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