xref: /openbmc/linux/security/smack/smack_lsm.c (revision 745b7908)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Simplified MAC Kernel (smack) security module
4  *
5  *  This file contains the smack hook function implementations.
6  *
7  *  Authors:
8  *	Casey Schaufler <casey@schaufler-ca.com>
9  *	Jarkko Sakkinen <jarkko.sakkinen@intel.com>
10  *
11  *  Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
12  *  Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
13  *                Paul Moore <paul@paul-moore.com>
14  *  Copyright (C) 2010 Nokia Corporation
15  *  Copyright (C) 2011 Intel Corporation.
16  */
17 
18 #include <linux/xattr.h>
19 #include <linux/pagemap.h>
20 #include <linux/mount.h>
21 #include <linux/stat.h>
22 #include <linux/kd.h>
23 #include <asm/ioctls.h>
24 #include <linux/ip.h>
25 #include <linux/tcp.h>
26 #include <linux/udp.h>
27 #include <linux/dccp.h>
28 #include <linux/icmpv6.h>
29 #include <linux/slab.h>
30 #include <linux/mutex.h>
31 #include <net/cipso_ipv4.h>
32 #include <net/ip.h>
33 #include <net/ipv6.h>
34 #include <linux/audit.h>
35 #include <linux/magic.h>
36 #include <linux/dcache.h>
37 #include <linux/personality.h>
38 #include <linux/msg.h>
39 #include <linux/shm.h>
40 #include <linux/binfmts.h>
41 #include <linux/parser.h>
42 #include <linux/fs_context.h>
43 #include <linux/fs_parser.h>
44 #include <linux/watch_queue.h>
45 #include <linux/io_uring.h>
46 #include "smack.h"
47 
48 #define TRANS_TRUE	"TRUE"
49 #define TRANS_TRUE_SIZE	4
50 
51 #define SMK_CONNECTING	0
52 #define SMK_RECEIVING	1
53 #define SMK_SENDING	2
54 
55 #ifdef SMACK_IPV6_PORT_LABELING
56 static DEFINE_MUTEX(smack_ipv6_lock);
57 static LIST_HEAD(smk_ipv6_port_list);
58 #endif
59 struct kmem_cache *smack_rule_cache;
60 int smack_enabled __initdata;
61 
62 #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
63 static struct {
64 	const char *name;
65 	int len;
66 	int opt;
67 } smk_mount_opts[] = {
68 	{"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault},
69 	A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
70 };
71 #undef A
72 
73 static int match_opt_prefix(char *s, int l, char **arg)
74 {
75 	int i;
76 
77 	for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
78 		size_t len = smk_mount_opts[i].len;
79 		if (len > l || memcmp(s, smk_mount_opts[i].name, len))
80 			continue;
81 		if (len == l || s[len] != '=')
82 			continue;
83 		*arg = s + len + 1;
84 		return smk_mount_opts[i].opt;
85 	}
86 	return Opt_error;
87 }
88 
89 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
90 static char *smk_bu_mess[] = {
91 	"Bringup Error",	/* Unused */
92 	"Bringup",		/* SMACK_BRINGUP_ALLOW */
93 	"Unconfined Subject",	/* SMACK_UNCONFINED_SUBJECT */
94 	"Unconfined Object",	/* SMACK_UNCONFINED_OBJECT */
95 };
96 
97 static void smk_bu_mode(int mode, char *s)
98 {
99 	int i = 0;
100 
101 	if (mode & MAY_READ)
102 		s[i++] = 'r';
103 	if (mode & MAY_WRITE)
104 		s[i++] = 'w';
105 	if (mode & MAY_EXEC)
106 		s[i++] = 'x';
107 	if (mode & MAY_APPEND)
108 		s[i++] = 'a';
109 	if (mode & MAY_TRANSMUTE)
110 		s[i++] = 't';
111 	if (mode & MAY_LOCK)
112 		s[i++] = 'l';
113 	if (i == 0)
114 		s[i++] = '-';
115 	s[i] = '\0';
116 }
117 #endif
118 
119 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
120 static int smk_bu_note(char *note, struct smack_known *sskp,
121 		       struct smack_known *oskp, int mode, int rc)
122 {
123 	char acc[SMK_NUM_ACCESS_TYPE + 1];
124 
125 	if (rc <= 0)
126 		return rc;
127 	if (rc > SMACK_UNCONFINED_OBJECT)
128 		rc = 0;
129 
130 	smk_bu_mode(mode, acc);
131 	pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
132 		sskp->smk_known, oskp->smk_known, acc, note);
133 	return 0;
134 }
135 #else
136 #define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
137 #endif
138 
139 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
140 static int smk_bu_current(char *note, struct smack_known *oskp,
141 			  int mode, int rc)
142 {
143 	struct task_smack *tsp = smack_cred(current_cred());
144 	char acc[SMK_NUM_ACCESS_TYPE + 1];
145 
146 	if (rc <= 0)
147 		return rc;
148 	if (rc > SMACK_UNCONFINED_OBJECT)
149 		rc = 0;
150 
151 	smk_bu_mode(mode, acc);
152 	pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
153 		tsp->smk_task->smk_known, oskp->smk_known,
154 		acc, current->comm, note);
155 	return 0;
156 }
157 #else
158 #define smk_bu_current(note, oskp, mode, RC) (RC)
159 #endif
160 
161 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
162 static int smk_bu_task(struct task_struct *otp, int mode, int rc)
163 {
164 	struct task_smack *tsp = smack_cred(current_cred());
165 	struct smack_known *smk_task = smk_of_task_struct_obj(otp);
166 	char acc[SMK_NUM_ACCESS_TYPE + 1];
167 
168 	if (rc <= 0)
169 		return rc;
170 	if (rc > SMACK_UNCONFINED_OBJECT)
171 		rc = 0;
172 
173 	smk_bu_mode(mode, acc);
174 	pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
175 		tsp->smk_task->smk_known, smk_task->smk_known, acc,
176 		current->comm, otp->comm);
177 	return 0;
178 }
179 #else
180 #define smk_bu_task(otp, mode, RC) (RC)
181 #endif
182 
183 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
184 static int smk_bu_inode(struct inode *inode, int mode, int rc)
185 {
186 	struct task_smack *tsp = smack_cred(current_cred());
187 	struct inode_smack *isp = smack_inode(inode);
188 	char acc[SMK_NUM_ACCESS_TYPE + 1];
189 
190 	if (isp->smk_flags & SMK_INODE_IMPURE)
191 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
192 			inode->i_sb->s_id, inode->i_ino, current->comm);
193 
194 	if (rc <= 0)
195 		return rc;
196 	if (rc > SMACK_UNCONFINED_OBJECT)
197 		rc = 0;
198 	if (rc == SMACK_UNCONFINED_SUBJECT &&
199 	    (mode & (MAY_WRITE | MAY_APPEND)))
200 		isp->smk_flags |= SMK_INODE_IMPURE;
201 
202 	smk_bu_mode(mode, acc);
203 
204 	pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
205 		tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
206 		inode->i_sb->s_id, inode->i_ino, current->comm);
207 	return 0;
208 }
209 #else
210 #define smk_bu_inode(inode, mode, RC) (RC)
211 #endif
212 
213 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
214 static int smk_bu_file(struct file *file, int mode, int rc)
215 {
216 	struct task_smack *tsp = smack_cred(current_cred());
217 	struct smack_known *sskp = tsp->smk_task;
218 	struct inode *inode = file_inode(file);
219 	struct inode_smack *isp = smack_inode(inode);
220 	char acc[SMK_NUM_ACCESS_TYPE + 1];
221 
222 	if (isp->smk_flags & SMK_INODE_IMPURE)
223 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
224 			inode->i_sb->s_id, inode->i_ino, current->comm);
225 
226 	if (rc <= 0)
227 		return rc;
228 	if (rc > SMACK_UNCONFINED_OBJECT)
229 		rc = 0;
230 
231 	smk_bu_mode(mode, acc);
232 	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
233 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
234 		inode->i_sb->s_id, inode->i_ino, file,
235 		current->comm);
236 	return 0;
237 }
238 #else
239 #define smk_bu_file(file, mode, RC) (RC)
240 #endif
241 
242 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
243 static int smk_bu_credfile(const struct cred *cred, struct file *file,
244 				int mode, int rc)
245 {
246 	struct task_smack *tsp = smack_cred(cred);
247 	struct smack_known *sskp = tsp->smk_task;
248 	struct inode *inode = file_inode(file);
249 	struct inode_smack *isp = smack_inode(inode);
250 	char acc[SMK_NUM_ACCESS_TYPE + 1];
251 
252 	if (isp->smk_flags & SMK_INODE_IMPURE)
253 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
254 			inode->i_sb->s_id, inode->i_ino, current->comm);
255 
256 	if (rc <= 0)
257 		return rc;
258 	if (rc > SMACK_UNCONFINED_OBJECT)
259 		rc = 0;
260 
261 	smk_bu_mode(mode, acc);
262 	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
263 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
264 		inode->i_sb->s_id, inode->i_ino, file,
265 		current->comm);
266 	return 0;
267 }
268 #else
269 #define smk_bu_credfile(cred, file, mode, RC) (RC)
270 #endif
271 
272 /**
273  * smk_fetch - Fetch the smack label from a file.
274  * @name: type of the label (attribute)
275  * @ip: a pointer to the inode
276  * @dp: a pointer to the dentry
277  *
278  * Returns a pointer to the master list entry for the Smack label,
279  * NULL if there was no label to fetch, or an error code.
280  */
281 static struct smack_known *smk_fetch(const char *name, struct inode *ip,
282 					struct dentry *dp)
283 {
284 	int rc;
285 	char *buffer;
286 	struct smack_known *skp = NULL;
287 
288 	if (!(ip->i_opflags & IOP_XATTR))
289 		return ERR_PTR(-EOPNOTSUPP);
290 
291 	buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
292 	if (buffer == NULL)
293 		return ERR_PTR(-ENOMEM);
294 
295 	rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
296 	if (rc < 0)
297 		skp = ERR_PTR(rc);
298 	else if (rc == 0)
299 		skp = NULL;
300 	else
301 		skp = smk_import_entry(buffer, rc);
302 
303 	kfree(buffer);
304 
305 	return skp;
306 }
307 
308 /**
309  * init_inode_smack - initialize an inode security blob
310  * @inode: inode to extract the info from
311  * @skp: a pointer to the Smack label entry to use in the blob
312  *
313  */
314 static void init_inode_smack(struct inode *inode, struct smack_known *skp)
315 {
316 	struct inode_smack *isp = smack_inode(inode);
317 
318 	isp->smk_inode = skp;
319 	isp->smk_flags = 0;
320 }
321 
322 /**
323  * init_task_smack - initialize a task security blob
324  * @tsp: blob to initialize
325  * @task: a pointer to the Smack label for the running task
326  * @forked: a pointer to the Smack label for the forked task
327  *
328  */
329 static void init_task_smack(struct task_smack *tsp, struct smack_known *task,
330 					struct smack_known *forked)
331 {
332 	tsp->smk_task = task;
333 	tsp->smk_forked = forked;
334 	INIT_LIST_HEAD(&tsp->smk_rules);
335 	INIT_LIST_HEAD(&tsp->smk_relabel);
336 	mutex_init(&tsp->smk_rules_lock);
337 }
338 
339 /**
340  * smk_copy_rules - copy a rule set
341  * @nhead: new rules header pointer
342  * @ohead: old rules header pointer
343  * @gfp: type of the memory for the allocation
344  *
345  * Returns 0 on success, -ENOMEM on error
346  */
347 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
348 				gfp_t gfp)
349 {
350 	struct smack_rule *nrp;
351 	struct smack_rule *orp;
352 	int rc = 0;
353 
354 	list_for_each_entry_rcu(orp, ohead, list) {
355 		nrp = kmem_cache_zalloc(smack_rule_cache, gfp);
356 		if (nrp == NULL) {
357 			rc = -ENOMEM;
358 			break;
359 		}
360 		*nrp = *orp;
361 		list_add_rcu(&nrp->list, nhead);
362 	}
363 	return rc;
364 }
365 
366 /**
367  * smk_copy_relabel - copy smk_relabel labels list
368  * @nhead: new rules header pointer
369  * @ohead: old rules header pointer
370  * @gfp: type of the memory for the allocation
371  *
372  * Returns 0 on success, -ENOMEM on error
373  */
374 static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
375 				gfp_t gfp)
376 {
377 	struct smack_known_list_elem *nklep;
378 	struct smack_known_list_elem *oklep;
379 
380 	list_for_each_entry(oklep, ohead, list) {
381 		nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
382 		if (nklep == NULL) {
383 			smk_destroy_label_list(nhead);
384 			return -ENOMEM;
385 		}
386 		nklep->smk_label = oklep->smk_label;
387 		list_add(&nklep->list, nhead);
388 	}
389 
390 	return 0;
391 }
392 
393 /**
394  * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
395  * @mode: input mode in form of PTRACE_MODE_*
396  *
397  * Returns a converted MAY_* mode usable by smack rules
398  */
399 static inline unsigned int smk_ptrace_mode(unsigned int mode)
400 {
401 	if (mode & PTRACE_MODE_ATTACH)
402 		return MAY_READWRITE;
403 	if (mode & PTRACE_MODE_READ)
404 		return MAY_READ;
405 
406 	return 0;
407 }
408 
409 /**
410  * smk_ptrace_rule_check - helper for ptrace access
411  * @tracer: tracer process
412  * @tracee_known: label entry of the process that's about to be traced
413  * @mode: ptrace attachment mode (PTRACE_MODE_*)
414  * @func: name of the function that called us, used for audit
415  *
416  * Returns 0 on access granted, -error on error
417  */
418 static int smk_ptrace_rule_check(struct task_struct *tracer,
419 				 struct smack_known *tracee_known,
420 				 unsigned int mode, const char *func)
421 {
422 	int rc;
423 	struct smk_audit_info ad, *saip = NULL;
424 	struct task_smack *tsp;
425 	struct smack_known *tracer_known;
426 	const struct cred *tracercred;
427 
428 	if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
429 		smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
430 		smk_ad_setfield_u_tsk(&ad, tracer);
431 		saip = &ad;
432 	}
433 
434 	rcu_read_lock();
435 	tracercred = __task_cred(tracer);
436 	tsp = smack_cred(tracercred);
437 	tracer_known = smk_of_task(tsp);
438 
439 	if ((mode & PTRACE_MODE_ATTACH) &&
440 	    (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
441 	     smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
442 		if (tracer_known->smk_known == tracee_known->smk_known)
443 			rc = 0;
444 		else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
445 			rc = -EACCES;
446 		else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
447 			rc = 0;
448 		else
449 			rc = -EACCES;
450 
451 		if (saip)
452 			smack_log(tracer_known->smk_known,
453 				  tracee_known->smk_known,
454 				  0, rc, saip);
455 
456 		rcu_read_unlock();
457 		return rc;
458 	}
459 
460 	/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
461 	rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
462 
463 	rcu_read_unlock();
464 	return rc;
465 }
466 
467 /*
468  * LSM hooks.
469  * We he, that is fun!
470  */
471 
472 /**
473  * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
474  * @ctp: child task pointer
475  * @mode: ptrace attachment mode (PTRACE_MODE_*)
476  *
477  * Returns 0 if access is OK, an error code otherwise
478  *
479  * Do the capability checks.
480  */
481 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
482 {
483 	struct smack_known *skp;
484 
485 	skp = smk_of_task_struct_obj(ctp);
486 
487 	return smk_ptrace_rule_check(current, skp, mode, __func__);
488 }
489 
490 /**
491  * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
492  * @ptp: parent task pointer
493  *
494  * Returns 0 if access is OK, an error code otherwise
495  *
496  * Do the capability checks, and require PTRACE_MODE_ATTACH.
497  */
498 static int smack_ptrace_traceme(struct task_struct *ptp)
499 {
500 	struct smack_known *skp;
501 
502 	skp = smk_of_task(smack_cred(current_cred()));
503 
504 	return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
505 }
506 
507 /**
508  * smack_syslog - Smack approval on syslog
509  * @typefrom_file: unused
510  *
511  * Returns 0 on success, error code otherwise.
512  */
513 static int smack_syslog(int typefrom_file)
514 {
515 	int rc = 0;
516 	struct smack_known *skp = smk_of_current();
517 
518 	if (smack_privileged(CAP_MAC_OVERRIDE))
519 		return 0;
520 
521 	if (smack_syslog_label != NULL && smack_syslog_label != skp)
522 		rc = -EACCES;
523 
524 	return rc;
525 }
526 
527 /*
528  * Superblock Hooks.
529  */
530 
531 /**
532  * smack_sb_alloc_security - allocate a superblock blob
533  * @sb: the superblock getting the blob
534  *
535  * Returns 0 on success or -ENOMEM on error.
536  */
537 static int smack_sb_alloc_security(struct super_block *sb)
538 {
539 	struct superblock_smack *sbsp = smack_superblock(sb);
540 
541 	sbsp->smk_root = &smack_known_floor;
542 	sbsp->smk_default = &smack_known_floor;
543 	sbsp->smk_floor = &smack_known_floor;
544 	sbsp->smk_hat = &smack_known_hat;
545 	/*
546 	 * SMK_SB_INITIALIZED will be zero from kzalloc.
547 	 */
548 
549 	return 0;
550 }
551 
552 struct smack_mnt_opts {
553 	const char *fsdefault;
554 	const char *fsfloor;
555 	const char *fshat;
556 	const char *fsroot;
557 	const char *fstransmute;
558 };
559 
560 static void smack_free_mnt_opts(void *mnt_opts)
561 {
562 	kfree(mnt_opts);
563 }
564 
565 static int smack_add_opt(int token, const char *s, void **mnt_opts)
566 {
567 	struct smack_mnt_opts *opts = *mnt_opts;
568 	struct smack_known *skp;
569 
570 	if (!opts) {
571 		opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
572 		if (!opts)
573 			return -ENOMEM;
574 		*mnt_opts = opts;
575 	}
576 	if (!s)
577 		return -ENOMEM;
578 
579 	skp = smk_import_entry(s, 0);
580 	if (IS_ERR(skp))
581 		return PTR_ERR(skp);
582 
583 	switch (token) {
584 	case Opt_fsdefault:
585 		if (opts->fsdefault)
586 			goto out_opt_err;
587 		opts->fsdefault = skp->smk_known;
588 		break;
589 	case Opt_fsfloor:
590 		if (opts->fsfloor)
591 			goto out_opt_err;
592 		opts->fsfloor = skp->smk_known;
593 		break;
594 	case Opt_fshat:
595 		if (opts->fshat)
596 			goto out_opt_err;
597 		opts->fshat = skp->smk_known;
598 		break;
599 	case Opt_fsroot:
600 		if (opts->fsroot)
601 			goto out_opt_err;
602 		opts->fsroot = skp->smk_known;
603 		break;
604 	case Opt_fstransmute:
605 		if (opts->fstransmute)
606 			goto out_opt_err;
607 		opts->fstransmute = skp->smk_known;
608 		break;
609 	}
610 	return 0;
611 
612 out_opt_err:
613 	pr_warn("Smack: duplicate mount options\n");
614 	return -EINVAL;
615 }
616 
617 /**
618  * smack_fs_context_dup - Duplicate the security data on fs_context duplication
619  * @fc: The new filesystem context.
620  * @src_fc: The source filesystem context being duplicated.
621  *
622  * Returns 0 on success or -ENOMEM on error.
623  */
624 static int smack_fs_context_dup(struct fs_context *fc,
625 				struct fs_context *src_fc)
626 {
627 	struct smack_mnt_opts *dst, *src = src_fc->security;
628 
629 	if (!src)
630 		return 0;
631 
632 	fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
633 	if (!fc->security)
634 		return -ENOMEM;
635 
636 	dst = fc->security;
637 	dst->fsdefault = src->fsdefault;
638 	dst->fsfloor = src->fsfloor;
639 	dst->fshat = src->fshat;
640 	dst->fsroot = src->fsroot;
641 	dst->fstransmute = src->fstransmute;
642 
643 	return 0;
644 }
645 
646 static const struct fs_parameter_spec smack_fs_parameters[] = {
647 	fsparam_string("smackfsdef",		Opt_fsdefault),
648 	fsparam_string("smackfsdefault",	Opt_fsdefault),
649 	fsparam_string("smackfsfloor",		Opt_fsfloor),
650 	fsparam_string("smackfshat",		Opt_fshat),
651 	fsparam_string("smackfsroot",		Opt_fsroot),
652 	fsparam_string("smackfstransmute",	Opt_fstransmute),
653 	{}
654 };
655 
656 /**
657  * smack_fs_context_parse_param - Parse a single mount parameter
658  * @fc: The new filesystem context being constructed.
659  * @param: The parameter.
660  *
661  * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on
662  * error.
663  */
664 static int smack_fs_context_parse_param(struct fs_context *fc,
665 					struct fs_parameter *param)
666 {
667 	struct fs_parse_result result;
668 	int opt, rc;
669 
670 	opt = fs_parse(fc, smack_fs_parameters, param, &result);
671 	if (opt < 0)
672 		return opt;
673 
674 	rc = smack_add_opt(opt, param->string, &fc->security);
675 	if (!rc)
676 		param->string = NULL;
677 	return rc;
678 }
679 
680 static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
681 {
682 	char *from = options, *to = options;
683 	bool first = true;
684 
685 	while (1) {
686 		char *next = strchr(from, ',');
687 		int token, len, rc;
688 		char *arg = NULL;
689 
690 		if (next)
691 			len = next - from;
692 		else
693 			len = strlen(from);
694 
695 		token = match_opt_prefix(from, len, &arg);
696 		if (token != Opt_error) {
697 			arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
698 			rc = smack_add_opt(token, arg, mnt_opts);
699 			kfree(arg);
700 			if (unlikely(rc)) {
701 				if (*mnt_opts)
702 					smack_free_mnt_opts(*mnt_opts);
703 				*mnt_opts = NULL;
704 				return rc;
705 			}
706 		} else {
707 			if (!first) {	// copy with preceding comma
708 				from--;
709 				len++;
710 			}
711 			if (to != from)
712 				memmove(to, from, len);
713 			to += len;
714 			first = false;
715 		}
716 		if (!from[len])
717 			break;
718 		from += len + 1;
719 	}
720 	*to = '\0';
721 	return 0;
722 }
723 
724 /**
725  * smack_set_mnt_opts - set Smack specific mount options
726  * @sb: the file system superblock
727  * @mnt_opts: Smack mount options
728  * @kern_flags: mount option from kernel space or user space
729  * @set_kern_flags: where to store converted mount opts
730  *
731  * Returns 0 on success, an error code on failure
732  *
733  * Allow filesystems with binary mount data to explicitly set Smack mount
734  * labels.
735  */
736 static int smack_set_mnt_opts(struct super_block *sb,
737 		void *mnt_opts,
738 		unsigned long kern_flags,
739 		unsigned long *set_kern_flags)
740 {
741 	struct dentry *root = sb->s_root;
742 	struct inode *inode = d_backing_inode(root);
743 	struct superblock_smack *sp = smack_superblock(sb);
744 	struct inode_smack *isp;
745 	struct smack_known *skp;
746 	struct smack_mnt_opts *opts = mnt_opts;
747 	bool transmute = false;
748 
749 	if (sp->smk_flags & SMK_SB_INITIALIZED)
750 		return 0;
751 
752 	if (!smack_privileged(CAP_MAC_ADMIN)) {
753 		/*
754 		 * Unprivileged mounts don't get to specify Smack values.
755 		 */
756 		if (opts)
757 			return -EPERM;
758 		/*
759 		 * Unprivileged mounts get root and default from the caller.
760 		 */
761 		skp = smk_of_current();
762 		sp->smk_root = skp;
763 		sp->smk_default = skp;
764 		/*
765 		 * For a handful of fs types with no user-controlled
766 		 * backing store it's okay to trust security labels
767 		 * in the filesystem. The rest are untrusted.
768 		 */
769 		if (sb->s_user_ns != &init_user_ns &&
770 		    sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
771 		    sb->s_magic != RAMFS_MAGIC) {
772 			transmute = true;
773 			sp->smk_flags |= SMK_SB_UNTRUSTED;
774 		}
775 	}
776 
777 	sp->smk_flags |= SMK_SB_INITIALIZED;
778 
779 	if (opts) {
780 		if (opts->fsdefault) {
781 			skp = smk_import_entry(opts->fsdefault, 0);
782 			if (IS_ERR(skp))
783 				return PTR_ERR(skp);
784 			sp->smk_default = skp;
785 		}
786 		if (opts->fsfloor) {
787 			skp = smk_import_entry(opts->fsfloor, 0);
788 			if (IS_ERR(skp))
789 				return PTR_ERR(skp);
790 			sp->smk_floor = skp;
791 		}
792 		if (opts->fshat) {
793 			skp = smk_import_entry(opts->fshat, 0);
794 			if (IS_ERR(skp))
795 				return PTR_ERR(skp);
796 			sp->smk_hat = skp;
797 		}
798 		if (opts->fsroot) {
799 			skp = smk_import_entry(opts->fsroot, 0);
800 			if (IS_ERR(skp))
801 				return PTR_ERR(skp);
802 			sp->smk_root = skp;
803 		}
804 		if (opts->fstransmute) {
805 			skp = smk_import_entry(opts->fstransmute, 0);
806 			if (IS_ERR(skp))
807 				return PTR_ERR(skp);
808 			sp->smk_root = skp;
809 			transmute = true;
810 		}
811 	}
812 
813 	/*
814 	 * Initialize the root inode.
815 	 */
816 	init_inode_smack(inode, sp->smk_root);
817 
818 	if (transmute) {
819 		isp = smack_inode(inode);
820 		isp->smk_flags |= SMK_INODE_TRANSMUTE;
821 	}
822 
823 	return 0;
824 }
825 
826 /**
827  * smack_sb_statfs - Smack check on statfs
828  * @dentry: identifies the file system in question
829  *
830  * Returns 0 if current can read the floor of the filesystem,
831  * and error code otherwise
832  */
833 static int smack_sb_statfs(struct dentry *dentry)
834 {
835 	struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
836 	int rc;
837 	struct smk_audit_info ad;
838 
839 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
840 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
841 
842 	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
843 	rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
844 	return rc;
845 }
846 
847 /*
848  * BPRM hooks
849  */
850 
851 /**
852  * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec
853  * @bprm: the exec information
854  *
855  * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
856  */
857 static int smack_bprm_creds_for_exec(struct linux_binprm *bprm)
858 {
859 	struct inode *inode = file_inode(bprm->file);
860 	struct task_smack *bsp = smack_cred(bprm->cred);
861 	struct inode_smack *isp;
862 	struct superblock_smack *sbsp;
863 	int rc;
864 
865 	isp = smack_inode(inode);
866 	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
867 		return 0;
868 
869 	sbsp = smack_superblock(inode->i_sb);
870 	if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
871 	    isp->smk_task != sbsp->smk_root)
872 		return 0;
873 
874 	if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
875 		struct task_struct *tracer;
876 		rc = 0;
877 
878 		rcu_read_lock();
879 		tracer = ptrace_parent(current);
880 		if (likely(tracer != NULL))
881 			rc = smk_ptrace_rule_check(tracer,
882 						   isp->smk_task,
883 						   PTRACE_MODE_ATTACH,
884 						   __func__);
885 		rcu_read_unlock();
886 
887 		if (rc != 0)
888 			return rc;
889 	}
890 	if (bprm->unsafe & ~LSM_UNSAFE_PTRACE)
891 		return -EPERM;
892 
893 	bsp->smk_task = isp->smk_task;
894 	bprm->per_clear |= PER_CLEAR_ON_SETID;
895 
896 	/* Decide if this is a secure exec. */
897 	if (bsp->smk_task != bsp->smk_forked)
898 		bprm->secureexec = 1;
899 
900 	return 0;
901 }
902 
903 /*
904  * Inode hooks
905  */
906 
907 /**
908  * smack_inode_alloc_security - allocate an inode blob
909  * @inode: the inode in need of a blob
910  *
911  * Returns 0
912  */
913 static int smack_inode_alloc_security(struct inode *inode)
914 {
915 	struct smack_known *skp = smk_of_current();
916 
917 	init_inode_smack(inode, skp);
918 	return 0;
919 }
920 
921 /**
922  * smack_inode_init_security - copy out the smack from an inode
923  * @inode: the newly created inode
924  * @dir: containing directory object
925  * @qstr: unused
926  * @name: where to put the attribute name
927  * @value: where to put the attribute value
928  * @len: where to put the length of the attribute
929  *
930  * Returns 0 if it all works out, -ENOMEM if there's no memory
931  */
932 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
933 				     const struct qstr *qstr, const char **name,
934 				     void **value, size_t *len)
935 {
936 	struct inode_smack *issp = smack_inode(inode);
937 	struct smack_known *skp = smk_of_current();
938 	struct smack_known *isp = smk_of_inode(inode);
939 	struct smack_known *dsp = smk_of_inode(dir);
940 	int may;
941 
942 	if (name)
943 		*name = XATTR_SMACK_SUFFIX;
944 
945 	if (value && len) {
946 		rcu_read_lock();
947 		may = smk_access_entry(skp->smk_known, dsp->smk_known,
948 				       &skp->smk_rules);
949 		rcu_read_unlock();
950 
951 		/*
952 		 * If the access rule allows transmutation and
953 		 * the directory requests transmutation then
954 		 * by all means transmute.
955 		 * Mark the inode as changed.
956 		 */
957 		if (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
958 		    smk_inode_transmutable(dir)) {
959 			isp = dsp;
960 			issp->smk_flags |= SMK_INODE_CHANGED;
961 		}
962 
963 		*value = kstrdup(isp->smk_known, GFP_NOFS);
964 		if (*value == NULL)
965 			return -ENOMEM;
966 
967 		*len = strlen(isp->smk_known);
968 	}
969 
970 	return 0;
971 }
972 
973 /**
974  * smack_inode_link - Smack check on link
975  * @old_dentry: the existing object
976  * @dir: unused
977  * @new_dentry: the new object
978  *
979  * Returns 0 if access is permitted, an error code otherwise
980  */
981 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
982 			    struct dentry *new_dentry)
983 {
984 	struct smack_known *isp;
985 	struct smk_audit_info ad;
986 	int rc;
987 
988 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
989 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
990 
991 	isp = smk_of_inode(d_backing_inode(old_dentry));
992 	rc = smk_curacc(isp, MAY_WRITE, &ad);
993 	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
994 
995 	if (rc == 0 && d_is_positive(new_dentry)) {
996 		isp = smk_of_inode(d_backing_inode(new_dentry));
997 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
998 		rc = smk_curacc(isp, MAY_WRITE, &ad);
999 		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
1000 	}
1001 
1002 	return rc;
1003 }
1004 
1005 /**
1006  * smack_inode_unlink - Smack check on inode deletion
1007  * @dir: containing directory object
1008  * @dentry: file to unlink
1009  *
1010  * Returns 0 if current can write the containing directory
1011  * and the object, error code otherwise
1012  */
1013 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
1014 {
1015 	struct inode *ip = d_backing_inode(dentry);
1016 	struct smk_audit_info ad;
1017 	int rc;
1018 
1019 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1020 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1021 
1022 	/*
1023 	 * You need write access to the thing you're unlinking
1024 	 */
1025 	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
1026 	rc = smk_bu_inode(ip, MAY_WRITE, rc);
1027 	if (rc == 0) {
1028 		/*
1029 		 * You also need write access to the containing directory
1030 		 */
1031 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1032 		smk_ad_setfield_u_fs_inode(&ad, dir);
1033 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1034 		rc = smk_bu_inode(dir, MAY_WRITE, rc);
1035 	}
1036 	return rc;
1037 }
1038 
1039 /**
1040  * smack_inode_rmdir - Smack check on directory deletion
1041  * @dir: containing directory object
1042  * @dentry: directory to unlink
1043  *
1044  * Returns 0 if current can write the containing directory
1045  * and the directory, error code otherwise
1046  */
1047 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
1048 {
1049 	struct smk_audit_info ad;
1050 	int rc;
1051 
1052 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1053 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1054 
1055 	/*
1056 	 * You need write access to the thing you're removing
1057 	 */
1058 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1059 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1060 	if (rc == 0) {
1061 		/*
1062 		 * You also need write access to the containing directory
1063 		 */
1064 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1065 		smk_ad_setfield_u_fs_inode(&ad, dir);
1066 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1067 		rc = smk_bu_inode(dir, MAY_WRITE, rc);
1068 	}
1069 
1070 	return rc;
1071 }
1072 
1073 /**
1074  * smack_inode_rename - Smack check on rename
1075  * @old_inode: unused
1076  * @old_dentry: the old object
1077  * @new_inode: unused
1078  * @new_dentry: the new object
1079  *
1080  * Read and write access is required on both the old and
1081  * new directories.
1082  *
1083  * Returns 0 if access is permitted, an error code otherwise
1084  */
1085 static int smack_inode_rename(struct inode *old_inode,
1086 			      struct dentry *old_dentry,
1087 			      struct inode *new_inode,
1088 			      struct dentry *new_dentry)
1089 {
1090 	int rc;
1091 	struct smack_known *isp;
1092 	struct smk_audit_info ad;
1093 
1094 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1095 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1096 
1097 	isp = smk_of_inode(d_backing_inode(old_dentry));
1098 	rc = smk_curacc(isp, MAY_READWRITE, &ad);
1099 	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
1100 
1101 	if (rc == 0 && d_is_positive(new_dentry)) {
1102 		isp = smk_of_inode(d_backing_inode(new_dentry));
1103 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1104 		rc = smk_curacc(isp, MAY_READWRITE, &ad);
1105 		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
1106 	}
1107 	return rc;
1108 }
1109 
1110 /**
1111  * smack_inode_permission - Smack version of permission()
1112  * @inode: the inode in question
1113  * @mask: the access requested
1114  *
1115  * This is the important Smack hook.
1116  *
1117  * Returns 0 if access is permitted, an error code otherwise
1118  */
1119 static int smack_inode_permission(struct inode *inode, int mask)
1120 {
1121 	struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
1122 	struct smk_audit_info ad;
1123 	int no_block = mask & MAY_NOT_BLOCK;
1124 	int rc;
1125 
1126 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
1127 	/*
1128 	 * No permission to check. Existence test. Yup, it's there.
1129 	 */
1130 	if (mask == 0)
1131 		return 0;
1132 
1133 	if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
1134 		if (smk_of_inode(inode) != sbsp->smk_root)
1135 			return -EACCES;
1136 	}
1137 
1138 	/* May be droppable after audit */
1139 	if (no_block)
1140 		return -ECHILD;
1141 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1142 	smk_ad_setfield_u_fs_inode(&ad, inode);
1143 	rc = smk_curacc(smk_of_inode(inode), mask, &ad);
1144 	rc = smk_bu_inode(inode, mask, rc);
1145 	return rc;
1146 }
1147 
1148 /**
1149  * smack_inode_setattr - Smack check for setting attributes
1150  * @dentry: the object
1151  * @iattr: for the force flag
1152  *
1153  * Returns 0 if access is permitted, an error code otherwise
1154  */
1155 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
1156 {
1157 	struct smk_audit_info ad;
1158 	int rc;
1159 
1160 	/*
1161 	 * Need to allow for clearing the setuid bit.
1162 	 */
1163 	if (iattr->ia_valid & ATTR_FORCE)
1164 		return 0;
1165 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1166 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1167 
1168 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1169 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1170 	return rc;
1171 }
1172 
1173 /**
1174  * smack_inode_getattr - Smack check for getting attributes
1175  * @path: path to extract the info from
1176  *
1177  * Returns 0 if access is permitted, an error code otherwise
1178  */
1179 static int smack_inode_getattr(const struct path *path)
1180 {
1181 	struct smk_audit_info ad;
1182 	struct inode *inode = d_backing_inode(path->dentry);
1183 	int rc;
1184 
1185 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1186 	smk_ad_setfield_u_fs_path(&ad, *path);
1187 	rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1188 	rc = smk_bu_inode(inode, MAY_READ, rc);
1189 	return rc;
1190 }
1191 
1192 /**
1193  * smack_inode_setxattr - Smack check for setting xattrs
1194  * @idmap: idmap of the mount
1195  * @dentry: the object
1196  * @name: name of the attribute
1197  * @value: value of the attribute
1198  * @size: size of the value
1199  * @flags: unused
1200  *
1201  * This protects the Smack attribute explicitly.
1202  *
1203  * Returns 0 if access is permitted, an error code otherwise
1204  */
1205 static int smack_inode_setxattr(struct mnt_idmap *idmap,
1206 				struct dentry *dentry, const char *name,
1207 				const void *value, size_t size, int flags)
1208 {
1209 	struct smk_audit_info ad;
1210 	struct smack_known *skp;
1211 	int check_priv = 0;
1212 	int check_import = 0;
1213 	int check_star = 0;
1214 	int rc = 0;
1215 
1216 	/*
1217 	 * Check label validity here so import won't fail in post_setxattr
1218 	 */
1219 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1220 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1221 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
1222 		check_priv = 1;
1223 		check_import = 1;
1224 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1225 		   strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1226 		check_priv = 1;
1227 		check_import = 1;
1228 		check_star = 1;
1229 	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1230 		check_priv = 1;
1231 		if (size != TRANS_TRUE_SIZE ||
1232 		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
1233 			rc = -EINVAL;
1234 	} else
1235 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
1236 
1237 	if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
1238 		rc = -EPERM;
1239 
1240 	if (rc == 0 && check_import) {
1241 		skp = size ? smk_import_entry(value, size) : NULL;
1242 		if (IS_ERR(skp))
1243 			rc = PTR_ERR(skp);
1244 		else if (skp == NULL || (check_star &&
1245 		    (skp == &smack_known_star || skp == &smack_known_web)))
1246 			rc = -EINVAL;
1247 	}
1248 
1249 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1250 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1251 
1252 	if (rc == 0) {
1253 		rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1254 		rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1255 	}
1256 
1257 	return rc;
1258 }
1259 
1260 /**
1261  * smack_inode_post_setxattr - Apply the Smack update approved above
1262  * @dentry: object
1263  * @name: attribute name
1264  * @value: attribute value
1265  * @size: attribute size
1266  * @flags: unused
1267  *
1268  * Set the pointer in the inode blob to the entry found
1269  * in the master label list.
1270  */
1271 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
1272 				      const void *value, size_t size, int flags)
1273 {
1274 	struct smack_known *skp;
1275 	struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
1276 
1277 	if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1278 		isp->smk_flags |= SMK_INODE_TRANSMUTE;
1279 		return;
1280 	}
1281 
1282 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1283 		skp = smk_import_entry(value, size);
1284 		if (!IS_ERR(skp))
1285 			isp->smk_inode = skp;
1286 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1287 		skp = smk_import_entry(value, size);
1288 		if (!IS_ERR(skp))
1289 			isp->smk_task = skp;
1290 	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1291 		skp = smk_import_entry(value, size);
1292 		if (!IS_ERR(skp))
1293 			isp->smk_mmap = skp;
1294 	}
1295 
1296 	return;
1297 }
1298 
1299 /**
1300  * smack_inode_getxattr - Smack check on getxattr
1301  * @dentry: the object
1302  * @name: unused
1303  *
1304  * Returns 0 if access is permitted, an error code otherwise
1305  */
1306 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
1307 {
1308 	struct smk_audit_info ad;
1309 	int rc;
1310 
1311 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1312 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1313 
1314 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1315 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1316 	return rc;
1317 }
1318 
1319 /**
1320  * smack_inode_removexattr - Smack check on removexattr
1321  * @idmap: idmap of the mount
1322  * @dentry: the object
1323  * @name: name of the attribute
1324  *
1325  * Removing the Smack attribute requires CAP_MAC_ADMIN
1326  *
1327  * Returns 0 if access is permitted, an error code otherwise
1328  */
1329 static int smack_inode_removexattr(struct mnt_idmap *idmap,
1330 				   struct dentry *dentry, const char *name)
1331 {
1332 	struct inode_smack *isp;
1333 	struct smk_audit_info ad;
1334 	int rc = 0;
1335 
1336 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1337 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1338 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1339 	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1340 	    strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
1341 	    strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1342 		if (!smack_privileged(CAP_MAC_ADMIN))
1343 			rc = -EPERM;
1344 	} else
1345 		rc = cap_inode_removexattr(idmap, dentry, name);
1346 
1347 	if (rc != 0)
1348 		return rc;
1349 
1350 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1351 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1352 
1353 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1354 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1355 	if (rc != 0)
1356 		return rc;
1357 
1358 	isp = smack_inode(d_backing_inode(dentry));
1359 	/*
1360 	 * Don't do anything special for these.
1361 	 *	XATTR_NAME_SMACKIPIN
1362 	 *	XATTR_NAME_SMACKIPOUT
1363 	 */
1364 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1365 		struct super_block *sbp = dentry->d_sb;
1366 		struct superblock_smack *sbsp = smack_superblock(sbp);
1367 
1368 		isp->smk_inode = sbsp->smk_default;
1369 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
1370 		isp->smk_task = NULL;
1371 	else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1372 		isp->smk_mmap = NULL;
1373 	else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
1374 		isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1375 
1376 	return 0;
1377 }
1378 
1379 /**
1380  * smack_inode_set_acl - Smack check for setting posix acls
1381  * @idmap: idmap of the mnt this request came from
1382  * @dentry: the object
1383  * @acl_name: name of the posix acl
1384  * @kacl: the posix acls
1385  *
1386  * Returns 0 if access is permitted, an error code otherwise
1387  */
1388 static int smack_inode_set_acl(struct mnt_idmap *idmap,
1389 			       struct dentry *dentry, const char *acl_name,
1390 			       struct posix_acl *kacl)
1391 {
1392 	struct smk_audit_info ad;
1393 	int rc;
1394 
1395 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1396 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1397 
1398 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1399 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1400 	return rc;
1401 }
1402 
1403 /**
1404  * smack_inode_get_acl - Smack check for getting posix acls
1405  * @idmap: idmap of the mnt this request came from
1406  * @dentry: the object
1407  * @acl_name: name of the posix acl
1408  *
1409  * Returns 0 if access is permitted, an error code otherwise
1410  */
1411 static int smack_inode_get_acl(struct mnt_idmap *idmap,
1412 			       struct dentry *dentry, const char *acl_name)
1413 {
1414 	struct smk_audit_info ad;
1415 	int rc;
1416 
1417 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1418 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1419 
1420 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1421 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1422 	return rc;
1423 }
1424 
1425 /**
1426  * smack_inode_remove_acl - Smack check for getting posix acls
1427  * @idmap: idmap of the mnt this request came from
1428  * @dentry: the object
1429  * @acl_name: name of the posix acl
1430  *
1431  * Returns 0 if access is permitted, an error code otherwise
1432  */
1433 static int smack_inode_remove_acl(struct mnt_idmap *idmap,
1434 				  struct dentry *dentry, const char *acl_name)
1435 {
1436 	struct smk_audit_info ad;
1437 	int rc;
1438 
1439 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1440 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1441 
1442 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1443 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1444 	return rc;
1445 }
1446 
1447 /**
1448  * smack_inode_getsecurity - get smack xattrs
1449  * @idmap: idmap of the mount
1450  * @inode: the object
1451  * @name: attribute name
1452  * @buffer: where to put the result
1453  * @alloc: duplicate memory
1454  *
1455  * Returns the size of the attribute or an error code
1456  */
1457 static int smack_inode_getsecurity(struct mnt_idmap *idmap,
1458 				   struct inode *inode, const char *name,
1459 				   void **buffer, bool alloc)
1460 {
1461 	struct socket_smack *ssp;
1462 	struct socket *sock;
1463 	struct super_block *sbp;
1464 	struct inode *ip = inode;
1465 	struct smack_known *isp;
1466 
1467 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0)
1468 		isp = smk_of_inode(inode);
1469 	else {
1470 		/*
1471 		 * The rest of the Smack xattrs are only on sockets.
1472 		 */
1473 		sbp = ip->i_sb;
1474 		if (sbp->s_magic != SOCKFS_MAGIC)
1475 			return -EOPNOTSUPP;
1476 
1477 		sock = SOCKET_I(ip);
1478 		if (sock == NULL || sock->sk == NULL)
1479 			return -EOPNOTSUPP;
1480 
1481 		ssp = sock->sk->sk_security;
1482 
1483 		if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1484 			isp = ssp->smk_in;
1485 		else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1486 			isp = ssp->smk_out;
1487 		else
1488 			return -EOPNOTSUPP;
1489 	}
1490 
1491 	if (alloc) {
1492 		*buffer = kstrdup(isp->smk_known, GFP_KERNEL);
1493 		if (*buffer == NULL)
1494 			return -ENOMEM;
1495 	}
1496 
1497 	return strlen(isp->smk_known);
1498 }
1499 
1500 
1501 /**
1502  * smack_inode_listsecurity - list the Smack attributes
1503  * @inode: the object
1504  * @buffer: where they go
1505  * @buffer_size: size of buffer
1506  */
1507 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1508 				    size_t buffer_size)
1509 {
1510 	int len = sizeof(XATTR_NAME_SMACK);
1511 
1512 	if (buffer != NULL && len <= buffer_size)
1513 		memcpy(buffer, XATTR_NAME_SMACK, len);
1514 
1515 	return len;
1516 }
1517 
1518 /**
1519  * smack_inode_getsecid - Extract inode's security id
1520  * @inode: inode to extract the info from
1521  * @secid: where result will be saved
1522  */
1523 static void smack_inode_getsecid(struct inode *inode, u32 *secid)
1524 {
1525 	struct smack_known *skp = smk_of_inode(inode);
1526 
1527 	*secid = skp->smk_secid;
1528 }
1529 
1530 /*
1531  * File Hooks
1532  */
1533 
1534 /*
1535  * There is no smack_file_permission hook
1536  *
1537  * Should access checks be done on each read or write?
1538  * UNICOS and SELinux say yes.
1539  * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1540  *
1541  * I'll say no for now. Smack does not do the frequent
1542  * label changing that SELinux does.
1543  */
1544 
1545 /**
1546  * smack_file_alloc_security - assign a file security blob
1547  * @file: the object
1548  *
1549  * The security blob for a file is a pointer to the master
1550  * label list, so no allocation is done.
1551  *
1552  * f_security is the owner security information. It
1553  * isn't used on file access checks, it's for send_sigio.
1554  *
1555  * Returns 0
1556  */
1557 static int smack_file_alloc_security(struct file *file)
1558 {
1559 	struct smack_known **blob = smack_file(file);
1560 
1561 	*blob = smk_of_current();
1562 	return 0;
1563 }
1564 
1565 /**
1566  * smack_file_ioctl - Smack check on ioctls
1567  * @file: the object
1568  * @cmd: what to do
1569  * @arg: unused
1570  *
1571  * Relies heavily on the correct use of the ioctl command conventions.
1572  *
1573  * Returns 0 if allowed, error code otherwise
1574  */
1575 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1576 			    unsigned long arg)
1577 {
1578 	int rc = 0;
1579 	struct smk_audit_info ad;
1580 	struct inode *inode = file_inode(file);
1581 
1582 	if (unlikely(IS_PRIVATE(inode)))
1583 		return 0;
1584 
1585 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1586 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1587 
1588 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
1589 		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1590 		rc = smk_bu_file(file, MAY_WRITE, rc);
1591 	}
1592 
1593 	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
1594 		rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1595 		rc = smk_bu_file(file, MAY_READ, rc);
1596 	}
1597 
1598 	return rc;
1599 }
1600 
1601 /**
1602  * smack_file_lock - Smack check on file locking
1603  * @file: the object
1604  * @cmd: unused
1605  *
1606  * Returns 0 if current has lock access, error code otherwise
1607  */
1608 static int smack_file_lock(struct file *file, unsigned int cmd)
1609 {
1610 	struct smk_audit_info ad;
1611 	int rc;
1612 	struct inode *inode = file_inode(file);
1613 
1614 	if (unlikely(IS_PRIVATE(inode)))
1615 		return 0;
1616 
1617 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1618 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1619 	rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1620 	rc = smk_bu_file(file, MAY_LOCK, rc);
1621 	return rc;
1622 }
1623 
1624 /**
1625  * smack_file_fcntl - Smack check on fcntl
1626  * @file: the object
1627  * @cmd: what action to check
1628  * @arg: unused
1629  *
1630  * Generally these operations are harmless.
1631  * File locking operations present an obvious mechanism
1632  * for passing information, so they require write access.
1633  *
1634  * Returns 0 if current has access, error code otherwise
1635  */
1636 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1637 			    unsigned long arg)
1638 {
1639 	struct smk_audit_info ad;
1640 	int rc = 0;
1641 	struct inode *inode = file_inode(file);
1642 
1643 	if (unlikely(IS_PRIVATE(inode)))
1644 		return 0;
1645 
1646 	switch (cmd) {
1647 	case F_GETLK:
1648 		break;
1649 	case F_SETLK:
1650 	case F_SETLKW:
1651 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1652 		smk_ad_setfield_u_fs_path(&ad, file->f_path);
1653 		rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1654 		rc = smk_bu_file(file, MAY_LOCK, rc);
1655 		break;
1656 	case F_SETOWN:
1657 	case F_SETSIG:
1658 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1659 		smk_ad_setfield_u_fs_path(&ad, file->f_path);
1660 		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1661 		rc = smk_bu_file(file, MAY_WRITE, rc);
1662 		break;
1663 	default:
1664 		break;
1665 	}
1666 
1667 	return rc;
1668 }
1669 
1670 /**
1671  * smack_mmap_file - Check permissions for a mmap operation.
1672  * @file: contains the file structure for file to map (may be NULL).
1673  * @reqprot: contains the protection requested by the application.
1674  * @prot: contains the protection that will be applied by the kernel.
1675  * @flags: contains the operational flags.
1676  *
1677  * The @file may be NULL, e.g. if mapping anonymous memory.
1678  *
1679  * Return 0 if permission is granted.
1680  */
1681 static int smack_mmap_file(struct file *file,
1682 			   unsigned long reqprot, unsigned long prot,
1683 			   unsigned long flags)
1684 {
1685 	struct smack_known *skp;
1686 	struct smack_known *mkp;
1687 	struct smack_rule *srp;
1688 	struct task_smack *tsp;
1689 	struct smack_known *okp;
1690 	struct inode_smack *isp;
1691 	struct superblock_smack *sbsp;
1692 	int may;
1693 	int mmay;
1694 	int tmay;
1695 	int rc;
1696 
1697 	if (file == NULL)
1698 		return 0;
1699 
1700 	if (unlikely(IS_PRIVATE(file_inode(file))))
1701 		return 0;
1702 
1703 	isp = smack_inode(file_inode(file));
1704 	if (isp->smk_mmap == NULL)
1705 		return 0;
1706 	sbsp = smack_superblock(file_inode(file)->i_sb);
1707 	if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
1708 	    isp->smk_mmap != sbsp->smk_root)
1709 		return -EACCES;
1710 	mkp = isp->smk_mmap;
1711 
1712 	tsp = smack_cred(current_cred());
1713 	skp = smk_of_current();
1714 	rc = 0;
1715 
1716 	rcu_read_lock();
1717 	/*
1718 	 * For each Smack rule associated with the subject
1719 	 * label verify that the SMACK64MMAP also has access
1720 	 * to that rule's object label.
1721 	 */
1722 	list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1723 		okp = srp->smk_object;
1724 		/*
1725 		 * Matching labels always allows access.
1726 		 */
1727 		if (mkp->smk_known == okp->smk_known)
1728 			continue;
1729 		/*
1730 		 * If there is a matching local rule take
1731 		 * that into account as well.
1732 		 */
1733 		may = smk_access_entry(srp->smk_subject->smk_known,
1734 				       okp->smk_known,
1735 				       &tsp->smk_rules);
1736 		if (may == -ENOENT)
1737 			may = srp->smk_access;
1738 		else
1739 			may &= srp->smk_access;
1740 		/*
1741 		 * If may is zero the SMACK64MMAP subject can't
1742 		 * possibly have less access.
1743 		 */
1744 		if (may == 0)
1745 			continue;
1746 
1747 		/*
1748 		 * Fetch the global list entry.
1749 		 * If there isn't one a SMACK64MMAP subject
1750 		 * can't have as much access as current.
1751 		 */
1752 		mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1753 					&mkp->smk_rules);
1754 		if (mmay == -ENOENT) {
1755 			rc = -EACCES;
1756 			break;
1757 		}
1758 		/*
1759 		 * If there is a local entry it modifies the
1760 		 * potential access, too.
1761 		 */
1762 		tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1763 					&tsp->smk_rules);
1764 		if (tmay != -ENOENT)
1765 			mmay &= tmay;
1766 
1767 		/*
1768 		 * If there is any access available to current that is
1769 		 * not available to a SMACK64MMAP subject
1770 		 * deny access.
1771 		 */
1772 		if ((may | mmay) != mmay) {
1773 			rc = -EACCES;
1774 			break;
1775 		}
1776 	}
1777 
1778 	rcu_read_unlock();
1779 
1780 	return rc;
1781 }
1782 
1783 /**
1784  * smack_file_set_fowner - set the file security blob value
1785  * @file: object in question
1786  *
1787  */
1788 static void smack_file_set_fowner(struct file *file)
1789 {
1790 	struct smack_known **blob = smack_file(file);
1791 
1792 	*blob = smk_of_current();
1793 }
1794 
1795 /**
1796  * smack_file_send_sigiotask - Smack on sigio
1797  * @tsk: The target task
1798  * @fown: the object the signal come from
1799  * @signum: unused
1800  *
1801  * Allow a privileged task to get signals even if it shouldn't
1802  *
1803  * Returns 0 if a subject with the object's smack could
1804  * write to the task, an error code otherwise.
1805  */
1806 static int smack_file_send_sigiotask(struct task_struct *tsk,
1807 				     struct fown_struct *fown, int signum)
1808 {
1809 	struct smack_known **blob;
1810 	struct smack_known *skp;
1811 	struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
1812 	const struct cred *tcred;
1813 	struct file *file;
1814 	int rc;
1815 	struct smk_audit_info ad;
1816 
1817 	/*
1818 	 * struct fown_struct is never outside the context of a struct file
1819 	 */
1820 	file = container_of(fown, struct file, f_owner);
1821 
1822 	/* we don't log here as rc can be overriden */
1823 	blob = smack_file(file);
1824 	skp = *blob;
1825 	rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
1826 	rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
1827 
1828 	rcu_read_lock();
1829 	tcred = __task_cred(tsk);
1830 	if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred))
1831 		rc = 0;
1832 	rcu_read_unlock();
1833 
1834 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1835 	smk_ad_setfield_u_tsk(&ad, tsk);
1836 	smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
1837 	return rc;
1838 }
1839 
1840 /**
1841  * smack_file_receive - Smack file receive check
1842  * @file: the object
1843  *
1844  * Returns 0 if current has access, error code otherwise
1845  */
1846 static int smack_file_receive(struct file *file)
1847 {
1848 	int rc;
1849 	int may = 0;
1850 	struct smk_audit_info ad;
1851 	struct inode *inode = file_inode(file);
1852 	struct socket *sock;
1853 	struct task_smack *tsp;
1854 	struct socket_smack *ssp;
1855 
1856 	if (unlikely(IS_PRIVATE(inode)))
1857 		return 0;
1858 
1859 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1860 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1861 
1862 	if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
1863 		sock = SOCKET_I(inode);
1864 		ssp = sock->sk->sk_security;
1865 		tsp = smack_cred(current_cred());
1866 		/*
1867 		 * If the receiving process can't write to the
1868 		 * passed socket or if the passed socket can't
1869 		 * write to the receiving process don't accept
1870 		 * the passed socket.
1871 		 */
1872 		rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
1873 		rc = smk_bu_file(file, may, rc);
1874 		if (rc < 0)
1875 			return rc;
1876 		rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
1877 		rc = smk_bu_file(file, may, rc);
1878 		return rc;
1879 	}
1880 	/*
1881 	 * This code relies on bitmasks.
1882 	 */
1883 	if (file->f_mode & FMODE_READ)
1884 		may = MAY_READ;
1885 	if (file->f_mode & FMODE_WRITE)
1886 		may |= MAY_WRITE;
1887 
1888 	rc = smk_curacc(smk_of_inode(inode), may, &ad);
1889 	rc = smk_bu_file(file, may, rc);
1890 	return rc;
1891 }
1892 
1893 /**
1894  * smack_file_open - Smack dentry open processing
1895  * @file: the object
1896  *
1897  * Set the security blob in the file structure.
1898  * Allow the open only if the task has read access. There are
1899  * many read operations (e.g. fstat) that you can do with an
1900  * fd even if you have the file open write-only.
1901  *
1902  * Returns 0 if current has access, error code otherwise
1903  */
1904 static int smack_file_open(struct file *file)
1905 {
1906 	struct task_smack *tsp = smack_cred(file->f_cred);
1907 	struct inode *inode = file_inode(file);
1908 	struct smk_audit_info ad;
1909 	int rc;
1910 
1911 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1912 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1913 	rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
1914 	rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
1915 
1916 	return rc;
1917 }
1918 
1919 /*
1920  * Task hooks
1921  */
1922 
1923 /**
1924  * smack_cred_alloc_blank - "allocate" blank task-level security credentials
1925  * @cred: the new credentials
1926  * @gfp: the atomicity of any memory allocations
1927  *
1928  * Prepare a blank set of credentials for modification.  This must allocate all
1929  * the memory the LSM module might require such that cred_transfer() can
1930  * complete without error.
1931  */
1932 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
1933 {
1934 	init_task_smack(smack_cred(cred), NULL, NULL);
1935 	return 0;
1936 }
1937 
1938 
1939 /**
1940  * smack_cred_free - "free" task-level security credentials
1941  * @cred: the credentials in question
1942  *
1943  */
1944 static void smack_cred_free(struct cred *cred)
1945 {
1946 	struct task_smack *tsp = smack_cred(cred);
1947 	struct smack_rule *rp;
1948 	struct list_head *l;
1949 	struct list_head *n;
1950 
1951 	smk_destroy_label_list(&tsp->smk_relabel);
1952 
1953 	list_for_each_safe(l, n, &tsp->smk_rules) {
1954 		rp = list_entry(l, struct smack_rule, list);
1955 		list_del(&rp->list);
1956 		kmem_cache_free(smack_rule_cache, rp);
1957 	}
1958 }
1959 
1960 /**
1961  * smack_cred_prepare - prepare new set of credentials for modification
1962  * @new: the new credentials
1963  * @old: the original credentials
1964  * @gfp: the atomicity of any memory allocations
1965  *
1966  * Prepare a new set of credentials for modification.
1967  */
1968 static int smack_cred_prepare(struct cred *new, const struct cred *old,
1969 			      gfp_t gfp)
1970 {
1971 	struct task_smack *old_tsp = smack_cred(old);
1972 	struct task_smack *new_tsp = smack_cred(new);
1973 	int rc;
1974 
1975 	init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
1976 
1977 	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
1978 	if (rc != 0)
1979 		return rc;
1980 
1981 	rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
1982 				gfp);
1983 	return rc;
1984 }
1985 
1986 /**
1987  * smack_cred_transfer - Transfer the old credentials to the new credentials
1988  * @new: the new credentials
1989  * @old: the original credentials
1990  *
1991  * Fill in a set of blank credentials from another set of credentials.
1992  */
1993 static void smack_cred_transfer(struct cred *new, const struct cred *old)
1994 {
1995 	struct task_smack *old_tsp = smack_cred(old);
1996 	struct task_smack *new_tsp = smack_cred(new);
1997 
1998 	new_tsp->smk_task = old_tsp->smk_task;
1999 	new_tsp->smk_forked = old_tsp->smk_task;
2000 	mutex_init(&new_tsp->smk_rules_lock);
2001 	INIT_LIST_HEAD(&new_tsp->smk_rules);
2002 
2003 	/* cbs copy rule list */
2004 }
2005 
2006 /**
2007  * smack_cred_getsecid - get the secid corresponding to a creds structure
2008  * @cred: the object creds
2009  * @secid: where to put the result
2010  *
2011  * Sets the secid to contain a u32 version of the smack label.
2012  */
2013 static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
2014 {
2015 	struct smack_known *skp;
2016 
2017 	rcu_read_lock();
2018 	skp = smk_of_task(smack_cred(cred));
2019 	*secid = skp->smk_secid;
2020 	rcu_read_unlock();
2021 }
2022 
2023 /**
2024  * smack_kernel_act_as - Set the subjective context in a set of credentials
2025  * @new: points to the set of credentials to be modified.
2026  * @secid: specifies the security ID to be set
2027  *
2028  * Set the security data for a kernel service.
2029  */
2030 static int smack_kernel_act_as(struct cred *new, u32 secid)
2031 {
2032 	struct task_smack *new_tsp = smack_cred(new);
2033 
2034 	new_tsp->smk_task = smack_from_secid(secid);
2035 	return 0;
2036 }
2037 
2038 /**
2039  * smack_kernel_create_files_as - Set the file creation label in a set of creds
2040  * @new: points to the set of credentials to be modified
2041  * @inode: points to the inode to use as a reference
2042  *
2043  * Set the file creation context in a set of credentials to the same
2044  * as the objective context of the specified inode
2045  */
2046 static int smack_kernel_create_files_as(struct cred *new,
2047 					struct inode *inode)
2048 {
2049 	struct inode_smack *isp = smack_inode(inode);
2050 	struct task_smack *tsp = smack_cred(new);
2051 
2052 	tsp->smk_forked = isp->smk_inode;
2053 	tsp->smk_task = tsp->smk_forked;
2054 	return 0;
2055 }
2056 
2057 /**
2058  * smk_curacc_on_task - helper to log task related access
2059  * @p: the task object
2060  * @access: the access requested
2061  * @caller: name of the calling function for audit
2062  *
2063  * Return 0 if access is permitted
2064  */
2065 static int smk_curacc_on_task(struct task_struct *p, int access,
2066 				const char *caller)
2067 {
2068 	struct smk_audit_info ad;
2069 	struct smack_known *skp = smk_of_task_struct_obj(p);
2070 	int rc;
2071 
2072 	smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
2073 	smk_ad_setfield_u_tsk(&ad, p);
2074 	rc = smk_curacc(skp, access, &ad);
2075 	rc = smk_bu_task(p, access, rc);
2076 	return rc;
2077 }
2078 
2079 /**
2080  * smack_task_setpgid - Smack check on setting pgid
2081  * @p: the task object
2082  * @pgid: unused
2083  *
2084  * Return 0 if write access is permitted
2085  */
2086 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
2087 {
2088 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2089 }
2090 
2091 /**
2092  * smack_task_getpgid - Smack access check for getpgid
2093  * @p: the object task
2094  *
2095  * Returns 0 if current can read the object task, error code otherwise
2096  */
2097 static int smack_task_getpgid(struct task_struct *p)
2098 {
2099 	return smk_curacc_on_task(p, MAY_READ, __func__);
2100 }
2101 
2102 /**
2103  * smack_task_getsid - Smack access check for getsid
2104  * @p: the object task
2105  *
2106  * Returns 0 if current can read the object task, error code otherwise
2107  */
2108 static int smack_task_getsid(struct task_struct *p)
2109 {
2110 	return smk_curacc_on_task(p, MAY_READ, __func__);
2111 }
2112 
2113 /**
2114  * smack_current_getsecid_subj - get the subjective secid of the current task
2115  * @secid: where to put the result
2116  *
2117  * Sets the secid to contain a u32 version of the task's subjective smack label.
2118  */
2119 static void smack_current_getsecid_subj(u32 *secid)
2120 {
2121 	struct smack_known *skp = smk_of_current();
2122 
2123 	*secid = skp->smk_secid;
2124 }
2125 
2126 /**
2127  * smack_task_getsecid_obj - get the objective secid of the task
2128  * @p: the task
2129  * @secid: where to put the result
2130  *
2131  * Sets the secid to contain a u32 version of the task's objective smack label.
2132  */
2133 static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
2134 {
2135 	struct smack_known *skp = smk_of_task_struct_obj(p);
2136 
2137 	*secid = skp->smk_secid;
2138 }
2139 
2140 /**
2141  * smack_task_setnice - Smack check on setting nice
2142  * @p: the task object
2143  * @nice: unused
2144  *
2145  * Return 0 if write access is permitted
2146  */
2147 static int smack_task_setnice(struct task_struct *p, int nice)
2148 {
2149 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2150 }
2151 
2152 /**
2153  * smack_task_setioprio - Smack check on setting ioprio
2154  * @p: the task object
2155  * @ioprio: unused
2156  *
2157  * Return 0 if write access is permitted
2158  */
2159 static int smack_task_setioprio(struct task_struct *p, int ioprio)
2160 {
2161 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2162 }
2163 
2164 /**
2165  * smack_task_getioprio - Smack check on reading ioprio
2166  * @p: the task object
2167  *
2168  * Return 0 if read access is permitted
2169  */
2170 static int smack_task_getioprio(struct task_struct *p)
2171 {
2172 	return smk_curacc_on_task(p, MAY_READ, __func__);
2173 }
2174 
2175 /**
2176  * smack_task_setscheduler - Smack check on setting scheduler
2177  * @p: the task object
2178  *
2179  * Return 0 if read access is permitted
2180  */
2181 static int smack_task_setscheduler(struct task_struct *p)
2182 {
2183 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2184 }
2185 
2186 /**
2187  * smack_task_getscheduler - Smack check on reading scheduler
2188  * @p: the task object
2189  *
2190  * Return 0 if read access is permitted
2191  */
2192 static int smack_task_getscheduler(struct task_struct *p)
2193 {
2194 	return smk_curacc_on_task(p, MAY_READ, __func__);
2195 }
2196 
2197 /**
2198  * smack_task_movememory - Smack check on moving memory
2199  * @p: the task object
2200  *
2201  * Return 0 if write access is permitted
2202  */
2203 static int smack_task_movememory(struct task_struct *p)
2204 {
2205 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2206 }
2207 
2208 /**
2209  * smack_task_kill - Smack check on signal delivery
2210  * @p: the task object
2211  * @info: unused
2212  * @sig: unused
2213  * @cred: identifies the cred to use in lieu of current's
2214  *
2215  * Return 0 if write access is permitted
2216  *
2217  */
2218 static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
2219 			   int sig, const struct cred *cred)
2220 {
2221 	struct smk_audit_info ad;
2222 	struct smack_known *skp;
2223 	struct smack_known *tkp = smk_of_task_struct_obj(p);
2224 	int rc;
2225 
2226 	if (!sig)
2227 		return 0; /* null signal; existence test */
2228 
2229 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
2230 	smk_ad_setfield_u_tsk(&ad, p);
2231 	/*
2232 	 * Sending a signal requires that the sender
2233 	 * can write the receiver.
2234 	 */
2235 	if (cred == NULL) {
2236 		rc = smk_curacc(tkp, MAY_DELIVER, &ad);
2237 		rc = smk_bu_task(p, MAY_DELIVER, rc);
2238 		return rc;
2239 	}
2240 	/*
2241 	 * If the cred isn't NULL we're dealing with some USB IO
2242 	 * specific behavior. This is not clean. For one thing
2243 	 * we can't take privilege into account.
2244 	 */
2245 	skp = smk_of_task(smack_cred(cred));
2246 	rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
2247 	rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
2248 	return rc;
2249 }
2250 
2251 /**
2252  * smack_task_to_inode - copy task smack into the inode blob
2253  * @p: task to copy from
2254  * @inode: inode to copy to
2255  *
2256  * Sets the smack pointer in the inode security blob
2257  */
2258 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
2259 {
2260 	struct inode_smack *isp = smack_inode(inode);
2261 	struct smack_known *skp = smk_of_task_struct_obj(p);
2262 
2263 	isp->smk_inode = skp;
2264 	isp->smk_flags |= SMK_INODE_INSTANT;
2265 }
2266 
2267 /*
2268  * Socket hooks.
2269  */
2270 
2271 /**
2272  * smack_sk_alloc_security - Allocate a socket blob
2273  * @sk: the socket
2274  * @family: unused
2275  * @gfp_flags: memory allocation flags
2276  *
2277  * Assign Smack pointers to current
2278  *
2279  * Returns 0 on success, -ENOMEM is there's no memory
2280  */
2281 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
2282 {
2283 	struct smack_known *skp = smk_of_current();
2284 	struct socket_smack *ssp;
2285 
2286 	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
2287 	if (ssp == NULL)
2288 		return -ENOMEM;
2289 
2290 	/*
2291 	 * Sockets created by kernel threads receive web label.
2292 	 */
2293 	if (unlikely(current->flags & PF_KTHREAD)) {
2294 		ssp->smk_in = &smack_known_web;
2295 		ssp->smk_out = &smack_known_web;
2296 	} else {
2297 		ssp->smk_in = skp;
2298 		ssp->smk_out = skp;
2299 	}
2300 	ssp->smk_packet = NULL;
2301 
2302 	sk->sk_security = ssp;
2303 
2304 	return 0;
2305 }
2306 
2307 /**
2308  * smack_sk_free_security - Free a socket blob
2309  * @sk: the socket
2310  *
2311  * Clears the blob pointer
2312  */
2313 static void smack_sk_free_security(struct sock *sk)
2314 {
2315 #ifdef SMACK_IPV6_PORT_LABELING
2316 	struct smk_port_label *spp;
2317 
2318 	if (sk->sk_family == PF_INET6) {
2319 		rcu_read_lock();
2320 		list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2321 			if (spp->smk_sock != sk)
2322 				continue;
2323 			spp->smk_can_reuse = 1;
2324 			break;
2325 		}
2326 		rcu_read_unlock();
2327 	}
2328 #endif
2329 	kfree(sk->sk_security);
2330 }
2331 
2332 /**
2333  * smack_sk_clone_security - Copy security context
2334  * @sk: the old socket
2335  * @newsk: the new socket
2336  *
2337  * Copy the security context of the old socket pointer to the cloned
2338  */
2339 static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk)
2340 {
2341 	struct socket_smack *ssp_old = sk->sk_security;
2342 	struct socket_smack *ssp_new = newsk->sk_security;
2343 
2344 	*ssp_new = *ssp_old;
2345 }
2346 
2347 /**
2348 * smack_ipv4host_label - check host based restrictions
2349 * @sip: the object end
2350 *
2351 * looks for host based access restrictions
2352 *
2353 * This version will only be appropriate for really small sets of single label
2354 * hosts.  The caller is responsible for ensuring that the RCU read lock is
2355 * taken before calling this function.
2356 *
2357 * Returns the label of the far end or NULL if it's not special.
2358 */
2359 static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
2360 {
2361 	struct smk_net4addr *snp;
2362 	struct in_addr *siap = &sip->sin_addr;
2363 
2364 	if (siap->s_addr == 0)
2365 		return NULL;
2366 
2367 	list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
2368 		/*
2369 		 * we break after finding the first match because
2370 		 * the list is sorted from longest to shortest mask
2371 		 * so we have found the most specific match
2372 		 */
2373 		if (snp->smk_host.s_addr ==
2374 		    (siap->s_addr & snp->smk_mask.s_addr))
2375 			return snp->smk_label;
2376 
2377 	return NULL;
2378 }
2379 
2380 /*
2381  * smk_ipv6_localhost - Check for local ipv6 host address
2382  * @sip: the address
2383  *
2384  * Returns boolean true if this is the localhost address
2385  */
2386 static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
2387 {
2388 	__be16 *be16p = (__be16 *)&sip->sin6_addr;
2389 	__be32 *be32p = (__be32 *)&sip->sin6_addr;
2390 
2391 	if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
2392 	    ntohs(be16p[7]) == 1)
2393 		return true;
2394 	return false;
2395 }
2396 
2397 /**
2398 * smack_ipv6host_label - check host based restrictions
2399 * @sip: the object end
2400 *
2401 * looks for host based access restrictions
2402 *
2403 * This version will only be appropriate for really small sets of single label
2404 * hosts.  The caller is responsible for ensuring that the RCU read lock is
2405 * taken before calling this function.
2406 *
2407 * Returns the label of the far end or NULL if it's not special.
2408 */
2409 static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
2410 {
2411 	struct smk_net6addr *snp;
2412 	struct in6_addr *sap = &sip->sin6_addr;
2413 	int i;
2414 	int found = 0;
2415 
2416 	/*
2417 	 * It's local. Don't look for a host label.
2418 	 */
2419 	if (smk_ipv6_localhost(sip))
2420 		return NULL;
2421 
2422 	list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
2423 		/*
2424 		 * If the label is NULL the entry has
2425 		 * been renounced. Ignore it.
2426 		 */
2427 		if (snp->smk_label == NULL)
2428 			continue;
2429 		/*
2430 		* we break after finding the first match because
2431 		* the list is sorted from longest to shortest mask
2432 		* so we have found the most specific match
2433 		*/
2434 		for (found = 1, i = 0; i < 8; i++) {
2435 			if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
2436 			    snp->smk_host.s6_addr16[i]) {
2437 				found = 0;
2438 				break;
2439 			}
2440 		}
2441 		if (found)
2442 			return snp->smk_label;
2443 	}
2444 
2445 	return NULL;
2446 }
2447 
2448 /**
2449  * smack_netlbl_add - Set the secattr on a socket
2450  * @sk: the socket
2451  *
2452  * Attach the outbound smack value (smk_out) to the socket.
2453  *
2454  * Returns 0 on success or an error code
2455  */
2456 static int smack_netlbl_add(struct sock *sk)
2457 {
2458 	struct socket_smack *ssp = sk->sk_security;
2459 	struct smack_known *skp = ssp->smk_out;
2460 	int rc;
2461 
2462 	local_bh_disable();
2463 	bh_lock_sock_nested(sk);
2464 
2465 	rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2466 	switch (rc) {
2467 	case 0:
2468 		ssp->smk_state = SMK_NETLBL_LABELED;
2469 		break;
2470 	case -EDESTADDRREQ:
2471 		ssp->smk_state = SMK_NETLBL_REQSKB;
2472 		rc = 0;
2473 		break;
2474 	}
2475 
2476 	bh_unlock_sock(sk);
2477 	local_bh_enable();
2478 
2479 	return rc;
2480 }
2481 
2482 /**
2483  * smack_netlbl_delete - Remove the secattr from a socket
2484  * @sk: the socket
2485  *
2486  * Remove the outbound smack value from a socket
2487  */
2488 static void smack_netlbl_delete(struct sock *sk)
2489 {
2490 	struct socket_smack *ssp = sk->sk_security;
2491 
2492 	/*
2493 	 * Take the label off the socket if one is set.
2494 	 */
2495 	if (ssp->smk_state != SMK_NETLBL_LABELED)
2496 		return;
2497 
2498 	local_bh_disable();
2499 	bh_lock_sock_nested(sk);
2500 	netlbl_sock_delattr(sk);
2501 	bh_unlock_sock(sk);
2502 	local_bh_enable();
2503 	ssp->smk_state = SMK_NETLBL_UNLABELED;
2504 }
2505 
2506 /**
2507  * smk_ipv4_check - Perform IPv4 host access checks
2508  * @sk: the socket
2509  * @sap: the destination address
2510  *
2511  * Set the correct secattr for the given socket based on the destination
2512  * address and perform any outbound access checks needed.
2513  *
2514  * Returns 0 on success or an error code.
2515  *
2516  */
2517 static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
2518 {
2519 	struct smack_known *skp;
2520 	int rc = 0;
2521 	struct smack_known *hkp;
2522 	struct socket_smack *ssp = sk->sk_security;
2523 	struct smk_audit_info ad;
2524 
2525 	rcu_read_lock();
2526 	hkp = smack_ipv4host_label(sap);
2527 	if (hkp != NULL) {
2528 #ifdef CONFIG_AUDIT
2529 		struct lsm_network_audit net;
2530 
2531 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2532 		ad.a.u.net->family = sap->sin_family;
2533 		ad.a.u.net->dport = sap->sin_port;
2534 		ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
2535 #endif
2536 		skp = ssp->smk_out;
2537 		rc = smk_access(skp, hkp, MAY_WRITE, &ad);
2538 		rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2539 		/*
2540 		 * Clear the socket netlabel if it's set.
2541 		 */
2542 		if (!rc)
2543 			smack_netlbl_delete(sk);
2544 	}
2545 	rcu_read_unlock();
2546 
2547 	return rc;
2548 }
2549 
2550 /**
2551  * smk_ipv6_check - check Smack access
2552  * @subject: subject Smack label
2553  * @object: object Smack label
2554  * @address: address
2555  * @act: the action being taken
2556  *
2557  * Check an IPv6 access
2558  */
2559 static int smk_ipv6_check(struct smack_known *subject,
2560 				struct smack_known *object,
2561 				struct sockaddr_in6 *address, int act)
2562 {
2563 #ifdef CONFIG_AUDIT
2564 	struct lsm_network_audit net;
2565 #endif
2566 	struct smk_audit_info ad;
2567 	int rc;
2568 
2569 #ifdef CONFIG_AUDIT
2570 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2571 	ad.a.u.net->family = PF_INET6;
2572 	ad.a.u.net->dport = address->sin6_port;
2573 	if (act == SMK_RECEIVING)
2574 		ad.a.u.net->v6info.saddr = address->sin6_addr;
2575 	else
2576 		ad.a.u.net->v6info.daddr = address->sin6_addr;
2577 #endif
2578 	rc = smk_access(subject, object, MAY_WRITE, &ad);
2579 	rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
2580 	return rc;
2581 }
2582 
2583 #ifdef SMACK_IPV6_PORT_LABELING
2584 /**
2585  * smk_ipv6_port_label - Smack port access table management
2586  * @sock: socket
2587  * @address: address
2588  *
2589  * Create or update the port list entry
2590  */
2591 static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
2592 {
2593 	struct sock *sk = sock->sk;
2594 	struct sockaddr_in6 *addr6;
2595 	struct socket_smack *ssp = sock->sk->sk_security;
2596 	struct smk_port_label *spp;
2597 	unsigned short port = 0;
2598 
2599 	if (address == NULL) {
2600 		/*
2601 		 * This operation is changing the Smack information
2602 		 * on the bound socket. Take the changes to the port
2603 		 * as well.
2604 		 */
2605 		rcu_read_lock();
2606 		list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2607 			if (sk != spp->smk_sock)
2608 				continue;
2609 			spp->smk_in = ssp->smk_in;
2610 			spp->smk_out = ssp->smk_out;
2611 			rcu_read_unlock();
2612 			return;
2613 		}
2614 		/*
2615 		 * A NULL address is only used for updating existing
2616 		 * bound entries. If there isn't one, it's OK.
2617 		 */
2618 		rcu_read_unlock();
2619 		return;
2620 	}
2621 
2622 	addr6 = (struct sockaddr_in6 *)address;
2623 	port = ntohs(addr6->sin6_port);
2624 	/*
2625 	 * This is a special case that is safely ignored.
2626 	 */
2627 	if (port == 0)
2628 		return;
2629 
2630 	/*
2631 	 * Look for an existing port list entry.
2632 	 * This is an indication that a port is getting reused.
2633 	 */
2634 	rcu_read_lock();
2635 	list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2636 		if (spp->smk_port != port || spp->smk_sock_type != sock->type)
2637 			continue;
2638 		if (spp->smk_can_reuse != 1) {
2639 			rcu_read_unlock();
2640 			return;
2641 		}
2642 		spp->smk_port = port;
2643 		spp->smk_sock = sk;
2644 		spp->smk_in = ssp->smk_in;
2645 		spp->smk_out = ssp->smk_out;
2646 		spp->smk_can_reuse = 0;
2647 		rcu_read_unlock();
2648 		return;
2649 	}
2650 	rcu_read_unlock();
2651 	/*
2652 	 * A new port entry is required.
2653 	 */
2654 	spp = kzalloc(sizeof(*spp), GFP_KERNEL);
2655 	if (spp == NULL)
2656 		return;
2657 
2658 	spp->smk_port = port;
2659 	spp->smk_sock = sk;
2660 	spp->smk_in = ssp->smk_in;
2661 	spp->smk_out = ssp->smk_out;
2662 	spp->smk_sock_type = sock->type;
2663 	spp->smk_can_reuse = 0;
2664 
2665 	mutex_lock(&smack_ipv6_lock);
2666 	list_add_rcu(&spp->list, &smk_ipv6_port_list);
2667 	mutex_unlock(&smack_ipv6_lock);
2668 	return;
2669 }
2670 
2671 /**
2672  * smk_ipv6_port_check - check Smack port access
2673  * @sk: socket
2674  * @address: address
2675  * @act: the action being taken
2676  *
2677  * Create or update the port list entry
2678  */
2679 static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2680 				int act)
2681 {
2682 	struct smk_port_label *spp;
2683 	struct socket_smack *ssp = sk->sk_security;
2684 	struct smack_known *skp = NULL;
2685 	unsigned short port;
2686 	struct smack_known *object;
2687 
2688 	if (act == SMK_RECEIVING) {
2689 		skp = smack_ipv6host_label(address);
2690 		object = ssp->smk_in;
2691 	} else {
2692 		skp = ssp->smk_out;
2693 		object = smack_ipv6host_label(address);
2694 	}
2695 
2696 	/*
2697 	 * The other end is a single label host.
2698 	 */
2699 	if (skp != NULL && object != NULL)
2700 		return smk_ipv6_check(skp, object, address, act);
2701 	if (skp == NULL)
2702 		skp = smack_net_ambient;
2703 	if (object == NULL)
2704 		object = smack_net_ambient;
2705 
2706 	/*
2707 	 * It's remote, so port lookup does no good.
2708 	 */
2709 	if (!smk_ipv6_localhost(address))
2710 		return smk_ipv6_check(skp, object, address, act);
2711 
2712 	/*
2713 	 * It's local so the send check has to have passed.
2714 	 */
2715 	if (act == SMK_RECEIVING)
2716 		return 0;
2717 
2718 	port = ntohs(address->sin6_port);
2719 	rcu_read_lock();
2720 	list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2721 		if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
2722 			continue;
2723 		object = spp->smk_in;
2724 		if (act == SMK_CONNECTING)
2725 			ssp->smk_packet = spp->smk_out;
2726 		break;
2727 	}
2728 	rcu_read_unlock();
2729 
2730 	return smk_ipv6_check(skp, object, address, act);
2731 }
2732 #endif
2733 
2734 /**
2735  * smack_inode_setsecurity - set smack xattrs
2736  * @inode: the object
2737  * @name: attribute name
2738  * @value: attribute value
2739  * @size: size of the attribute
2740  * @flags: unused
2741  *
2742  * Sets the named attribute in the appropriate blob
2743  *
2744  * Returns 0 on success, or an error code
2745  */
2746 static int smack_inode_setsecurity(struct inode *inode, const char *name,
2747 				   const void *value, size_t size, int flags)
2748 {
2749 	struct smack_known *skp;
2750 	struct inode_smack *nsp = smack_inode(inode);
2751 	struct socket_smack *ssp;
2752 	struct socket *sock;
2753 	int rc = 0;
2754 
2755 	if (value == NULL || size > SMK_LONGLABEL || size == 0)
2756 		return -EINVAL;
2757 
2758 	skp = smk_import_entry(value, size);
2759 	if (IS_ERR(skp))
2760 		return PTR_ERR(skp);
2761 
2762 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2763 		nsp->smk_inode = skp;
2764 		nsp->smk_flags |= SMK_INODE_INSTANT;
2765 		return 0;
2766 	}
2767 	/*
2768 	 * The rest of the Smack xattrs are only on sockets.
2769 	 */
2770 	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2771 		return -EOPNOTSUPP;
2772 
2773 	sock = SOCKET_I(inode);
2774 	if (sock == NULL || sock->sk == NULL)
2775 		return -EOPNOTSUPP;
2776 
2777 	ssp = sock->sk->sk_security;
2778 
2779 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2780 		ssp->smk_in = skp;
2781 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2782 		ssp->smk_out = skp;
2783 		if (sock->sk->sk_family == PF_INET) {
2784 			rc = smack_netlbl_add(sock->sk);
2785 			if (rc != 0)
2786 				printk(KERN_WARNING
2787 					"Smack: \"%s\" netlbl error %d.\n",
2788 					__func__, -rc);
2789 		}
2790 	} else
2791 		return -EOPNOTSUPP;
2792 
2793 #ifdef SMACK_IPV6_PORT_LABELING
2794 	if (sock->sk->sk_family == PF_INET6)
2795 		smk_ipv6_port_label(sock, NULL);
2796 #endif
2797 
2798 	return 0;
2799 }
2800 
2801 /**
2802  * smack_socket_post_create - finish socket setup
2803  * @sock: the socket
2804  * @family: protocol family
2805  * @type: unused
2806  * @protocol: unused
2807  * @kern: unused
2808  *
2809  * Sets the netlabel information on the socket
2810  *
2811  * Returns 0 on success, and error code otherwise
2812  */
2813 static int smack_socket_post_create(struct socket *sock, int family,
2814 				    int type, int protocol, int kern)
2815 {
2816 	struct socket_smack *ssp;
2817 
2818 	if (sock->sk == NULL)
2819 		return 0;
2820 
2821 	/*
2822 	 * Sockets created by kernel threads receive web label.
2823 	 */
2824 	if (unlikely(current->flags & PF_KTHREAD)) {
2825 		ssp = sock->sk->sk_security;
2826 		ssp->smk_in = &smack_known_web;
2827 		ssp->smk_out = &smack_known_web;
2828 	}
2829 
2830 	if (family != PF_INET)
2831 		return 0;
2832 	/*
2833 	 * Set the outbound netlbl.
2834 	 */
2835 	return smack_netlbl_add(sock->sk);
2836 }
2837 
2838 /**
2839  * smack_socket_socketpair - create socket pair
2840  * @socka: one socket
2841  * @sockb: another socket
2842  *
2843  * Cross reference the peer labels for SO_PEERSEC
2844  *
2845  * Returns 0
2846  */
2847 static int smack_socket_socketpair(struct socket *socka,
2848 		                   struct socket *sockb)
2849 {
2850 	struct socket_smack *asp = socka->sk->sk_security;
2851 	struct socket_smack *bsp = sockb->sk->sk_security;
2852 
2853 	asp->smk_packet = bsp->smk_out;
2854 	bsp->smk_packet = asp->smk_out;
2855 
2856 	return 0;
2857 }
2858 
2859 #ifdef SMACK_IPV6_PORT_LABELING
2860 /**
2861  * smack_socket_bind - record port binding information.
2862  * @sock: the socket
2863  * @address: the port address
2864  * @addrlen: size of the address
2865  *
2866  * Records the label bound to a port.
2867  *
2868  * Returns 0 on success, and error code otherwise
2869  */
2870 static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
2871 				int addrlen)
2872 {
2873 	if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) {
2874 		if (addrlen < SIN6_LEN_RFC2133 ||
2875 		    address->sa_family != AF_INET6)
2876 			return -EINVAL;
2877 		smk_ipv6_port_label(sock, address);
2878 	}
2879 	return 0;
2880 }
2881 #endif /* SMACK_IPV6_PORT_LABELING */
2882 
2883 /**
2884  * smack_socket_connect - connect access check
2885  * @sock: the socket
2886  * @sap: the other end
2887  * @addrlen: size of sap
2888  *
2889  * Verifies that a connection may be possible
2890  *
2891  * Returns 0 on success, and error code otherwise
2892  */
2893 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2894 				int addrlen)
2895 {
2896 	int rc = 0;
2897 
2898 	if (sock->sk == NULL)
2899 		return 0;
2900 	if (sock->sk->sk_family != PF_INET &&
2901 	    (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6))
2902 		return 0;
2903 	if (addrlen < offsetofend(struct sockaddr, sa_family))
2904 		return 0;
2905 	if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) {
2906 		struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
2907 		struct smack_known *rsp = NULL;
2908 
2909 		if (addrlen < SIN6_LEN_RFC2133)
2910 			return 0;
2911 		if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
2912 			rsp = smack_ipv6host_label(sip);
2913 		if (rsp != NULL) {
2914 			struct socket_smack *ssp = sock->sk->sk_security;
2915 
2916 			rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
2917 					    SMK_CONNECTING);
2918 		}
2919 #ifdef SMACK_IPV6_PORT_LABELING
2920 		rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
2921 #endif
2922 
2923 		return rc;
2924 	}
2925 	if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
2926 		return 0;
2927 	rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
2928 	return rc;
2929 }
2930 
2931 /**
2932  * smack_flags_to_may - convert S_ to MAY_ values
2933  * @flags: the S_ value
2934  *
2935  * Returns the equivalent MAY_ value
2936  */
2937 static int smack_flags_to_may(int flags)
2938 {
2939 	int may = 0;
2940 
2941 	if (flags & S_IRUGO)
2942 		may |= MAY_READ;
2943 	if (flags & S_IWUGO)
2944 		may |= MAY_WRITE;
2945 	if (flags & S_IXUGO)
2946 		may |= MAY_EXEC;
2947 
2948 	return may;
2949 }
2950 
2951 /**
2952  * smack_msg_msg_alloc_security - Set the security blob for msg_msg
2953  * @msg: the object
2954  *
2955  * Returns 0
2956  */
2957 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
2958 {
2959 	struct smack_known **blob = smack_msg_msg(msg);
2960 
2961 	*blob = smk_of_current();
2962 	return 0;
2963 }
2964 
2965 /**
2966  * smack_of_ipc - the smack pointer for the ipc
2967  * @isp: the object
2968  *
2969  * Returns a pointer to the smack value
2970  */
2971 static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
2972 {
2973 	struct smack_known **blob = smack_ipc(isp);
2974 
2975 	return *blob;
2976 }
2977 
2978 /**
2979  * smack_ipc_alloc_security - Set the security blob for ipc
2980  * @isp: the object
2981  *
2982  * Returns 0
2983  */
2984 static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
2985 {
2986 	struct smack_known **blob = smack_ipc(isp);
2987 
2988 	*blob = smk_of_current();
2989 	return 0;
2990 }
2991 
2992 /**
2993  * smk_curacc_shm : check if current has access on shm
2994  * @isp : the object
2995  * @access : access requested
2996  *
2997  * Returns 0 if current has the requested access, error code otherwise
2998  */
2999 static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
3000 {
3001 	struct smack_known *ssp = smack_of_ipc(isp);
3002 	struct smk_audit_info ad;
3003 	int rc;
3004 
3005 #ifdef CONFIG_AUDIT
3006 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3007 	ad.a.u.ipc_id = isp->id;
3008 #endif
3009 	rc = smk_curacc(ssp, access, &ad);
3010 	rc = smk_bu_current("shm", ssp, access, rc);
3011 	return rc;
3012 }
3013 
3014 /**
3015  * smack_shm_associate - Smack access check for shm
3016  * @isp: the object
3017  * @shmflg: access requested
3018  *
3019  * Returns 0 if current has the requested access, error code otherwise
3020  */
3021 static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
3022 {
3023 	int may;
3024 
3025 	may = smack_flags_to_may(shmflg);
3026 	return smk_curacc_shm(isp, may);
3027 }
3028 
3029 /**
3030  * smack_shm_shmctl - Smack access check for shm
3031  * @isp: the object
3032  * @cmd: what it wants to do
3033  *
3034  * Returns 0 if current has the requested access, error code otherwise
3035  */
3036 static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
3037 {
3038 	int may;
3039 
3040 	switch (cmd) {
3041 	case IPC_STAT:
3042 	case SHM_STAT:
3043 	case SHM_STAT_ANY:
3044 		may = MAY_READ;
3045 		break;
3046 	case IPC_SET:
3047 	case SHM_LOCK:
3048 	case SHM_UNLOCK:
3049 	case IPC_RMID:
3050 		may = MAY_READWRITE;
3051 		break;
3052 	case IPC_INFO:
3053 	case SHM_INFO:
3054 		/*
3055 		 * System level information.
3056 		 */
3057 		return 0;
3058 	default:
3059 		return -EINVAL;
3060 	}
3061 	return smk_curacc_shm(isp, may);
3062 }
3063 
3064 /**
3065  * smack_shm_shmat - Smack access for shmat
3066  * @isp: the object
3067  * @shmaddr: unused
3068  * @shmflg: access requested
3069  *
3070  * Returns 0 if current has the requested access, error code otherwise
3071  */
3072 static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr,
3073 			   int shmflg)
3074 {
3075 	int may;
3076 
3077 	may = smack_flags_to_may(shmflg);
3078 	return smk_curacc_shm(isp, may);
3079 }
3080 
3081 /**
3082  * smk_curacc_sem : check if current has access on sem
3083  * @isp : the object
3084  * @access : access requested
3085  *
3086  * Returns 0 if current has the requested access, error code otherwise
3087  */
3088 static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
3089 {
3090 	struct smack_known *ssp = smack_of_ipc(isp);
3091 	struct smk_audit_info ad;
3092 	int rc;
3093 
3094 #ifdef CONFIG_AUDIT
3095 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3096 	ad.a.u.ipc_id = isp->id;
3097 #endif
3098 	rc = smk_curacc(ssp, access, &ad);
3099 	rc = smk_bu_current("sem", ssp, access, rc);
3100 	return rc;
3101 }
3102 
3103 /**
3104  * smack_sem_associate - Smack access check for sem
3105  * @isp: the object
3106  * @semflg: access requested
3107  *
3108  * Returns 0 if current has the requested access, error code otherwise
3109  */
3110 static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
3111 {
3112 	int may;
3113 
3114 	may = smack_flags_to_may(semflg);
3115 	return smk_curacc_sem(isp, may);
3116 }
3117 
3118 /**
3119  * smack_sem_semctl - Smack access check for sem
3120  * @isp: the object
3121  * @cmd: what it wants to do
3122  *
3123  * Returns 0 if current has the requested access, error code otherwise
3124  */
3125 static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
3126 {
3127 	int may;
3128 
3129 	switch (cmd) {
3130 	case GETPID:
3131 	case GETNCNT:
3132 	case GETZCNT:
3133 	case GETVAL:
3134 	case GETALL:
3135 	case IPC_STAT:
3136 	case SEM_STAT:
3137 	case SEM_STAT_ANY:
3138 		may = MAY_READ;
3139 		break;
3140 	case SETVAL:
3141 	case SETALL:
3142 	case IPC_RMID:
3143 	case IPC_SET:
3144 		may = MAY_READWRITE;
3145 		break;
3146 	case IPC_INFO:
3147 	case SEM_INFO:
3148 		/*
3149 		 * System level information
3150 		 */
3151 		return 0;
3152 	default:
3153 		return -EINVAL;
3154 	}
3155 
3156 	return smk_curacc_sem(isp, may);
3157 }
3158 
3159 /**
3160  * smack_sem_semop - Smack checks of semaphore operations
3161  * @isp: the object
3162  * @sops: unused
3163  * @nsops: unused
3164  * @alter: unused
3165  *
3166  * Treated as read and write in all cases.
3167  *
3168  * Returns 0 if access is allowed, error code otherwise
3169  */
3170 static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
3171 			   unsigned nsops, int alter)
3172 {
3173 	return smk_curacc_sem(isp, MAY_READWRITE);
3174 }
3175 
3176 /**
3177  * smk_curacc_msq : helper to check if current has access on msq
3178  * @isp : the msq
3179  * @access : access requested
3180  *
3181  * return 0 if current has access, error otherwise
3182  */
3183 static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
3184 {
3185 	struct smack_known *msp = smack_of_ipc(isp);
3186 	struct smk_audit_info ad;
3187 	int rc;
3188 
3189 #ifdef CONFIG_AUDIT
3190 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3191 	ad.a.u.ipc_id = isp->id;
3192 #endif
3193 	rc = smk_curacc(msp, access, &ad);
3194 	rc = smk_bu_current("msq", msp, access, rc);
3195 	return rc;
3196 }
3197 
3198 /**
3199  * smack_msg_queue_associate - Smack access check for msg_queue
3200  * @isp: the object
3201  * @msqflg: access requested
3202  *
3203  * Returns 0 if current has the requested access, error code otherwise
3204  */
3205 static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
3206 {
3207 	int may;
3208 
3209 	may = smack_flags_to_may(msqflg);
3210 	return smk_curacc_msq(isp, may);
3211 }
3212 
3213 /**
3214  * smack_msg_queue_msgctl - Smack access check for msg_queue
3215  * @isp: the object
3216  * @cmd: what it wants to do
3217  *
3218  * Returns 0 if current has the requested access, error code otherwise
3219  */
3220 static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
3221 {
3222 	int may;
3223 
3224 	switch (cmd) {
3225 	case IPC_STAT:
3226 	case MSG_STAT:
3227 	case MSG_STAT_ANY:
3228 		may = MAY_READ;
3229 		break;
3230 	case IPC_SET:
3231 	case IPC_RMID:
3232 		may = MAY_READWRITE;
3233 		break;
3234 	case IPC_INFO:
3235 	case MSG_INFO:
3236 		/*
3237 		 * System level information
3238 		 */
3239 		return 0;
3240 	default:
3241 		return -EINVAL;
3242 	}
3243 
3244 	return smk_curacc_msq(isp, may);
3245 }
3246 
3247 /**
3248  * smack_msg_queue_msgsnd - Smack access check for msg_queue
3249  * @isp: the object
3250  * @msg: unused
3251  * @msqflg: access requested
3252  *
3253  * Returns 0 if current has the requested access, error code otherwise
3254  */
3255 static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
3256 				  int msqflg)
3257 {
3258 	int may;
3259 
3260 	may = smack_flags_to_may(msqflg);
3261 	return smk_curacc_msq(isp, may);
3262 }
3263 
3264 /**
3265  * smack_msg_queue_msgrcv - Smack access check for msg_queue
3266  * @isp: the object
3267  * @msg: unused
3268  * @target: unused
3269  * @type: unused
3270  * @mode: unused
3271  *
3272  * Returns 0 if current has read and write access, error code otherwise
3273  */
3274 static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp,
3275 				  struct msg_msg *msg,
3276 				  struct task_struct *target, long type,
3277 				  int mode)
3278 {
3279 	return smk_curacc_msq(isp, MAY_READWRITE);
3280 }
3281 
3282 /**
3283  * smack_ipc_permission - Smack access for ipc_permission()
3284  * @ipp: the object permissions
3285  * @flag: access requested
3286  *
3287  * Returns 0 if current has read and write access, error code otherwise
3288  */
3289 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
3290 {
3291 	struct smack_known **blob = smack_ipc(ipp);
3292 	struct smack_known *iskp = *blob;
3293 	int may = smack_flags_to_may(flag);
3294 	struct smk_audit_info ad;
3295 	int rc;
3296 
3297 #ifdef CONFIG_AUDIT
3298 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3299 	ad.a.u.ipc_id = ipp->id;
3300 #endif
3301 	rc = smk_curacc(iskp, may, &ad);
3302 	rc = smk_bu_current("svipc", iskp, may, rc);
3303 	return rc;
3304 }
3305 
3306 /**
3307  * smack_ipc_getsecid - Extract smack security id
3308  * @ipp: the object permissions
3309  * @secid: where result will be saved
3310  */
3311 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
3312 {
3313 	struct smack_known **blob = smack_ipc(ipp);
3314 	struct smack_known *iskp = *blob;
3315 
3316 	*secid = iskp->smk_secid;
3317 }
3318 
3319 /**
3320  * smack_d_instantiate - Make sure the blob is correct on an inode
3321  * @opt_dentry: dentry where inode will be attached
3322  * @inode: the object
3323  *
3324  * Set the inode's security blob if it hasn't been done already.
3325  */
3326 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
3327 {
3328 	struct super_block *sbp;
3329 	struct superblock_smack *sbsp;
3330 	struct inode_smack *isp;
3331 	struct smack_known *skp;
3332 	struct smack_known *ckp = smk_of_current();
3333 	struct smack_known *final;
3334 	char trattr[TRANS_TRUE_SIZE];
3335 	int transflag = 0;
3336 	int rc;
3337 	struct dentry *dp;
3338 
3339 	if (inode == NULL)
3340 		return;
3341 
3342 	isp = smack_inode(inode);
3343 
3344 	/*
3345 	 * If the inode is already instantiated
3346 	 * take the quick way out
3347 	 */
3348 	if (isp->smk_flags & SMK_INODE_INSTANT)
3349 		return;
3350 
3351 	sbp = inode->i_sb;
3352 	sbsp = smack_superblock(sbp);
3353 	/*
3354 	 * We're going to use the superblock default label
3355 	 * if there's no label on the file.
3356 	 */
3357 	final = sbsp->smk_default;
3358 
3359 	/*
3360 	 * If this is the root inode the superblock
3361 	 * may be in the process of initialization.
3362 	 * If that is the case use the root value out
3363 	 * of the superblock.
3364 	 */
3365 	if (opt_dentry->d_parent == opt_dentry) {
3366 		switch (sbp->s_magic) {
3367 		case CGROUP_SUPER_MAGIC:
3368 		case CGROUP2_SUPER_MAGIC:
3369 			/*
3370 			 * The cgroup filesystem is never mounted,
3371 			 * so there's no opportunity to set the mount
3372 			 * options.
3373 			 */
3374 			sbsp->smk_root = &smack_known_star;
3375 			sbsp->smk_default = &smack_known_star;
3376 			isp->smk_inode = sbsp->smk_root;
3377 			break;
3378 		case TMPFS_MAGIC:
3379 			/*
3380 			 * What about shmem/tmpfs anonymous files with dentry
3381 			 * obtained from d_alloc_pseudo()?
3382 			 */
3383 			isp->smk_inode = smk_of_current();
3384 			break;
3385 		case PIPEFS_MAGIC:
3386 			isp->smk_inode = smk_of_current();
3387 			break;
3388 		case SOCKFS_MAGIC:
3389 			/*
3390 			 * Socket access is controlled by the socket
3391 			 * structures associated with the task involved.
3392 			 */
3393 			isp->smk_inode = &smack_known_star;
3394 			break;
3395 		default:
3396 			isp->smk_inode = sbsp->smk_root;
3397 			break;
3398 		}
3399 		isp->smk_flags |= SMK_INODE_INSTANT;
3400 		return;
3401 	}
3402 
3403 	/*
3404 	 * This is pretty hackish.
3405 	 * Casey says that we shouldn't have to do
3406 	 * file system specific code, but it does help
3407 	 * with keeping it simple.
3408 	 */
3409 	switch (sbp->s_magic) {
3410 	case SMACK_MAGIC:
3411 	case CGROUP_SUPER_MAGIC:
3412 	case CGROUP2_SUPER_MAGIC:
3413 		/*
3414 		 * Casey says that it's a little embarrassing
3415 		 * that the smack file system doesn't do
3416 		 * extended attributes.
3417 		 *
3418 		 * Cgroupfs is special
3419 		 */
3420 		final = &smack_known_star;
3421 		break;
3422 	case DEVPTS_SUPER_MAGIC:
3423 		/*
3424 		 * devpts seems content with the label of the task.
3425 		 * Programs that change smack have to treat the
3426 		 * pty with respect.
3427 		 */
3428 		final = ckp;
3429 		break;
3430 	case PROC_SUPER_MAGIC:
3431 		/*
3432 		 * Casey says procfs appears not to care.
3433 		 * The superblock default suffices.
3434 		 */
3435 		break;
3436 	case TMPFS_MAGIC:
3437 		/*
3438 		 * Device labels should come from the filesystem,
3439 		 * but watch out, because they're volitile,
3440 		 * getting recreated on every reboot.
3441 		 */
3442 		final = &smack_known_star;
3443 		/*
3444 		 * If a smack value has been set we want to use it,
3445 		 * but since tmpfs isn't giving us the opportunity
3446 		 * to set mount options simulate setting the
3447 		 * superblock default.
3448 		 */
3449 		fallthrough;
3450 	default:
3451 		/*
3452 		 * This isn't an understood special case.
3453 		 * Get the value from the xattr.
3454 		 */
3455 
3456 		/*
3457 		 * UNIX domain sockets use lower level socket data.
3458 		 */
3459 		if (S_ISSOCK(inode->i_mode)) {
3460 			final = &smack_known_star;
3461 			break;
3462 		}
3463 		/*
3464 		 * No xattr support means, alas, no SMACK label.
3465 		 * Use the aforeapplied default.
3466 		 * It would be curious if the label of the task
3467 		 * does not match that assigned.
3468 		 */
3469 		if (!(inode->i_opflags & IOP_XATTR))
3470 		        break;
3471 		/*
3472 		 * Get the dentry for xattr.
3473 		 */
3474 		dp = dget(opt_dentry);
3475 		skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
3476 		if (!IS_ERR_OR_NULL(skp))
3477 			final = skp;
3478 
3479 		/*
3480 		 * Transmuting directory
3481 		 */
3482 		if (S_ISDIR(inode->i_mode)) {
3483 			/*
3484 			 * If this is a new directory and the label was
3485 			 * transmuted when the inode was initialized
3486 			 * set the transmute attribute on the directory
3487 			 * and mark the inode.
3488 			 *
3489 			 * If there is a transmute attribute on the
3490 			 * directory mark the inode.
3491 			 */
3492 			if (isp->smk_flags & SMK_INODE_CHANGED) {
3493 				isp->smk_flags &= ~SMK_INODE_CHANGED;
3494 				rc = __vfs_setxattr(&nop_mnt_idmap, dp, inode,
3495 					XATTR_NAME_SMACKTRANSMUTE,
3496 					TRANS_TRUE, TRANS_TRUE_SIZE,
3497 					0);
3498 			} else {
3499 				rc = __vfs_getxattr(dp, inode,
3500 					XATTR_NAME_SMACKTRANSMUTE, trattr,
3501 					TRANS_TRUE_SIZE);
3502 				if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
3503 						       TRANS_TRUE_SIZE) != 0)
3504 					rc = -EINVAL;
3505 			}
3506 			if (rc >= 0)
3507 				transflag = SMK_INODE_TRANSMUTE;
3508 		}
3509 		/*
3510 		 * Don't let the exec or mmap label be "*" or "@".
3511 		 */
3512 		skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
3513 		if (IS_ERR(skp) || skp == &smack_known_star ||
3514 		    skp == &smack_known_web)
3515 			skp = NULL;
3516 		isp->smk_task = skp;
3517 
3518 		skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
3519 		if (IS_ERR(skp) || skp == &smack_known_star ||
3520 		    skp == &smack_known_web)
3521 			skp = NULL;
3522 		isp->smk_mmap = skp;
3523 
3524 		dput(dp);
3525 		break;
3526 	}
3527 
3528 	if (final == NULL)
3529 		isp->smk_inode = ckp;
3530 	else
3531 		isp->smk_inode = final;
3532 
3533 	isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3534 
3535 	return;
3536 }
3537 
3538 /**
3539  * smack_getprocattr - Smack process attribute access
3540  * @p: the object task
3541  * @name: the name of the attribute in /proc/.../attr
3542  * @value: where to put the result
3543  *
3544  * Places a copy of the task Smack into value
3545  *
3546  * Returns the length of the smack label or an error code
3547  */
3548 static int smack_getprocattr(struct task_struct *p, const char *name, char **value)
3549 {
3550 	struct smack_known *skp = smk_of_task_struct_obj(p);
3551 	char *cp;
3552 	int slen;
3553 
3554 	if (strcmp(name, "current") != 0)
3555 		return -EINVAL;
3556 
3557 	cp = kstrdup(skp->smk_known, GFP_KERNEL);
3558 	if (cp == NULL)
3559 		return -ENOMEM;
3560 
3561 	slen = strlen(cp);
3562 	*value = cp;
3563 	return slen;
3564 }
3565 
3566 /**
3567  * smack_setprocattr - Smack process attribute setting
3568  * @name: the name of the attribute in /proc/.../attr
3569  * @value: the value to set
3570  * @size: the size of the value
3571  *
3572  * Sets the Smack value of the task. Only setting self
3573  * is permitted and only with privilege
3574  *
3575  * Returns the length of the smack label or an error code
3576  */
3577 static int smack_setprocattr(const char *name, void *value, size_t size)
3578 {
3579 	struct task_smack *tsp = smack_cred(current_cred());
3580 	struct cred *new;
3581 	struct smack_known *skp;
3582 	struct smack_known_list_elem *sklep;
3583 	int rc;
3584 
3585 	if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
3586 		return -EPERM;
3587 
3588 	if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3589 		return -EINVAL;
3590 
3591 	if (strcmp(name, "current") != 0)
3592 		return -EINVAL;
3593 
3594 	skp = smk_import_entry(value, size);
3595 	if (IS_ERR(skp))
3596 		return PTR_ERR(skp);
3597 
3598 	/*
3599 	 * No process is ever allowed the web ("@") label
3600 	 * and the star ("*") label.
3601 	 */
3602 	if (skp == &smack_known_web || skp == &smack_known_star)
3603 		return -EINVAL;
3604 
3605 	if (!smack_privileged(CAP_MAC_ADMIN)) {
3606 		rc = -EPERM;
3607 		list_for_each_entry(sklep, &tsp->smk_relabel, list)
3608 			if (sklep->smk_label == skp) {
3609 				rc = 0;
3610 				break;
3611 			}
3612 		if (rc)
3613 			return rc;
3614 	}
3615 
3616 	new = prepare_creds();
3617 	if (new == NULL)
3618 		return -ENOMEM;
3619 
3620 	tsp = smack_cred(new);
3621 	tsp->smk_task = skp;
3622 	/*
3623 	 * process can change its label only once
3624 	 */
3625 	smk_destroy_label_list(&tsp->smk_relabel);
3626 
3627 	commit_creds(new);
3628 	return size;
3629 }
3630 
3631 /**
3632  * smack_unix_stream_connect - Smack access on UDS
3633  * @sock: one sock
3634  * @other: the other sock
3635  * @newsk: unused
3636  *
3637  * Return 0 if a subject with the smack of sock could access
3638  * an object with the smack of other, otherwise an error code
3639  */
3640 static int smack_unix_stream_connect(struct sock *sock,
3641 				     struct sock *other, struct sock *newsk)
3642 {
3643 	struct smack_known *skp;
3644 	struct smack_known *okp;
3645 	struct socket_smack *ssp = sock->sk_security;
3646 	struct socket_smack *osp = other->sk_security;
3647 	struct socket_smack *nsp = newsk->sk_security;
3648 	struct smk_audit_info ad;
3649 	int rc = 0;
3650 #ifdef CONFIG_AUDIT
3651 	struct lsm_network_audit net;
3652 #endif
3653 
3654 	if (!smack_privileged(CAP_MAC_OVERRIDE)) {
3655 		skp = ssp->smk_out;
3656 		okp = osp->smk_in;
3657 #ifdef CONFIG_AUDIT
3658 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3659 		smk_ad_setfield_u_net_sk(&ad, other);
3660 #endif
3661 		rc = smk_access(skp, okp, MAY_WRITE, &ad);
3662 		rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
3663 		if (rc == 0) {
3664 			okp = osp->smk_out;
3665 			skp = ssp->smk_in;
3666 			rc = smk_access(okp, skp, MAY_WRITE, &ad);
3667 			rc = smk_bu_note("UDS connect", okp, skp,
3668 						MAY_WRITE, rc);
3669 		}
3670 	}
3671 
3672 	/*
3673 	 * Cross reference the peer labels for SO_PEERSEC.
3674 	 */
3675 	if (rc == 0) {
3676 		nsp->smk_packet = ssp->smk_out;
3677 		ssp->smk_packet = osp->smk_out;
3678 	}
3679 
3680 	return rc;
3681 }
3682 
3683 /**
3684  * smack_unix_may_send - Smack access on UDS
3685  * @sock: one socket
3686  * @other: the other socket
3687  *
3688  * Return 0 if a subject with the smack of sock could access
3689  * an object with the smack of other, otherwise an error code
3690  */
3691 static int smack_unix_may_send(struct socket *sock, struct socket *other)
3692 {
3693 	struct socket_smack *ssp = sock->sk->sk_security;
3694 	struct socket_smack *osp = other->sk->sk_security;
3695 	struct smk_audit_info ad;
3696 	int rc;
3697 
3698 #ifdef CONFIG_AUDIT
3699 	struct lsm_network_audit net;
3700 
3701 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3702 	smk_ad_setfield_u_net_sk(&ad, other->sk);
3703 #endif
3704 
3705 	if (smack_privileged(CAP_MAC_OVERRIDE))
3706 		return 0;
3707 
3708 	rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
3709 	rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
3710 	return rc;
3711 }
3712 
3713 /**
3714  * smack_socket_sendmsg - Smack check based on destination host
3715  * @sock: the socket
3716  * @msg: the message
3717  * @size: the size of the message
3718  *
3719  * Return 0 if the current subject can write to the destination host.
3720  * For IPv4 this is only a question if the destination is a single label host.
3721  * For IPv6 this is a check against the label of the port.
3722  */
3723 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3724 				int size)
3725 {
3726 	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3727 #if IS_ENABLED(CONFIG_IPV6)
3728 	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3729 #endif
3730 #ifdef SMACK_IPV6_SECMARK_LABELING
3731 	struct socket_smack *ssp = sock->sk->sk_security;
3732 	struct smack_known *rsp;
3733 #endif
3734 	int rc = 0;
3735 
3736 	/*
3737 	 * Perfectly reasonable for this to be NULL
3738 	 */
3739 	if (sip == NULL)
3740 		return 0;
3741 
3742 	switch (sock->sk->sk_family) {
3743 	case AF_INET:
3744 		if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
3745 		    sip->sin_family != AF_INET)
3746 			return -EINVAL;
3747 		rc = smk_ipv4_check(sock->sk, sip);
3748 		break;
3749 #if IS_ENABLED(CONFIG_IPV6)
3750 	case AF_INET6:
3751 		if (msg->msg_namelen < SIN6_LEN_RFC2133 ||
3752 		    sap->sin6_family != AF_INET6)
3753 			return -EINVAL;
3754 #ifdef SMACK_IPV6_SECMARK_LABELING
3755 		rsp = smack_ipv6host_label(sap);
3756 		if (rsp != NULL)
3757 			rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
3758 						SMK_CONNECTING);
3759 #endif
3760 #ifdef SMACK_IPV6_PORT_LABELING
3761 		rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3762 #endif
3763 #endif /* IS_ENABLED(CONFIG_IPV6) */
3764 		break;
3765 	}
3766 	return rc;
3767 }
3768 
3769 /**
3770  * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3771  * @sap: netlabel secattr
3772  * @ssp: socket security information
3773  *
3774  * Returns a pointer to a Smack label entry found on the label list.
3775  */
3776 static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
3777 						struct socket_smack *ssp)
3778 {
3779 	struct smack_known *skp;
3780 	int found = 0;
3781 	int acat;
3782 	int kcat;
3783 
3784 	/*
3785 	 * Netlabel found it in the cache.
3786 	 */
3787 	if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
3788 		return (struct smack_known *)sap->cache->data;
3789 
3790 	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
3791 		/*
3792 		 * Looks like a fallback, which gives us a secid.
3793 		 */
3794 		return smack_from_secid(sap->attr.secid);
3795 
3796 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3797 		/*
3798 		 * Looks like a CIPSO packet.
3799 		 * If there are flags but no level netlabel isn't
3800 		 * behaving the way we expect it to.
3801 		 *
3802 		 * Look it up in the label table
3803 		 * Without guidance regarding the smack value
3804 		 * for the packet fall back on the network
3805 		 * ambient value.
3806 		 */
3807 		rcu_read_lock();
3808 		list_for_each_entry_rcu(skp, &smack_known_list, list) {
3809 			if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3810 				continue;
3811 			/*
3812 			 * Compare the catsets. Use the netlbl APIs.
3813 			 */
3814 			if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
3815 				if ((skp->smk_netlabel.flags &
3816 				     NETLBL_SECATTR_MLS_CAT) == 0)
3817 					found = 1;
3818 				break;
3819 			}
3820 			for (acat = -1, kcat = -1; acat == kcat; ) {
3821 				acat = netlbl_catmap_walk(sap->attr.mls.cat,
3822 							  acat + 1);
3823 				kcat = netlbl_catmap_walk(
3824 					skp->smk_netlabel.attr.mls.cat,
3825 					kcat + 1);
3826 				if (acat < 0 || kcat < 0)
3827 					break;
3828 			}
3829 			if (acat == kcat) {
3830 				found = 1;
3831 				break;
3832 			}
3833 		}
3834 		rcu_read_unlock();
3835 
3836 		if (found)
3837 			return skp;
3838 
3839 		if (ssp != NULL && ssp->smk_in == &smack_known_star)
3840 			return &smack_known_web;
3841 		return &smack_known_star;
3842 	}
3843 	/*
3844 	 * Without guidance regarding the smack value
3845 	 * for the packet fall back on the network
3846 	 * ambient value.
3847 	 */
3848 	return smack_net_ambient;
3849 }
3850 
3851 #if IS_ENABLED(CONFIG_IPV6)
3852 static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3853 {
3854 	u8 nexthdr;
3855 	int offset;
3856 	int proto = -EINVAL;
3857 	struct ipv6hdr _ipv6h;
3858 	struct ipv6hdr *ip6;
3859 	__be16 frag_off;
3860 	struct tcphdr _tcph, *th;
3861 	struct udphdr _udph, *uh;
3862 	struct dccp_hdr _dccph, *dh;
3863 
3864 	sip->sin6_port = 0;
3865 
3866 	offset = skb_network_offset(skb);
3867 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3868 	if (ip6 == NULL)
3869 		return -EINVAL;
3870 	sip->sin6_addr = ip6->saddr;
3871 
3872 	nexthdr = ip6->nexthdr;
3873 	offset += sizeof(_ipv6h);
3874 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3875 	if (offset < 0)
3876 		return -EINVAL;
3877 
3878 	proto = nexthdr;
3879 	switch (proto) {
3880 	case IPPROTO_TCP:
3881 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3882 		if (th != NULL)
3883 			sip->sin6_port = th->source;
3884 		break;
3885 	case IPPROTO_UDP:
3886 	case IPPROTO_UDPLITE:
3887 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3888 		if (uh != NULL)
3889 			sip->sin6_port = uh->source;
3890 		break;
3891 	case IPPROTO_DCCP:
3892 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3893 		if (dh != NULL)
3894 			sip->sin6_port = dh->dccph_sport;
3895 		break;
3896 	}
3897 	return proto;
3898 }
3899 #endif /* CONFIG_IPV6 */
3900 
3901 /**
3902  * smack_from_skb - Smack data from the secmark in an skb
3903  * @skb: packet
3904  *
3905  * Returns smack_known of the secmark or NULL if that won't work.
3906  */
3907 #ifdef CONFIG_NETWORK_SECMARK
3908 static struct smack_known *smack_from_skb(struct sk_buff *skb)
3909 {
3910 	if (skb == NULL || skb->secmark == 0)
3911 		return NULL;
3912 
3913 	return smack_from_secid(skb->secmark);
3914 }
3915 #else
3916 static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
3917 {
3918 	return NULL;
3919 }
3920 #endif
3921 
3922 /**
3923  * smack_from_netlbl - Smack data from the IP options in an skb
3924  * @sk: socket data came in on
3925  * @family: address family
3926  * @skb: packet
3927  *
3928  * Find the Smack label in the IP options. If it hasn't been
3929  * added to the netlabel cache, add it here.
3930  *
3931  * Returns smack_known of the IP options or NULL if that won't work.
3932  */
3933 static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
3934 					     struct sk_buff *skb)
3935 {
3936 	struct netlbl_lsm_secattr secattr;
3937 	struct socket_smack *ssp = NULL;
3938 	struct smack_known *skp = NULL;
3939 
3940 	netlbl_secattr_init(&secattr);
3941 
3942 	if (sk)
3943 		ssp = sk->sk_security;
3944 
3945 	if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
3946 		skp = smack_from_secattr(&secattr, ssp);
3947 		if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
3948 			netlbl_cache_add(skb, family, &skp->smk_netlabel);
3949 	}
3950 
3951 	netlbl_secattr_destroy(&secattr);
3952 
3953 	return skp;
3954 }
3955 
3956 /**
3957  * smack_socket_sock_rcv_skb - Smack packet delivery access check
3958  * @sk: socket
3959  * @skb: packet
3960  *
3961  * Returns 0 if the packet should be delivered, an error code otherwise
3962  */
3963 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
3964 {
3965 	struct socket_smack *ssp = sk->sk_security;
3966 	struct smack_known *skp = NULL;
3967 	int rc = 0;
3968 	struct smk_audit_info ad;
3969 	u16 family = sk->sk_family;
3970 #ifdef CONFIG_AUDIT
3971 	struct lsm_network_audit net;
3972 #endif
3973 #if IS_ENABLED(CONFIG_IPV6)
3974 	struct sockaddr_in6 sadd;
3975 	int proto;
3976 
3977 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
3978 		family = PF_INET;
3979 #endif /* CONFIG_IPV6 */
3980 
3981 	switch (family) {
3982 	case PF_INET:
3983 		/*
3984 		 * If there is a secmark use it rather than the CIPSO label.
3985 		 * If there is no secmark fall back to CIPSO.
3986 		 * The secmark is assumed to reflect policy better.
3987 		 */
3988 		skp = smack_from_skb(skb);
3989 		if (skp == NULL) {
3990 			skp = smack_from_netlbl(sk, family, skb);
3991 			if (skp == NULL)
3992 				skp = smack_net_ambient;
3993 		}
3994 
3995 #ifdef CONFIG_AUDIT
3996 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3997 		ad.a.u.net->family = family;
3998 		ad.a.u.net->netif = skb->skb_iif;
3999 		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4000 #endif
4001 		/*
4002 		 * Receiving a packet requires that the other end
4003 		 * be able to write here. Read access is not required.
4004 		 * This is the simplist possible security model
4005 		 * for networking.
4006 		 */
4007 		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4008 		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
4009 					MAY_WRITE, rc);
4010 		if (rc != 0)
4011 			netlbl_skbuff_err(skb, family, rc, 0);
4012 		break;
4013 #if IS_ENABLED(CONFIG_IPV6)
4014 	case PF_INET6:
4015 		proto = smk_skb_to_addr_ipv6(skb, &sadd);
4016 		if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE &&
4017 		    proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
4018 			break;
4019 #ifdef SMACK_IPV6_SECMARK_LABELING
4020 		skp = smack_from_skb(skb);
4021 		if (skp == NULL) {
4022 			if (smk_ipv6_localhost(&sadd))
4023 				break;
4024 			skp = smack_ipv6host_label(&sadd);
4025 			if (skp == NULL)
4026 				skp = smack_net_ambient;
4027 		}
4028 #ifdef CONFIG_AUDIT
4029 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4030 		ad.a.u.net->family = family;
4031 		ad.a.u.net->netif = skb->skb_iif;
4032 		ipv6_skb_to_auditdata(skb, &ad.a, NULL);
4033 #endif /* CONFIG_AUDIT */
4034 		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4035 		rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
4036 					MAY_WRITE, rc);
4037 #endif /* SMACK_IPV6_SECMARK_LABELING */
4038 #ifdef SMACK_IPV6_PORT_LABELING
4039 		rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
4040 #endif /* SMACK_IPV6_PORT_LABELING */
4041 		if (rc != 0)
4042 			icmpv6_send(skb, ICMPV6_DEST_UNREACH,
4043 					ICMPV6_ADM_PROHIBITED, 0);
4044 		break;
4045 #endif /* CONFIG_IPV6 */
4046 	}
4047 
4048 	return rc;
4049 }
4050 
4051 /**
4052  * smack_socket_getpeersec_stream - pull in packet label
4053  * @sock: the socket
4054  * @optval: user's destination
4055  * @optlen: size thereof
4056  * @len: max thereof
4057  *
4058  * returns zero on success, an error code otherwise
4059  */
4060 static int smack_socket_getpeersec_stream(struct socket *sock,
4061 					  sockptr_t optval, sockptr_t optlen,
4062 					  unsigned int len)
4063 {
4064 	struct socket_smack *ssp;
4065 	char *rcp = "";
4066 	u32 slen = 1;
4067 	int rc = 0;
4068 
4069 	ssp = sock->sk->sk_security;
4070 	if (ssp->smk_packet != NULL) {
4071 		rcp = ssp->smk_packet->smk_known;
4072 		slen = strlen(rcp) + 1;
4073 	}
4074 	if (slen > len) {
4075 		rc = -ERANGE;
4076 		goto out_len;
4077 	}
4078 
4079 	if (copy_to_sockptr(optval, rcp, slen))
4080 		rc = -EFAULT;
4081 out_len:
4082 	if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
4083 		rc = -EFAULT;
4084 	return rc;
4085 }
4086 
4087 
4088 /**
4089  * smack_socket_getpeersec_dgram - pull in packet label
4090  * @sock: the peer socket
4091  * @skb: packet data
4092  * @secid: pointer to where to put the secid of the packet
4093  *
4094  * Sets the netlabel socket state on sk from parent
4095  */
4096 static int smack_socket_getpeersec_dgram(struct socket *sock,
4097 					 struct sk_buff *skb, u32 *secid)
4098 
4099 {
4100 	struct socket_smack *ssp = NULL;
4101 	struct smack_known *skp;
4102 	struct sock *sk = NULL;
4103 	int family = PF_UNSPEC;
4104 	u32 s = 0;	/* 0 is the invalid secid */
4105 
4106 	if (skb != NULL) {
4107 		if (skb->protocol == htons(ETH_P_IP))
4108 			family = PF_INET;
4109 #if IS_ENABLED(CONFIG_IPV6)
4110 		else if (skb->protocol == htons(ETH_P_IPV6))
4111 			family = PF_INET6;
4112 #endif /* CONFIG_IPV6 */
4113 	}
4114 	if (family == PF_UNSPEC && sock != NULL)
4115 		family = sock->sk->sk_family;
4116 
4117 	switch (family) {
4118 	case PF_UNIX:
4119 		ssp = sock->sk->sk_security;
4120 		s = ssp->smk_out->smk_secid;
4121 		break;
4122 	case PF_INET:
4123 		skp = smack_from_skb(skb);
4124 		if (skp) {
4125 			s = skp->smk_secid;
4126 			break;
4127 		}
4128 		/*
4129 		 * Translate what netlabel gave us.
4130 		 */
4131 		if (sock != NULL)
4132 			sk = sock->sk;
4133 		skp = smack_from_netlbl(sk, family, skb);
4134 		if (skp != NULL)
4135 			s = skp->smk_secid;
4136 		break;
4137 	case PF_INET6:
4138 #ifdef SMACK_IPV6_SECMARK_LABELING
4139 		skp = smack_from_skb(skb);
4140 		if (skp)
4141 			s = skp->smk_secid;
4142 #endif
4143 		break;
4144 	}
4145 	*secid = s;
4146 	if (s == 0)
4147 		return -EINVAL;
4148 	return 0;
4149 }
4150 
4151 /**
4152  * smack_sock_graft - Initialize a newly created socket with an existing sock
4153  * @sk: child sock
4154  * @parent: parent socket
4155  *
4156  * Set the smk_{in,out} state of an existing sock based on the process that
4157  * is creating the new socket.
4158  */
4159 static void smack_sock_graft(struct sock *sk, struct socket *parent)
4160 {
4161 	struct socket_smack *ssp;
4162 	struct smack_known *skp = smk_of_current();
4163 
4164 	if (sk == NULL ||
4165 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
4166 		return;
4167 
4168 	ssp = sk->sk_security;
4169 	ssp->smk_in = skp;
4170 	ssp->smk_out = skp;
4171 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
4172 }
4173 
4174 /**
4175  * smack_inet_conn_request - Smack access check on connect
4176  * @sk: socket involved
4177  * @skb: packet
4178  * @req: unused
4179  *
4180  * Returns 0 if a task with the packet label could write to
4181  * the socket, otherwise an error code
4182  */
4183 static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
4184 				   struct request_sock *req)
4185 {
4186 	u16 family = sk->sk_family;
4187 	struct smack_known *skp;
4188 	struct socket_smack *ssp = sk->sk_security;
4189 	struct sockaddr_in addr;
4190 	struct iphdr *hdr;
4191 	struct smack_known *hskp;
4192 	int rc;
4193 	struct smk_audit_info ad;
4194 #ifdef CONFIG_AUDIT
4195 	struct lsm_network_audit net;
4196 #endif
4197 
4198 #if IS_ENABLED(CONFIG_IPV6)
4199 	if (family == PF_INET6) {
4200 		/*
4201 		 * Handle mapped IPv4 packets arriving
4202 		 * via IPv6 sockets. Don't set up netlabel
4203 		 * processing on IPv6.
4204 		 */
4205 		if (skb->protocol == htons(ETH_P_IP))
4206 			family = PF_INET;
4207 		else
4208 			return 0;
4209 	}
4210 #endif /* CONFIG_IPV6 */
4211 
4212 	/*
4213 	 * If there is a secmark use it rather than the CIPSO label.
4214 	 * If there is no secmark fall back to CIPSO.
4215 	 * The secmark is assumed to reflect policy better.
4216 	 */
4217 	skp = smack_from_skb(skb);
4218 	if (skp == NULL) {
4219 		skp = smack_from_netlbl(sk, family, skb);
4220 		if (skp == NULL)
4221 			skp = &smack_known_huh;
4222 	}
4223 
4224 #ifdef CONFIG_AUDIT
4225 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4226 	ad.a.u.net->family = family;
4227 	ad.a.u.net->netif = skb->skb_iif;
4228 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4229 #endif
4230 	/*
4231 	 * Receiving a packet requires that the other end be able to write
4232 	 * here. Read access is not required.
4233 	 */
4234 	rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4235 	rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
4236 	if (rc != 0)
4237 		return rc;
4238 
4239 	/*
4240 	 * Save the peer's label in the request_sock so we can later setup
4241 	 * smk_packet in the child socket so that SO_PEERCRED can report it.
4242 	 */
4243 	req->peer_secid = skp->smk_secid;
4244 
4245 	/*
4246 	 * We need to decide if we want to label the incoming connection here
4247 	 * if we do we only need to label the request_sock and the stack will
4248 	 * propagate the wire-label to the sock when it is created.
4249 	 */
4250 	hdr = ip_hdr(skb);
4251 	addr.sin_addr.s_addr = hdr->saddr;
4252 	rcu_read_lock();
4253 	hskp = smack_ipv4host_label(&addr);
4254 	rcu_read_unlock();
4255 
4256 	if (hskp == NULL)
4257 		rc = netlbl_req_setattr(req, &skp->smk_netlabel);
4258 	else
4259 		netlbl_req_delattr(req);
4260 
4261 	return rc;
4262 }
4263 
4264 /**
4265  * smack_inet_csk_clone - Copy the connection information to the new socket
4266  * @sk: the new socket
4267  * @req: the connection's request_sock
4268  *
4269  * Transfer the connection's peer label to the newly created socket.
4270  */
4271 static void smack_inet_csk_clone(struct sock *sk,
4272 				 const struct request_sock *req)
4273 {
4274 	struct socket_smack *ssp = sk->sk_security;
4275 	struct smack_known *skp;
4276 
4277 	if (req->peer_secid != 0) {
4278 		skp = smack_from_secid(req->peer_secid);
4279 		ssp->smk_packet = skp;
4280 	} else
4281 		ssp->smk_packet = NULL;
4282 }
4283 
4284 /*
4285  * Key management security hooks
4286  *
4287  * Casey has not tested key support very heavily.
4288  * The permission check is most likely too restrictive.
4289  * If you care about keys please have a look.
4290  */
4291 #ifdef CONFIG_KEYS
4292 
4293 /**
4294  * smack_key_alloc - Set the key security blob
4295  * @key: object
4296  * @cred: the credentials to use
4297  * @flags: unused
4298  *
4299  * No allocation required
4300  *
4301  * Returns 0
4302  */
4303 static int smack_key_alloc(struct key *key, const struct cred *cred,
4304 			   unsigned long flags)
4305 {
4306 	struct smack_known *skp = smk_of_task(smack_cred(cred));
4307 
4308 	key->security = skp;
4309 	return 0;
4310 }
4311 
4312 /**
4313  * smack_key_free - Clear the key security blob
4314  * @key: the object
4315  *
4316  * Clear the blob pointer
4317  */
4318 static void smack_key_free(struct key *key)
4319 {
4320 	key->security = NULL;
4321 }
4322 
4323 /**
4324  * smack_key_permission - Smack access on a key
4325  * @key_ref: gets to the object
4326  * @cred: the credentials to use
4327  * @need_perm: requested key permission
4328  *
4329  * Return 0 if the task has read and write to the object,
4330  * an error code otherwise
4331  */
4332 static int smack_key_permission(key_ref_t key_ref,
4333 				const struct cred *cred,
4334 				enum key_need_perm need_perm)
4335 {
4336 	struct key *keyp;
4337 	struct smk_audit_info ad;
4338 	struct smack_known *tkp = smk_of_task(smack_cred(cred));
4339 	int request = 0;
4340 	int rc;
4341 
4342 	/*
4343 	 * Validate requested permissions
4344 	 */
4345 	switch (need_perm) {
4346 	case KEY_NEED_READ:
4347 	case KEY_NEED_SEARCH:
4348 	case KEY_NEED_VIEW:
4349 		request |= MAY_READ;
4350 		break;
4351 	case KEY_NEED_WRITE:
4352 	case KEY_NEED_LINK:
4353 	case KEY_NEED_SETATTR:
4354 		request |= MAY_WRITE;
4355 		break;
4356 	case KEY_NEED_UNSPECIFIED:
4357 	case KEY_NEED_UNLINK:
4358 	case KEY_SYSADMIN_OVERRIDE:
4359 	case KEY_AUTHTOKEN_OVERRIDE:
4360 	case KEY_DEFER_PERM_CHECK:
4361 		return 0;
4362 	default:
4363 		return -EINVAL;
4364 	}
4365 
4366 	keyp = key_ref_to_ptr(key_ref);
4367 	if (keyp == NULL)
4368 		return -EINVAL;
4369 	/*
4370 	 * If the key hasn't been initialized give it access so that
4371 	 * it may do so.
4372 	 */
4373 	if (keyp->security == NULL)
4374 		return 0;
4375 	/*
4376 	 * This should not occur
4377 	 */
4378 	if (tkp == NULL)
4379 		return -EACCES;
4380 
4381 	if (smack_privileged(CAP_MAC_OVERRIDE))
4382 		return 0;
4383 
4384 #ifdef CONFIG_AUDIT
4385 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4386 	ad.a.u.key_struct.key = keyp->serial;
4387 	ad.a.u.key_struct.key_desc = keyp->description;
4388 #endif
4389 	rc = smk_access(tkp, keyp->security, request, &ad);
4390 	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
4391 	return rc;
4392 }
4393 
4394 /*
4395  * smack_key_getsecurity - Smack label tagging the key
4396  * @key points to the key to be queried
4397  * @_buffer points to a pointer that should be set to point to the
4398  * resulting string (if no label or an error occurs).
4399  * Return the length of the string (including terminating NUL) or -ve if
4400  * an error.
4401  * May also return 0 (and a NULL buffer pointer) if there is no label.
4402  */
4403 static int smack_key_getsecurity(struct key *key, char **_buffer)
4404 {
4405 	struct smack_known *skp = key->security;
4406 	size_t length;
4407 	char *copy;
4408 
4409 	if (key->security == NULL) {
4410 		*_buffer = NULL;
4411 		return 0;
4412 	}
4413 
4414 	copy = kstrdup(skp->smk_known, GFP_KERNEL);
4415 	if (copy == NULL)
4416 		return -ENOMEM;
4417 	length = strlen(copy) + 1;
4418 
4419 	*_buffer = copy;
4420 	return length;
4421 }
4422 
4423 
4424 #ifdef CONFIG_KEY_NOTIFICATIONS
4425 /**
4426  * smack_watch_key - Smack access to watch a key for notifications.
4427  * @key: The key to be watched
4428  *
4429  * Return 0 if the @watch->cred has permission to read from the key object and
4430  * an error otherwise.
4431  */
4432 static int smack_watch_key(struct key *key)
4433 {
4434 	struct smk_audit_info ad;
4435 	struct smack_known *tkp = smk_of_current();
4436 	int rc;
4437 
4438 	if (key == NULL)
4439 		return -EINVAL;
4440 	/*
4441 	 * If the key hasn't been initialized give it access so that
4442 	 * it may do so.
4443 	 */
4444 	if (key->security == NULL)
4445 		return 0;
4446 	/*
4447 	 * This should not occur
4448 	 */
4449 	if (tkp == NULL)
4450 		return -EACCES;
4451 
4452 	if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4453 		return 0;
4454 
4455 #ifdef CONFIG_AUDIT
4456 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4457 	ad.a.u.key_struct.key = key->serial;
4458 	ad.a.u.key_struct.key_desc = key->description;
4459 #endif
4460 	rc = smk_access(tkp, key->security, MAY_READ, &ad);
4461 	rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc);
4462 	return rc;
4463 }
4464 #endif /* CONFIG_KEY_NOTIFICATIONS */
4465 #endif /* CONFIG_KEYS */
4466 
4467 #ifdef CONFIG_WATCH_QUEUE
4468 /**
4469  * smack_post_notification - Smack access to post a notification to a queue
4470  * @w_cred: The credentials of the watcher.
4471  * @cred: The credentials of the event source (may be NULL).
4472  * @n: The notification message to be posted.
4473  */
4474 static int smack_post_notification(const struct cred *w_cred,
4475 				   const struct cred *cred,
4476 				   struct watch_notification *n)
4477 {
4478 	struct smk_audit_info ad;
4479 	struct smack_known *subj, *obj;
4480 	int rc;
4481 
4482 	/* Always let maintenance notifications through. */
4483 	if (n->type == WATCH_TYPE_META)
4484 		return 0;
4485 
4486 	if (!cred)
4487 		return 0;
4488 	subj = smk_of_task(smack_cred(cred));
4489 	obj = smk_of_task(smack_cred(w_cred));
4490 
4491 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION);
4492 	rc = smk_access(subj, obj, MAY_WRITE, &ad);
4493 	rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc);
4494 	return rc;
4495 }
4496 #endif /* CONFIG_WATCH_QUEUE */
4497 
4498 /*
4499  * Smack Audit hooks
4500  *
4501  * Audit requires a unique representation of each Smack specific
4502  * rule. This unique representation is used to distinguish the
4503  * object to be audited from remaining kernel objects and also
4504  * works as a glue between the audit hooks.
4505  *
4506  * Since repository entries are added but never deleted, we'll use
4507  * the smack_known label address related to the given audit rule as
4508  * the needed unique representation. This also better fits the smack
4509  * model where nearly everything is a label.
4510  */
4511 #ifdef CONFIG_AUDIT
4512 
4513 /**
4514  * smack_audit_rule_init - Initialize a smack audit rule
4515  * @field: audit rule fields given from user-space (audit.h)
4516  * @op: required testing operator (=, !=, >, <, ...)
4517  * @rulestr: smack label to be audited
4518  * @vrule: pointer to save our own audit rule representation
4519  *
4520  * Prepare to audit cases where (@field @op @rulestr) is true.
4521  * The label to be audited is created if necessay.
4522  */
4523 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
4524 {
4525 	struct smack_known *skp;
4526 	char **rule = (char **)vrule;
4527 	*rule = NULL;
4528 
4529 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4530 		return -EINVAL;
4531 
4532 	if (op != Audit_equal && op != Audit_not_equal)
4533 		return -EINVAL;
4534 
4535 	skp = smk_import_entry(rulestr, 0);
4536 	if (IS_ERR(skp))
4537 		return PTR_ERR(skp);
4538 
4539 	*rule = skp->smk_known;
4540 
4541 	return 0;
4542 }
4543 
4544 /**
4545  * smack_audit_rule_known - Distinguish Smack audit rules
4546  * @krule: rule of interest, in Audit kernel representation format
4547  *
4548  * This is used to filter Smack rules from remaining Audit ones.
4549  * If it's proved that this rule belongs to us, the
4550  * audit_rule_match hook will be called to do the final judgement.
4551  */
4552 static int smack_audit_rule_known(struct audit_krule *krule)
4553 {
4554 	struct audit_field *f;
4555 	int i;
4556 
4557 	for (i = 0; i < krule->field_count; i++) {
4558 		f = &krule->fields[i];
4559 
4560 		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
4561 			return 1;
4562 	}
4563 
4564 	return 0;
4565 }
4566 
4567 /**
4568  * smack_audit_rule_match - Audit given object ?
4569  * @secid: security id for identifying the object to test
4570  * @field: audit rule flags given from user-space
4571  * @op: required testing operator
4572  * @vrule: smack internal rule presentation
4573  *
4574  * The core Audit hook. It's used to take the decision of
4575  * whether to audit or not to audit a given object.
4576  */
4577 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
4578 {
4579 	struct smack_known *skp;
4580 	char *rule = vrule;
4581 
4582 	if (unlikely(!rule)) {
4583 		WARN_ONCE(1, "Smack: missing rule\n");
4584 		return -ENOENT;
4585 	}
4586 
4587 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4588 		return 0;
4589 
4590 	skp = smack_from_secid(secid);
4591 
4592 	/*
4593 	 * No need to do string comparisons. If a match occurs,
4594 	 * both pointers will point to the same smack_known
4595 	 * label.
4596 	 */
4597 	if (op == Audit_equal)
4598 		return (rule == skp->smk_known);
4599 	if (op == Audit_not_equal)
4600 		return (rule != skp->smk_known);
4601 
4602 	return 0;
4603 }
4604 
4605 /*
4606  * There is no need for a smack_audit_rule_free hook.
4607  * No memory was allocated.
4608  */
4609 
4610 #endif /* CONFIG_AUDIT */
4611 
4612 /**
4613  * smack_ismaclabel - check if xattr @name references a smack MAC label
4614  * @name: Full xattr name to check.
4615  */
4616 static int smack_ismaclabel(const char *name)
4617 {
4618 	return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
4619 }
4620 
4621 
4622 /**
4623  * smack_secid_to_secctx - return the smack label for a secid
4624  * @secid: incoming integer
4625  * @secdata: destination
4626  * @seclen: how long it is
4627  *
4628  * Exists for networking code.
4629  */
4630 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
4631 {
4632 	struct smack_known *skp = smack_from_secid(secid);
4633 
4634 	if (secdata)
4635 		*secdata = skp->smk_known;
4636 	*seclen = strlen(skp->smk_known);
4637 	return 0;
4638 }
4639 
4640 /**
4641  * smack_secctx_to_secid - return the secid for a smack label
4642  * @secdata: smack label
4643  * @seclen: how long result is
4644  * @secid: outgoing integer
4645  *
4646  * Exists for audit and networking code.
4647  */
4648 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4649 {
4650 	struct smack_known *skp = smk_find_entry(secdata);
4651 
4652 	if (skp)
4653 		*secid = skp->smk_secid;
4654 	else
4655 		*secid = 0;
4656 	return 0;
4657 }
4658 
4659 /*
4660  * There used to be a smack_release_secctx hook
4661  * that did nothing back when hooks were in a vector.
4662  * Now that there's a list such a hook adds cost.
4663  */
4664 
4665 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
4666 {
4667 	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx,
4668 				       ctxlen, 0);
4669 }
4670 
4671 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
4672 {
4673 	return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SMACK,
4674 				     ctx, ctxlen, 0);
4675 }
4676 
4677 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
4678 {
4679 	struct smack_known *skp = smk_of_inode(inode);
4680 
4681 	*ctx = skp->smk_known;
4682 	*ctxlen = strlen(skp->smk_known);
4683 	return 0;
4684 }
4685 
4686 static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
4687 {
4688 
4689 	struct task_smack *tsp;
4690 	struct smack_known *skp;
4691 	struct inode_smack *isp;
4692 	struct cred *new_creds = *new;
4693 
4694 	if (new_creds == NULL) {
4695 		new_creds = prepare_creds();
4696 		if (new_creds == NULL)
4697 			return -ENOMEM;
4698 	}
4699 
4700 	tsp = smack_cred(new_creds);
4701 
4702 	/*
4703 	 * Get label from overlay inode and set it in create_sid
4704 	 */
4705 	isp = smack_inode(d_inode(dentry));
4706 	skp = isp->smk_inode;
4707 	tsp->smk_task = skp;
4708 	*new = new_creds;
4709 	return 0;
4710 }
4711 
4712 static int smack_inode_copy_up_xattr(const char *name)
4713 {
4714 	/*
4715 	 * Return 1 if this is the smack access Smack attribute.
4716 	 */
4717 	if (strcmp(name, XATTR_NAME_SMACK) == 0)
4718 		return 1;
4719 
4720 	return -EOPNOTSUPP;
4721 }
4722 
4723 static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
4724 					struct qstr *name,
4725 					const struct cred *old,
4726 					struct cred *new)
4727 {
4728 	struct task_smack *otsp = smack_cred(old);
4729 	struct task_smack *ntsp = smack_cred(new);
4730 	struct inode_smack *isp;
4731 	int may;
4732 
4733 	/*
4734 	 * Use the process credential unless all of
4735 	 * the transmuting criteria are met
4736 	 */
4737 	ntsp->smk_task = otsp->smk_task;
4738 
4739 	/*
4740 	 * the attribute of the containing directory
4741 	 */
4742 	isp = smack_inode(d_inode(dentry->d_parent));
4743 
4744 	if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
4745 		rcu_read_lock();
4746 		may = smk_access_entry(otsp->smk_task->smk_known,
4747 				       isp->smk_inode->smk_known,
4748 				       &otsp->smk_task->smk_rules);
4749 		rcu_read_unlock();
4750 
4751 		/*
4752 		 * If the directory is transmuting and the rule
4753 		 * providing access is transmuting use the containing
4754 		 * directory label instead of the process label.
4755 		 */
4756 		if (may > 0 && (may & MAY_TRANSMUTE))
4757 			ntsp->smk_task = isp->smk_inode;
4758 	}
4759 	return 0;
4760 }
4761 
4762 #ifdef CONFIG_IO_URING
4763 /**
4764  * smack_uring_override_creds - Is io_uring cred override allowed?
4765  * @new: the target creds
4766  *
4767  * Check to see if the current task is allowed to override it's credentials
4768  * to service an io_uring operation.
4769  */
4770 static int smack_uring_override_creds(const struct cred *new)
4771 {
4772 	struct task_smack *tsp = smack_cred(current_cred());
4773 	struct task_smack *nsp = smack_cred(new);
4774 
4775 	/*
4776 	 * Allow the degenerate case where the new Smack value is
4777 	 * the same as the current Smack value.
4778 	 */
4779 	if (tsp->smk_task == nsp->smk_task)
4780 		return 0;
4781 
4782 	if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4783 		return 0;
4784 
4785 	return -EPERM;
4786 }
4787 
4788 /**
4789  * smack_uring_sqpoll - check if a io_uring polling thread can be created
4790  *
4791  * Check to see if the current task is allowed to create a new io_uring
4792  * kernel polling thread.
4793  */
4794 static int smack_uring_sqpoll(void)
4795 {
4796 	if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred()))
4797 		return 0;
4798 
4799 	return -EPERM;
4800 }
4801 
4802 /**
4803  * smack_uring_cmd - check on file operations for io_uring
4804  * @ioucmd: the command in question
4805  *
4806  * Make a best guess about whether a io_uring "command" should
4807  * be allowed. Use the same logic used for determining if the
4808  * file could be opened for read in the absence of better criteria.
4809  */
4810 static int smack_uring_cmd(struct io_uring_cmd *ioucmd)
4811 {
4812 	struct file *file = ioucmd->file;
4813 	struct smk_audit_info ad;
4814 	struct task_smack *tsp;
4815 	struct inode *inode;
4816 	int rc;
4817 
4818 	if (!file)
4819 		return -EINVAL;
4820 
4821 	tsp = smack_cred(file->f_cred);
4822 	inode = file_inode(file);
4823 
4824 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
4825 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
4826 	rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
4827 	rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
4828 
4829 	return rc;
4830 }
4831 
4832 #endif /* CONFIG_IO_URING */
4833 
4834 struct lsm_blob_sizes smack_blob_sizes __ro_after_init = {
4835 	.lbs_cred = sizeof(struct task_smack),
4836 	.lbs_file = sizeof(struct smack_known *),
4837 	.lbs_inode = sizeof(struct inode_smack),
4838 	.lbs_ipc = sizeof(struct smack_known *),
4839 	.lbs_msg_msg = sizeof(struct smack_known *),
4840 	.lbs_superblock = sizeof(struct superblock_smack),
4841 };
4842 
4843 static struct security_hook_list smack_hooks[] __ro_after_init = {
4844 	LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
4845 	LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
4846 	LSM_HOOK_INIT(syslog, smack_syslog),
4847 
4848 	LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
4849 	LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
4850 
4851 	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
4852 	LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
4853 	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
4854 	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
4855 	LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
4856 
4857 	LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec),
4858 
4859 	LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
4860 	LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
4861 	LSM_HOOK_INIT(inode_link, smack_inode_link),
4862 	LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
4863 	LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir),
4864 	LSM_HOOK_INIT(inode_rename, smack_inode_rename),
4865 	LSM_HOOK_INIT(inode_permission, smack_inode_permission),
4866 	LSM_HOOK_INIT(inode_setattr, smack_inode_setattr),
4867 	LSM_HOOK_INIT(inode_getattr, smack_inode_getattr),
4868 	LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr),
4869 	LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr),
4870 	LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr),
4871 	LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr),
4872 	LSM_HOOK_INIT(inode_set_acl, smack_inode_set_acl),
4873 	LSM_HOOK_INIT(inode_get_acl, smack_inode_get_acl),
4874 	LSM_HOOK_INIT(inode_remove_acl, smack_inode_remove_acl),
4875 	LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
4876 	LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
4877 	LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
4878 	LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),
4879 
4880 	LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
4881 	LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
4882 	LSM_HOOK_INIT(file_lock, smack_file_lock),
4883 	LSM_HOOK_INIT(file_fcntl, smack_file_fcntl),
4884 	LSM_HOOK_INIT(mmap_file, smack_mmap_file),
4885 	LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
4886 	LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner),
4887 	LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask),
4888 	LSM_HOOK_INIT(file_receive, smack_file_receive),
4889 
4890 	LSM_HOOK_INIT(file_open, smack_file_open),
4891 
4892 	LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank),
4893 	LSM_HOOK_INIT(cred_free, smack_cred_free),
4894 	LSM_HOOK_INIT(cred_prepare, smack_cred_prepare),
4895 	LSM_HOOK_INIT(cred_transfer, smack_cred_transfer),
4896 	LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid),
4897 	LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as),
4898 	LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as),
4899 	LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
4900 	LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
4901 	LSM_HOOK_INIT(task_getsid, smack_task_getsid),
4902 	LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj),
4903 	LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
4904 	LSM_HOOK_INIT(task_setnice, smack_task_setnice),
4905 	LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
4906 	LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
4907 	LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler),
4908 	LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler),
4909 	LSM_HOOK_INIT(task_movememory, smack_task_movememory),
4910 	LSM_HOOK_INIT(task_kill, smack_task_kill),
4911 	LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
4912 
4913 	LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
4914 	LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
4915 
4916 	LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
4917 
4918 	LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
4919 	LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
4920 	LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
4921 	LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
4922 	LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),
4923 
4924 	LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
4925 	LSM_HOOK_INIT(shm_associate, smack_shm_associate),
4926 	LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
4927 	LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),
4928 
4929 	LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
4930 	LSM_HOOK_INIT(sem_associate, smack_sem_associate),
4931 	LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
4932 	LSM_HOOK_INIT(sem_semop, smack_sem_semop),
4933 
4934 	LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),
4935 
4936 	LSM_HOOK_INIT(getprocattr, smack_getprocattr),
4937 	LSM_HOOK_INIT(setprocattr, smack_setprocattr),
4938 
4939 	LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect),
4940 	LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
4941 
4942 	LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
4943 	LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
4944 #ifdef SMACK_IPV6_PORT_LABELING
4945 	LSM_HOOK_INIT(socket_bind, smack_socket_bind),
4946 #endif
4947 	LSM_HOOK_INIT(socket_connect, smack_socket_connect),
4948 	LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
4949 	LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
4950 	LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
4951 	LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
4952 	LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
4953 	LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
4954 	LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security),
4955 	LSM_HOOK_INIT(sock_graft, smack_sock_graft),
4956 	LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
4957 	LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
4958 
4959  /* key management security hooks */
4960 #ifdef CONFIG_KEYS
4961 	LSM_HOOK_INIT(key_alloc, smack_key_alloc),
4962 	LSM_HOOK_INIT(key_free, smack_key_free),
4963 	LSM_HOOK_INIT(key_permission, smack_key_permission),
4964 	LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
4965 #ifdef CONFIG_KEY_NOTIFICATIONS
4966 	LSM_HOOK_INIT(watch_key, smack_watch_key),
4967 #endif
4968 #endif /* CONFIG_KEYS */
4969 
4970 #ifdef CONFIG_WATCH_QUEUE
4971 	LSM_HOOK_INIT(post_notification, smack_post_notification),
4972 #endif
4973 
4974  /* Audit hooks */
4975 #ifdef CONFIG_AUDIT
4976 	LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init),
4977 	LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known),
4978 	LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match),
4979 #endif /* CONFIG_AUDIT */
4980 
4981 	LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
4982 	LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
4983 	LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
4984 	LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
4985 	LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
4986 	LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
4987 	LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up),
4988 	LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr),
4989 	LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as),
4990 #ifdef CONFIG_IO_URING
4991 	LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds),
4992 	LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll),
4993 	LSM_HOOK_INIT(uring_cmd, smack_uring_cmd),
4994 #endif
4995 };
4996 
4997 
4998 static __init void init_smack_known_list(void)
4999 {
5000 	/*
5001 	 * Initialize rule list locks
5002 	 */
5003 	mutex_init(&smack_known_huh.smk_rules_lock);
5004 	mutex_init(&smack_known_hat.smk_rules_lock);
5005 	mutex_init(&smack_known_floor.smk_rules_lock);
5006 	mutex_init(&smack_known_star.smk_rules_lock);
5007 	mutex_init(&smack_known_web.smk_rules_lock);
5008 	/*
5009 	 * Initialize rule lists
5010 	 */
5011 	INIT_LIST_HEAD(&smack_known_huh.smk_rules);
5012 	INIT_LIST_HEAD(&smack_known_hat.smk_rules);
5013 	INIT_LIST_HEAD(&smack_known_star.smk_rules);
5014 	INIT_LIST_HEAD(&smack_known_floor.smk_rules);
5015 	INIT_LIST_HEAD(&smack_known_web.smk_rules);
5016 	/*
5017 	 * Create the known labels list
5018 	 */
5019 	smk_insert_entry(&smack_known_huh);
5020 	smk_insert_entry(&smack_known_hat);
5021 	smk_insert_entry(&smack_known_star);
5022 	smk_insert_entry(&smack_known_floor);
5023 	smk_insert_entry(&smack_known_web);
5024 }
5025 
5026 /**
5027  * smack_init - initialize the smack system
5028  *
5029  * Returns 0 on success, -ENOMEM is there's no memory
5030  */
5031 static __init int smack_init(void)
5032 {
5033 	struct cred *cred = (struct cred *) current->cred;
5034 	struct task_smack *tsp;
5035 
5036 	smack_rule_cache = KMEM_CACHE(smack_rule, 0);
5037 	if (!smack_rule_cache)
5038 		return -ENOMEM;
5039 
5040 	/*
5041 	 * Set the security state for the initial task.
5042 	 */
5043 	tsp = smack_cred(cred);
5044 	init_task_smack(tsp, &smack_known_floor, &smack_known_floor);
5045 
5046 	/*
5047 	 * Register with LSM
5048 	 */
5049 	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
5050 	smack_enabled = 1;
5051 
5052 	pr_info("Smack:  Initializing.\n");
5053 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
5054 	pr_info("Smack:  Netfilter enabled.\n");
5055 #endif
5056 #ifdef SMACK_IPV6_PORT_LABELING
5057 	pr_info("Smack:  IPv6 port labeling enabled.\n");
5058 #endif
5059 #ifdef SMACK_IPV6_SECMARK_LABELING
5060 	pr_info("Smack:  IPv6 Netfilter enabled.\n");
5061 #endif
5062 
5063 	/* initialize the smack_known_list */
5064 	init_smack_known_list();
5065 
5066 	return 0;
5067 }
5068 
5069 /*
5070  * Smack requires early initialization in order to label
5071  * all processes and objects when they are created.
5072  */
5073 DEFINE_LSM(smack) = {
5074 	.name = "smack",
5075 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
5076 	.blobs = &smack_blob_sizes,
5077 	.init = smack_init,
5078 };
5079