -ve if
4045  * an error.
4046  * May also return 0 (and a NULL buffer pointer) if there is no label.
4047  */
4048 static int smack_key_getsecurity(struct key *key, char **_buffer)
4049 {
4050 	struct smack_known *skp = key->security;
4051 	size_t length;
4052 	char *copy;
4053 
4054 	if (key->security == NULL) {
4055 		*_buffer = NULL;
4056 		return 0;
4057 	}
4058 
4059 	copy = kstrdup(skp->smk_known, GFP_KERNEL);
4060 	if (copy == NULL)
4061 		return -ENOMEM;
4062 	length = strlen(copy) + 1;
4063 
4064 	*_buffer = copy;
4065 	return length;
4066 }
4067 
4068 #endif /* CONFIG_KEYS */
4069 
4070 /*
4071  * Smack Audit hooks
4072  *
4073  * Audit requires a unique representation of each Smack specific
4074  * rule. This unique representation is used to distinguish the
4075  * object to be audited from remaining kernel objects and also
4076  * works as a glue between the audit hooks.
4077  *
4078  * Since repository entries are added but never deleted, we'll use
4079  * the smack_known label address related to the given audit rule as
4080  * the needed unique representation. This also better fits the smack
4081  * model where nearly everything is a label.
4082  */
4083 #ifdef CONFIG_AUDIT
4084 
4085 /**
4086  * smack_audit_rule_init - Initialize a smack audit rule
4087  * @field: audit rule fields given from user-space (audit.h)
4088  * @op: required testing operator (=, !=, >, <, ...)
4089  * @rulestr: smack label to be audited
4090  * @vrule: pointer to save our own audit rule representation
4091  *
4092  * Prepare to audit cases where (@field @op @rulestr) is true.
4093  * The label to be audited is created if necessay.
4094  */
4095 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
4096 {
4097 	struct smack_known *skp;
4098 	char **rule = (char **)vrule;
4099 	*rule = NULL;
4100 
4101 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4102 		return -EINVAL;
4103 
4104 	if (op != Audit_equal && op != Audit_not_equal)
4105 		return -EINVAL;
4106 
4107 	skp = smk_import_entry(rulestr, 0);
4108 	if (skp)
4109 		*rule = skp->smk_known;
4110 
4111 	return 0;
4112 }
4113 
4114 /**
4115  * smack_audit_rule_known - Distinguish Smack audit rules
4116  * @krule: rule of interest, in Audit kernel representation format
4117  *
4118  * This is used to filter Smack rules from remaining Audit ones.
4119  * If it's proved that this rule belongs to us, the
4120  * audit_rule_match hook will be called to do the final judgement.
4121  */
4122 static int smack_audit_rule_known(struct audit_krule *krule)
4123 {
4124 	struct audit_field *f;
4125 	int i;
4126 
4127 	for (i = 0; i < krule->field_count; i++) {
4128 		f = &krule->fields[i];
4129 
4130 		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
4131 			return 1;
4132 	}
4133 
4134 	return 0;
4135 }
4136 
4137 /**
4138  * smack_audit_rule_match - Audit given object ?
4139  * @secid: security id for identifying the object to test
4140  * @field: audit rule flags given from user-space
4141  * @op: required testing operator
4142  * @vrule: smack internal rule presentation
4143  * @actx: audit context associated with the check
4144  *
4145  * The core Audit hook. It's used to take the decision of
4146  * whether to audit or not to audit a given object.
4147  */
4148 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
4149 				  struct audit_context *actx)
4150 {
4151 	struct smack_known *skp;
4152 	char *rule = vrule;
4153 
4154 	if (unlikely(!rule)) {
4155 		WARN_ONCE(1, "Smack: missing rule\n");
4156 		return -ENOENT;
4157 	}
4158 
4159 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4160 		return 0;
4161 
4162 	skp = smack_from_secid(secid);
4163 
4164 	/*
4165 	 * No need to do string comparisons. If a match occurs,
4166 	 * both pointers will point to the same smack_known
4167 	 * label.
4168 	 */
4169 	if (op == Audit_equal)
4170 		return (rule == skp->smk_known);
4171 	if (op == Audit_not_equal)
4172 		return (rule != skp->smk_known);
4173 
4174 	return 0;
4175 }
4176 
4177 /**
4178  * smack_audit_rule_free - free smack rule representation
4179  * @vrule: rule to be freed.
4180  *
4181  * No memory was allocated.
4182  */
4183 static void smack_audit_rule_free(void *vrule)
4184 {
4185 	/* No-op */
4186 }
4187 
4188 #endif /* CONFIG_AUDIT */
4189 
4190 /**
4191  * smack_ismaclabel - check if xattr @name references a smack MAC label
4192  * @name: Full xattr name to check.
4193  */
4194 static int smack_ismaclabel(const char *name)
4195 {
4196 	return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
4197 }
4198 
4199 
4200 /**
4201  * smack_secid_to_secctx - return the smack label for a secid
4202  * @secid: incoming integer
4203  * @secdata: destination
4204  * @seclen: how long it is
4205  *
4206  * Exists for networking code.
4207  */
4208 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
4209 {
4210 	struct smack_known *skp = smack_from_secid(secid);
4211 
4212 	if (secdata)
4213 		*secdata = skp->smk_known;
4214 	*seclen = strlen(skp->smk_known);
4215 	return 0;
4216 }
4217 
4218 /**
4219  * smack_secctx_to_secid - return the secid for a smack label
4220  * @secdata: smack label
4221  * @seclen: how long result is
4222  * @secid: outgoing integer
4223  *
4224  * Exists for audit and networking code.
4225  */
4226 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4227 {
4228 	struct smack_known *skp = smk_find_entry(secdata);
4229 
4230 	if (skp)
4231 		*secid = skp->smk_secid;
4232 	else
4233 		*secid = 0;
4234 	return 0;
4235 }
4236 
4237 /**
4238  * smack_release_secctx - don't do anything.
4239  * @secdata: unused
4240  * @seclen: unused
4241  *
4242  * Exists to make sure nothing gets done, and properly
4243  */
4244 static void smack_release_secctx(char *secdata, u32 seclen)
4245 {
4246 }
4247 
4248 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
4249 {
4250 	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
4251 }
4252 
4253 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
4254 {
4255 	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
4256 }
4257 
4258 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
4259 {
4260 	int len = 0;
4261 	len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
4262 
4263 	if (len < 0)
4264 		return len;
4265 	*ctxlen = len;
4266 	return 0;
4267 }
4268 
4269 struct security_operations smack_ops = {
4270 	.name =				"smack",
4271 
4272 	.ptrace_access_check =		smack_ptrace_access_check,
4273 	.ptrace_traceme =		smack_ptrace_traceme,
4274 	.syslog = 			smack_syslog,
4275 
4276 	.sb_alloc_security = 		smack_sb_alloc_security,
4277 	.sb_free_security = 		smack_sb_free_security,
4278 	.sb_copy_data = 		smack_sb_copy_data,
4279 	.sb_kern_mount = 		smack_sb_kern_mount,
4280 	.sb_statfs = 			smack_sb_statfs,
4281 
4282 	.bprm_set_creds =		smack_bprm_set_creds,
4283 	.bprm_committing_creds =	smack_bprm_committing_creds,
4284 	.bprm_secureexec =		smack_bprm_secureexec,
4285 
4286 	.inode_alloc_security = 	smack_inode_alloc_security,
4287 	.inode_free_security = 		smack_inode_free_security,
4288 	.inode_init_security = 		smack_inode_init_security,
4289 	.inode_link = 			smack_inode_link,
4290 	.inode_unlink = 		smack_inode_unlink,
4291 	.inode_rmdir = 			smack_inode_rmdir,
4292 	.inode_rename = 		smack_inode_rename,
4293 	.inode_permission = 		smack_inode_permission,
4294 	.inode_setattr = 		smack_inode_setattr,
4295 	.inode_getattr = 		smack_inode_getattr,
4296 	.inode_setxattr = 		smack_inode_setxattr,
4297 	.inode_post_setxattr = 		smack_inode_post_setxattr,
4298 	.inode_getxattr = 		smack_inode_getxattr,
4299 	.inode_removexattr = 		smack_inode_removexattr,
4300 	.inode_getsecurity = 		smack_inode_getsecurity,
4301 	.inode_setsecurity = 		smack_inode_setsecurity,
4302 	.inode_listsecurity = 		smack_inode_listsecurity,
4303 	.inode_getsecid =		smack_inode_getsecid,
4304 
4305 	.file_permission = 		smack_file_permission,
4306 	.file_alloc_security = 		smack_file_alloc_security,
4307 	.file_free_security = 		smack_file_free_security,
4308 	.file_ioctl = 			smack_file_ioctl,
4309 	.file_lock = 			smack_file_lock,
4310 	.file_fcntl = 			smack_file_fcntl,
4311 	.mmap_file =			smack_mmap_file,
4312 	.mmap_addr =			cap_mmap_addr,
4313 	.file_set_fowner = 		smack_file_set_fowner,
4314 	.file_send_sigiotask = 		smack_file_send_sigiotask,
4315 	.file_receive = 		smack_file_receive,
4316 
4317 	.file_open =			smack_file_open,
4318 
4319 	.cred_alloc_blank =		smack_cred_alloc_blank,
4320 	.cred_free =			smack_cred_free,
4321 	.cred_prepare =			smack_cred_prepare,
4322 	.cred_transfer =		smack_cred_transfer,
4323 	.kernel_act_as =		smack_kernel_act_as,
4324 	.kernel_create_files_as =	smack_kernel_create_files_as,
4325 	.task_setpgid = 		smack_task_setpgid,
4326 	.task_getpgid = 		smack_task_getpgid,
4327 	.task_getsid = 			smack_task_getsid,
4328 	.task_getsecid = 		smack_task_getsecid,
4329 	.task_setnice = 		smack_task_setnice,
4330 	.task_setioprio = 		smack_task_setioprio,
4331 	.task_getioprio = 		smack_task_getioprio,
4332 	.task_setscheduler = 		smack_task_setscheduler,
4333 	.task_getscheduler = 		smack_task_getscheduler,
4334 	.task_movememory = 		smack_task_movememory,
4335 	.task_kill = 			smack_task_kill,
4336 	.task_wait = 			smack_task_wait,
4337 	.task_to_inode = 		smack_task_to_inode,
4338 
4339 	.ipc_permission = 		smack_ipc_permission,
4340 	.ipc_getsecid =			smack_ipc_getsecid,
4341 
4342 	.msg_msg_alloc_security = 	smack_msg_msg_alloc_security,
4343 	.msg_msg_free_security = 	smack_msg_msg_free_security,
4344 
4345 	.msg_queue_alloc_security = 	smack_msg_queue_alloc_security,
4346 	.msg_queue_free_security = 	smack_msg_queue_free_security,
4347 	.msg_queue_associate = 		smack_msg_queue_associate,
4348 	.msg_queue_msgctl = 		smack_msg_queue_msgctl,
4349 	.msg_queue_msgsnd = 		smack_msg_queue_msgsnd,
4350 	.msg_queue_msgrcv = 		smack_msg_queue_msgrcv,
4351 
4352 	.shm_alloc_security = 		smack_shm_alloc_security,
4353 	.shm_free_security = 		smack_shm_free_security,
4354 	.shm_associate = 		smack_shm_associate,
4355 	.shm_shmctl = 			smack_shm_shmctl,
4356 	.shm_shmat = 			smack_shm_shmat,
4357 
4358 	.sem_alloc_security = 		smack_sem_alloc_security,
4359 	.sem_free_security = 		smack_sem_free_security,
4360 	.sem_associate = 		smack_sem_associate,
4361 	.sem_semctl = 			smack_sem_semctl,
4362 	.sem_semop = 			smack_sem_semop,
4363 
4364 	.d_instantiate = 		smack_d_instantiate,
4365 
4366 	.getprocattr = 			smack_getprocattr,
4367 	.setprocattr = 			smack_setprocattr,
4368 
4369 	.unix_stream_connect = 		smack_unix_stream_connect,
4370 	.unix_may_send = 		smack_unix_may_send,
4371 
4372 	.socket_post_create = 		smack_socket_post_create,
4373 #ifndef CONFIG_SECURITY_SMACK_NETFILTER
4374 	.socket_bind =			smack_socket_bind,
4375 #endif /* CONFIG_SECURITY_SMACK_NETFILTER */
4376 	.socket_connect =		smack_socket_connect,
4377 	.socket_sendmsg =		smack_socket_sendmsg,
4378 	.socket_sock_rcv_skb = 		smack_socket_sock_rcv_skb,
4379 	.socket_getpeersec_stream =	smack_socket_getpeersec_stream,
4380 	.socket_getpeersec_dgram =	smack_socket_getpeersec_dgram,
4381 	.sk_alloc_security = 		smack_sk_alloc_security,
4382 	.sk_free_security = 		smack_sk_free_security,
4383 	.sock_graft = 			smack_sock_graft,
4384 	.inet_conn_request = 		smack_inet_conn_request,
4385 	.inet_csk_clone =		smack_inet_csk_clone,
4386 
4387  /* key management security hooks */
4388 #ifdef CONFIG_KEYS
4389 	.key_alloc = 			smack_key_alloc,
4390 	.key_free = 			smack_key_free,
4391 	.key_permission = 		smack_key_permission,
4392 	.key_getsecurity =		smack_key_getsecurity,
4393 #endif /* CONFIG_KEYS */
4394 
4395  /* Audit hooks */
4396 #ifdef CONFIG_AUDIT
4397 	.audit_rule_init =		smack_audit_rule_init,
4398 	.audit_rule_known =		smack_audit_rule_known,
4399 	.audit_rule_match =		smack_audit_rule_match,
4400 	.audit_rule_free =		smack_audit_rule_free,
4401 #endif /* CONFIG_AUDIT */
4402 
4403 	.ismaclabel =			smack_ismaclabel,
4404 	.secid_to_secctx = 		smack_secid_to_secctx,
4405 	.secctx_to_secid = 		smack_secctx_to_secid,
4406 	.release_secctx = 		smack_release_secctx,
4407 	.inode_notifysecctx =		smack_inode_notifysecctx,
4408 	.inode_setsecctx =		smack_inode_setsecctx,
4409 	.inode_getsecctx =		smack_inode_getsecctx,
4410 };
4411 
4412 
4413 static __init void init_smack_known_list(void)
4414 {
4415 	/*
4416 	 * Initialize rule list locks
4417 	 */
4418 	mutex_init(&smack_known_huh.smk_rules_lock);
4419 	mutex_init(&smack_known_hat.smk_rules_lock);
4420 	mutex_init(&smack_known_floor.smk_rules_lock);
4421 	mutex_init(&smack_known_star.smk_rules_lock);
4422 	mutex_init(&smack_known_invalid.smk_rules_lock);
4423 	mutex_init(&smack_known_web.smk_rules_lock);
4424 	/*
4425 	 * Initialize rule lists
4426 	 */
4427 	INIT_LIST_HEAD(&smack_known_huh.smk_rules);
4428 	INIT_LIST_HEAD(&smack_known_hat.smk_rules);
4429 	INIT_LIST_HEAD(&smack_known_star.smk_rules);
4430 	INIT_LIST_HEAD(&smack_known_floor.smk_rules);
4431 	INIT_LIST_HEAD(&smack_known_invalid.smk_rules);
4432 	INIT_LIST_HEAD(&smack_known_web.smk_rules);
4433 	/*
4434 	 * Create the known labels list
4435 	 */
4436 	smk_insert_entry(&smack_known_huh);
4437 	smk_insert_entry(&smack_known_hat);
4438 	smk_insert_entry(&smack_known_star);
4439 	smk_insert_entry(&smack_known_floor);
4440 	smk_insert_entry(&smack_known_invalid);
4441 	smk_insert_entry(&smack_known_web);
4442 }
4443 
4444 /**
4445  * smack_init - initialize the smack system
4446  *
4447  * Returns 0
4448  */
4449 static __init int smack_init(void)
4450 {
4451 	struct cred *cred;
4452 	struct task_smack *tsp;
4453 
4454 	if (!security_module_enable(&smack_ops))
4455 		return 0;
4456 
4457 	smack_enabled = 1;
4458 
4459 	smack_inode_cache = KMEM_CACHE(inode_smack, 0);
4460 	if (!smack_inode_cache)
4461 		return -ENOMEM;
4462 
4463 	tsp = new_task_smack(&smack_known_floor, &smack_known_floor,
4464 				GFP_KERNEL);
4465 	if (tsp == NULL) {
4466 		kmem_cache_destroy(smack_inode_cache);
4467 		return -ENOMEM;
4468 	}
4469 
4470 	printk(KERN_INFO "Smack:  Initializing.\n");
4471 
4472 	/*
4473 	 * Set the security state for the initial task.
4474 	 */
4475 	cred = (struct cred *) current->cred;
4476 	cred->security = tsp;
4477 
4478 	/* initialize the smack_known_list */
4479 	init_smack_known_list();
4480 
4481 	/*
4482 	 * Register with LSM
4483 	 */
4484 	if (register_security(&smack_ops))
4485 		panic("smack: Unable to register with kernel.\n");
4486 
4487 	return 0;
4488 }
4489 
4490 /*
4491  * Smack requires early initialization in order to label
4492  * all processes and objects when they are created.
4493  */
4494 security_initcall(smack_init);
4495