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 <ext-jarkko.2.sakkinen@nokia.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.moore@hp.com>
13  *  Copyright (C) 2010 Nokia Corporation
14  *
15  *	This program is free software; you can redistribute it and/or modify
16  *	it under the terms of the GNU General Public License version 2,
17  *      as published by the Free Software Foundation.
18  */
19 
20 #include <linux/xattr.h>
21 #include <linux/pagemap.h>
22 #include <linux/mount.h>
23 #include <linux/stat.h>
24 #include <linux/kd.h>
25 #include <asm/ioctls.h>
26 #include <linux/ip.h>
27 #include <linux/tcp.h>
28 #include <linux/udp.h>
29 #include <linux/slab.h>
30 #include <linux/mutex.h>
31 #include <linux/pipe_fs_i.h>
32 #include <net/netlabel.h>
33 #include <net/cipso_ipv4.h>
34 #include <linux/audit.h>
35 #include <linux/magic.h>
36 #include <linux/dcache.h>
37 #include "smack.h"
38 
39 #define task_security(task)	(task_cred_xxx((task), security))
40 
41 #define TRANS_TRUE	"TRUE"
42 #define TRANS_TRUE_SIZE	4
43 
44 /**
45  * smk_fetch - Fetch the smack label from a file.
46  * @ip: a pointer to the inode
47  * @dp: a pointer to the dentry
48  *
49  * Returns a pointer to the master list entry for the Smack label
50  * or NULL if there was no label to fetch.
51  */
smk_fetch(const char * name,struct inode * ip,struct dentry * dp)52 static char *smk_fetch(const char *name, struct inode *ip, struct dentry *dp)
53 {
54 	int rc;
55 	char in[SMK_LABELLEN];
56 
57 	if (ip->i_op->getxattr == NULL)
58 		return NULL;
59 
60 	rc = ip->i_op->getxattr(dp, name, in, SMK_LABELLEN);
61 	if (rc < 0)
62 		return NULL;
63 
64 	return smk_import(in, rc);
65 }
66 
67 /**
68  * new_inode_smack - allocate an inode security blob
69  * @smack: a pointer to the Smack label to use in the blob
70  *
71  * Returns the new blob or NULL if there's no memory available
72  */
new_inode_smack(char * smack)73 struct inode_smack *new_inode_smack(char *smack)
74 {
75 	struct inode_smack *isp;
76 
77 	isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
78 	if (isp == NULL)
79 		return NULL;
80 
81 	isp->smk_inode = smack;
82 	isp->smk_flags = 0;
83 	mutex_init(&isp->smk_lock);
84 
85 	return isp;
86 }
87 
88 /**
89  * new_task_smack - allocate a task security blob
90  * @smack: a pointer to the Smack label to use in the blob
91  *
92  * Returns the new blob or NULL if there's no memory available
93  */
new_task_smack(char * task,char * forked,gfp_t gfp)94 static struct task_smack *new_task_smack(char *task, char *forked, gfp_t gfp)
95 {
96 	struct task_smack *tsp;
97 
98 	tsp = kzalloc(sizeof(struct task_smack), gfp);
99 	if (tsp == NULL)
100 		return NULL;
101 
102 	tsp->smk_task = task;
103 	tsp->smk_forked = forked;
104 	INIT_LIST_HEAD(&tsp->smk_rules);
105 	mutex_init(&tsp->smk_rules_lock);
106 
107 	return tsp;
108 }
109 
110 /**
111  * smk_copy_rules - copy a rule set
112  * @nhead - new rules header pointer
113  * @ohead - old rules header pointer
114  *
115  * Returns 0 on success, -ENOMEM on error
116  */
smk_copy_rules(struct list_head * nhead,struct list_head * ohead,gfp_t gfp)117 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
118 				gfp_t gfp)
119 {
120 	struct smack_rule *nrp;
121 	struct smack_rule *orp;
122 	int rc = 0;
123 
124 	INIT_LIST_HEAD(nhead);
125 
126 	list_for_each_entry_rcu(orp, ohead, list) {
127 		nrp = kzalloc(sizeof(struct smack_rule), gfp);
128 		if (nrp == NULL) {
129 			rc = -ENOMEM;
130 			break;
131 		}
132 		*nrp = *orp;
133 		list_add_rcu(&nrp->list, nhead);
134 	}
135 	return rc;
136 }
137 
138 /*
139  * LSM hooks.
140  * We he, that is fun!
141  */
142 
143 /**
144  * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
145  * @ctp: child task pointer
146  * @mode: ptrace attachment mode
147  *
148  * Returns 0 if access is OK, an error code otherwise
149  *
150  * Do the capability checks, and require read and write.
151  */
smack_ptrace_access_check(struct task_struct * ctp,unsigned int mode)152 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
153 {
154 	int rc;
155 	struct smk_audit_info ad;
156 	char *tsp;
157 
158 	rc = cap_ptrace_access_check(ctp, mode);
159 	if (rc != 0)
160 		return rc;
161 
162 	tsp = smk_of_task(task_security(ctp));
163 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
164 	smk_ad_setfield_u_tsk(&ad, ctp);
165 
166 	rc = smk_curacc(tsp, MAY_READWRITE, &ad);
167 	return rc;
168 }
169 
170 /**
171  * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
172  * @ptp: parent task pointer
173  *
174  * Returns 0 if access is OK, an error code otherwise
175  *
176  * Do the capability checks, and require read and write.
177  */
smack_ptrace_traceme(struct task_struct * ptp)178 static int smack_ptrace_traceme(struct task_struct *ptp)
179 {
180 	int rc;
181 	struct smk_audit_info ad;
182 	char *tsp;
183 
184 	rc = cap_ptrace_traceme(ptp);
185 	if (rc != 0)
186 		return rc;
187 
188 	tsp = smk_of_task(task_security(ptp));
189 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
190 	smk_ad_setfield_u_tsk(&ad, ptp);
191 
192 	rc = smk_curacc(tsp, MAY_READWRITE, &ad);
193 	return rc;
194 }
195 
196 /**
197  * smack_syslog - Smack approval on syslog
198  * @type: message type
199  *
200  * Require that the task has the floor label
201  *
202  * Returns 0 on success, error code otherwise.
203  */
smack_syslog(int typefrom_file)204 static int smack_syslog(int typefrom_file)
205 {
206 	int rc = 0;
207 	char *sp = smk_of_current();
208 
209 	if (capable(CAP_MAC_OVERRIDE))
210 		return 0;
211 
212 	 if (sp != smack_known_floor.smk_known)
213 		rc = -EACCES;
214 
215 	return rc;
216 }
217 
218 
219 /*
220  * Superblock Hooks.
221  */
222 
223 /**
224  * smack_sb_alloc_security - allocate a superblock blob
225  * @sb: the superblock getting the blob
226  *
227  * Returns 0 on success or -ENOMEM on error.
228  */
smack_sb_alloc_security(struct super_block * sb)229 static int smack_sb_alloc_security(struct super_block *sb)
230 {
231 	struct superblock_smack *sbsp;
232 
233 	sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
234 
235 	if (sbsp == NULL)
236 		return -ENOMEM;
237 
238 	sbsp->smk_root = smack_known_floor.smk_known;
239 	sbsp->smk_default = smack_known_floor.smk_known;
240 	sbsp->smk_floor = smack_known_floor.smk_known;
241 	sbsp->smk_hat = smack_known_hat.smk_known;
242 	sbsp->smk_initialized = 0;
243 	spin_lock_init(&sbsp->smk_sblock);
244 
245 	sb->s_security = sbsp;
246 
247 	return 0;
248 }
249 
250 /**
251  * smack_sb_free_security - free a superblock blob
252  * @sb: the superblock getting the blob
253  *
254  */
smack_sb_free_security(struct super_block * sb)255 static void smack_sb_free_security(struct super_block *sb)
256 {
257 	kfree(sb->s_security);
258 	sb->s_security = NULL;
259 }
260 
261 /**
262  * smack_sb_copy_data - copy mount options data for processing
263  * @orig: where to start
264  * @smackopts: mount options string
265  *
266  * Returns 0 on success or -ENOMEM on error.
267  *
268  * Copy the Smack specific mount options out of the mount
269  * options list.
270  */
smack_sb_copy_data(char * orig,char * smackopts)271 static int smack_sb_copy_data(char *orig, char *smackopts)
272 {
273 	char *cp, *commap, *otheropts, *dp;
274 
275 	otheropts = (char *)get_zeroed_page(GFP_KERNEL);
276 	if (otheropts == NULL)
277 		return -ENOMEM;
278 
279 	for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
280 		if (strstr(cp, SMK_FSDEFAULT) == cp)
281 			dp = smackopts;
282 		else if (strstr(cp, SMK_FSFLOOR) == cp)
283 			dp = smackopts;
284 		else if (strstr(cp, SMK_FSHAT) == cp)
285 			dp = smackopts;
286 		else if (strstr(cp, SMK_FSROOT) == cp)
287 			dp = smackopts;
288 		else
289 			dp = otheropts;
290 
291 		commap = strchr(cp, ',');
292 		if (commap != NULL)
293 			*commap = '\0';
294 
295 		if (*dp != '\0')
296 			strcat(dp, ",");
297 		strcat(dp, cp);
298 	}
299 
300 	strcpy(orig, otheropts);
301 	free_page((unsigned long)otheropts);
302 
303 	return 0;
304 }
305 
306 /**
307  * smack_sb_kern_mount - Smack specific mount processing
308  * @sb: the file system superblock
309  * @flags: the mount flags
310  * @data: the smack mount options
311  *
312  * Returns 0 on success, an error code on failure
313  */
smack_sb_kern_mount(struct super_block * sb,int flags,void * data)314 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
315 {
316 	struct dentry *root = sb->s_root;
317 	struct inode *inode = root->d_inode;
318 	struct superblock_smack *sp = sb->s_security;
319 	struct inode_smack *isp;
320 	char *op;
321 	char *commap;
322 	char *nsp;
323 
324 	spin_lock(&sp->smk_sblock);
325 	if (sp->smk_initialized != 0) {
326 		spin_unlock(&sp->smk_sblock);
327 		return 0;
328 	}
329 	sp->smk_initialized = 1;
330 	spin_unlock(&sp->smk_sblock);
331 
332 	for (op = data; op != NULL; op = commap) {
333 		commap = strchr(op, ',');
334 		if (commap != NULL)
335 			*commap++ = '\0';
336 
337 		if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
338 			op += strlen(SMK_FSHAT);
339 			nsp = smk_import(op, 0);
340 			if (nsp != NULL)
341 				sp->smk_hat = nsp;
342 		} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
343 			op += strlen(SMK_FSFLOOR);
344 			nsp = smk_import(op, 0);
345 			if (nsp != NULL)
346 				sp->smk_floor = nsp;
347 		} else if (strncmp(op, SMK_FSDEFAULT,
348 				   strlen(SMK_FSDEFAULT)) == 0) {
349 			op += strlen(SMK_FSDEFAULT);
350 			nsp = smk_import(op, 0);
351 			if (nsp != NULL)
352 				sp->smk_default = nsp;
353 		} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
354 			op += strlen(SMK_FSROOT);
355 			nsp = smk_import(op, 0);
356 			if (nsp != NULL)
357 				sp->smk_root = nsp;
358 		}
359 	}
360 
361 	/*
362 	 * Initialize the root inode.
363 	 */
364 	isp = inode->i_security;
365 	if (isp == NULL)
366 		inode->i_security = new_inode_smack(sp->smk_root);
367 	else
368 		isp->smk_inode = sp->smk_root;
369 
370 	return 0;
371 }
372 
373 /**
374  * smack_sb_statfs - Smack check on statfs
375  * @dentry: identifies the file system in question
376  *
377  * Returns 0 if current can read the floor of the filesystem,
378  * and error code otherwise
379  */
smack_sb_statfs(struct dentry * dentry)380 static int smack_sb_statfs(struct dentry *dentry)
381 {
382 	struct superblock_smack *sbp = dentry->d_sb->s_security;
383 	int rc;
384 	struct smk_audit_info ad;
385 
386 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
387 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
388 
389 	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
390 	return rc;
391 }
392 
393 /**
394  * smack_sb_mount - Smack check for mounting
395  * @dev_name: unused
396  * @path: mount point
397  * @type: unused
398  * @flags: unused
399  * @data: unused
400  *
401  * Returns 0 if current can write the floor of the filesystem
402  * being mounted on, an error code otherwise.
403  */
smack_sb_mount(char * dev_name,struct path * path,char * type,unsigned long flags,void * data)404 static int smack_sb_mount(char *dev_name, struct path *path,
405 			  char *type, unsigned long flags, void *data)
406 {
407 	struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
408 	struct smk_audit_info ad;
409 
410 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
411 	smk_ad_setfield_u_fs_path(&ad, *path);
412 
413 	return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
414 }
415 
416 /**
417  * smack_sb_umount - Smack check for unmounting
418  * @mnt: file system to unmount
419  * @flags: unused
420  *
421  * Returns 0 if current can write the floor of the filesystem
422  * being unmounted, an error code otherwise.
423  */
smack_sb_umount(struct vfsmount * mnt,int flags)424 static int smack_sb_umount(struct vfsmount *mnt, int flags)
425 {
426 	struct superblock_smack *sbp;
427 	struct smk_audit_info ad;
428 
429 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
430 	smk_ad_setfield_u_fs_path_dentry(&ad, mnt->mnt_root);
431 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
432 
433 	sbp = mnt->mnt_sb->s_security;
434 	return smk_curacc(sbp->smk_floor, MAY_WRITE, &ad);
435 }
436 
437 /*
438  * BPRM hooks
439  */
440 
smack_bprm_set_creds(struct linux_binprm * bprm)441 static int smack_bprm_set_creds(struct linux_binprm *bprm)
442 {
443 	struct task_smack *tsp = bprm->cred->security;
444 	struct inode_smack *isp;
445 	struct dentry *dp;
446 	int rc;
447 
448 	rc = cap_bprm_set_creds(bprm);
449 	if (rc != 0)
450 		return rc;
451 
452 	if (bprm->cred_prepared)
453 		return 0;
454 
455 	if (bprm->file == NULL || bprm->file->f_dentry == NULL)
456 		return 0;
457 
458 	dp = bprm->file->f_dentry;
459 
460 	if (dp->d_inode == NULL)
461 		return 0;
462 
463 	isp = dp->d_inode->i_security;
464 
465 	if (isp->smk_task != NULL)
466 		tsp->smk_task = isp->smk_task;
467 
468 	return 0;
469 }
470 
471 /*
472  * Inode hooks
473  */
474 
475 /**
476  * smack_inode_alloc_security - allocate an inode blob
477  * @inode: the inode in need of a blob
478  *
479  * Returns 0 if it gets a blob, -ENOMEM otherwise
480  */
smack_inode_alloc_security(struct inode * inode)481 static int smack_inode_alloc_security(struct inode *inode)
482 {
483 	inode->i_security = new_inode_smack(smk_of_current());
484 	if (inode->i_security == NULL)
485 		return -ENOMEM;
486 	return 0;
487 }
488 
489 /**
490  * smack_inode_free_security - free an inode blob
491  * @inode: the inode with a blob
492  *
493  * Clears the blob pointer in inode
494  */
smack_inode_free_security(struct inode * inode)495 static void smack_inode_free_security(struct inode *inode)
496 {
497 	kfree(inode->i_security);
498 	inode->i_security = NULL;
499 }
500 
501 /**
502  * smack_inode_init_security - copy out the smack from an inode
503  * @inode: the inode
504  * @dir: unused
505  * @qstr: unused
506  * @name: where to put the attribute name
507  * @value: where to put the attribute value
508  * @len: where to put the length of the attribute
509  *
510  * Returns 0 if it all works out, -ENOMEM if there's no memory
511  */
smack_inode_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr,char ** name,void ** value,size_t * len)512 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
513 				     const struct qstr *qstr, char **name,
514 				     void **value, size_t *len)
515 {
516 	char *isp = smk_of_inode(inode);
517 	char *dsp = smk_of_inode(dir);
518 	int may;
519 
520 	if (name) {
521 		*name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
522 		if (*name == NULL)
523 			return -ENOMEM;
524 	}
525 
526 	if (value) {
527 		rcu_read_lock();
528 		may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
529 		rcu_read_unlock();
530 
531 		/*
532 		 * If the access rule allows transmutation and
533 		 * the directory requests transmutation then
534 		 * by all means transmute.
535 		 */
536 		if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
537 		    smk_inode_transmutable(dir))
538 			isp = dsp;
539 
540 		*value = kstrdup(isp, GFP_KERNEL);
541 		if (*value == NULL)
542 			return -ENOMEM;
543 	}
544 
545 	if (len)
546 		*len = strlen(isp) + 1;
547 
548 	return 0;
549 }
550 
551 /**
552  * smack_inode_link - Smack check on link
553  * @old_dentry: the existing object
554  * @dir: unused
555  * @new_dentry: the new object
556  *
557  * Returns 0 if access is permitted, an error code otherwise
558  */
smack_inode_link(struct dentry * old_dentry,struct inode * dir,struct dentry * new_dentry)559 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
560 			    struct dentry *new_dentry)
561 {
562 	char *isp;
563 	struct smk_audit_info ad;
564 	int rc;
565 
566 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
567 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
568 
569 	isp = smk_of_inode(old_dentry->d_inode);
570 	rc = smk_curacc(isp, MAY_WRITE, &ad);
571 
572 	if (rc == 0 && new_dentry->d_inode != NULL) {
573 		isp = smk_of_inode(new_dentry->d_inode);
574 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
575 		rc = smk_curacc(isp, MAY_WRITE, &ad);
576 	}
577 
578 	return rc;
579 }
580 
581 /**
582  * smack_inode_unlink - Smack check on inode deletion
583  * @dir: containing directory object
584  * @dentry: file to unlink
585  *
586  * Returns 0 if current can write the containing directory
587  * and the object, error code otherwise
588  */
smack_inode_unlink(struct inode * dir,struct dentry * dentry)589 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
590 {
591 	struct inode *ip = dentry->d_inode;
592 	struct smk_audit_info ad;
593 	int rc;
594 
595 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
596 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
597 
598 	/*
599 	 * You need write access to the thing you're unlinking
600 	 */
601 	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
602 	if (rc == 0) {
603 		/*
604 		 * You also need write access to the containing directory
605 		 */
606 		smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
607 		smk_ad_setfield_u_fs_inode(&ad, dir);
608 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
609 	}
610 	return rc;
611 }
612 
613 /**
614  * smack_inode_rmdir - Smack check on directory deletion
615  * @dir: containing directory object
616  * @dentry: directory to unlink
617  *
618  * Returns 0 if current can write the containing directory
619  * and the directory, error code otherwise
620  */
smack_inode_rmdir(struct inode * dir,struct dentry * dentry)621 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
622 {
623 	struct smk_audit_info ad;
624 	int rc;
625 
626 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
627 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
628 
629 	/*
630 	 * You need write access to the thing you're removing
631 	 */
632 	rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
633 	if (rc == 0) {
634 		/*
635 		 * You also need write access to the containing directory
636 		 */
637 		smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
638 		smk_ad_setfield_u_fs_inode(&ad, dir);
639 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
640 	}
641 
642 	return rc;
643 }
644 
645 /**
646  * smack_inode_rename - Smack check on rename
647  * @old_inode: the old directory
648  * @old_dentry: unused
649  * @new_inode: the new directory
650  * @new_dentry: unused
651  *
652  * Read and write access is required on both the old and
653  * new directories.
654  *
655  * Returns 0 if access is permitted, an error code otherwise
656  */
smack_inode_rename(struct inode * old_inode,struct dentry * old_dentry,struct inode * new_inode,struct dentry * new_dentry)657 static int smack_inode_rename(struct inode *old_inode,
658 			      struct dentry *old_dentry,
659 			      struct inode *new_inode,
660 			      struct dentry *new_dentry)
661 {
662 	int rc;
663 	char *isp;
664 	struct smk_audit_info ad;
665 
666 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
667 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
668 
669 	isp = smk_of_inode(old_dentry->d_inode);
670 	rc = smk_curacc(isp, MAY_READWRITE, &ad);
671 
672 	if (rc == 0 && new_dentry->d_inode != NULL) {
673 		isp = smk_of_inode(new_dentry->d_inode);
674 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
675 		rc = smk_curacc(isp, MAY_READWRITE, &ad);
676 	}
677 	return rc;
678 }
679 
680 /**
681  * smack_inode_permission - Smack version of permission()
682  * @inode: the inode in question
683  * @mask: the access requested
684  *
685  * This is the important Smack hook.
686  *
687  * Returns 0 if access is permitted, -EACCES otherwise
688  */
smack_inode_permission(struct inode * inode,int mask,unsigned flags)689 static int smack_inode_permission(struct inode *inode, int mask, unsigned flags)
690 {
691 	struct smk_audit_info ad;
692 
693 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
694 	/*
695 	 * No permission to check. Existence test. Yup, it's there.
696 	 */
697 	if (mask == 0)
698 		return 0;
699 
700 	/* May be droppable after audit */
701 	if (flags & IPERM_FLAG_RCU)
702 		return -ECHILD;
703 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
704 	smk_ad_setfield_u_fs_inode(&ad, inode);
705 	return smk_curacc(smk_of_inode(inode), mask, &ad);
706 }
707 
708 /**
709  * smack_inode_setattr - Smack check for setting attributes
710  * @dentry: the object
711  * @iattr: for the force flag
712  *
713  * Returns 0 if access is permitted, an error code otherwise
714  */
smack_inode_setattr(struct dentry * dentry,struct iattr * iattr)715 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
716 {
717 	struct smk_audit_info ad;
718 	/*
719 	 * Need to allow for clearing the setuid bit.
720 	 */
721 	if (iattr->ia_valid & ATTR_FORCE)
722 		return 0;
723 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
724 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
725 
726 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
727 }
728 
729 /**
730  * smack_inode_getattr - Smack check for getting attributes
731  * @mnt: unused
732  * @dentry: the object
733  *
734  * Returns 0 if access is permitted, an error code otherwise
735  */
smack_inode_getattr(struct vfsmount * mnt,struct dentry * dentry)736 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
737 {
738 	struct smk_audit_info ad;
739 
740 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
741 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
742 	smk_ad_setfield_u_fs_path_mnt(&ad, mnt);
743 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
744 }
745 
746 /**
747  * smack_inode_setxattr - Smack check for setting xattrs
748  * @dentry: the object
749  * @name: name of the attribute
750  * @value: unused
751  * @size: unused
752  * @flags: unused
753  *
754  * This protects the Smack attribute explicitly.
755  *
756  * Returns 0 if access is permitted, an error code otherwise
757  */
smack_inode_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)758 static int smack_inode_setxattr(struct dentry *dentry, const char *name,
759 				const void *value, size_t size, int flags)
760 {
761 	struct smk_audit_info ad;
762 	int rc = 0;
763 
764 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
765 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
766 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
767 	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
768 	    strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
769 		if (!capable(CAP_MAC_ADMIN))
770 			rc = -EPERM;
771 		/*
772 		 * check label validity here so import wont fail on
773 		 * post_setxattr
774 		 */
775 		if (size == 0 || size >= SMK_LABELLEN ||
776 		    smk_import(value, size) == NULL)
777 			rc = -EINVAL;
778 	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
779 		if (!capable(CAP_MAC_ADMIN))
780 			rc = -EPERM;
781 		if (size != TRANS_TRUE_SIZE ||
782 		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
783 			rc = -EINVAL;
784 	} else
785 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
786 
787 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
788 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
789 
790 	if (rc == 0)
791 		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
792 
793 	return rc;
794 }
795 
796 /**
797  * smack_inode_post_setxattr - Apply the Smack update approved above
798  * @dentry: object
799  * @name: attribute name
800  * @value: attribute value
801  * @size: attribute size
802  * @flags: unused
803  *
804  * Set the pointer in the inode blob to the entry found
805  * in the master label list.
806  */
smack_inode_post_setxattr(struct dentry * dentry,const char * name,const void * value,size_t size,int flags)807 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
808 				      const void *value, size_t size, int flags)
809 {
810 	char *nsp;
811 	struct inode_smack *isp = dentry->d_inode->i_security;
812 
813 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
814 		nsp = smk_import(value, size);
815 		if (nsp != NULL)
816 			isp->smk_inode = nsp;
817 		else
818 			isp->smk_inode = smack_known_invalid.smk_known;
819 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
820 		nsp = smk_import(value, size);
821 		if (nsp != NULL)
822 			isp->smk_task = nsp;
823 		else
824 			isp->smk_task = smack_known_invalid.smk_known;
825 	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
826 		nsp = smk_import(value, size);
827 		if (nsp != NULL)
828 			isp->smk_mmap = nsp;
829 		else
830 			isp->smk_mmap = smack_known_invalid.smk_known;
831 	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
832 		isp->smk_flags |= SMK_INODE_TRANSMUTE;
833 
834 	return;
835 }
836 
837 /*
838  * smack_inode_getxattr - Smack check on getxattr
839  * @dentry: the object
840  * @name: unused
841  *
842  * Returns 0 if access is permitted, an error code otherwise
843  */
smack_inode_getxattr(struct dentry * dentry,const char * name)844 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
845 {
846 	struct smk_audit_info ad;
847 
848 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
849 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
850 
851 	return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
852 }
853 
854 /*
855  * smack_inode_removexattr - Smack check on removexattr
856  * @dentry: the object
857  * @name: name of the attribute
858  *
859  * Removing the Smack attribute requires CAP_MAC_ADMIN
860  *
861  * Returns 0 if access is permitted, an error code otherwise
862  */
smack_inode_removexattr(struct dentry * dentry,const char * name)863 static int smack_inode_removexattr(struct dentry *dentry, const char *name)
864 {
865 	struct inode_smack *isp;
866 	struct smk_audit_info ad;
867 	int rc = 0;
868 
869 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
870 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
871 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
872 	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
873 	    strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
874 	    strcmp(name, XATTR_NAME_SMACKMMAP)) {
875 		if (!capable(CAP_MAC_ADMIN))
876 			rc = -EPERM;
877 	} else
878 		rc = cap_inode_removexattr(dentry, name);
879 
880 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
881 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
882 	if (rc == 0)
883 		rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE, &ad);
884 
885 	if (rc == 0) {
886 		isp = dentry->d_inode->i_security;
887 		isp->smk_task = NULL;
888 		isp->smk_mmap = NULL;
889 	}
890 
891 	return rc;
892 }
893 
894 /**
895  * smack_inode_getsecurity - get smack xattrs
896  * @inode: the object
897  * @name: attribute name
898  * @buffer: where to put the result
899  * @alloc: unused
900  *
901  * Returns the size of the attribute or an error code
902  */
smack_inode_getsecurity(const struct inode * inode,const char * name,void ** buffer,bool alloc)903 static int smack_inode_getsecurity(const struct inode *inode,
904 				   const char *name, void **buffer,
905 				   bool alloc)
906 {
907 	struct socket_smack *ssp;
908 	struct socket *sock;
909 	struct super_block *sbp;
910 	struct inode *ip = (struct inode *)inode;
911 	char *isp;
912 	int ilen;
913 	int rc = 0;
914 
915 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
916 		isp = smk_of_inode(inode);
917 		ilen = strlen(isp) + 1;
918 		*buffer = isp;
919 		return ilen;
920 	}
921 
922 	/*
923 	 * The rest of the Smack xattrs are only on sockets.
924 	 */
925 	sbp = ip->i_sb;
926 	if (sbp->s_magic != SOCKFS_MAGIC)
927 		return -EOPNOTSUPP;
928 
929 	sock = SOCKET_I(ip);
930 	if (sock == NULL || sock->sk == NULL)
931 		return -EOPNOTSUPP;
932 
933 	ssp = sock->sk->sk_security;
934 
935 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
936 		isp = ssp->smk_in;
937 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
938 		isp = ssp->smk_out;
939 	else
940 		return -EOPNOTSUPP;
941 
942 	ilen = strlen(isp) + 1;
943 	if (rc == 0) {
944 		*buffer = isp;
945 		rc = ilen;
946 	}
947 
948 	return rc;
949 }
950 
951 
952 /**
953  * smack_inode_listsecurity - list the Smack attributes
954  * @inode: the object
955  * @buffer: where they go
956  * @buffer_size: size of buffer
957  *
958  * Returns 0 on success, -EINVAL otherwise
959  */
smack_inode_listsecurity(struct inode * inode,char * buffer,size_t buffer_size)960 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
961 				    size_t buffer_size)
962 {
963 	int len = strlen(XATTR_NAME_SMACK);
964 
965 	if (buffer != NULL && len <= buffer_size) {
966 		memcpy(buffer, XATTR_NAME_SMACK, len);
967 		return len;
968 	}
969 	return -EINVAL;
970 }
971 
972 /**
973  * smack_inode_getsecid - Extract inode's security id
974  * @inode: inode to extract the info from
975  * @secid: where result will be saved
976  */
smack_inode_getsecid(const struct inode * inode,u32 * secid)977 static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
978 {
979 	struct inode_smack *isp = inode->i_security;
980 
981 	*secid = smack_to_secid(isp->smk_inode);
982 }
983 
984 /*
985  * File Hooks
986  */
987 
988 /**
989  * smack_file_permission - Smack check on file operations
990  * @file: unused
991  * @mask: unused
992  *
993  * Returns 0
994  *
995  * Should access checks be done on each read or write?
996  * UNICOS and SELinux say yes.
997  * Trusted Solaris, Trusted Irix, and just about everyone else says no.
998  *
999  * I'll say no for now. Smack does not do the frequent
1000  * label changing that SELinux does.
1001  */
smack_file_permission(struct file * file,int mask)1002 static int smack_file_permission(struct file *file, int mask)
1003 {
1004 	return 0;
1005 }
1006 
1007 /**
1008  * smack_file_alloc_security - assign a file security blob
1009  * @file: the object
1010  *
1011  * The security blob for a file is a pointer to the master
1012  * label list, so no allocation is done.
1013  *
1014  * Returns 0
1015  */
smack_file_alloc_security(struct file * file)1016 static int smack_file_alloc_security(struct file *file)
1017 {
1018 	file->f_security = smk_of_current();
1019 	return 0;
1020 }
1021 
1022 /**
1023  * smack_file_free_security - clear a file security blob
1024  * @file: the object
1025  *
1026  * The security blob for a file is a pointer to the master
1027  * label list, so no memory is freed.
1028  */
smack_file_free_security(struct file * file)1029 static void smack_file_free_security(struct file *file)
1030 {
1031 	file->f_security = NULL;
1032 }
1033 
1034 /**
1035  * smack_file_ioctl - Smack check on ioctls
1036  * @file: the object
1037  * @cmd: what to do
1038  * @arg: unused
1039  *
1040  * Relies heavily on the correct use of the ioctl command conventions.
1041  *
1042  * Returns 0 if allowed, error code otherwise
1043  */
smack_file_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1044 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1045 			    unsigned long arg)
1046 {
1047 	int rc = 0;
1048 	struct smk_audit_info ad;
1049 
1050 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
1051 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1052 
1053 	if (_IOC_DIR(cmd) & _IOC_WRITE)
1054 		rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1055 
1056 	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
1057 		rc = smk_curacc(file->f_security, MAY_READ, &ad);
1058 
1059 	return rc;
1060 }
1061 
1062 /**
1063  * smack_file_lock - Smack check on file locking
1064  * @file: the object
1065  * @cmd: unused
1066  *
1067  * Returns 0 if current has write access, error code otherwise
1068  */
smack_file_lock(struct file * file,unsigned int cmd)1069 static int smack_file_lock(struct file *file, unsigned int cmd)
1070 {
1071 	struct smk_audit_info ad;
1072 
1073 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
1074 	smk_ad_setfield_u_fs_path_dentry(&ad, file->f_path.dentry);
1075 	return smk_curacc(file->f_security, MAY_WRITE, &ad);
1076 }
1077 
1078 /**
1079  * smack_file_fcntl - Smack check on fcntl
1080  * @file: the object
1081  * @cmd: what action to check
1082  * @arg: unused
1083  *
1084  * Returns 0 if current has access, error code otherwise
1085  */
smack_file_fcntl(struct file * file,unsigned int cmd,unsigned long arg)1086 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1087 			    unsigned long arg)
1088 {
1089 	struct smk_audit_info ad;
1090 	int rc;
1091 
1092 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_FS);
1093 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1094 
1095 	switch (cmd) {
1096 	case F_DUPFD:
1097 	case F_GETFD:
1098 	case F_GETFL:
1099 	case F_GETLK:
1100 	case F_GETOWN:
1101 	case F_GETSIG:
1102 		rc = smk_curacc(file->f_security, MAY_READ, &ad);
1103 		break;
1104 	case F_SETFD:
1105 	case F_SETFL:
1106 	case F_SETLK:
1107 	case F_SETLKW:
1108 	case F_SETOWN:
1109 	case F_SETSIG:
1110 		rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
1111 		break;
1112 	default:
1113 		rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
1114 	}
1115 
1116 	return rc;
1117 }
1118 
1119 /**
1120  * smack_file_mmap :
1121  * Check permissions for a mmap operation.  The @file may be NULL, e.g.
1122  * if mapping anonymous memory.
1123  * @file contains the file structure for file to map (may be NULL).
1124  * @reqprot contains the protection requested by the application.
1125  * @prot contains the protection that will be applied by the kernel.
1126  * @flags contains the operational flags.
1127  * Return 0 if permission is granted.
1128  */
smack_file_mmap(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags,unsigned long addr,unsigned long addr_only)1129 static int smack_file_mmap(struct file *file,
1130 			   unsigned long reqprot, unsigned long prot,
1131 			   unsigned long flags, unsigned long addr,
1132 			   unsigned long addr_only)
1133 {
1134 	struct smack_rule *srp;
1135 	struct task_smack *tsp;
1136 	char *sp;
1137 	char *msmack;
1138 	char *osmack;
1139 	struct inode_smack *isp;
1140 	struct dentry *dp;
1141 	int may;
1142 	int mmay;
1143 	int tmay;
1144 	int rc;
1145 
1146 	/* do DAC check on address space usage */
1147 	rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
1148 	if (rc || addr_only)
1149 		return rc;
1150 
1151 	if (file == NULL || file->f_dentry == NULL)
1152 		return 0;
1153 
1154 	dp = file->f_dentry;
1155 
1156 	if (dp->d_inode == NULL)
1157 		return 0;
1158 
1159 	isp = dp->d_inode->i_security;
1160 	if (isp->smk_mmap == NULL)
1161 		return 0;
1162 	msmack = isp->smk_mmap;
1163 
1164 	tsp = current_security();
1165 	sp = smk_of_current();
1166 	rc = 0;
1167 
1168 	rcu_read_lock();
1169 	/*
1170 	 * For each Smack rule associated with the subject
1171 	 * label verify that the SMACK64MMAP also has access
1172 	 * to that rule's object label.
1173 	 *
1174 	 * Because neither of the labels comes
1175 	 * from the networking code it is sufficient
1176 	 * to compare pointers.
1177 	 */
1178 	list_for_each_entry_rcu(srp, &smack_rule_list, list) {
1179 		if (srp->smk_subject != sp)
1180 			continue;
1181 
1182 		osmack = srp->smk_object;
1183 		/*
1184 		 * Matching labels always allows access.
1185 		 */
1186 		if (msmack == osmack)
1187 			continue;
1188 		/*
1189 		 * If there is a matching local rule take
1190 		 * that into account as well.
1191 		 */
1192 		may = smk_access_entry(srp->smk_subject, osmack,
1193 					&tsp->smk_rules);
1194 		if (may == -ENOENT)
1195 			may = srp->smk_access;
1196 		else
1197 			may &= srp->smk_access;
1198 		/*
1199 		 * If may is zero the SMACK64MMAP subject can't
1200 		 * possibly have less access.
1201 		 */
1202 		if (may == 0)
1203 			continue;
1204 
1205 		/*
1206 		 * Fetch the global list entry.
1207 		 * If there isn't one a SMACK64MMAP subject
1208 		 * can't have as much access as current.
1209 		 */
1210 		mmay = smk_access_entry(msmack, osmack, &smack_rule_list);
1211 		if (mmay == -ENOENT) {
1212 			rc = -EACCES;
1213 			break;
1214 		}
1215 		/*
1216 		 * If there is a local entry it modifies the
1217 		 * potential access, too.
1218 		 */
1219 		tmay = smk_access_entry(msmack, osmack, &tsp->smk_rules);
1220 		if (tmay != -ENOENT)
1221 			mmay &= tmay;
1222 
1223 		/*
1224 		 * If there is any access available to current that is
1225 		 * not available to a SMACK64MMAP subject
1226 		 * deny access.
1227 		 */
1228 		if ((may | mmay) != mmay) {
1229 			rc = -EACCES;
1230 			break;
1231 		}
1232 	}
1233 
1234 	rcu_read_unlock();
1235 
1236 	return rc;
1237 }
1238 
1239 /**
1240  * smack_file_set_fowner - set the file security blob value
1241  * @file: object in question
1242  *
1243  * Returns 0
1244  * Further research may be required on this one.
1245  */
smack_file_set_fowner(struct file * file)1246 static int smack_file_set_fowner(struct file *file)
1247 {
1248 	file->f_security = smk_of_current();
1249 	return 0;
1250 }
1251 
1252 /**
1253  * smack_file_send_sigiotask - Smack on sigio
1254  * @tsk: The target task
1255  * @fown: the object the signal come from
1256  * @signum: unused
1257  *
1258  * Allow a privileged task to get signals even if it shouldn't
1259  *
1260  * Returns 0 if a subject with the object's smack could
1261  * write to the task, an error code otherwise.
1262  */
smack_file_send_sigiotask(struct task_struct * tsk,struct fown_struct * fown,int signum)1263 static int smack_file_send_sigiotask(struct task_struct *tsk,
1264 				     struct fown_struct *fown, int signum)
1265 {
1266 	struct file *file;
1267 	int rc;
1268 	char *tsp = smk_of_task(tsk->cred->security);
1269 	struct smk_audit_info ad;
1270 
1271 	/*
1272 	 * struct fown_struct is never outside the context of a struct file
1273 	 */
1274 	file = container_of(fown, struct file, f_owner);
1275 
1276 	/* we don't log here as rc can be overriden */
1277 	rc = smk_access(file->f_security, tsp, MAY_WRITE, NULL);
1278 	if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
1279 		rc = 0;
1280 
1281 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1282 	smk_ad_setfield_u_tsk(&ad, tsk);
1283 	smack_log(file->f_security, tsp, MAY_WRITE, rc, &ad);
1284 	return rc;
1285 }
1286 
1287 /**
1288  * smack_file_receive - Smack file receive check
1289  * @file: the object
1290  *
1291  * Returns 0 if current has access, error code otherwise
1292  */
smack_file_receive(struct file * file)1293 static int smack_file_receive(struct file *file)
1294 {
1295 	int may = 0;
1296 	struct smk_audit_info ad;
1297 
1298 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1299 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1300 	/*
1301 	 * This code relies on bitmasks.
1302 	 */
1303 	if (file->f_mode & FMODE_READ)
1304 		may = MAY_READ;
1305 	if (file->f_mode & FMODE_WRITE)
1306 		may |= MAY_WRITE;
1307 
1308 	return smk_curacc(file->f_security, may, &ad);
1309 }
1310 
1311 /*
1312  * Task hooks
1313  */
1314 
1315 /**
1316  * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1317  * @new: the new credentials
1318  * @gfp: the atomicity of any memory allocations
1319  *
1320  * Prepare a blank set of credentials for modification.  This must allocate all
1321  * the memory the LSM module might require such that cred_transfer() can
1322  * complete without error.
1323  */
smack_cred_alloc_blank(struct cred * cred,gfp_t gfp)1324 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1325 {
1326 	struct task_smack *tsp;
1327 
1328 	tsp = new_task_smack(NULL, NULL, gfp);
1329 	if (tsp == NULL)
1330 		return -ENOMEM;
1331 
1332 	cred->security = tsp;
1333 
1334 	return 0;
1335 }
1336 
1337 
1338 /**
1339  * smack_cred_free - "free" task-level security credentials
1340  * @cred: the credentials in question
1341  *
1342  */
smack_cred_free(struct cred * cred)1343 static void smack_cred_free(struct cred *cred)
1344 {
1345 	struct task_smack *tsp = cred->security;
1346 	struct smack_rule *rp;
1347 	struct list_head *l;
1348 	struct list_head *n;
1349 
1350 	if (tsp == NULL)
1351 		return;
1352 	cred->security = NULL;
1353 
1354 	list_for_each_safe(l, n, &tsp->smk_rules) {
1355 		rp = list_entry(l, struct smack_rule, list);
1356 		list_del(&rp->list);
1357 		kfree(rp);
1358 	}
1359 	kfree(tsp);
1360 }
1361 
1362 /**
1363  * smack_cred_prepare - prepare new set of credentials for modification
1364  * @new: the new credentials
1365  * @old: the original credentials
1366  * @gfp: the atomicity of any memory allocations
1367  *
1368  * Prepare a new set of credentials for modification.
1369  */
smack_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)1370 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1371 			      gfp_t gfp)
1372 {
1373 	struct task_smack *old_tsp = old->security;
1374 	struct task_smack *new_tsp;
1375 	int rc;
1376 
1377 	new_tsp = new_task_smack(old_tsp->smk_task, old_tsp->smk_task, gfp);
1378 	if (new_tsp == NULL)
1379 		return -ENOMEM;
1380 
1381 	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1382 	if (rc != 0)
1383 		return rc;
1384 
1385 	new->security = new_tsp;
1386 	return 0;
1387 }
1388 
1389 /**
1390  * smack_cred_transfer - Transfer the old credentials to the new credentials
1391  * @new: the new credentials
1392  * @old: the original credentials
1393  *
1394  * Fill in a set of blank credentials from another set of credentials.
1395  */
smack_cred_transfer(struct cred * new,const struct cred * old)1396 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1397 {
1398 	struct task_smack *old_tsp = old->security;
1399 	struct task_smack *new_tsp = new->security;
1400 
1401 	new_tsp->smk_task = old_tsp->smk_task;
1402 	new_tsp->smk_forked = old_tsp->smk_task;
1403 	mutex_init(&new_tsp->smk_rules_lock);
1404 	INIT_LIST_HEAD(&new_tsp->smk_rules);
1405 
1406 
1407 	/* cbs copy rule list */
1408 }
1409 
1410 /**
1411  * smack_kernel_act_as - Set the subjective context in a set of credentials
1412  * @new: points to the set of credentials to be modified.
1413  * @secid: specifies the security ID to be set
1414  *
1415  * Set the security data for a kernel service.
1416  */
smack_kernel_act_as(struct cred * new,u32 secid)1417 static int smack_kernel_act_as(struct cred *new, u32 secid)
1418 {
1419 	struct task_smack *new_tsp = new->security;
1420 	char *smack = smack_from_secid(secid);
1421 
1422 	if (smack == NULL)
1423 		return -EINVAL;
1424 
1425 	new_tsp->smk_task = smack;
1426 	return 0;
1427 }
1428 
1429 /**
1430  * smack_kernel_create_files_as - Set the file creation label in a set of creds
1431  * @new: points to the set of credentials to be modified
1432  * @inode: points to the inode to use as a reference
1433  *
1434  * Set the file creation context in a set of credentials to the same
1435  * as the objective context of the specified inode
1436  */
smack_kernel_create_files_as(struct cred * new,struct inode * inode)1437 static int smack_kernel_create_files_as(struct cred *new,
1438 					struct inode *inode)
1439 {
1440 	struct inode_smack *isp = inode->i_security;
1441 	struct task_smack *tsp = new->security;
1442 
1443 	tsp->smk_forked = isp->smk_inode;
1444 	tsp->smk_task = isp->smk_inode;
1445 	return 0;
1446 }
1447 
1448 /**
1449  * smk_curacc_on_task - helper to log task related access
1450  * @p: the task object
1451  * @access : the access requested
1452  *
1453  * Return 0 if access is permitted
1454  */
smk_curacc_on_task(struct task_struct * p,int access)1455 static int smk_curacc_on_task(struct task_struct *p, int access)
1456 {
1457 	struct smk_audit_info ad;
1458 
1459 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1460 	smk_ad_setfield_u_tsk(&ad, p);
1461 	return smk_curacc(smk_of_task(task_security(p)), access, &ad);
1462 }
1463 
1464 /**
1465  * smack_task_setpgid - Smack check on setting pgid
1466  * @p: the task object
1467  * @pgid: unused
1468  *
1469  * Return 0 if write access is permitted
1470  */
smack_task_setpgid(struct task_struct * p,pid_t pgid)1471 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
1472 {
1473 	return smk_curacc_on_task(p, MAY_WRITE);
1474 }
1475 
1476 /**
1477  * smack_task_getpgid - Smack access check for getpgid
1478  * @p: the object task
1479  *
1480  * Returns 0 if current can read the object task, error code otherwise
1481  */
smack_task_getpgid(struct task_struct * p)1482 static int smack_task_getpgid(struct task_struct *p)
1483 {
1484 	return smk_curacc_on_task(p, MAY_READ);
1485 }
1486 
1487 /**
1488  * smack_task_getsid - Smack access check for getsid
1489  * @p: the object task
1490  *
1491  * Returns 0 if current can read the object task, error code otherwise
1492  */
smack_task_getsid(struct task_struct * p)1493 static int smack_task_getsid(struct task_struct *p)
1494 {
1495 	return smk_curacc_on_task(p, MAY_READ);
1496 }
1497 
1498 /**
1499  * smack_task_getsecid - get the secid of the task
1500  * @p: the object task
1501  * @secid: where to put the result
1502  *
1503  * Sets the secid to contain a u32 version of the smack label.
1504  */
smack_task_getsecid(struct task_struct * p,u32 * secid)1505 static void smack_task_getsecid(struct task_struct *p, u32 *secid)
1506 {
1507 	*secid = smack_to_secid(smk_of_task(task_security(p)));
1508 }
1509 
1510 /**
1511  * smack_task_setnice - Smack check on setting nice
1512  * @p: the task object
1513  * @nice: unused
1514  *
1515  * Return 0 if write access is permitted
1516  */
smack_task_setnice(struct task_struct * p,int nice)1517 static int smack_task_setnice(struct task_struct *p, int nice)
1518 {
1519 	int rc;
1520 
1521 	rc = cap_task_setnice(p, nice);
1522 	if (rc == 0)
1523 		rc = smk_curacc_on_task(p, MAY_WRITE);
1524 	return rc;
1525 }
1526 
1527 /**
1528  * smack_task_setioprio - Smack check on setting ioprio
1529  * @p: the task object
1530  * @ioprio: unused
1531  *
1532  * Return 0 if write access is permitted
1533  */
smack_task_setioprio(struct task_struct * p,int ioprio)1534 static int smack_task_setioprio(struct task_struct *p, int ioprio)
1535 {
1536 	int rc;
1537 
1538 	rc = cap_task_setioprio(p, ioprio);
1539 	if (rc == 0)
1540 		rc = smk_curacc_on_task(p, MAY_WRITE);
1541 	return rc;
1542 }
1543 
1544 /**
1545  * smack_task_getioprio - Smack check on reading ioprio
1546  * @p: the task object
1547  *
1548  * Return 0 if read access is permitted
1549  */
smack_task_getioprio(struct task_struct * p)1550 static int smack_task_getioprio(struct task_struct *p)
1551 {
1552 	return smk_curacc_on_task(p, MAY_READ);
1553 }
1554 
1555 /**
1556  * smack_task_setscheduler - Smack check on setting scheduler
1557  * @p: the task object
1558  * @policy: unused
1559  * @lp: unused
1560  *
1561  * Return 0 if read access is permitted
1562  */
smack_task_setscheduler(struct task_struct * p)1563 static int smack_task_setscheduler(struct task_struct *p)
1564 {
1565 	int rc;
1566 
1567 	rc = cap_task_setscheduler(p);
1568 	if (rc == 0)
1569 		rc = smk_curacc_on_task(p, MAY_WRITE);
1570 	return rc;
1571 }
1572 
1573 /**
1574  * smack_task_getscheduler - Smack check on reading scheduler
1575  * @p: the task object
1576  *
1577  * Return 0 if read access is permitted
1578  */
smack_task_getscheduler(struct task_struct * p)1579 static int smack_task_getscheduler(struct task_struct *p)
1580 {
1581 	return smk_curacc_on_task(p, MAY_READ);
1582 }
1583 
1584 /**
1585  * smack_task_movememory - Smack check on moving memory
1586  * @p: the task object
1587  *
1588  * Return 0 if write access is permitted
1589  */
smack_task_movememory(struct task_struct * p)1590 static int smack_task_movememory(struct task_struct *p)
1591 {
1592 	return smk_curacc_on_task(p, MAY_WRITE);
1593 }
1594 
1595 /**
1596  * smack_task_kill - Smack check on signal delivery
1597  * @p: the task object
1598  * @info: unused
1599  * @sig: unused
1600  * @secid: identifies the smack to use in lieu of current's
1601  *
1602  * Return 0 if write access is permitted
1603  *
1604  * The secid behavior is an artifact of an SELinux hack
1605  * in the USB code. Someday it may go away.
1606  */
smack_task_kill(struct task_struct * p,struct siginfo * info,int sig,u32 secid)1607 static int smack_task_kill(struct task_struct *p, struct siginfo *info,
1608 			   int sig, u32 secid)
1609 {
1610 	struct smk_audit_info ad;
1611 
1612 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1613 	smk_ad_setfield_u_tsk(&ad, p);
1614 	/*
1615 	 * Sending a signal requires that the sender
1616 	 * can write the receiver.
1617 	 */
1618 	if (secid == 0)
1619 		return smk_curacc(smk_of_task(task_security(p)), MAY_WRITE,
1620 				  &ad);
1621 	/*
1622 	 * If the secid isn't 0 we're dealing with some USB IO
1623 	 * specific behavior. This is not clean. For one thing
1624 	 * we can't take privilege into account.
1625 	 */
1626 	return smk_access(smack_from_secid(secid),
1627 			  smk_of_task(task_security(p)), MAY_WRITE, &ad);
1628 }
1629 
1630 /**
1631  * smack_task_wait - Smack access check for waiting
1632  * @p: task to wait for
1633  *
1634  * Returns 0 if current can wait for p, error code otherwise
1635  */
smack_task_wait(struct task_struct * p)1636 static int smack_task_wait(struct task_struct *p)
1637 {
1638 	struct smk_audit_info ad;
1639 	char *sp = smk_of_current();
1640 	char *tsp = smk_of_forked(task_security(p));
1641 	int rc;
1642 
1643 	/* we don't log here, we can be overriden */
1644 	rc = smk_access(tsp, sp, MAY_WRITE, NULL);
1645 	if (rc == 0)
1646 		goto out_log;
1647 
1648 	/*
1649 	 * Allow the operation to succeed if either task
1650 	 * has privilege to perform operations that might
1651 	 * account for the smack labels having gotten to
1652 	 * be different in the first place.
1653 	 *
1654 	 * This breaks the strict subject/object access
1655 	 * control ideal, taking the object's privilege
1656 	 * state into account in the decision as well as
1657 	 * the smack value.
1658 	 */
1659 	if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
1660 		rc = 0;
1661 	/* we log only if we didn't get overriden */
1662  out_log:
1663 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1664 	smk_ad_setfield_u_tsk(&ad, p);
1665 	smack_log(tsp, sp, MAY_WRITE, rc, &ad);
1666 	return rc;
1667 }
1668 
1669 /**
1670  * smack_task_to_inode - copy task smack into the inode blob
1671  * @p: task to copy from
1672  * @inode: inode to copy to
1673  *
1674  * Sets the smack pointer in the inode security blob
1675  */
smack_task_to_inode(struct task_struct * p,struct inode * inode)1676 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
1677 {
1678 	struct inode_smack *isp = inode->i_security;
1679 	isp->smk_inode = smk_of_task(task_security(p));
1680 }
1681 
1682 /*
1683  * Socket hooks.
1684  */
1685 
1686 /**
1687  * smack_sk_alloc_security - Allocate a socket blob
1688  * @sk: the socket
1689  * @family: unused
1690  * @gfp_flags: memory allocation flags
1691  *
1692  * Assign Smack pointers to current
1693  *
1694  * Returns 0 on success, -ENOMEM is there's no memory
1695  */
smack_sk_alloc_security(struct sock * sk,int family,gfp_t gfp_flags)1696 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
1697 {
1698 	char *csp = smk_of_current();
1699 	struct socket_smack *ssp;
1700 
1701 	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
1702 	if (ssp == NULL)
1703 		return -ENOMEM;
1704 
1705 	ssp->smk_in = csp;
1706 	ssp->smk_out = csp;
1707 	ssp->smk_packet[0] = '\0';
1708 
1709 	sk->sk_security = ssp;
1710 
1711 	return 0;
1712 }
1713 
1714 /**
1715  * smack_sk_free_security - Free a socket blob
1716  * @sk: the socket
1717  *
1718  * Clears the blob pointer
1719  */
smack_sk_free_security(struct sock * sk)1720 static void smack_sk_free_security(struct sock *sk)
1721 {
1722 	kfree(sk->sk_security);
1723 }
1724 
1725 /**
1726 * smack_host_label - check host based restrictions
1727 * @sip: the object end
1728 *
1729 * looks for host based access restrictions
1730 *
1731 * This version will only be appropriate for really small sets of single label
1732 * hosts.  The caller is responsible for ensuring that the RCU read lock is
1733 * taken before calling this function.
1734 *
1735 * Returns the label of the far end or NULL if it's not special.
1736 */
smack_host_label(struct sockaddr_in * sip)1737 static char *smack_host_label(struct sockaddr_in *sip)
1738 {
1739 	struct smk_netlbladdr *snp;
1740 	struct in_addr *siap = &sip->sin_addr;
1741 
1742 	if (siap->s_addr == 0)
1743 		return NULL;
1744 
1745 	list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list)
1746 		/*
1747 		* we break after finding the first match because
1748 		* the list is sorted from longest to shortest mask
1749 		* so we have found the most specific match
1750 		*/
1751 		if ((&snp->smk_host.sin_addr)->s_addr ==
1752 		    (siap->s_addr & (&snp->smk_mask)->s_addr)) {
1753 			/* we have found the special CIPSO option */
1754 			if (snp->smk_label == smack_cipso_option)
1755 				return NULL;
1756 			return snp->smk_label;
1757 		}
1758 
1759 	return NULL;
1760 }
1761 
1762 /**
1763  * smack_set_catset - convert a capset to netlabel mls categories
1764  * @catset: the Smack categories
1765  * @sap: where to put the netlabel categories
1766  *
1767  * Allocates and fills attr.mls.cat
1768  */
smack_set_catset(char * catset,struct netlbl_lsm_secattr * sap)1769 static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
1770 {
1771 	unsigned char *cp;
1772 	unsigned char m;
1773 	int cat;
1774 	int rc;
1775 	int byte;
1776 
1777 	if (!catset)
1778 		return;
1779 
1780 	sap->flags |= NETLBL_SECATTR_MLS_CAT;
1781 	sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
1782 	sap->attr.mls.cat->startbit = 0;
1783 
1784 	for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
1785 		for (m = 0x80; m != 0; m >>= 1, cat++) {
1786 			if ((m & *cp) == 0)
1787 				continue;
1788 			rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
1789 							  cat, GFP_ATOMIC);
1790 		}
1791 }
1792 
1793 /**
1794  * smack_to_secattr - fill a secattr from a smack value
1795  * @smack: the smack value
1796  * @nlsp: where the result goes
1797  *
1798  * Casey says that CIPSO is good enough for now.
1799  * It can be used to effect.
1800  * It can also be abused to effect when necessary.
1801  * Apologies to the TSIG group in general and GW in particular.
1802  */
smack_to_secattr(char * smack,struct netlbl_lsm_secattr * nlsp)1803 static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
1804 {
1805 	struct smack_cipso cipso;
1806 	int rc;
1807 
1808 	nlsp->domain = smack;
1809 	nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
1810 
1811 	rc = smack_to_cipso(smack, &cipso);
1812 	if (rc == 0) {
1813 		nlsp->attr.mls.lvl = cipso.smk_level;
1814 		smack_set_catset(cipso.smk_catset, nlsp);
1815 	} else {
1816 		nlsp->attr.mls.lvl = smack_cipso_direct;
1817 		smack_set_catset(smack, nlsp);
1818 	}
1819 }
1820 
1821 /**
1822  * smack_netlabel - Set the secattr on a socket
1823  * @sk: the socket
1824  * @labeled: socket label scheme
1825  *
1826  * Convert the outbound smack value (smk_out) to a
1827  * secattr and attach it to the socket.
1828  *
1829  * Returns 0 on success or an error code
1830  */
smack_netlabel(struct sock * sk,int labeled)1831 static int smack_netlabel(struct sock *sk, int labeled)
1832 {
1833 	struct socket_smack *ssp = sk->sk_security;
1834 	struct netlbl_lsm_secattr secattr;
1835 	int rc = 0;
1836 
1837 	/*
1838 	 * Usually the netlabel code will handle changing the
1839 	 * packet labeling based on the label.
1840 	 * The case of a single label host is different, because
1841 	 * a single label host should never get a labeled packet
1842 	 * even though the label is usually associated with a packet
1843 	 * label.
1844 	 */
1845 	local_bh_disable();
1846 	bh_lock_sock_nested(sk);
1847 
1848 	if (ssp->smk_out == smack_net_ambient ||
1849 	    labeled == SMACK_UNLABELED_SOCKET)
1850 		netlbl_sock_delattr(sk);
1851 	else {
1852 		netlbl_secattr_init(&secattr);
1853 		smack_to_secattr(ssp->smk_out, &secattr);
1854 		rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr);
1855 		netlbl_secattr_destroy(&secattr);
1856 	}
1857 
1858 	bh_unlock_sock(sk);
1859 	local_bh_enable();
1860 
1861 	return rc;
1862 }
1863 
1864 /**
1865  * smack_netlbel_send - Set the secattr on a socket and perform access checks
1866  * @sk: the socket
1867  * @sap: the destination address
1868  *
1869  * Set the correct secattr for the given socket based on the destination
1870  * address and perform any outbound access checks needed.
1871  *
1872  * Returns 0 on success or an error code.
1873  *
1874  */
smack_netlabel_send(struct sock * sk,struct sockaddr_in * sap)1875 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
1876 {
1877 	int rc;
1878 	int sk_lbl;
1879 	char *hostsp;
1880 	struct socket_smack *ssp = sk->sk_security;
1881 	struct smk_audit_info ad;
1882 
1883 	rcu_read_lock();
1884 	hostsp = smack_host_label(sap);
1885 	if (hostsp != NULL) {
1886 		sk_lbl = SMACK_UNLABELED_SOCKET;
1887 #ifdef CONFIG_AUDIT
1888 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
1889 		ad.a.u.net.family = sap->sin_family;
1890 		ad.a.u.net.dport = sap->sin_port;
1891 		ad.a.u.net.v4info.daddr = sap->sin_addr.s_addr;
1892 #endif
1893 		rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE, &ad);
1894 	} else {
1895 		sk_lbl = SMACK_CIPSO_SOCKET;
1896 		rc = 0;
1897 	}
1898 	rcu_read_unlock();
1899 	if (rc != 0)
1900 		return rc;
1901 
1902 	return smack_netlabel(sk, sk_lbl);
1903 }
1904 
1905 /**
1906  * smack_inode_setsecurity - set smack xattrs
1907  * @inode: the object
1908  * @name: attribute name
1909  * @value: attribute value
1910  * @size: size of the attribute
1911  * @flags: unused
1912  *
1913  * Sets the named attribute in the appropriate blob
1914  *
1915  * Returns 0 on success, or an error code
1916  */
smack_inode_setsecurity(struct inode * inode,const char * name,const void * value,size_t size,int flags)1917 static int smack_inode_setsecurity(struct inode *inode, const char *name,
1918 				   const void *value, size_t size, int flags)
1919 {
1920 	char *sp;
1921 	struct inode_smack *nsp = inode->i_security;
1922 	struct socket_smack *ssp;
1923 	struct socket *sock;
1924 	int rc = 0;
1925 
1926 	if (value == NULL || size > SMK_LABELLEN || size == 0)
1927 		return -EACCES;
1928 
1929 	sp = smk_import(value, size);
1930 	if (sp == NULL)
1931 		return -EINVAL;
1932 
1933 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1934 		nsp->smk_inode = sp;
1935 		nsp->smk_flags |= SMK_INODE_INSTANT;
1936 		return 0;
1937 	}
1938 	/*
1939 	 * The rest of the Smack xattrs are only on sockets.
1940 	 */
1941 	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
1942 		return -EOPNOTSUPP;
1943 
1944 	sock = SOCKET_I(inode);
1945 	if (sock == NULL || sock->sk == NULL)
1946 		return -EOPNOTSUPP;
1947 
1948 	ssp = sock->sk->sk_security;
1949 
1950 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1951 		ssp->smk_in = sp;
1952 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
1953 		ssp->smk_out = sp;
1954 		if (sock->sk->sk_family != PF_UNIX) {
1955 			rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1956 			if (rc != 0)
1957 				printk(KERN_WARNING
1958 					"Smack: \"%s\" netlbl error %d.\n",
1959 					__func__, -rc);
1960 		}
1961 	} else
1962 		return -EOPNOTSUPP;
1963 
1964 	return 0;
1965 }
1966 
1967 /**
1968  * smack_socket_post_create - finish socket setup
1969  * @sock: the socket
1970  * @family: protocol family
1971  * @type: unused
1972  * @protocol: unused
1973  * @kern: unused
1974  *
1975  * Sets the netlabel information on the socket
1976  *
1977  * Returns 0 on success, and error code otherwise
1978  */
smack_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)1979 static int smack_socket_post_create(struct socket *sock, int family,
1980 				    int type, int protocol, int kern)
1981 {
1982 	if (family != PF_INET || sock->sk == NULL)
1983 		return 0;
1984 	/*
1985 	 * Set the outbound netlbl.
1986 	 */
1987 	return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
1988 }
1989 
1990 /**
1991  * smack_socket_connect - connect access check
1992  * @sock: the socket
1993  * @sap: the other end
1994  * @addrlen: size of sap
1995  *
1996  * Verifies that a connection may be possible
1997  *
1998  * Returns 0 on success, and error code otherwise
1999  */
smack_socket_connect(struct socket * sock,struct sockaddr * sap,int addrlen)2000 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2001 				int addrlen)
2002 {
2003 	if (sock->sk == NULL || sock->sk->sk_family != PF_INET)
2004 		return 0;
2005 	if (addrlen < sizeof(struct sockaddr_in))
2006 		return -EINVAL;
2007 
2008 	return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
2009 }
2010 
2011 /**
2012  * smack_flags_to_may - convert S_ to MAY_ values
2013  * @flags: the S_ value
2014  *
2015  * Returns the equivalent MAY_ value
2016  */
smack_flags_to_may(int flags)2017 static int smack_flags_to_may(int flags)
2018 {
2019 	int may = 0;
2020 
2021 	if (flags & S_IRUGO)
2022 		may |= MAY_READ;
2023 	if (flags & S_IWUGO)
2024 		may |= MAY_WRITE;
2025 	if (flags & S_IXUGO)
2026 		may |= MAY_EXEC;
2027 
2028 	return may;
2029 }
2030 
2031 /**
2032  * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2033  * @msg: the object
2034  *
2035  * Returns 0
2036  */
smack_msg_msg_alloc_security(struct msg_msg * msg)2037 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2038 {
2039 	msg->security = smk_of_current();
2040 	return 0;
2041 }
2042 
2043 /**
2044  * smack_msg_msg_free_security - Clear the security blob for msg_msg
2045  * @msg: the object
2046  *
2047  * Clears the blob pointer
2048  */
smack_msg_msg_free_security(struct msg_msg * msg)2049 static void smack_msg_msg_free_security(struct msg_msg *msg)
2050 {
2051 	msg->security = NULL;
2052 }
2053 
2054 /**
2055  * smack_of_shm - the smack pointer for the shm
2056  * @shp: the object
2057  *
2058  * Returns a pointer to the smack value
2059  */
smack_of_shm(struct shmid_kernel * shp)2060 static char *smack_of_shm(struct shmid_kernel *shp)
2061 {
2062 	return (char *)shp->shm_perm.security;
2063 }
2064 
2065 /**
2066  * smack_shm_alloc_security - Set the security blob for shm
2067  * @shp: the object
2068  *
2069  * Returns 0
2070  */
smack_shm_alloc_security(struct shmid_kernel * shp)2071 static int smack_shm_alloc_security(struct shmid_kernel *shp)
2072 {
2073 	struct kern_ipc_perm *isp = &shp->shm_perm;
2074 
2075 	isp->security = smk_of_current();
2076 	return 0;
2077 }
2078 
2079 /**
2080  * smack_shm_free_security - Clear the security blob for shm
2081  * @shp: the object
2082  *
2083  * Clears the blob pointer
2084  */
smack_shm_free_security(struct shmid_kernel * shp)2085 static void smack_shm_free_security(struct shmid_kernel *shp)
2086 {
2087 	struct kern_ipc_perm *isp = &shp->shm_perm;
2088 
2089 	isp->security = NULL;
2090 }
2091 
2092 /**
2093  * smk_curacc_shm : check if current has access on shm
2094  * @shp : the object
2095  * @access : access requested
2096  *
2097  * Returns 0 if current has the requested access, error code otherwise
2098  */
smk_curacc_shm(struct shmid_kernel * shp,int access)2099 static int smk_curacc_shm(struct shmid_kernel *shp, int access)
2100 {
2101 	char *ssp = smack_of_shm(shp);
2102 	struct smk_audit_info ad;
2103 
2104 #ifdef CONFIG_AUDIT
2105 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2106 	ad.a.u.ipc_id = shp->shm_perm.id;
2107 #endif
2108 	return smk_curacc(ssp, access, &ad);
2109 }
2110 
2111 /**
2112  * smack_shm_associate - Smack access check for shm
2113  * @shp: the object
2114  * @shmflg: access requested
2115  *
2116  * Returns 0 if current has the requested access, error code otherwise
2117  */
smack_shm_associate(struct shmid_kernel * shp,int shmflg)2118 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
2119 {
2120 	int may;
2121 
2122 	may = smack_flags_to_may(shmflg);
2123 	return smk_curacc_shm(shp, may);
2124 }
2125 
2126 /**
2127  * smack_shm_shmctl - Smack access check for shm
2128  * @shp: the object
2129  * @cmd: what it wants to do
2130  *
2131  * Returns 0 if current has the requested access, error code otherwise
2132  */
smack_shm_shmctl(struct shmid_kernel * shp,int cmd)2133 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
2134 {
2135 	int may;
2136 
2137 	switch (cmd) {
2138 	case IPC_STAT:
2139 	case SHM_STAT:
2140 		may = MAY_READ;
2141 		break;
2142 	case IPC_SET:
2143 	case SHM_LOCK:
2144 	case SHM_UNLOCK:
2145 	case IPC_RMID:
2146 		may = MAY_READWRITE;
2147 		break;
2148 	case IPC_INFO:
2149 	case SHM_INFO:
2150 		/*
2151 		 * System level information.
2152 		 */
2153 		return 0;
2154 	default:
2155 		return -EINVAL;
2156 	}
2157 	return smk_curacc_shm(shp, may);
2158 }
2159 
2160 /**
2161  * smack_shm_shmat - Smack access for shmat
2162  * @shp: the object
2163  * @shmaddr: unused
2164  * @shmflg: access requested
2165  *
2166  * Returns 0 if current has the requested access, error code otherwise
2167  */
smack_shm_shmat(struct shmid_kernel * shp,char __user * shmaddr,int shmflg)2168 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
2169 			   int shmflg)
2170 {
2171 	int may;
2172 
2173 	may = smack_flags_to_may(shmflg);
2174 	return smk_curacc_shm(shp, may);
2175 }
2176 
2177 /**
2178  * smack_of_sem - the smack pointer for the sem
2179  * @sma: the object
2180  *
2181  * Returns a pointer to the smack value
2182  */
smack_of_sem(struct sem_array * sma)2183 static char *smack_of_sem(struct sem_array *sma)
2184 {
2185 	return (char *)sma->sem_perm.security;
2186 }
2187 
2188 /**
2189  * smack_sem_alloc_security - Set the security blob for sem
2190  * @sma: the object
2191  *
2192  * Returns 0
2193  */
smack_sem_alloc_security(struct sem_array * sma)2194 static int smack_sem_alloc_security(struct sem_array *sma)
2195 {
2196 	struct kern_ipc_perm *isp = &sma->sem_perm;
2197 
2198 	isp->security = smk_of_current();
2199 	return 0;
2200 }
2201 
2202 /**
2203  * smack_sem_free_security - Clear the security blob for sem
2204  * @sma: the object
2205  *
2206  * Clears the blob pointer
2207  */
smack_sem_free_security(struct sem_array * sma)2208 static void smack_sem_free_security(struct sem_array *sma)
2209 {
2210 	struct kern_ipc_perm *isp = &sma->sem_perm;
2211 
2212 	isp->security = NULL;
2213 }
2214 
2215 /**
2216  * smk_curacc_sem : check if current has access on sem
2217  * @sma : the object
2218  * @access : access requested
2219  *
2220  * Returns 0 if current has the requested access, error code otherwise
2221  */
smk_curacc_sem(struct sem_array * sma,int access)2222 static int smk_curacc_sem(struct sem_array *sma, int access)
2223 {
2224 	char *ssp = smack_of_sem(sma);
2225 	struct smk_audit_info ad;
2226 
2227 #ifdef CONFIG_AUDIT
2228 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2229 	ad.a.u.ipc_id = sma->sem_perm.id;
2230 #endif
2231 	return smk_curacc(ssp, access, &ad);
2232 }
2233 
2234 /**
2235  * smack_sem_associate - Smack access check for sem
2236  * @sma: the object
2237  * @semflg: access requested
2238  *
2239  * Returns 0 if current has the requested access, error code otherwise
2240  */
smack_sem_associate(struct sem_array * sma,int semflg)2241 static int smack_sem_associate(struct sem_array *sma, int semflg)
2242 {
2243 	int may;
2244 
2245 	may = smack_flags_to_may(semflg);
2246 	return smk_curacc_sem(sma, may);
2247 }
2248 
2249 /**
2250  * smack_sem_shmctl - Smack access check for sem
2251  * @sma: the object
2252  * @cmd: what it wants to do
2253  *
2254  * Returns 0 if current has the requested access, error code otherwise
2255  */
smack_sem_semctl(struct sem_array * sma,int cmd)2256 static int smack_sem_semctl(struct sem_array *sma, int cmd)
2257 {
2258 	int may;
2259 
2260 	switch (cmd) {
2261 	case GETPID:
2262 	case GETNCNT:
2263 	case GETZCNT:
2264 	case GETVAL:
2265 	case GETALL:
2266 	case IPC_STAT:
2267 	case SEM_STAT:
2268 		may = MAY_READ;
2269 		break;
2270 	case SETVAL:
2271 	case SETALL:
2272 	case IPC_RMID:
2273 	case IPC_SET:
2274 		may = MAY_READWRITE;
2275 		break;
2276 	case IPC_INFO:
2277 	case SEM_INFO:
2278 		/*
2279 		 * System level information
2280 		 */
2281 		return 0;
2282 	default:
2283 		return -EINVAL;
2284 	}
2285 
2286 	return smk_curacc_sem(sma, may);
2287 }
2288 
2289 /**
2290  * smack_sem_semop - Smack checks of semaphore operations
2291  * @sma: the object
2292  * @sops: unused
2293  * @nsops: unused
2294  * @alter: unused
2295  *
2296  * Treated as read and write in all cases.
2297  *
2298  * Returns 0 if access is allowed, error code otherwise
2299  */
smack_sem_semop(struct sem_array * sma,struct sembuf * sops,unsigned nsops,int alter)2300 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
2301 			   unsigned nsops, int alter)
2302 {
2303 	return smk_curacc_sem(sma, MAY_READWRITE);
2304 }
2305 
2306 /**
2307  * smack_msg_alloc_security - Set the security blob for msg
2308  * @msq: the object
2309  *
2310  * Returns 0
2311  */
smack_msg_queue_alloc_security(struct msg_queue * msq)2312 static int smack_msg_queue_alloc_security(struct msg_queue *msq)
2313 {
2314 	struct kern_ipc_perm *kisp = &msq->q_perm;
2315 
2316 	kisp->security = smk_of_current();
2317 	return 0;
2318 }
2319 
2320 /**
2321  * smack_msg_free_security - Clear the security blob for msg
2322  * @msq: the object
2323  *
2324  * Clears the blob pointer
2325  */
smack_msg_queue_free_security(struct msg_queue * msq)2326 static void smack_msg_queue_free_security(struct msg_queue *msq)
2327 {
2328 	struct kern_ipc_perm *kisp = &msq->q_perm;
2329 
2330 	kisp->security = NULL;
2331 }
2332 
2333 /**
2334  * smack_of_msq - the smack pointer for the msq
2335  * @msq: the object
2336  *
2337  * Returns a pointer to the smack value
2338  */
smack_of_msq(struct msg_queue * msq)2339 static char *smack_of_msq(struct msg_queue *msq)
2340 {
2341 	return (char *)msq->q_perm.security;
2342 }
2343 
2344 /**
2345  * smk_curacc_msq : helper to check if current has access on msq
2346  * @msq : the msq
2347  * @access : access requested
2348  *
2349  * return 0 if current has access, error otherwise
2350  */
smk_curacc_msq(struct msg_queue * msq,int access)2351 static int smk_curacc_msq(struct msg_queue *msq, int access)
2352 {
2353 	char *msp = smack_of_msq(msq);
2354 	struct smk_audit_info ad;
2355 
2356 #ifdef CONFIG_AUDIT
2357 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2358 	ad.a.u.ipc_id = msq->q_perm.id;
2359 #endif
2360 	return smk_curacc(msp, access, &ad);
2361 }
2362 
2363 /**
2364  * smack_msg_queue_associate - Smack access check for msg_queue
2365  * @msq: the object
2366  * @msqflg: access requested
2367  *
2368  * Returns 0 if current has the requested access, error code otherwise
2369  */
smack_msg_queue_associate(struct msg_queue * msq,int msqflg)2370 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
2371 {
2372 	int may;
2373 
2374 	may = smack_flags_to_may(msqflg);
2375 	return smk_curacc_msq(msq, may);
2376 }
2377 
2378 /**
2379  * smack_msg_queue_msgctl - Smack access check for msg_queue
2380  * @msq: the object
2381  * @cmd: what it wants to do
2382  *
2383  * Returns 0 if current has the requested access, error code otherwise
2384  */
smack_msg_queue_msgctl(struct msg_queue * msq,int cmd)2385 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
2386 {
2387 	int may;
2388 
2389 	switch (cmd) {
2390 	case IPC_STAT:
2391 	case MSG_STAT:
2392 		may = MAY_READ;
2393 		break;
2394 	case IPC_SET:
2395 	case IPC_RMID:
2396 		may = MAY_READWRITE;
2397 		break;
2398 	case IPC_INFO:
2399 	case MSG_INFO:
2400 		/*
2401 		 * System level information
2402 		 */
2403 		return 0;
2404 	default:
2405 		return -EINVAL;
2406 	}
2407 
2408 	return smk_curacc_msq(msq, may);
2409 }
2410 
2411 /**
2412  * smack_msg_queue_msgsnd - Smack access check for msg_queue
2413  * @msq: the object
2414  * @msg: unused
2415  * @msqflg: access requested
2416  *
2417  * Returns 0 if current has the requested access, error code otherwise
2418  */
smack_msg_queue_msgsnd(struct msg_queue * msq,struct msg_msg * msg,int msqflg)2419 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
2420 				  int msqflg)
2421 {
2422 	int may;
2423 
2424 	may = smack_flags_to_may(msqflg);
2425 	return smk_curacc_msq(msq, may);
2426 }
2427 
2428 /**
2429  * smack_msg_queue_msgsnd - Smack access check for msg_queue
2430  * @msq: the object
2431  * @msg: unused
2432  * @target: unused
2433  * @type: unused
2434  * @mode: unused
2435  *
2436  * Returns 0 if current has read and write access, error code otherwise
2437  */
smack_msg_queue_msgrcv(struct msg_queue * msq,struct msg_msg * msg,struct task_struct * target,long type,int mode)2438 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
2439 			struct task_struct *target, long type, int mode)
2440 {
2441 	return smk_curacc_msq(msq, MAY_READWRITE);
2442 }
2443 
2444 /**
2445  * smack_ipc_permission - Smack access for ipc_permission()
2446  * @ipp: the object permissions
2447  * @flag: access requested
2448  *
2449  * Returns 0 if current has read and write access, error code otherwise
2450  */
smack_ipc_permission(struct kern_ipc_perm * ipp,short flag)2451 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
2452 {
2453 	char *isp = ipp->security;
2454 	int may = smack_flags_to_may(flag);
2455 	struct smk_audit_info ad;
2456 
2457 #ifdef CONFIG_AUDIT
2458 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
2459 	ad.a.u.ipc_id = ipp->id;
2460 #endif
2461 	return smk_curacc(isp, may, &ad);
2462 }
2463 
2464 /**
2465  * smack_ipc_getsecid - Extract smack security id
2466  * @ipp: the object permissions
2467  * @secid: where result will be saved
2468  */
smack_ipc_getsecid(struct kern_ipc_perm * ipp,u32 * secid)2469 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
2470 {
2471 	char *smack = ipp->security;
2472 
2473 	*secid = smack_to_secid(smack);
2474 }
2475 
2476 /**
2477  * smack_d_instantiate - Make sure the blob is correct on an inode
2478  * @opt_dentry: dentry where inode will be attached
2479  * @inode: the object
2480  *
2481  * Set the inode's security blob if it hasn't been done already.
2482  */
smack_d_instantiate(struct dentry * opt_dentry,struct inode * inode)2483 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
2484 {
2485 	struct super_block *sbp;
2486 	struct superblock_smack *sbsp;
2487 	struct inode_smack *isp;
2488 	char *csp = smk_of_current();
2489 	char *fetched;
2490 	char *final;
2491 	char trattr[TRANS_TRUE_SIZE];
2492 	int transflag = 0;
2493 	struct dentry *dp;
2494 
2495 	if (inode == NULL)
2496 		return;
2497 
2498 	isp = inode->i_security;
2499 
2500 	mutex_lock(&isp->smk_lock);
2501 	/*
2502 	 * If the inode is already instantiated
2503 	 * take the quick way out
2504 	 */
2505 	if (isp->smk_flags & SMK_INODE_INSTANT)
2506 		goto unlockandout;
2507 
2508 	sbp = inode->i_sb;
2509 	sbsp = sbp->s_security;
2510 	/*
2511 	 * We're going to use the superblock default label
2512 	 * if there's no label on the file.
2513 	 */
2514 	final = sbsp->smk_default;
2515 
2516 	/*
2517 	 * If this is the root inode the superblock
2518 	 * may be in the process of initialization.
2519 	 * If that is the case use the root value out
2520 	 * of the superblock.
2521 	 */
2522 	if (opt_dentry->d_parent == opt_dentry) {
2523 		isp->smk_inode = sbsp->smk_root;
2524 		isp->smk_flags |= SMK_INODE_INSTANT;
2525 		goto unlockandout;
2526 	}
2527 
2528 	/*
2529 	 * This is pretty hackish.
2530 	 * Casey says that we shouldn't have to do
2531 	 * file system specific code, but it does help
2532 	 * with keeping it simple.
2533 	 */
2534 	switch (sbp->s_magic) {
2535 	case SMACK_MAGIC:
2536 		/*
2537 		 * Casey says that it's a little embarrassing
2538 		 * that the smack file system doesn't do
2539 		 * extended attributes.
2540 		 */
2541 		final = smack_known_star.smk_known;
2542 		break;
2543 	case PIPEFS_MAGIC:
2544 		/*
2545 		 * Casey says pipes are easy (?)
2546 		 */
2547 		final = smack_known_star.smk_known;
2548 		break;
2549 	case DEVPTS_SUPER_MAGIC:
2550 		/*
2551 		 * devpts seems content with the label of the task.
2552 		 * Programs that change smack have to treat the
2553 		 * pty with respect.
2554 		 */
2555 		final = csp;
2556 		break;
2557 	case SOCKFS_MAGIC:
2558 		/*
2559 		 * Socket access is controlled by the socket
2560 		 * structures associated with the task involved.
2561 		 */
2562 		final = smack_known_star.smk_known;
2563 		break;
2564 	case PROC_SUPER_MAGIC:
2565 		/*
2566 		 * Casey says procfs appears not to care.
2567 		 * The superblock default suffices.
2568 		 */
2569 		break;
2570 	case TMPFS_MAGIC:
2571 		/*
2572 		 * Device labels should come from the filesystem,
2573 		 * but watch out, because they're volitile,
2574 		 * getting recreated on every reboot.
2575 		 */
2576 		final = smack_known_star.smk_known;
2577 		/*
2578 		 * No break.
2579 		 *
2580 		 * If a smack value has been set we want to use it,
2581 		 * but since tmpfs isn't giving us the opportunity
2582 		 * to set mount options simulate setting the
2583 		 * superblock default.
2584 		 */
2585 	default:
2586 		/*
2587 		 * This isn't an understood special case.
2588 		 * Get the value from the xattr.
2589 		 */
2590 
2591 		/*
2592 		 * UNIX domain sockets use lower level socket data.
2593 		 */
2594 		if (S_ISSOCK(inode->i_mode)) {
2595 			final = smack_known_star.smk_known;
2596 			break;
2597 		}
2598 		/*
2599 		 * No xattr support means, alas, no SMACK label.
2600 		 * Use the aforeapplied default.
2601 		 * It would be curious if the label of the task
2602 		 * does not match that assigned.
2603 		 */
2604 		if (inode->i_op->getxattr == NULL)
2605 			break;
2606 		/*
2607 		 * Get the dentry for xattr.
2608 		 */
2609 		dp = dget(opt_dentry);
2610 		fetched = smk_fetch(XATTR_NAME_SMACK, inode, dp);
2611 		if (fetched != NULL) {
2612 			final = fetched;
2613 			if (S_ISDIR(inode->i_mode)) {
2614 				trattr[0] = '\0';
2615 				inode->i_op->getxattr(dp,
2616 					XATTR_NAME_SMACKTRANSMUTE,
2617 					trattr, TRANS_TRUE_SIZE);
2618 				if (strncmp(trattr, TRANS_TRUE,
2619 					    TRANS_TRUE_SIZE) == 0)
2620 					transflag = SMK_INODE_TRANSMUTE;
2621 			}
2622 		}
2623 		isp->smk_task = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
2624 		isp->smk_mmap = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
2625 
2626 		dput(dp);
2627 		break;
2628 	}
2629 
2630 	if (final == NULL)
2631 		isp->smk_inode = csp;
2632 	else
2633 		isp->smk_inode = final;
2634 
2635 	isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
2636 
2637 unlockandout:
2638 	mutex_unlock(&isp->smk_lock);
2639 	return;
2640 }
2641 
2642 /**
2643  * smack_getprocattr - Smack process attribute access
2644  * @p: the object task
2645  * @name: the name of the attribute in /proc/.../attr
2646  * @value: where to put the result
2647  *
2648  * Places a copy of the task Smack into value
2649  *
2650  * Returns the length of the smack label or an error code
2651  */
smack_getprocattr(struct task_struct * p,char * name,char ** value)2652 static int smack_getprocattr(struct task_struct *p, char *name, char **value)
2653 {
2654 	char *cp;
2655 	int slen;
2656 
2657 	if (strcmp(name, "current") != 0)
2658 		return -EINVAL;
2659 
2660 	cp = kstrdup(smk_of_task(task_security(p)), GFP_KERNEL);
2661 	if (cp == NULL)
2662 		return -ENOMEM;
2663 
2664 	slen = strlen(cp);
2665 	*value = cp;
2666 	return slen;
2667 }
2668 
2669 /**
2670  * smack_setprocattr - Smack process attribute setting
2671  * @p: the object task
2672  * @name: the name of the attribute in /proc/.../attr
2673  * @value: the value to set
2674  * @size: the size of the value
2675  *
2676  * Sets the Smack value of the task. Only setting self
2677  * is permitted and only with privilege
2678  *
2679  * Returns the length of the smack label or an error code
2680  */
smack_setprocattr(struct task_struct * p,char * name,void * value,size_t size)2681 static int smack_setprocattr(struct task_struct *p, char *name,
2682 			     void *value, size_t size)
2683 {
2684 	int rc;
2685 	struct task_smack *tsp;
2686 	struct task_smack *oldtsp;
2687 	struct cred *new;
2688 	char *newsmack;
2689 
2690 	/*
2691 	 * Changing another process' Smack value is too dangerous
2692 	 * and supports no sane use case.
2693 	 */
2694 	if (p != current)
2695 		return -EPERM;
2696 
2697 	if (!capable(CAP_MAC_ADMIN))
2698 		return -EPERM;
2699 
2700 	if (value == NULL || size == 0 || size >= SMK_LABELLEN)
2701 		return -EINVAL;
2702 
2703 	if (strcmp(name, "current") != 0)
2704 		return -EINVAL;
2705 
2706 	newsmack = smk_import(value, size);
2707 	if (newsmack == NULL)
2708 		return -EINVAL;
2709 
2710 	/*
2711 	 * No process is ever allowed the web ("@") label.
2712 	 */
2713 	if (newsmack == smack_known_web.smk_known)
2714 		return -EPERM;
2715 
2716 	oldtsp = p->cred->security;
2717 	new = prepare_creds();
2718 	if (new == NULL)
2719 		return -ENOMEM;
2720 
2721 	tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
2722 	if (tsp == NULL) {
2723 		kfree(new);
2724 		return -ENOMEM;
2725 	}
2726 	rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
2727 	if (rc != 0)
2728 		return rc;
2729 
2730 	new->security = tsp;
2731 	commit_creds(new);
2732 	return size;
2733 }
2734 
2735 /**
2736  * smack_unix_stream_connect - Smack access on UDS
2737  * @sock: one sock
2738  * @other: the other sock
2739  * @newsk: unused
2740  *
2741  * Return 0 if a subject with the smack of sock could access
2742  * an object with the smack of other, otherwise an error code
2743  */
smack_unix_stream_connect(struct sock * sock,struct sock * other,struct sock * newsk)2744 static int smack_unix_stream_connect(struct sock *sock,
2745 				     struct sock *other, struct sock *newsk)
2746 {
2747 	struct socket_smack *ssp = sock->sk_security;
2748 	struct socket_smack *osp = other->sk_security;
2749 	struct smk_audit_info ad;
2750 	int rc = 0;
2751 
2752 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2753 	smk_ad_setfield_u_net_sk(&ad, other);
2754 
2755 	if (!capable(CAP_MAC_OVERRIDE))
2756 		rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
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 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2777 	smk_ad_setfield_u_net_sk(&ad, other->sk);
2778 
2779 	if (!capable(CAP_MAC_OVERRIDE))
2780 		rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
2781 
2782 	return rc;
2783 }
2784 
2785 /**
2786  * smack_socket_sendmsg - Smack check based on destination host
2787  * @sock: the socket
2788  * @msg: the message
2789  * @size: the size of the message
2790  *
2791  * Return 0 if the current subject can write to the destination
2792  * host. This is only a question if the destination is a single
2793  * label host.
2794  */
smack_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)2795 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
2796 				int size)
2797 {
2798 	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
2799 
2800 	/*
2801 	 * Perfectly reasonable for this to be NULL
2802 	 */
2803 	if (sip == NULL || sip->sin_family != AF_INET)
2804 		return 0;
2805 
2806 	return smack_netlabel_send(sock->sk, sip);
2807 }
2808 
2809 
2810 /**
2811  * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
2812  * @sap: netlabel secattr
2813  * @sip: where to put the result
2814  *
2815  * Copies a smack label into sip
2816  */
smack_from_secattr(struct netlbl_lsm_secattr * sap,char * sip)2817 static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
2818 {
2819 	char smack[SMK_LABELLEN];
2820 	char *sp;
2821 	int pcat;
2822 
2823 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
2824 		/*
2825 		 * Looks like a CIPSO packet.
2826 		 * If there are flags but no level netlabel isn't
2827 		 * behaving the way we expect it to.
2828 		 *
2829 		 * Get the categories, if any
2830 		 * Without guidance regarding the smack value
2831 		 * for the packet fall back on the network
2832 		 * ambient value.
2833 		 */
2834 		memset(smack, '\0', SMK_LABELLEN);
2835 		if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
2836 			for (pcat = -1;;) {
2837 				pcat = netlbl_secattr_catmap_walk(
2838 					sap->attr.mls.cat, pcat + 1);
2839 				if (pcat < 0)
2840 					break;
2841 				smack_catset_bit(pcat, smack);
2842 			}
2843 		/*
2844 		 * If it is CIPSO using smack direct mapping
2845 		 * we are already done. WeeHee.
2846 		 */
2847 		if (sap->attr.mls.lvl == smack_cipso_direct) {
2848 			memcpy(sip, smack, SMK_MAXLEN);
2849 			return;
2850 		}
2851 		/*
2852 		 * Look it up in the supplied table if it is not
2853 		 * a direct mapping.
2854 		 */
2855 		smack_from_cipso(sap->attr.mls.lvl, smack, sip);
2856 		return;
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 		strncpy(sip, sp, SMK_MAXLEN);
2872 		return;
2873 	}
2874 	/*
2875 	 * Without guidance regarding the smack value
2876 	 * for the packet fall back on the network
2877 	 * ambient value.
2878 	 */
2879 	strncpy(sip, smack_net_ambient, SMK_MAXLEN);
2880 	return;
2881 }
2882 
2883 /**
2884  * smack_socket_sock_rcv_skb - Smack packet delivery access check
2885  * @sk: socket
2886  * @skb: packet
2887  *
2888  * Returns 0 if the packet should be delivered, an error code otherwise
2889  */
smack_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)2890 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
2891 {
2892 	struct netlbl_lsm_secattr secattr;
2893 	struct socket_smack *ssp = sk->sk_security;
2894 	char smack[SMK_LABELLEN];
2895 	char *csp;
2896 	int rc;
2897 	struct smk_audit_info ad;
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 		smack_from_secattr(&secattr, smack);
2909 		csp = smack;
2910 	} else
2911 		csp = smack_net_ambient;
2912 
2913 	netlbl_secattr_destroy(&secattr);
2914 
2915 #ifdef CONFIG_AUDIT
2916 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
2917 	ad.a.u.net.family = sk->sk_family;
2918 	ad.a.u.net.netif = skb->skb_iif;
2919 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
2920 #endif
2921 	/*
2922 	 * Receiving a packet requires that the other end
2923 	 * be able to write here. Read access is not required.
2924 	 * This is the simplist possible security model
2925 	 * for networking.
2926 	 */
2927 	rc = smk_access(csp, ssp->smk_in, MAY_WRITE, &ad);
2928 	if (rc != 0)
2929 		netlbl_skbuff_err(skb, rc, 0);
2930 	return rc;
2931 }
2932 
2933 /**
2934  * smack_socket_getpeersec_stream - pull in packet label
2935  * @sock: the socket
2936  * @optval: user's destination
2937  * @optlen: size thereof
2938  * @len: max thereof
2939  *
2940  * returns zero on success, an error code otherwise
2941  */
smack_socket_getpeersec_stream(struct socket * sock,char __user * optval,int __user * optlen,unsigned len)2942 static int smack_socket_getpeersec_stream(struct socket *sock,
2943 					  char __user *optval,
2944 					  int __user *optlen, unsigned len)
2945 {
2946 	struct socket_smack *ssp;
2947 	int slen;
2948 	int rc = 0;
2949 
2950 	ssp = sock->sk->sk_security;
2951 	slen = strlen(ssp->smk_packet) + 1;
2952 
2953 	if (slen > len)
2954 		rc = -ERANGE;
2955 	else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
2956 		rc = -EFAULT;
2957 
2958 	if (put_user(slen, optlen) != 0)
2959 		rc = -EFAULT;
2960 
2961 	return rc;
2962 }
2963 
2964 
2965 /**
2966  * smack_socket_getpeersec_dgram - pull in packet label
2967  * @sock: the peer socket
2968  * @skb: packet data
2969  * @secid: pointer to where to put the secid of the packet
2970  *
2971  * Sets the netlabel socket state on sk from parent
2972  */
smack_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)2973 static int smack_socket_getpeersec_dgram(struct socket *sock,
2974 					 struct sk_buff *skb, u32 *secid)
2975 
2976 {
2977 	struct netlbl_lsm_secattr secattr;
2978 	struct socket_smack *sp;
2979 	char smack[SMK_LABELLEN];
2980 	int family = PF_UNSPEC;
2981 	u32 s = 0;	/* 0 is the invalid secid */
2982 	int rc;
2983 
2984 	if (skb != NULL) {
2985 		if (skb->protocol == htons(ETH_P_IP))
2986 			family = PF_INET;
2987 		else if (skb->protocol == htons(ETH_P_IPV6))
2988 			family = PF_INET6;
2989 	}
2990 	if (family == PF_UNSPEC && sock != NULL)
2991 		family = sock->sk->sk_family;
2992 
2993 	if (family == PF_UNIX) {
2994 		sp = sock->sk->sk_security;
2995 		s = smack_to_secid(sp->smk_out);
2996 	} else if (family == PF_INET || family == PF_INET6) {
2997 		/*
2998 		 * Translate what netlabel gave us.
2999 		 */
3000 		netlbl_secattr_init(&secattr);
3001 		rc = netlbl_skbuff_getattr(skb, family, &secattr);
3002 		if (rc == 0) {
3003 			smack_from_secattr(&secattr, smack);
3004 			s = smack_to_secid(smack);
3005 		}
3006 		netlbl_secattr_destroy(&secattr);
3007 	}
3008 	*secid = s;
3009 	if (s == 0)
3010 		return -EINVAL;
3011 	return 0;
3012 }
3013 
3014 /**
3015  * smack_sock_graft - Initialize a newly created socket with an existing sock
3016  * @sk: child sock
3017  * @parent: parent socket
3018  *
3019  * Set the smk_{in,out} state of an existing sock based on the process that
3020  * is creating the new socket.
3021  */
smack_sock_graft(struct sock * sk,struct socket * parent)3022 static void smack_sock_graft(struct sock *sk, struct socket *parent)
3023 {
3024 	struct socket_smack *ssp;
3025 
3026 	if (sk == NULL ||
3027 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
3028 		return;
3029 
3030 	ssp = sk->sk_security;
3031 	ssp->smk_in = ssp->smk_out = smk_of_current();
3032 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
3033 }
3034 
3035 /**
3036  * smack_inet_conn_request - Smack access check on connect
3037  * @sk: socket involved
3038  * @skb: packet
3039  * @req: unused
3040  *
3041  * Returns 0 if a task with the packet label could write to
3042  * the socket, otherwise an error code
3043  */
smack_inet_conn_request(struct sock * sk,struct sk_buff * skb,struct request_sock * req)3044 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
3045 				   struct request_sock *req)
3046 {
3047 	u16 family = sk->sk_family;
3048 	struct socket_smack *ssp = sk->sk_security;
3049 	struct netlbl_lsm_secattr secattr;
3050 	struct sockaddr_in addr;
3051 	struct iphdr *hdr;
3052 	char smack[SMK_LABELLEN];
3053 	int rc;
3054 	struct smk_audit_info ad;
3055 
3056 	/* handle mapped IPv4 packets arriving via IPv6 sockets */
3057 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3058 		family = PF_INET;
3059 
3060 	netlbl_secattr_init(&secattr);
3061 	rc = netlbl_skbuff_getattr(skb, family, &secattr);
3062 	if (rc == 0)
3063 		smack_from_secattr(&secattr, smack);
3064 	else
3065 		strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
3066 	netlbl_secattr_destroy(&secattr);
3067 
3068 #ifdef CONFIG_AUDIT
3069 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NET);
3070 	ad.a.u.net.family = family;
3071 	ad.a.u.net.netif = skb->skb_iif;
3072 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
3073 #endif
3074 	/*
3075 	 * Receiving a packet requires that the other end be able to write
3076 	 * here. Read access is not required.
3077 	 */
3078 	rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
3079 	if (rc != 0)
3080 		return rc;
3081 
3082 	/*
3083 	 * Save the peer's label in the request_sock so we can later setup
3084 	 * smk_packet in the child socket so that SO_PEERCRED can report it.
3085 	 */
3086 	req->peer_secid = smack_to_secid(smack);
3087 
3088 	/*
3089 	 * We need to decide if we want to label the incoming connection here
3090 	 * if we do we only need to label the request_sock and the stack will
3091 	 * propagate the wire-label to the sock when it is created.
3092 	 */
3093 	hdr = ip_hdr(skb);
3094 	addr.sin_addr.s_addr = hdr->saddr;
3095 	rcu_read_lock();
3096 	if (smack_host_label(&addr) == NULL) {
3097 		rcu_read_unlock();
3098 		netlbl_secattr_init(&secattr);
3099 		smack_to_secattr(smack, &secattr);
3100 		rc = netlbl_req_setattr(req, &secattr);
3101 		netlbl_secattr_destroy(&secattr);
3102 	} else {
3103 		rcu_read_unlock();
3104 		netlbl_req_delattr(req);
3105 	}
3106 
3107 	return rc;
3108 }
3109 
3110 /**
3111  * smack_inet_csk_clone - Copy the connection information to the new socket
3112  * @sk: the new socket
3113  * @req: the connection's request_sock
3114  *
3115  * Transfer the connection's peer label to the newly created socket.
3116  */
smack_inet_csk_clone(struct sock * sk,const struct request_sock * req)3117 static void smack_inet_csk_clone(struct sock *sk,
3118 				 const struct request_sock *req)
3119 {
3120 	struct socket_smack *ssp = sk->sk_security;
3121 	char *smack;
3122 
3123 	if (req->peer_secid != 0) {
3124 		smack = smack_from_secid(req->peer_secid);
3125 		strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
3126 	} else
3127 		ssp->smk_packet[0] = '\0';
3128 }
3129 
3130 /*
3131  * Key management security hooks
3132  *
3133  * Casey has not tested key support very heavily.
3134  * The permission check is most likely too restrictive.
3135  * If you care about keys please have a look.
3136  */
3137 #ifdef CONFIG_KEYS
3138 
3139 /**
3140  * smack_key_alloc - Set the key security blob
3141  * @key: object
3142  * @cred: the credentials to use
3143  * @flags: unused
3144  *
3145  * No allocation required
3146  *
3147  * Returns 0
3148  */
smack_key_alloc(struct key * key,const struct cred * cred,unsigned long flags)3149 static int smack_key_alloc(struct key *key, const struct cred *cred,
3150 			   unsigned long flags)
3151 {
3152 	key->security = smk_of_task(cred->security);
3153 	return 0;
3154 }
3155 
3156 /**
3157  * smack_key_free - Clear the key security blob
3158  * @key: the object
3159  *
3160  * Clear the blob pointer
3161  */
smack_key_free(struct key * key)3162 static void smack_key_free(struct key *key)
3163 {
3164 	key->security = NULL;
3165 }
3166 
3167 /*
3168  * smack_key_permission - Smack access on a key
3169  * @key_ref: gets to the object
3170  * @cred: the credentials to use
3171  * @perm: unused
3172  *
3173  * Return 0 if the task has read and write to the object,
3174  * an error code otherwise
3175  */
smack_key_permission(key_ref_t key_ref,const struct cred * cred,key_perm_t perm)3176 static int smack_key_permission(key_ref_t key_ref,
3177 				const struct cred *cred, key_perm_t perm)
3178 {
3179 	struct key *keyp;
3180 	struct smk_audit_info ad;
3181 	char *tsp = smk_of_task(cred->security);
3182 
3183 	keyp = key_ref_to_ptr(key_ref);
3184 	if (keyp == NULL)
3185 		return -EINVAL;
3186 	/*
3187 	 * If the key hasn't been initialized give it access so that
3188 	 * it may do so.
3189 	 */
3190 	if (keyp->security == NULL)
3191 		return 0;
3192 	/*
3193 	 * This should not occur
3194 	 */
3195 	if (tsp == NULL)
3196 		return -EACCES;
3197 #ifdef CONFIG_AUDIT
3198 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
3199 	ad.a.u.key_struct.key = keyp->serial;
3200 	ad.a.u.key_struct.key_desc = keyp->description;
3201 #endif
3202 	return smk_access(tsp, keyp->security,
3203 				 MAY_READWRITE, &ad);
3204 }
3205 #endif /* CONFIG_KEYS */
3206 
3207 /*
3208  * Smack Audit hooks
3209  *
3210  * Audit requires a unique representation of each Smack specific
3211  * rule. This unique representation is used to distinguish the
3212  * object to be audited from remaining kernel objects and also
3213  * works as a glue between the audit hooks.
3214  *
3215  * Since repository entries are added but never deleted, we'll use
3216  * the smack_known label address related to the given audit rule as
3217  * the needed unique representation. This also better fits the smack
3218  * model where nearly everything is a label.
3219  */
3220 #ifdef CONFIG_AUDIT
3221 
3222 /**
3223  * smack_audit_rule_init - Initialize a smack audit rule
3224  * @field: audit rule fields given from user-space (audit.h)
3225  * @op: required testing operator (=, !=, >, <, ...)
3226  * @rulestr: smack label to be audited
3227  * @vrule: pointer to save our own audit rule representation
3228  *
3229  * Prepare to audit cases where (@field @op @rulestr) is true.
3230  * The label to be audited is created if necessay.
3231  */
smack_audit_rule_init(u32 field,u32 op,char * rulestr,void ** vrule)3232 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
3233 {
3234 	char **rule = (char **)vrule;
3235 	*rule = NULL;
3236 
3237 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3238 		return -EINVAL;
3239 
3240 	if (op != Audit_equal && op != Audit_not_equal)
3241 		return -EINVAL;
3242 
3243 	*rule = smk_import(rulestr, 0);
3244 
3245 	return 0;
3246 }
3247 
3248 /**
3249  * smack_audit_rule_known - Distinguish Smack audit rules
3250  * @krule: rule of interest, in Audit kernel representation format
3251  *
3252  * This is used to filter Smack rules from remaining Audit ones.
3253  * If it's proved that this rule belongs to us, the
3254  * audit_rule_match hook will be called to do the final judgement.
3255  */
smack_audit_rule_known(struct audit_krule * krule)3256 static int smack_audit_rule_known(struct audit_krule *krule)
3257 {
3258 	struct audit_field *f;
3259 	int i;
3260 
3261 	for (i = 0; i < krule->field_count; i++) {
3262 		f = &krule->fields[i];
3263 
3264 		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
3265 			return 1;
3266 	}
3267 
3268 	return 0;
3269 }
3270 
3271 /**
3272  * smack_audit_rule_match - Audit given object ?
3273  * @secid: security id for identifying the object to test
3274  * @field: audit rule flags given from user-space
3275  * @op: required testing operator
3276  * @vrule: smack internal rule presentation
3277  * @actx: audit context associated with the check
3278  *
3279  * The core Audit hook. It's used to take the decision of
3280  * whether to audit or not to audit a given object.
3281  */
smack_audit_rule_match(u32 secid,u32 field,u32 op,void * vrule,struct audit_context * actx)3282 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
3283 				  struct audit_context *actx)
3284 {
3285 	char *smack;
3286 	char *rule = vrule;
3287 
3288 	if (!rule) {
3289 		audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
3290 			  "Smack: missing rule\n");
3291 		return -ENOENT;
3292 	}
3293 
3294 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
3295 		return 0;
3296 
3297 	smack = smack_from_secid(secid);
3298 
3299 	/*
3300 	 * No need to do string comparisons. If a match occurs,
3301 	 * both pointers will point to the same smack_known
3302 	 * label.
3303 	 */
3304 	if (op == Audit_equal)
3305 		return (rule == smack);
3306 	if (op == Audit_not_equal)
3307 		return (rule != smack);
3308 
3309 	return 0;
3310 }
3311 
3312 /**
3313  * smack_audit_rule_free - free smack rule representation
3314  * @vrule: rule to be freed.
3315  *
3316  * No memory was allocated.
3317  */
smack_audit_rule_free(void * vrule)3318 static void smack_audit_rule_free(void *vrule)
3319 {
3320 	/* No-op */
3321 }
3322 
3323 #endif /* CONFIG_AUDIT */
3324 
3325 /**
3326  * smack_secid_to_secctx - return the smack label for a secid
3327  * @secid: incoming integer
3328  * @secdata: destination
3329  * @seclen: how long it is
3330  *
3331  * Exists for networking code.
3332  */
smack_secid_to_secctx(u32 secid,char ** secdata,u32 * seclen)3333 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
3334 {
3335 	char *sp = smack_from_secid(secid);
3336 
3337 	if (secdata)
3338 		*secdata = sp;
3339 	*seclen = strlen(sp);
3340 	return 0;
3341 }
3342 
3343 /**
3344  * smack_secctx_to_secid - return the secid for a smack label
3345  * @secdata: smack label
3346  * @seclen: how long result is
3347  * @secid: outgoing integer
3348  *
3349  * Exists for audit and networking code.
3350  */
smack_secctx_to_secid(const char * secdata,u32 seclen,u32 * secid)3351 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
3352 {
3353 	*secid = smack_to_secid(secdata);
3354 	return 0;
3355 }
3356 
3357 /**
3358  * smack_release_secctx - don't do anything.
3359  * @secdata: unused
3360  * @seclen: unused
3361  *
3362  * Exists to make sure nothing gets done, and properly
3363  */
smack_release_secctx(char * secdata,u32 seclen)3364 static void smack_release_secctx(char *secdata, u32 seclen)
3365 {
3366 }
3367 
smack_inode_notifysecctx(struct inode * inode,void * ctx,u32 ctxlen)3368 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
3369 {
3370 	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx, ctxlen, 0);
3371 }
3372 
smack_inode_setsecctx(struct dentry * dentry,void * ctx,u32 ctxlen)3373 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
3374 {
3375 	return __vfs_setxattr_noperm(dentry, XATTR_NAME_SMACK, ctx, ctxlen, 0);
3376 }
3377 
smack_inode_getsecctx(struct inode * inode,void ** ctx,u32 * ctxlen)3378 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
3379 {
3380 	int len = 0;
3381 	len = smack_inode_getsecurity(inode, XATTR_SMACK_SUFFIX, ctx, true);
3382 
3383 	if (len < 0)
3384 		return len;
3385 	*ctxlen = len;
3386 	return 0;
3387 }
3388 
3389 struct security_operations smack_ops = {
3390 	.name =				"smack",
3391 
3392 	.ptrace_access_check =		smack_ptrace_access_check,
3393 	.ptrace_traceme =		smack_ptrace_traceme,
3394 	.syslog = 			smack_syslog,
3395 
3396 	.sb_alloc_security = 		smack_sb_alloc_security,
3397 	.sb_free_security = 		smack_sb_free_security,
3398 	.sb_copy_data = 		smack_sb_copy_data,
3399 	.sb_kern_mount = 		smack_sb_kern_mount,
3400 	.sb_statfs = 			smack_sb_statfs,
3401 	.sb_mount = 			smack_sb_mount,
3402 	.sb_umount = 			smack_sb_umount,
3403 
3404 	.bprm_set_creds =		smack_bprm_set_creds,
3405 
3406 	.inode_alloc_security = 	smack_inode_alloc_security,
3407 	.inode_free_security = 		smack_inode_free_security,
3408 	.inode_init_security = 		smack_inode_init_security,
3409 	.inode_link = 			smack_inode_link,
3410 	.inode_unlink = 		smack_inode_unlink,
3411 	.inode_rmdir = 			smack_inode_rmdir,
3412 	.inode_rename = 		smack_inode_rename,
3413 	.inode_permission = 		smack_inode_permission,
3414 	.inode_setattr = 		smack_inode_setattr,
3415 	.inode_getattr = 		smack_inode_getattr,
3416 	.inode_setxattr = 		smack_inode_setxattr,
3417 	.inode_post_setxattr = 		smack_inode_post_setxattr,
3418 	.inode_getxattr = 		smack_inode_getxattr,
3419 	.inode_removexattr = 		smack_inode_removexattr,
3420 	.inode_getsecurity = 		smack_inode_getsecurity,
3421 	.inode_setsecurity = 		smack_inode_setsecurity,
3422 	.inode_listsecurity = 		smack_inode_listsecurity,
3423 	.inode_getsecid =		smack_inode_getsecid,
3424 
3425 	.file_permission = 		smack_file_permission,
3426 	.file_alloc_security = 		smack_file_alloc_security,
3427 	.file_free_security = 		smack_file_free_security,
3428 	.file_ioctl = 			smack_file_ioctl,
3429 	.file_lock = 			smack_file_lock,
3430 	.file_fcntl = 			smack_file_fcntl,
3431 	.file_mmap =			smack_file_mmap,
3432 	.file_set_fowner = 		smack_file_set_fowner,
3433 	.file_send_sigiotask = 		smack_file_send_sigiotask,
3434 	.file_receive = 		smack_file_receive,
3435 
3436 	.cred_alloc_blank =		smack_cred_alloc_blank,
3437 	.cred_free =			smack_cred_free,
3438 	.cred_prepare =			smack_cred_prepare,
3439 	.cred_transfer =		smack_cred_transfer,
3440 	.kernel_act_as =		smack_kernel_act_as,
3441 	.kernel_create_files_as =	smack_kernel_create_files_as,
3442 	.task_setpgid = 		smack_task_setpgid,
3443 	.task_getpgid = 		smack_task_getpgid,
3444 	.task_getsid = 			smack_task_getsid,
3445 	.task_getsecid = 		smack_task_getsecid,
3446 	.task_setnice = 		smack_task_setnice,
3447 	.task_setioprio = 		smack_task_setioprio,
3448 	.task_getioprio = 		smack_task_getioprio,
3449 	.task_setscheduler = 		smack_task_setscheduler,
3450 	.task_getscheduler = 		smack_task_getscheduler,
3451 	.task_movememory = 		smack_task_movememory,
3452 	.task_kill = 			smack_task_kill,
3453 	.task_wait = 			smack_task_wait,
3454 	.task_to_inode = 		smack_task_to_inode,
3455 
3456 	.ipc_permission = 		smack_ipc_permission,
3457 	.ipc_getsecid =			smack_ipc_getsecid,
3458 
3459 	.msg_msg_alloc_security = 	smack_msg_msg_alloc_security,
3460 	.msg_msg_free_security = 	smack_msg_msg_free_security,
3461 
3462 	.msg_queue_alloc_security = 	smack_msg_queue_alloc_security,
3463 	.msg_queue_free_security = 	smack_msg_queue_free_security,
3464 	.msg_queue_associate = 		smack_msg_queue_associate,
3465 	.msg_queue_msgctl = 		smack_msg_queue_msgctl,
3466 	.msg_queue_msgsnd = 		smack_msg_queue_msgsnd,
3467 	.msg_queue_msgrcv = 		smack_msg_queue_msgrcv,
3468 
3469 	.shm_alloc_security = 		smack_shm_alloc_security,
3470 	.shm_free_security = 		smack_shm_free_security,
3471 	.shm_associate = 		smack_shm_associate,
3472 	.shm_shmctl = 			smack_shm_shmctl,
3473 	.shm_shmat = 			smack_shm_shmat,
3474 
3475 	.sem_alloc_security = 		smack_sem_alloc_security,
3476 	.sem_free_security = 		smack_sem_free_security,
3477 	.sem_associate = 		smack_sem_associate,
3478 	.sem_semctl = 			smack_sem_semctl,
3479 	.sem_semop = 			smack_sem_semop,
3480 
3481 	.d_instantiate = 		smack_d_instantiate,
3482 
3483 	.getprocattr = 			smack_getprocattr,
3484 	.setprocattr = 			smack_setprocattr,
3485 
3486 	.unix_stream_connect = 		smack_unix_stream_connect,
3487 	.unix_may_send = 		smack_unix_may_send,
3488 
3489 	.socket_post_create = 		smack_socket_post_create,
3490 	.socket_connect =		smack_socket_connect,
3491 	.socket_sendmsg =		smack_socket_sendmsg,
3492 	.socket_sock_rcv_skb = 		smack_socket_sock_rcv_skb,
3493 	.socket_getpeersec_stream =	smack_socket_getpeersec_stream,
3494 	.socket_getpeersec_dgram =	smack_socket_getpeersec_dgram,
3495 	.sk_alloc_security = 		smack_sk_alloc_security,
3496 	.sk_free_security = 		smack_sk_free_security,
3497 	.sock_graft = 			smack_sock_graft,
3498 	.inet_conn_request = 		smack_inet_conn_request,
3499 	.inet_csk_clone =		smack_inet_csk_clone,
3500 
3501  /* key management security hooks */
3502 #ifdef CONFIG_KEYS
3503 	.key_alloc = 			smack_key_alloc,
3504 	.key_free = 			smack_key_free,
3505 	.key_permission = 		smack_key_permission,
3506 #endif /* CONFIG_KEYS */
3507 
3508  /* Audit hooks */
3509 #ifdef CONFIG_AUDIT
3510 	.audit_rule_init =		smack_audit_rule_init,
3511 	.audit_rule_known =		smack_audit_rule_known,
3512 	.audit_rule_match =		smack_audit_rule_match,
3513 	.audit_rule_free =		smack_audit_rule_free,
3514 #endif /* CONFIG_AUDIT */
3515 
3516 	.secid_to_secctx = 		smack_secid_to_secctx,
3517 	.secctx_to_secid = 		smack_secctx_to_secid,
3518 	.release_secctx = 		smack_release_secctx,
3519 	.inode_notifysecctx =		smack_inode_notifysecctx,
3520 	.inode_setsecctx =		smack_inode_setsecctx,
3521 	.inode_getsecctx =		smack_inode_getsecctx,
3522 };
3523 
3524 
init_smack_know_list(void)3525 static __init void init_smack_know_list(void)
3526 {
3527 	list_add(&smack_known_huh.list, &smack_known_list);
3528 	list_add(&smack_known_hat.list, &smack_known_list);
3529 	list_add(&smack_known_star.list, &smack_known_list);
3530 	list_add(&smack_known_floor.list, &smack_known_list);
3531 	list_add(&smack_known_invalid.list, &smack_known_list);
3532 	list_add(&smack_known_web.list, &smack_known_list);
3533 }
3534 
3535 /**
3536  * smack_init - initialize the smack system
3537  *
3538  * Returns 0
3539  */
smack_init(void)3540 static __init int smack_init(void)
3541 {
3542 	struct cred *cred;
3543 	struct task_smack *tsp;
3544 
3545 	if (!security_module_enable(&smack_ops))
3546 		return 0;
3547 
3548 	tsp = new_task_smack(smack_known_floor.smk_known,
3549 				smack_known_floor.smk_known, GFP_KERNEL);
3550 	if (tsp == NULL)
3551 		return -ENOMEM;
3552 
3553 	printk(KERN_INFO "Smack:  Initializing.\n");
3554 
3555 	/*
3556 	 * Set the security state for the initial task.
3557 	 */
3558 	cred = (struct cred *) current->cred;
3559 	cred->security = tsp;
3560 
3561 	/* initialize the smack_know_list */
3562 	init_smack_know_list();
3563 	/*
3564 	 * Initialize locks
3565 	 */
3566 	spin_lock_init(&smack_known_huh.smk_cipsolock);
3567 	spin_lock_init(&smack_known_hat.smk_cipsolock);
3568 	spin_lock_init(&smack_known_star.smk_cipsolock);
3569 	spin_lock_init(&smack_known_floor.smk_cipsolock);
3570 	spin_lock_init(&smack_known_invalid.smk_cipsolock);
3571 
3572 	/*
3573 	 * Register with LSM
3574 	 */
3575 	if (register_security(&smack_ops))
3576 		panic("smack: Unable to register with kernel.\n");
3577 
3578 	return 0;
3579 }
3580 
3581 /*
3582  * Smack requires early initialization in order to label
3583  * all processes and objects when they are created.
3584  */
3585 security_initcall(smack_init);
3586