xref: /openbmc/linux/security/smack/smack_lsm.c (revision 46e35a50)
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 /*
56  * Smack uses multiple xattrs.
57  * SMACK64 - for access control,
58  * SMACK64TRANSMUTE - label initialization,
59  * Not saved on files - SMACK64IPIN and SMACK64IPOUT,
60  * Must be set explicitly - SMACK64EXEC and SMACK64MMAP
61  */
62 #define SMACK_INODE_INIT_XATTRS 2
63 
64 #ifdef SMACK_IPV6_PORT_LABELING
65 static DEFINE_MUTEX(smack_ipv6_lock);
66 static LIST_HEAD(smk_ipv6_port_list);
67 #endif
68 struct kmem_cache *smack_rule_cache;
69 int smack_enabled __initdata;
70 
71 #define A(s) {"smack"#s, sizeof("smack"#s) - 1, Opt_##s}
72 static struct {
73 	const char *name;
74 	int len;
75 	int opt;
76 } smk_mount_opts[] = {
77 	{"smackfsdef", sizeof("smackfsdef") - 1, Opt_fsdefault},
78 	A(fsdefault), A(fsfloor), A(fshat), A(fsroot), A(fstransmute)
79 };
80 #undef A
81 
82 static int match_opt_prefix(char *s, int l, char **arg)
83 {
84 	int i;
85 
86 	for (i = 0; i < ARRAY_SIZE(smk_mount_opts); i++) {
87 		size_t len = smk_mount_opts[i].len;
88 		if (len > l || memcmp(s, smk_mount_opts[i].name, len))
89 			continue;
90 		if (len == l || s[len] != '=')
91 			continue;
92 		*arg = s + len + 1;
93 		return smk_mount_opts[i].opt;
94 	}
95 	return Opt_error;
96 }
97 
98 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
99 static char *smk_bu_mess[] = {
100 	"Bringup Error",	/* Unused */
101 	"Bringup",		/* SMACK_BRINGUP_ALLOW */
102 	"Unconfined Subject",	/* SMACK_UNCONFINED_SUBJECT */
103 	"Unconfined Object",	/* SMACK_UNCONFINED_OBJECT */
104 };
105 
106 static void smk_bu_mode(int mode, char *s)
107 {
108 	int i = 0;
109 
110 	if (mode & MAY_READ)
111 		s[i++] = 'r';
112 	if (mode & MAY_WRITE)
113 		s[i++] = 'w';
114 	if (mode & MAY_EXEC)
115 		s[i++] = 'x';
116 	if (mode & MAY_APPEND)
117 		s[i++] = 'a';
118 	if (mode & MAY_TRANSMUTE)
119 		s[i++] = 't';
120 	if (mode & MAY_LOCK)
121 		s[i++] = 'l';
122 	if (i == 0)
123 		s[i++] = '-';
124 	s[i] = '\0';
125 }
126 #endif
127 
128 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
129 static int smk_bu_note(char *note, struct smack_known *sskp,
130 		       struct smack_known *oskp, int mode, int rc)
131 {
132 	char acc[SMK_NUM_ACCESS_TYPE + 1];
133 
134 	if (rc <= 0)
135 		return rc;
136 	if (rc > SMACK_UNCONFINED_OBJECT)
137 		rc = 0;
138 
139 	smk_bu_mode(mode, acc);
140 	pr_info("Smack %s: (%s %s %s) %s\n", smk_bu_mess[rc],
141 		sskp->smk_known, oskp->smk_known, acc, note);
142 	return 0;
143 }
144 #else
145 #define smk_bu_note(note, sskp, oskp, mode, RC) (RC)
146 #endif
147 
148 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
149 static int smk_bu_current(char *note, struct smack_known *oskp,
150 			  int mode, int rc)
151 {
152 	struct task_smack *tsp = smack_cred(current_cred());
153 	char acc[SMK_NUM_ACCESS_TYPE + 1];
154 
155 	if (rc <= 0)
156 		return rc;
157 	if (rc > SMACK_UNCONFINED_OBJECT)
158 		rc = 0;
159 
160 	smk_bu_mode(mode, acc);
161 	pr_info("Smack %s: (%s %s %s) %s %s\n", smk_bu_mess[rc],
162 		tsp->smk_task->smk_known, oskp->smk_known,
163 		acc, current->comm, note);
164 	return 0;
165 }
166 #else
167 #define smk_bu_current(note, oskp, mode, RC) (RC)
168 #endif
169 
170 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
171 static int smk_bu_task(struct task_struct *otp, int mode, int rc)
172 {
173 	struct task_smack *tsp = smack_cred(current_cred());
174 	struct smack_known *smk_task = smk_of_task_struct_obj(otp);
175 	char acc[SMK_NUM_ACCESS_TYPE + 1];
176 
177 	if (rc <= 0)
178 		return rc;
179 	if (rc > SMACK_UNCONFINED_OBJECT)
180 		rc = 0;
181 
182 	smk_bu_mode(mode, acc);
183 	pr_info("Smack %s: (%s %s %s) %s to %s\n", smk_bu_mess[rc],
184 		tsp->smk_task->smk_known, smk_task->smk_known, acc,
185 		current->comm, otp->comm);
186 	return 0;
187 }
188 #else
189 #define smk_bu_task(otp, mode, RC) (RC)
190 #endif
191 
192 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
193 static int smk_bu_inode(struct inode *inode, int mode, int rc)
194 {
195 	struct task_smack *tsp = smack_cred(current_cred());
196 	struct inode_smack *isp = smack_inode(inode);
197 	char acc[SMK_NUM_ACCESS_TYPE + 1];
198 
199 	if (isp->smk_flags & SMK_INODE_IMPURE)
200 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
201 			inode->i_sb->s_id, inode->i_ino, current->comm);
202 
203 	if (rc <= 0)
204 		return rc;
205 	if (rc > SMACK_UNCONFINED_OBJECT)
206 		rc = 0;
207 	if (rc == SMACK_UNCONFINED_SUBJECT &&
208 	    (mode & (MAY_WRITE | MAY_APPEND)))
209 		isp->smk_flags |= SMK_INODE_IMPURE;
210 
211 	smk_bu_mode(mode, acc);
212 
213 	pr_info("Smack %s: (%s %s %s) inode=(%s %ld) %s\n", smk_bu_mess[rc],
214 		tsp->smk_task->smk_known, isp->smk_inode->smk_known, acc,
215 		inode->i_sb->s_id, inode->i_ino, current->comm);
216 	return 0;
217 }
218 #else
219 #define smk_bu_inode(inode, mode, RC) (RC)
220 #endif
221 
222 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
223 static int smk_bu_file(struct file *file, int mode, int rc)
224 {
225 	struct task_smack *tsp = smack_cred(current_cred());
226 	struct smack_known *sskp = tsp->smk_task;
227 	struct inode *inode = file_inode(file);
228 	struct inode_smack *isp = smack_inode(inode);
229 	char acc[SMK_NUM_ACCESS_TYPE + 1];
230 
231 	if (isp->smk_flags & SMK_INODE_IMPURE)
232 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
233 			inode->i_sb->s_id, inode->i_ino, current->comm);
234 
235 	if (rc <= 0)
236 		return rc;
237 	if (rc > SMACK_UNCONFINED_OBJECT)
238 		rc = 0;
239 
240 	smk_bu_mode(mode, acc);
241 	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
242 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
243 		inode->i_sb->s_id, inode->i_ino, file,
244 		current->comm);
245 	return 0;
246 }
247 #else
248 #define smk_bu_file(file, mode, RC) (RC)
249 #endif
250 
251 #ifdef CONFIG_SECURITY_SMACK_BRINGUP
252 static int smk_bu_credfile(const struct cred *cred, struct file *file,
253 				int mode, int rc)
254 {
255 	struct task_smack *tsp = smack_cred(cred);
256 	struct smack_known *sskp = tsp->smk_task;
257 	struct inode *inode = file_inode(file);
258 	struct inode_smack *isp = smack_inode(inode);
259 	char acc[SMK_NUM_ACCESS_TYPE + 1];
260 
261 	if (isp->smk_flags & SMK_INODE_IMPURE)
262 		pr_info("Smack Unconfined Corruption: inode=(%s %ld) %s\n",
263 			inode->i_sb->s_id, inode->i_ino, current->comm);
264 
265 	if (rc <= 0)
266 		return rc;
267 	if (rc > SMACK_UNCONFINED_OBJECT)
268 		rc = 0;
269 
270 	smk_bu_mode(mode, acc);
271 	pr_info("Smack %s: (%s %s %s) file=(%s %ld %pD) %s\n", smk_bu_mess[rc],
272 		sskp->smk_known, smk_of_inode(inode)->smk_known, acc,
273 		inode->i_sb->s_id, inode->i_ino, file,
274 		current->comm);
275 	return 0;
276 }
277 #else
278 #define smk_bu_credfile(cred, file, mode, RC) (RC)
279 #endif
280 
281 /**
282  * smk_fetch - Fetch the smack label from a file.
283  * @name: type of the label (attribute)
284  * @ip: a pointer to the inode
285  * @dp: a pointer to the dentry
286  *
287  * Returns a pointer to the master list entry for the Smack label,
288  * NULL if there was no label to fetch, or an error code.
289  */
290 static struct smack_known *smk_fetch(const char *name, struct inode *ip,
291 					struct dentry *dp)
292 {
293 	int rc;
294 	char *buffer;
295 	struct smack_known *skp = NULL;
296 
297 	if (!(ip->i_opflags & IOP_XATTR))
298 		return ERR_PTR(-EOPNOTSUPP);
299 
300 	buffer = kzalloc(SMK_LONGLABEL, GFP_NOFS);
301 	if (buffer == NULL)
302 		return ERR_PTR(-ENOMEM);
303 
304 	rc = __vfs_getxattr(dp, ip, name, buffer, SMK_LONGLABEL);
305 	if (rc < 0)
306 		skp = ERR_PTR(rc);
307 	else if (rc == 0)
308 		skp = NULL;
309 	else
310 		skp = smk_import_entry(buffer, rc);
311 
312 	kfree(buffer);
313 
314 	return skp;
315 }
316 
317 /**
318  * init_inode_smack - initialize an inode security blob
319  * @inode: inode to extract the info from
320  * @skp: a pointer to the Smack label entry to use in the blob
321  *
322  */
323 static void init_inode_smack(struct inode *inode, struct smack_known *skp)
324 {
325 	struct inode_smack *isp = smack_inode(inode);
326 
327 	isp->smk_inode = skp;
328 	isp->smk_flags = 0;
329 }
330 
331 /**
332  * init_task_smack - initialize a task security blob
333  * @tsp: blob to initialize
334  * @task: a pointer to the Smack label for the running task
335  * @forked: a pointer to the Smack label for the forked task
336  *
337  */
338 static void init_task_smack(struct task_smack *tsp, struct smack_known *task,
339 					struct smack_known *forked)
340 {
341 	tsp->smk_task = task;
342 	tsp->smk_forked = forked;
343 	INIT_LIST_HEAD(&tsp->smk_rules);
344 	INIT_LIST_HEAD(&tsp->smk_relabel);
345 	mutex_init(&tsp->smk_rules_lock);
346 }
347 
348 /**
349  * smk_copy_rules - copy a rule set
350  * @nhead: new rules header pointer
351  * @ohead: old rules header pointer
352  * @gfp: type of the memory for the allocation
353  *
354  * Returns 0 on success, -ENOMEM on error
355  */
356 static int smk_copy_rules(struct list_head *nhead, struct list_head *ohead,
357 				gfp_t gfp)
358 {
359 	struct smack_rule *nrp;
360 	struct smack_rule *orp;
361 	int rc = 0;
362 
363 	list_for_each_entry_rcu(orp, ohead, list) {
364 		nrp = kmem_cache_zalloc(smack_rule_cache, gfp);
365 		if (nrp == NULL) {
366 			rc = -ENOMEM;
367 			break;
368 		}
369 		*nrp = *orp;
370 		list_add_rcu(&nrp->list, nhead);
371 	}
372 	return rc;
373 }
374 
375 /**
376  * smk_copy_relabel - copy smk_relabel labels list
377  * @nhead: new rules header pointer
378  * @ohead: old rules header pointer
379  * @gfp: type of the memory for the allocation
380  *
381  * Returns 0 on success, -ENOMEM on error
382  */
383 static int smk_copy_relabel(struct list_head *nhead, struct list_head *ohead,
384 				gfp_t gfp)
385 {
386 	struct smack_known_list_elem *nklep;
387 	struct smack_known_list_elem *oklep;
388 
389 	list_for_each_entry(oklep, ohead, list) {
390 		nklep = kzalloc(sizeof(struct smack_known_list_elem), gfp);
391 		if (nklep == NULL) {
392 			smk_destroy_label_list(nhead);
393 			return -ENOMEM;
394 		}
395 		nklep->smk_label = oklep->smk_label;
396 		list_add(&nklep->list, nhead);
397 	}
398 
399 	return 0;
400 }
401 
402 /**
403  * smk_ptrace_mode - helper function for converting PTRACE_MODE_* into MAY_*
404  * @mode: input mode in form of PTRACE_MODE_*
405  *
406  * Returns a converted MAY_* mode usable by smack rules
407  */
408 static inline unsigned int smk_ptrace_mode(unsigned int mode)
409 {
410 	if (mode & PTRACE_MODE_ATTACH)
411 		return MAY_READWRITE;
412 	if (mode & PTRACE_MODE_READ)
413 		return MAY_READ;
414 
415 	return 0;
416 }
417 
418 /**
419  * smk_ptrace_rule_check - helper for ptrace access
420  * @tracer: tracer process
421  * @tracee_known: label entry of the process that's about to be traced
422  * @mode: ptrace attachment mode (PTRACE_MODE_*)
423  * @func: name of the function that called us, used for audit
424  *
425  * Returns 0 on access granted, -error on error
426  */
427 static int smk_ptrace_rule_check(struct task_struct *tracer,
428 				 struct smack_known *tracee_known,
429 				 unsigned int mode, const char *func)
430 {
431 	int rc;
432 	struct smk_audit_info ad, *saip = NULL;
433 	struct task_smack *tsp;
434 	struct smack_known *tracer_known;
435 	const struct cred *tracercred;
436 
437 	if ((mode & PTRACE_MODE_NOAUDIT) == 0) {
438 		smk_ad_init(&ad, func, LSM_AUDIT_DATA_TASK);
439 		smk_ad_setfield_u_tsk(&ad, tracer);
440 		saip = &ad;
441 	}
442 
443 	rcu_read_lock();
444 	tracercred = __task_cred(tracer);
445 	tsp = smack_cred(tracercred);
446 	tracer_known = smk_of_task(tsp);
447 
448 	if ((mode & PTRACE_MODE_ATTACH) &&
449 	    (smack_ptrace_rule == SMACK_PTRACE_EXACT ||
450 	     smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)) {
451 		if (tracer_known->smk_known == tracee_known->smk_known)
452 			rc = 0;
453 		else if (smack_ptrace_rule == SMACK_PTRACE_DRACONIAN)
454 			rc = -EACCES;
455 		else if (smack_privileged_cred(CAP_SYS_PTRACE, tracercred))
456 			rc = 0;
457 		else
458 			rc = -EACCES;
459 
460 		if (saip)
461 			smack_log(tracer_known->smk_known,
462 				  tracee_known->smk_known,
463 				  0, rc, saip);
464 
465 		rcu_read_unlock();
466 		return rc;
467 	}
468 
469 	/* In case of rule==SMACK_PTRACE_DEFAULT or mode==PTRACE_MODE_READ */
470 	rc = smk_tskacc(tsp, tracee_known, smk_ptrace_mode(mode), saip);
471 
472 	rcu_read_unlock();
473 	return rc;
474 }
475 
476 /*
477  * LSM hooks.
478  * We he, that is fun!
479  */
480 
481 /**
482  * smack_ptrace_access_check - Smack approval on PTRACE_ATTACH
483  * @ctp: child task pointer
484  * @mode: ptrace attachment mode (PTRACE_MODE_*)
485  *
486  * Returns 0 if access is OK, an error code otherwise
487  *
488  * Do the capability checks.
489  */
490 static int smack_ptrace_access_check(struct task_struct *ctp, unsigned int mode)
491 {
492 	struct smack_known *skp;
493 
494 	skp = smk_of_task_struct_obj(ctp);
495 
496 	return smk_ptrace_rule_check(current, skp, mode, __func__);
497 }
498 
499 /**
500  * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
501  * @ptp: parent task pointer
502  *
503  * Returns 0 if access is OK, an error code otherwise
504  *
505  * Do the capability checks, and require PTRACE_MODE_ATTACH.
506  */
507 static int smack_ptrace_traceme(struct task_struct *ptp)
508 {
509 	struct smack_known *skp;
510 
511 	skp = smk_of_task(smack_cred(current_cred()));
512 
513 	return smk_ptrace_rule_check(ptp, skp, PTRACE_MODE_ATTACH, __func__);
514 }
515 
516 /**
517  * smack_syslog - Smack approval on syslog
518  * @typefrom_file: unused
519  *
520  * Returns 0 on success, error code otherwise.
521  */
522 static int smack_syslog(int typefrom_file)
523 {
524 	int rc = 0;
525 	struct smack_known *skp = smk_of_current();
526 
527 	if (smack_privileged(CAP_MAC_OVERRIDE))
528 		return 0;
529 
530 	if (smack_syslog_label != NULL && smack_syslog_label != skp)
531 		rc = -EACCES;
532 
533 	return rc;
534 }
535 
536 /*
537  * Superblock Hooks.
538  */
539 
540 /**
541  * smack_sb_alloc_security - allocate a superblock blob
542  * @sb: the superblock getting the blob
543  *
544  * Returns 0 on success or -ENOMEM on error.
545  */
546 static int smack_sb_alloc_security(struct super_block *sb)
547 {
548 	struct superblock_smack *sbsp = smack_superblock(sb);
549 
550 	sbsp->smk_root = &smack_known_floor;
551 	sbsp->smk_default = &smack_known_floor;
552 	sbsp->smk_floor = &smack_known_floor;
553 	sbsp->smk_hat = &smack_known_hat;
554 	/*
555 	 * SMK_SB_INITIALIZED will be zero from kzalloc.
556 	 */
557 
558 	return 0;
559 }
560 
561 struct smack_mnt_opts {
562 	const char *fsdefault;
563 	const char *fsfloor;
564 	const char *fshat;
565 	const char *fsroot;
566 	const char *fstransmute;
567 };
568 
569 static void smack_free_mnt_opts(void *mnt_opts)
570 {
571 	kfree(mnt_opts);
572 }
573 
574 static int smack_add_opt(int token, const char *s, void **mnt_opts)
575 {
576 	struct smack_mnt_opts *opts = *mnt_opts;
577 	struct smack_known *skp;
578 
579 	if (!opts) {
580 		opts = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
581 		if (!opts)
582 			return -ENOMEM;
583 		*mnt_opts = opts;
584 	}
585 	if (!s)
586 		return -ENOMEM;
587 
588 	skp = smk_import_entry(s, 0);
589 	if (IS_ERR(skp))
590 		return PTR_ERR(skp);
591 
592 	switch (token) {
593 	case Opt_fsdefault:
594 		if (opts->fsdefault)
595 			goto out_opt_err;
596 		opts->fsdefault = skp->smk_known;
597 		break;
598 	case Opt_fsfloor:
599 		if (opts->fsfloor)
600 			goto out_opt_err;
601 		opts->fsfloor = skp->smk_known;
602 		break;
603 	case Opt_fshat:
604 		if (opts->fshat)
605 			goto out_opt_err;
606 		opts->fshat = skp->smk_known;
607 		break;
608 	case Opt_fsroot:
609 		if (opts->fsroot)
610 			goto out_opt_err;
611 		opts->fsroot = skp->smk_known;
612 		break;
613 	case Opt_fstransmute:
614 		if (opts->fstransmute)
615 			goto out_opt_err;
616 		opts->fstransmute = skp->smk_known;
617 		break;
618 	}
619 	return 0;
620 
621 out_opt_err:
622 	pr_warn("Smack: duplicate mount options\n");
623 	return -EINVAL;
624 }
625 
626 /**
627  * smack_fs_context_submount - Initialise security data for a filesystem context
628  * @fc: The filesystem context.
629  * @reference: reference superblock
630  *
631  * Returns 0 on success or -ENOMEM on error.
632  */
633 static int smack_fs_context_submount(struct fs_context *fc,
634 				 struct super_block *reference)
635 {
636 	struct superblock_smack *sbsp;
637 	struct smack_mnt_opts *ctx;
638 	struct inode_smack *isp;
639 
640 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
641 	if (!ctx)
642 		return -ENOMEM;
643 	fc->security = ctx;
644 
645 	sbsp = smack_superblock(reference);
646 	isp = smack_inode(reference->s_root->d_inode);
647 
648 	if (sbsp->smk_default) {
649 		ctx->fsdefault = kstrdup(sbsp->smk_default->smk_known, GFP_KERNEL);
650 		if (!ctx->fsdefault)
651 			return -ENOMEM;
652 	}
653 
654 	if (sbsp->smk_floor) {
655 		ctx->fsfloor = kstrdup(sbsp->smk_floor->smk_known, GFP_KERNEL);
656 		if (!ctx->fsfloor)
657 			return -ENOMEM;
658 	}
659 
660 	if (sbsp->smk_hat) {
661 		ctx->fshat = kstrdup(sbsp->smk_hat->smk_known, GFP_KERNEL);
662 		if (!ctx->fshat)
663 			return -ENOMEM;
664 	}
665 
666 	if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
667 		if (sbsp->smk_root) {
668 			ctx->fstransmute = kstrdup(sbsp->smk_root->smk_known, GFP_KERNEL);
669 			if (!ctx->fstransmute)
670 				return -ENOMEM;
671 		}
672 	}
673 	return 0;
674 }
675 
676 /**
677  * smack_fs_context_dup - Duplicate the security data on fs_context duplication
678  * @fc: The new filesystem context.
679  * @src_fc: The source filesystem context being duplicated.
680  *
681  * Returns 0 on success or -ENOMEM on error.
682  */
683 static int smack_fs_context_dup(struct fs_context *fc,
684 				struct fs_context *src_fc)
685 {
686 	struct smack_mnt_opts *dst, *src = src_fc->security;
687 
688 	if (!src)
689 		return 0;
690 
691 	fc->security = kzalloc(sizeof(struct smack_mnt_opts), GFP_KERNEL);
692 	if (!fc->security)
693 		return -ENOMEM;
694 
695 	dst = fc->security;
696 	dst->fsdefault = src->fsdefault;
697 	dst->fsfloor = src->fsfloor;
698 	dst->fshat = src->fshat;
699 	dst->fsroot = src->fsroot;
700 	dst->fstransmute = src->fstransmute;
701 
702 	return 0;
703 }
704 
705 static const struct fs_parameter_spec smack_fs_parameters[] = {
706 	fsparam_string("smackfsdef",		Opt_fsdefault),
707 	fsparam_string("smackfsdefault",	Opt_fsdefault),
708 	fsparam_string("smackfsfloor",		Opt_fsfloor),
709 	fsparam_string("smackfshat",		Opt_fshat),
710 	fsparam_string("smackfsroot",		Opt_fsroot),
711 	fsparam_string("smackfstransmute",	Opt_fstransmute),
712 	{}
713 };
714 
715 /**
716  * smack_fs_context_parse_param - Parse a single mount parameter
717  * @fc: The new filesystem context being constructed.
718  * @param: The parameter.
719  *
720  * Returns 0 on success, -ENOPARAM to pass the parameter on or anything else on
721  * error.
722  */
723 static int smack_fs_context_parse_param(struct fs_context *fc,
724 					struct fs_parameter *param)
725 {
726 	struct fs_parse_result result;
727 	int opt, rc;
728 
729 	opt = fs_parse(fc, smack_fs_parameters, param, &result);
730 	if (opt < 0)
731 		return opt;
732 
733 	rc = smack_add_opt(opt, param->string, &fc->security);
734 	if (!rc)
735 		param->string = NULL;
736 	return rc;
737 }
738 
739 static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
740 {
741 	char *from = options, *to = options;
742 	bool first = true;
743 
744 	while (1) {
745 		char *next = strchr(from, ',');
746 		int token, len, rc;
747 		char *arg = NULL;
748 
749 		if (next)
750 			len = next - from;
751 		else
752 			len = strlen(from);
753 
754 		token = match_opt_prefix(from, len, &arg);
755 		if (token != Opt_error) {
756 			arg = kmemdup_nul(arg, from + len - arg, GFP_KERNEL);
757 			rc = smack_add_opt(token, arg, mnt_opts);
758 			kfree(arg);
759 			if (unlikely(rc)) {
760 				if (*mnt_opts)
761 					smack_free_mnt_opts(*mnt_opts);
762 				*mnt_opts = NULL;
763 				return rc;
764 			}
765 		} else {
766 			if (!first) {	// copy with preceding comma
767 				from--;
768 				len++;
769 			}
770 			if (to != from)
771 				memmove(to, from, len);
772 			to += len;
773 			first = false;
774 		}
775 		if (!from[len])
776 			break;
777 		from += len + 1;
778 	}
779 	*to = '\0';
780 	return 0;
781 }
782 
783 /**
784  * smack_set_mnt_opts - set Smack specific mount options
785  * @sb: the file system superblock
786  * @mnt_opts: Smack mount options
787  * @kern_flags: mount option from kernel space or user space
788  * @set_kern_flags: where to store converted mount opts
789  *
790  * Returns 0 on success, an error code on failure
791  *
792  * Allow filesystems with binary mount data to explicitly set Smack mount
793  * labels.
794  */
795 static int smack_set_mnt_opts(struct super_block *sb,
796 		void *mnt_opts,
797 		unsigned long kern_flags,
798 		unsigned long *set_kern_flags)
799 {
800 	struct dentry *root = sb->s_root;
801 	struct inode *inode = d_backing_inode(root);
802 	struct superblock_smack *sp = smack_superblock(sb);
803 	struct inode_smack *isp;
804 	struct smack_known *skp;
805 	struct smack_mnt_opts *opts = mnt_opts;
806 	bool transmute = false;
807 
808 	if (sp->smk_flags & SMK_SB_INITIALIZED)
809 		return 0;
810 
811 	if (!smack_privileged(CAP_MAC_ADMIN)) {
812 		/*
813 		 * Unprivileged mounts don't get to specify Smack values.
814 		 */
815 		if (opts)
816 			return -EPERM;
817 		/*
818 		 * Unprivileged mounts get root and default from the caller.
819 		 */
820 		skp = smk_of_current();
821 		sp->smk_root = skp;
822 		sp->smk_default = skp;
823 		/*
824 		 * For a handful of fs types with no user-controlled
825 		 * backing store it's okay to trust security labels
826 		 * in the filesystem. The rest are untrusted.
827 		 */
828 		if (sb->s_user_ns != &init_user_ns &&
829 		    sb->s_magic != SYSFS_MAGIC && sb->s_magic != TMPFS_MAGIC &&
830 		    sb->s_magic != RAMFS_MAGIC) {
831 			transmute = true;
832 			sp->smk_flags |= SMK_SB_UNTRUSTED;
833 		}
834 	}
835 
836 	sp->smk_flags |= SMK_SB_INITIALIZED;
837 
838 	if (opts) {
839 		if (opts->fsdefault) {
840 			skp = smk_import_entry(opts->fsdefault, 0);
841 			if (IS_ERR(skp))
842 				return PTR_ERR(skp);
843 			sp->smk_default = skp;
844 		}
845 		if (opts->fsfloor) {
846 			skp = smk_import_entry(opts->fsfloor, 0);
847 			if (IS_ERR(skp))
848 				return PTR_ERR(skp);
849 			sp->smk_floor = skp;
850 		}
851 		if (opts->fshat) {
852 			skp = smk_import_entry(opts->fshat, 0);
853 			if (IS_ERR(skp))
854 				return PTR_ERR(skp);
855 			sp->smk_hat = skp;
856 		}
857 		if (opts->fsroot) {
858 			skp = smk_import_entry(opts->fsroot, 0);
859 			if (IS_ERR(skp))
860 				return PTR_ERR(skp);
861 			sp->smk_root = skp;
862 		}
863 		if (opts->fstransmute) {
864 			skp = smk_import_entry(opts->fstransmute, 0);
865 			if (IS_ERR(skp))
866 				return PTR_ERR(skp);
867 			sp->smk_root = skp;
868 			transmute = true;
869 		}
870 	}
871 
872 	/*
873 	 * Initialize the root inode.
874 	 */
875 	init_inode_smack(inode, sp->smk_root);
876 
877 	if (transmute) {
878 		isp = smack_inode(inode);
879 		isp->smk_flags |= SMK_INODE_TRANSMUTE;
880 	}
881 
882 	return 0;
883 }
884 
885 /**
886  * smack_sb_statfs - Smack check on statfs
887  * @dentry: identifies the file system in question
888  *
889  * Returns 0 if current can read the floor of the filesystem,
890  * and error code otherwise
891  */
892 static int smack_sb_statfs(struct dentry *dentry)
893 {
894 	struct superblock_smack *sbp = smack_superblock(dentry->d_sb);
895 	int rc;
896 	struct smk_audit_info ad;
897 
898 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
899 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
900 
901 	rc = smk_curacc(sbp->smk_floor, MAY_READ, &ad);
902 	rc = smk_bu_current("statfs", sbp->smk_floor, MAY_READ, rc);
903 	return rc;
904 }
905 
906 /*
907  * BPRM hooks
908  */
909 
910 /**
911  * smack_bprm_creds_for_exec - Update bprm->cred if needed for exec
912  * @bprm: the exec information
913  *
914  * Returns 0 if it gets a blob, -EPERM if exec forbidden and -ENOMEM otherwise
915  */
916 static int smack_bprm_creds_for_exec(struct linux_binprm *bprm)
917 {
918 	struct inode *inode = file_inode(bprm->file);
919 	struct task_smack *bsp = smack_cred(bprm->cred);
920 	struct inode_smack *isp;
921 	struct superblock_smack *sbsp;
922 	int rc;
923 
924 	isp = smack_inode(inode);
925 	if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
926 		return 0;
927 
928 	sbsp = smack_superblock(inode->i_sb);
929 	if ((sbsp->smk_flags & SMK_SB_UNTRUSTED) &&
930 	    isp->smk_task != sbsp->smk_root)
931 		return 0;
932 
933 	if (bprm->unsafe & LSM_UNSAFE_PTRACE) {
934 		struct task_struct *tracer;
935 		rc = 0;
936 
937 		rcu_read_lock();
938 		tracer = ptrace_parent(current);
939 		if (likely(tracer != NULL))
940 			rc = smk_ptrace_rule_check(tracer,
941 						   isp->smk_task,
942 						   PTRACE_MODE_ATTACH,
943 						   __func__);
944 		rcu_read_unlock();
945 
946 		if (rc != 0)
947 			return rc;
948 	}
949 	if (bprm->unsafe & ~LSM_UNSAFE_PTRACE)
950 		return -EPERM;
951 
952 	bsp->smk_task = isp->smk_task;
953 	bprm->per_clear |= PER_CLEAR_ON_SETID;
954 
955 	/* Decide if this is a secure exec. */
956 	if (bsp->smk_task != bsp->smk_forked)
957 		bprm->secureexec = 1;
958 
959 	return 0;
960 }
961 
962 /*
963  * Inode hooks
964  */
965 
966 /**
967  * smack_inode_alloc_security - allocate an inode blob
968  * @inode: the inode in need of a blob
969  *
970  * Returns 0
971  */
972 static int smack_inode_alloc_security(struct inode *inode)
973 {
974 	struct smack_known *skp = smk_of_current();
975 
976 	init_inode_smack(inode, skp);
977 	return 0;
978 }
979 
980 /**
981  * smack_inode_init_security - copy out the smack from an inode
982  * @inode: the newly created inode
983  * @dir: containing directory object
984  * @qstr: unused
985  * @xattrs: where to put the attributes
986  * @xattr_count: current number of LSM-provided xattrs (updated)
987  *
988  * Returns 0 if it all works out, -ENOMEM if there's no memory
989  */
990 static int smack_inode_init_security(struct inode *inode, struct inode *dir,
991 				     const struct qstr *qstr,
992 				     struct xattr *xattrs, int *xattr_count)
993 {
994 	struct task_smack *tsp = smack_cred(current_cred());
995 	struct smack_known *skp = smk_of_task(tsp);
996 	struct smack_known *isp = smk_of_inode(inode);
997 	struct smack_known *dsp = smk_of_inode(dir);
998 	struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
999 	int may;
1000 
1001 	if (xattr) {
1002 		/*
1003 		 * If equal, transmuting already occurred in
1004 		 * smack_dentry_create_files_as(). No need to check again.
1005 		 */
1006 		if (tsp->smk_task != tsp->smk_transmuted) {
1007 			rcu_read_lock();
1008 			may = smk_access_entry(skp->smk_known, dsp->smk_known,
1009 					       &skp->smk_rules);
1010 			rcu_read_unlock();
1011 		}
1012 
1013 		/*
1014 		 * In addition to having smk_task equal to smk_transmuted,
1015 		 * if the access rule allows transmutation and the directory
1016 		 * requests transmutation then by all means transmute.
1017 		 * Mark the inode as changed.
1018 		 */
1019 		if ((tsp->smk_task == tsp->smk_transmuted) ||
1020 		    (may > 0 && ((may & MAY_TRANSMUTE) != 0) &&
1021 		     smk_inode_transmutable(dir))) {
1022 			struct xattr *xattr_transmute;
1023 
1024 			/*
1025 			 * The caller of smack_dentry_create_files_as()
1026 			 * should have overridden the current cred, so the
1027 			 * inode label was already set correctly in
1028 			 * smack_inode_alloc_security().
1029 			 */
1030 			if (tsp->smk_task != tsp->smk_transmuted)
1031 				isp = dsp;
1032 			xattr_transmute = lsm_get_xattr_slot(xattrs,
1033 							     xattr_count);
1034 			if (xattr_transmute) {
1035 				xattr_transmute->value = kmemdup(TRANS_TRUE,
1036 								 TRANS_TRUE_SIZE,
1037 								 GFP_NOFS);
1038 				if (!xattr_transmute->value)
1039 					return -ENOMEM;
1040 
1041 				xattr_transmute->value_len = TRANS_TRUE_SIZE;
1042 				xattr_transmute->name = XATTR_SMACK_TRANSMUTE;
1043 			}
1044 		}
1045 
1046 		xattr->value = kstrdup(isp->smk_known, GFP_NOFS);
1047 		if (!xattr->value)
1048 			return -ENOMEM;
1049 
1050 		xattr->value_len = strlen(isp->smk_known);
1051 		xattr->name = XATTR_SMACK_SUFFIX;
1052 	}
1053 
1054 	return 0;
1055 }
1056 
1057 /**
1058  * smack_inode_link - Smack check on link
1059  * @old_dentry: the existing object
1060  * @dir: unused
1061  * @new_dentry: the new object
1062  *
1063  * Returns 0 if access is permitted, an error code otherwise
1064  */
1065 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
1066 			    struct dentry *new_dentry)
1067 {
1068 	struct smack_known *isp;
1069 	struct smk_audit_info ad;
1070 	int rc;
1071 
1072 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1073 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1074 
1075 	isp = smk_of_inode(d_backing_inode(old_dentry));
1076 	rc = smk_curacc(isp, MAY_WRITE, &ad);
1077 	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_WRITE, rc);
1078 
1079 	if (rc == 0 && d_is_positive(new_dentry)) {
1080 		isp = smk_of_inode(d_backing_inode(new_dentry));
1081 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1082 		rc = smk_curacc(isp, MAY_WRITE, &ad);
1083 		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_WRITE, rc);
1084 	}
1085 
1086 	return rc;
1087 }
1088 
1089 /**
1090  * smack_inode_unlink - Smack check on inode deletion
1091  * @dir: containing directory object
1092  * @dentry: file to unlink
1093  *
1094  * Returns 0 if current can write the containing directory
1095  * and the object, error code otherwise
1096  */
1097 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
1098 {
1099 	struct inode *ip = d_backing_inode(dentry);
1100 	struct smk_audit_info ad;
1101 	int rc;
1102 
1103 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1104 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1105 
1106 	/*
1107 	 * You need write access to the thing you're unlinking
1108 	 */
1109 	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
1110 	rc = smk_bu_inode(ip, MAY_WRITE, rc);
1111 	if (rc == 0) {
1112 		/*
1113 		 * You also need write access to the containing directory
1114 		 */
1115 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1116 		smk_ad_setfield_u_fs_inode(&ad, dir);
1117 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1118 		rc = smk_bu_inode(dir, MAY_WRITE, rc);
1119 	}
1120 	return rc;
1121 }
1122 
1123 /**
1124  * smack_inode_rmdir - Smack check on directory deletion
1125  * @dir: containing directory object
1126  * @dentry: directory to unlink
1127  *
1128  * Returns 0 if current can write the containing directory
1129  * and the directory, error code otherwise
1130  */
1131 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
1132 {
1133 	struct smk_audit_info ad;
1134 	int rc;
1135 
1136 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1137 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1138 
1139 	/*
1140 	 * You need write access to the thing you're removing
1141 	 */
1142 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1143 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1144 	if (rc == 0) {
1145 		/*
1146 		 * You also need write access to the containing directory
1147 		 */
1148 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1149 		smk_ad_setfield_u_fs_inode(&ad, dir);
1150 		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
1151 		rc = smk_bu_inode(dir, MAY_WRITE, rc);
1152 	}
1153 
1154 	return rc;
1155 }
1156 
1157 /**
1158  * smack_inode_rename - Smack check on rename
1159  * @old_inode: unused
1160  * @old_dentry: the old object
1161  * @new_inode: unused
1162  * @new_dentry: the new object
1163  *
1164  * Read and write access is required on both the old and
1165  * new directories.
1166  *
1167  * Returns 0 if access is permitted, an error code otherwise
1168  */
1169 static int smack_inode_rename(struct inode *old_inode,
1170 			      struct dentry *old_dentry,
1171 			      struct inode *new_inode,
1172 			      struct dentry *new_dentry)
1173 {
1174 	int rc;
1175 	struct smack_known *isp;
1176 	struct smk_audit_info ad;
1177 
1178 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1179 	smk_ad_setfield_u_fs_path_dentry(&ad, old_dentry);
1180 
1181 	isp = smk_of_inode(d_backing_inode(old_dentry));
1182 	rc = smk_curacc(isp, MAY_READWRITE, &ad);
1183 	rc = smk_bu_inode(d_backing_inode(old_dentry), MAY_READWRITE, rc);
1184 
1185 	if (rc == 0 && d_is_positive(new_dentry)) {
1186 		isp = smk_of_inode(d_backing_inode(new_dentry));
1187 		smk_ad_setfield_u_fs_path_dentry(&ad, new_dentry);
1188 		rc = smk_curacc(isp, MAY_READWRITE, &ad);
1189 		rc = smk_bu_inode(d_backing_inode(new_dentry), MAY_READWRITE, rc);
1190 	}
1191 	return rc;
1192 }
1193 
1194 /**
1195  * smack_inode_permission - Smack version of permission()
1196  * @inode: the inode in question
1197  * @mask: the access requested
1198  *
1199  * This is the important Smack hook.
1200  *
1201  * Returns 0 if access is permitted, an error code otherwise
1202  */
1203 static int smack_inode_permission(struct inode *inode, int mask)
1204 {
1205 	struct superblock_smack *sbsp = smack_superblock(inode->i_sb);
1206 	struct smk_audit_info ad;
1207 	int no_block = mask & MAY_NOT_BLOCK;
1208 	int rc;
1209 
1210 	mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
1211 	/*
1212 	 * No permission to check. Existence test. Yup, it's there.
1213 	 */
1214 	if (mask == 0)
1215 		return 0;
1216 
1217 	if (sbsp->smk_flags & SMK_SB_UNTRUSTED) {
1218 		if (smk_of_inode(inode) != sbsp->smk_root)
1219 			return -EACCES;
1220 	}
1221 
1222 	/* May be droppable after audit */
1223 	if (no_block)
1224 		return -ECHILD;
1225 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_INODE);
1226 	smk_ad_setfield_u_fs_inode(&ad, inode);
1227 	rc = smk_curacc(smk_of_inode(inode), mask, &ad);
1228 	rc = smk_bu_inode(inode, mask, rc);
1229 	return rc;
1230 }
1231 
1232 /**
1233  * smack_inode_setattr - Smack check for setting attributes
1234  * @dentry: the object
1235  * @iattr: for the force flag
1236  *
1237  * Returns 0 if access is permitted, an error code otherwise
1238  */
1239 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
1240 {
1241 	struct smk_audit_info ad;
1242 	int rc;
1243 
1244 	/*
1245 	 * Need to allow for clearing the setuid bit.
1246 	 */
1247 	if (iattr->ia_valid & ATTR_FORCE)
1248 		return 0;
1249 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1250 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1251 
1252 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1253 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1254 	return rc;
1255 }
1256 
1257 /**
1258  * smack_inode_getattr - Smack check for getting attributes
1259  * @path: path to extract the info from
1260  *
1261  * Returns 0 if access is permitted, an error code otherwise
1262  */
1263 static int smack_inode_getattr(const struct path *path)
1264 {
1265 	struct smk_audit_info ad;
1266 	struct inode *inode = d_backing_inode(path->dentry);
1267 	int rc;
1268 
1269 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1270 	smk_ad_setfield_u_fs_path(&ad, *path);
1271 	rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1272 	rc = smk_bu_inode(inode, MAY_READ, rc);
1273 	return rc;
1274 }
1275 
1276 /**
1277  * smack_inode_setxattr - Smack check for setting xattrs
1278  * @idmap: idmap of the mount
1279  * @dentry: the object
1280  * @name: name of the attribute
1281  * @value: value of the attribute
1282  * @size: size of the value
1283  * @flags: unused
1284  *
1285  * This protects the Smack attribute explicitly.
1286  *
1287  * Returns 0 if access is permitted, an error code otherwise
1288  */
1289 static int smack_inode_setxattr(struct mnt_idmap *idmap,
1290 				struct dentry *dentry, const char *name,
1291 				const void *value, size_t size, int flags)
1292 {
1293 	struct smk_audit_info ad;
1294 	struct smack_known *skp;
1295 	int check_priv = 0;
1296 	int check_import = 0;
1297 	int check_star = 0;
1298 	int rc = 0;
1299 
1300 	/*
1301 	 * Check label validity here so import won't fail in post_setxattr
1302 	 */
1303 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1304 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1305 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
1306 		check_priv = 1;
1307 		check_import = 1;
1308 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1309 		   strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1310 		check_priv = 1;
1311 		check_import = 1;
1312 		check_star = 1;
1313 	} else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1314 		check_priv = 1;
1315 		if (size != TRANS_TRUE_SIZE ||
1316 		    strncmp(value, TRANS_TRUE, TRANS_TRUE_SIZE) != 0)
1317 			rc = -EINVAL;
1318 	} else
1319 		rc = cap_inode_setxattr(dentry, name, value, size, flags);
1320 
1321 	if (check_priv && !smack_privileged(CAP_MAC_ADMIN))
1322 		rc = -EPERM;
1323 
1324 	if (rc == 0 && check_import) {
1325 		skp = size ? smk_import_entry(value, size) : NULL;
1326 		if (IS_ERR(skp))
1327 			rc = PTR_ERR(skp);
1328 		else if (skp == NULL || (check_star &&
1329 		    (skp == &smack_known_star || skp == &smack_known_web)))
1330 			rc = -EINVAL;
1331 	}
1332 
1333 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1334 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1335 
1336 	if (rc == 0) {
1337 		rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1338 		rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1339 	}
1340 
1341 	return rc;
1342 }
1343 
1344 /**
1345  * smack_inode_post_setxattr - Apply the Smack update approved above
1346  * @dentry: object
1347  * @name: attribute name
1348  * @value: attribute value
1349  * @size: attribute size
1350  * @flags: unused
1351  *
1352  * Set the pointer in the inode blob to the entry found
1353  * in the master label list.
1354  */
1355 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
1356 				      const void *value, size_t size, int flags)
1357 {
1358 	struct smack_known *skp;
1359 	struct inode_smack *isp = smack_inode(d_backing_inode(dentry));
1360 
1361 	if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0) {
1362 		isp->smk_flags |= SMK_INODE_TRANSMUTE;
1363 		return;
1364 	}
1365 
1366 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1367 		skp = smk_import_entry(value, size);
1368 		if (!IS_ERR(skp))
1369 			isp->smk_inode = skp;
1370 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0) {
1371 		skp = smk_import_entry(value, size);
1372 		if (!IS_ERR(skp))
1373 			isp->smk_task = skp;
1374 	} else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1375 		skp = smk_import_entry(value, size);
1376 		if (!IS_ERR(skp))
1377 			isp->smk_mmap = skp;
1378 	}
1379 
1380 	return;
1381 }
1382 
1383 /**
1384  * smack_inode_getxattr - Smack check on getxattr
1385  * @dentry: the object
1386  * @name: unused
1387  *
1388  * Returns 0 if access is permitted, an error code otherwise
1389  */
1390 static int smack_inode_getxattr(struct dentry *dentry, const char *name)
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_READ, &ad);
1399 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1400 	return rc;
1401 }
1402 
1403 /**
1404  * smack_inode_removexattr - Smack check on removexattr
1405  * @idmap: idmap of the mount
1406  * @dentry: the object
1407  * @name: name of the attribute
1408  *
1409  * Removing the Smack attribute requires CAP_MAC_ADMIN
1410  *
1411  * Returns 0 if access is permitted, an error code otherwise
1412  */
1413 static int smack_inode_removexattr(struct mnt_idmap *idmap,
1414 				   struct dentry *dentry, const char *name)
1415 {
1416 	struct inode_smack *isp;
1417 	struct smk_audit_info ad;
1418 	int rc = 0;
1419 
1420 	if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
1421 	    strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
1422 	    strcmp(name, XATTR_NAME_SMACKIPOUT) == 0 ||
1423 	    strcmp(name, XATTR_NAME_SMACKEXEC) == 0 ||
1424 	    strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0 ||
1425 	    strcmp(name, XATTR_NAME_SMACKMMAP) == 0) {
1426 		if (!smack_privileged(CAP_MAC_ADMIN))
1427 			rc = -EPERM;
1428 	} else
1429 		rc = cap_inode_removexattr(idmap, dentry, name);
1430 
1431 	if (rc != 0)
1432 		return rc;
1433 
1434 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1435 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1436 
1437 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1438 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1439 	if (rc != 0)
1440 		return rc;
1441 
1442 	isp = smack_inode(d_backing_inode(dentry));
1443 	/*
1444 	 * Don't do anything special for these.
1445 	 *	XATTR_NAME_SMACKIPIN
1446 	 *	XATTR_NAME_SMACKIPOUT
1447 	 */
1448 	if (strcmp(name, XATTR_NAME_SMACK) == 0) {
1449 		struct super_block *sbp = dentry->d_sb;
1450 		struct superblock_smack *sbsp = smack_superblock(sbp);
1451 
1452 		isp->smk_inode = sbsp->smk_default;
1453 	} else if (strcmp(name, XATTR_NAME_SMACKEXEC) == 0)
1454 		isp->smk_task = NULL;
1455 	else if (strcmp(name, XATTR_NAME_SMACKMMAP) == 0)
1456 		isp->smk_mmap = NULL;
1457 	else if (strcmp(name, XATTR_NAME_SMACKTRANSMUTE) == 0)
1458 		isp->smk_flags &= ~SMK_INODE_TRANSMUTE;
1459 
1460 	return 0;
1461 }
1462 
1463 /**
1464  * smack_inode_set_acl - Smack check for setting posix acls
1465  * @idmap: idmap of the mnt this request came from
1466  * @dentry: the object
1467  * @acl_name: name of the posix acl
1468  * @kacl: the posix acls
1469  *
1470  * Returns 0 if access is permitted, an error code otherwise
1471  */
1472 static int smack_inode_set_acl(struct mnt_idmap *idmap,
1473 			       struct dentry *dentry, const char *acl_name,
1474 			       struct posix_acl *kacl)
1475 {
1476 	struct smk_audit_info ad;
1477 	int rc;
1478 
1479 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1480 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1481 
1482 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1483 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1484 	return rc;
1485 }
1486 
1487 /**
1488  * smack_inode_get_acl - Smack check for getting posix acls
1489  * @idmap: idmap of the mnt this request came from
1490  * @dentry: the object
1491  * @acl_name: name of the posix acl
1492  *
1493  * Returns 0 if access is permitted, an error code otherwise
1494  */
1495 static int smack_inode_get_acl(struct mnt_idmap *idmap,
1496 			       struct dentry *dentry, const char *acl_name)
1497 {
1498 	struct smk_audit_info ad;
1499 	int rc;
1500 
1501 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1502 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1503 
1504 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_READ, &ad);
1505 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_READ, rc);
1506 	return rc;
1507 }
1508 
1509 /**
1510  * smack_inode_remove_acl - Smack check for getting posix acls
1511  * @idmap: idmap of the mnt this request came from
1512  * @dentry: the object
1513  * @acl_name: name of the posix acl
1514  *
1515  * Returns 0 if access is permitted, an error code otherwise
1516  */
1517 static int smack_inode_remove_acl(struct mnt_idmap *idmap,
1518 				  struct dentry *dentry, const char *acl_name)
1519 {
1520 	struct smk_audit_info ad;
1521 	int rc;
1522 
1523 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
1524 	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);
1525 
1526 	rc = smk_curacc(smk_of_inode(d_backing_inode(dentry)), MAY_WRITE, &ad);
1527 	rc = smk_bu_inode(d_backing_inode(dentry), MAY_WRITE, rc);
1528 	return rc;
1529 }
1530 
1531 /**
1532  * smack_inode_getsecurity - get smack xattrs
1533  * @idmap: idmap of the mount
1534  * @inode: the object
1535  * @name: attribute name
1536  * @buffer: where to put the result
1537  * @alloc: duplicate memory
1538  *
1539  * Returns the size of the attribute or an error code
1540  */
1541 static int smack_inode_getsecurity(struct mnt_idmap *idmap,
1542 				   struct inode *inode, const char *name,
1543 				   void **buffer, bool alloc)
1544 {
1545 	struct socket_smack *ssp;
1546 	struct socket *sock;
1547 	struct super_block *sbp;
1548 	struct inode *ip = inode;
1549 	struct smack_known *isp;
1550 	struct inode_smack *ispp;
1551 	size_t label_len;
1552 	char *label = NULL;
1553 
1554 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
1555 		isp = smk_of_inode(inode);
1556 	} else if (strcmp(name, XATTR_SMACK_TRANSMUTE) == 0) {
1557 		ispp = smack_inode(inode);
1558 		if (ispp->smk_flags & SMK_INODE_TRANSMUTE)
1559 			label = TRANS_TRUE;
1560 		else
1561 			label = "";
1562 	} else {
1563 		/*
1564 		 * The rest of the Smack xattrs are only on sockets.
1565 		 */
1566 		sbp = ip->i_sb;
1567 		if (sbp->s_magic != SOCKFS_MAGIC)
1568 			return -EOPNOTSUPP;
1569 
1570 		sock = SOCKET_I(ip);
1571 		if (sock == NULL || sock->sk == NULL)
1572 			return -EOPNOTSUPP;
1573 
1574 		ssp = sock->sk->sk_security;
1575 
1576 		if (strcmp(name, XATTR_SMACK_IPIN) == 0)
1577 			isp = ssp->smk_in;
1578 		else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
1579 			isp = ssp->smk_out;
1580 		else
1581 			return -EOPNOTSUPP;
1582 	}
1583 
1584 	if (!label)
1585 		label = isp->smk_known;
1586 
1587 	label_len = strlen(label);
1588 
1589 	if (alloc) {
1590 		*buffer = kstrdup(label, GFP_KERNEL);
1591 		if (*buffer == NULL)
1592 			return -ENOMEM;
1593 	}
1594 
1595 	return label_len;
1596 }
1597 
1598 
1599 /**
1600  * smack_inode_listsecurity - list the Smack attributes
1601  * @inode: the object
1602  * @buffer: where they go
1603  * @buffer_size: size of buffer
1604  */
1605 static int smack_inode_listsecurity(struct inode *inode, char *buffer,
1606 				    size_t buffer_size)
1607 {
1608 	int len = sizeof(XATTR_NAME_SMACK);
1609 
1610 	if (buffer != NULL && len <= buffer_size)
1611 		memcpy(buffer, XATTR_NAME_SMACK, len);
1612 
1613 	return len;
1614 }
1615 
1616 /**
1617  * smack_inode_getsecid - Extract inode's security id
1618  * @inode: inode to extract the info from
1619  * @secid: where result will be saved
1620  */
1621 static void smack_inode_getsecid(struct inode *inode, u32 *secid)
1622 {
1623 	struct smack_known *skp = smk_of_inode(inode);
1624 
1625 	*secid = skp->smk_secid;
1626 }
1627 
1628 /*
1629  * File Hooks
1630  */
1631 
1632 /*
1633  * There is no smack_file_permission hook
1634  *
1635  * Should access checks be done on each read or write?
1636  * UNICOS and SELinux say yes.
1637  * Trusted Solaris, Trusted Irix, and just about everyone else says no.
1638  *
1639  * I'll say no for now. Smack does not do the frequent
1640  * label changing that SELinux does.
1641  */
1642 
1643 /**
1644  * smack_file_alloc_security - assign a file security blob
1645  * @file: the object
1646  *
1647  * The security blob for a file is a pointer to the master
1648  * label list, so no allocation is done.
1649  *
1650  * f_security is the owner security information. It
1651  * isn't used on file access checks, it's for send_sigio.
1652  *
1653  * Returns 0
1654  */
1655 static int smack_file_alloc_security(struct file *file)
1656 {
1657 	struct smack_known **blob = smack_file(file);
1658 
1659 	*blob = smk_of_current();
1660 	return 0;
1661 }
1662 
1663 /**
1664  * smack_file_ioctl - Smack check on ioctls
1665  * @file: the object
1666  * @cmd: what to do
1667  * @arg: unused
1668  *
1669  * Relies heavily on the correct use of the ioctl command conventions.
1670  *
1671  * Returns 0 if allowed, error code otherwise
1672  */
1673 static int smack_file_ioctl(struct file *file, unsigned int cmd,
1674 			    unsigned long arg)
1675 {
1676 	int rc = 0;
1677 	struct smk_audit_info ad;
1678 	struct inode *inode = file_inode(file);
1679 
1680 	if (unlikely(IS_PRIVATE(inode)))
1681 		return 0;
1682 
1683 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1684 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1685 
1686 	if (_IOC_DIR(cmd) & _IOC_WRITE) {
1687 		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1688 		rc = smk_bu_file(file, MAY_WRITE, rc);
1689 	}
1690 
1691 	if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) {
1692 		rc = smk_curacc(smk_of_inode(inode), MAY_READ, &ad);
1693 		rc = smk_bu_file(file, MAY_READ, rc);
1694 	}
1695 
1696 	return rc;
1697 }
1698 
1699 /**
1700  * smack_file_lock - Smack check on file locking
1701  * @file: the object
1702  * @cmd: unused
1703  *
1704  * Returns 0 if current has lock access, error code otherwise
1705  */
1706 static int smack_file_lock(struct file *file, unsigned int cmd)
1707 {
1708 	struct smk_audit_info ad;
1709 	int rc;
1710 	struct inode *inode = file_inode(file);
1711 
1712 	if (unlikely(IS_PRIVATE(inode)))
1713 		return 0;
1714 
1715 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1716 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1717 	rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1718 	rc = smk_bu_file(file, MAY_LOCK, rc);
1719 	return rc;
1720 }
1721 
1722 /**
1723  * smack_file_fcntl - Smack check on fcntl
1724  * @file: the object
1725  * @cmd: what action to check
1726  * @arg: unused
1727  *
1728  * Generally these operations are harmless.
1729  * File locking operations present an obvious mechanism
1730  * for passing information, so they require write access.
1731  *
1732  * Returns 0 if current has access, error code otherwise
1733  */
1734 static int smack_file_fcntl(struct file *file, unsigned int cmd,
1735 			    unsigned long arg)
1736 {
1737 	struct smk_audit_info ad;
1738 	int rc = 0;
1739 	struct inode *inode = file_inode(file);
1740 
1741 	if (unlikely(IS_PRIVATE(inode)))
1742 		return 0;
1743 
1744 	switch (cmd) {
1745 	case F_GETLK:
1746 		break;
1747 	case F_SETLK:
1748 	case F_SETLKW:
1749 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1750 		smk_ad_setfield_u_fs_path(&ad, file->f_path);
1751 		rc = smk_curacc(smk_of_inode(inode), MAY_LOCK, &ad);
1752 		rc = smk_bu_file(file, MAY_LOCK, rc);
1753 		break;
1754 	case F_SETOWN:
1755 	case F_SETSIG:
1756 		smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1757 		smk_ad_setfield_u_fs_path(&ad, file->f_path);
1758 		rc = smk_curacc(smk_of_inode(inode), MAY_WRITE, &ad);
1759 		rc = smk_bu_file(file, MAY_WRITE, rc);
1760 		break;
1761 	default:
1762 		break;
1763 	}
1764 
1765 	return rc;
1766 }
1767 
1768 /**
1769  * smack_mmap_file - Check permissions for a mmap operation.
1770  * @file: contains the file structure for file to map (may be NULL).
1771  * @reqprot: contains the protection requested by the application.
1772  * @prot: contains the protection that will be applied by the kernel.
1773  * @flags: contains the operational flags.
1774  *
1775  * The @file may be NULL, e.g. if mapping anonymous memory.
1776  *
1777  * Return 0 if permission is granted.
1778  */
1779 static int smack_mmap_file(struct file *file,
1780 			   unsigned long reqprot, unsigned long prot,
1781 			   unsigned long flags)
1782 {
1783 	struct smack_known *skp;
1784 	struct smack_known *mkp;
1785 	struct smack_rule *srp;
1786 	struct task_smack *tsp;
1787 	struct smack_known *okp;
1788 	struct inode_smack *isp;
1789 	struct superblock_smack *sbsp;
1790 	int may;
1791 	int mmay;
1792 	int tmay;
1793 	int rc;
1794 
1795 	if (file == NULL)
1796 		return 0;
1797 
1798 	if (unlikely(IS_PRIVATE(file_inode(file))))
1799 		return 0;
1800 
1801 	isp = smack_inode(file_inode(file));
1802 	if (isp->smk_mmap == NULL)
1803 		return 0;
1804 	sbsp = smack_superblock(file_inode(file)->i_sb);
1805 	if (sbsp->smk_flags & SMK_SB_UNTRUSTED &&
1806 	    isp->smk_mmap != sbsp->smk_root)
1807 		return -EACCES;
1808 	mkp = isp->smk_mmap;
1809 
1810 	tsp = smack_cred(current_cred());
1811 	skp = smk_of_current();
1812 	rc = 0;
1813 
1814 	rcu_read_lock();
1815 	/*
1816 	 * For each Smack rule associated with the subject
1817 	 * label verify that the SMACK64MMAP also has access
1818 	 * to that rule's object label.
1819 	 */
1820 	list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
1821 		okp = srp->smk_object;
1822 		/*
1823 		 * Matching labels always allows access.
1824 		 */
1825 		if (mkp->smk_known == okp->smk_known)
1826 			continue;
1827 		/*
1828 		 * If there is a matching local rule take
1829 		 * that into account as well.
1830 		 */
1831 		may = smk_access_entry(srp->smk_subject->smk_known,
1832 				       okp->smk_known,
1833 				       &tsp->smk_rules);
1834 		if (may == -ENOENT)
1835 			may = srp->smk_access;
1836 		else
1837 			may &= srp->smk_access;
1838 		/*
1839 		 * If may is zero the SMACK64MMAP subject can't
1840 		 * possibly have less access.
1841 		 */
1842 		if (may == 0)
1843 			continue;
1844 
1845 		/*
1846 		 * Fetch the global list entry.
1847 		 * If there isn't one a SMACK64MMAP subject
1848 		 * can't have as much access as current.
1849 		 */
1850 		mmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1851 					&mkp->smk_rules);
1852 		if (mmay == -ENOENT) {
1853 			rc = -EACCES;
1854 			break;
1855 		}
1856 		/*
1857 		 * If there is a local entry it modifies the
1858 		 * potential access, too.
1859 		 */
1860 		tmay = smk_access_entry(mkp->smk_known, okp->smk_known,
1861 					&tsp->smk_rules);
1862 		if (tmay != -ENOENT)
1863 			mmay &= tmay;
1864 
1865 		/*
1866 		 * If there is any access available to current that is
1867 		 * not available to a SMACK64MMAP subject
1868 		 * deny access.
1869 		 */
1870 		if ((may | mmay) != mmay) {
1871 			rc = -EACCES;
1872 			break;
1873 		}
1874 	}
1875 
1876 	rcu_read_unlock();
1877 
1878 	return rc;
1879 }
1880 
1881 /**
1882  * smack_file_set_fowner - set the file security blob value
1883  * @file: object in question
1884  *
1885  */
1886 static void smack_file_set_fowner(struct file *file)
1887 {
1888 	struct smack_known **blob = smack_file(file);
1889 
1890 	*blob = smk_of_current();
1891 }
1892 
1893 /**
1894  * smack_file_send_sigiotask - Smack on sigio
1895  * @tsk: The target task
1896  * @fown: the object the signal come from
1897  * @signum: unused
1898  *
1899  * Allow a privileged task to get signals even if it shouldn't
1900  *
1901  * Returns 0 if a subject with the object's smack could
1902  * write to the task, an error code otherwise.
1903  */
1904 static int smack_file_send_sigiotask(struct task_struct *tsk,
1905 				     struct fown_struct *fown, int signum)
1906 {
1907 	struct smack_known **blob;
1908 	struct smack_known *skp;
1909 	struct smack_known *tkp = smk_of_task(smack_cred(tsk->cred));
1910 	const struct cred *tcred;
1911 	struct file *file;
1912 	int rc;
1913 	struct smk_audit_info ad;
1914 
1915 	/*
1916 	 * struct fown_struct is never outside the context of a struct file
1917 	 */
1918 	file = container_of(fown, struct file, f_owner);
1919 
1920 	/* we don't log here as rc can be overriden */
1921 	blob = smack_file(file);
1922 	skp = *blob;
1923 	rc = smk_access(skp, tkp, MAY_DELIVER, NULL);
1924 	rc = smk_bu_note("sigiotask", skp, tkp, MAY_DELIVER, rc);
1925 
1926 	rcu_read_lock();
1927 	tcred = __task_cred(tsk);
1928 	if (rc != 0 && smack_privileged_cred(CAP_MAC_OVERRIDE, tcred))
1929 		rc = 0;
1930 	rcu_read_unlock();
1931 
1932 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
1933 	smk_ad_setfield_u_tsk(&ad, tsk);
1934 	smack_log(skp->smk_known, tkp->smk_known, MAY_DELIVER, rc, &ad);
1935 	return rc;
1936 }
1937 
1938 /**
1939  * smack_file_receive - Smack file receive check
1940  * @file: the object
1941  *
1942  * Returns 0 if current has access, error code otherwise
1943  */
1944 static int smack_file_receive(struct file *file)
1945 {
1946 	int rc;
1947 	int may = 0;
1948 	struct smk_audit_info ad;
1949 	struct inode *inode = file_inode(file);
1950 	struct socket *sock;
1951 	struct task_smack *tsp;
1952 	struct socket_smack *ssp;
1953 
1954 	if (unlikely(IS_PRIVATE(inode)))
1955 		return 0;
1956 
1957 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
1958 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
1959 
1960 	if (inode->i_sb->s_magic == SOCKFS_MAGIC) {
1961 		sock = SOCKET_I(inode);
1962 		ssp = sock->sk->sk_security;
1963 		tsp = smack_cred(current_cred());
1964 		/*
1965 		 * If the receiving process can't write to the
1966 		 * passed socket or if the passed socket can't
1967 		 * write to the receiving process don't accept
1968 		 * the passed socket.
1969 		 */
1970 		rc = smk_access(tsp->smk_task, ssp->smk_out, MAY_WRITE, &ad);
1971 		rc = smk_bu_file(file, may, rc);
1972 		if (rc < 0)
1973 			return rc;
1974 		rc = smk_access(ssp->smk_in, tsp->smk_task, MAY_WRITE, &ad);
1975 		rc = smk_bu_file(file, may, rc);
1976 		return rc;
1977 	}
1978 	/*
1979 	 * This code relies on bitmasks.
1980 	 */
1981 	if (file->f_mode & FMODE_READ)
1982 		may = MAY_READ;
1983 	if (file->f_mode & FMODE_WRITE)
1984 		may |= MAY_WRITE;
1985 
1986 	rc = smk_curacc(smk_of_inode(inode), may, &ad);
1987 	rc = smk_bu_file(file, may, rc);
1988 	return rc;
1989 }
1990 
1991 /**
1992  * smack_file_open - Smack dentry open processing
1993  * @file: the object
1994  *
1995  * Set the security blob in the file structure.
1996  * Allow the open only if the task has read access. There are
1997  * many read operations (e.g. fstat) that you can do with an
1998  * fd even if you have the file open write-only.
1999  *
2000  * Returns 0 if current has access, error code otherwise
2001  */
2002 static int smack_file_open(struct file *file)
2003 {
2004 	struct task_smack *tsp = smack_cred(file->f_cred);
2005 	struct inode *inode = file_inode(file);
2006 	struct smk_audit_info ad;
2007 	int rc;
2008 
2009 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
2010 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
2011 	rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
2012 	rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
2013 
2014 	return rc;
2015 }
2016 
2017 /*
2018  * Task hooks
2019  */
2020 
2021 /**
2022  * smack_cred_alloc_blank - "allocate" blank task-level security credentials
2023  * @cred: the new credentials
2024  * @gfp: the atomicity of any memory allocations
2025  *
2026  * Prepare a blank set of credentials for modification.  This must allocate all
2027  * the memory the LSM module might require such that cred_transfer() can
2028  * complete without error.
2029  */
2030 static int smack_cred_alloc_blank(struct cred *cred, gfp_t gfp)
2031 {
2032 	init_task_smack(smack_cred(cred), NULL, NULL);
2033 	return 0;
2034 }
2035 
2036 
2037 /**
2038  * smack_cred_free - "free" task-level security credentials
2039  * @cred: the credentials in question
2040  *
2041  */
2042 static void smack_cred_free(struct cred *cred)
2043 {
2044 	struct task_smack *tsp = smack_cred(cred);
2045 	struct smack_rule *rp;
2046 	struct list_head *l;
2047 	struct list_head *n;
2048 
2049 	smk_destroy_label_list(&tsp->smk_relabel);
2050 
2051 	list_for_each_safe(l, n, &tsp->smk_rules) {
2052 		rp = list_entry(l, struct smack_rule, list);
2053 		list_del(&rp->list);
2054 		kmem_cache_free(smack_rule_cache, rp);
2055 	}
2056 }
2057 
2058 /**
2059  * smack_cred_prepare - prepare new set of credentials for modification
2060  * @new: the new credentials
2061  * @old: the original credentials
2062  * @gfp: the atomicity of any memory allocations
2063  *
2064  * Prepare a new set of credentials for modification.
2065  */
2066 static int smack_cred_prepare(struct cred *new, const struct cred *old,
2067 			      gfp_t gfp)
2068 {
2069 	struct task_smack *old_tsp = smack_cred(old);
2070 	struct task_smack *new_tsp = smack_cred(new);
2071 	int rc;
2072 
2073 	init_task_smack(new_tsp, old_tsp->smk_task, old_tsp->smk_task);
2074 
2075 	rc = smk_copy_rules(&new_tsp->smk_rules, &old_tsp->smk_rules, gfp);
2076 	if (rc != 0)
2077 		return rc;
2078 
2079 	rc = smk_copy_relabel(&new_tsp->smk_relabel, &old_tsp->smk_relabel,
2080 				gfp);
2081 	return rc;
2082 }
2083 
2084 /**
2085  * smack_cred_transfer - Transfer the old credentials to the new credentials
2086  * @new: the new credentials
2087  * @old: the original credentials
2088  *
2089  * Fill in a set of blank credentials from another set of credentials.
2090  */
2091 static void smack_cred_transfer(struct cred *new, const struct cred *old)
2092 {
2093 	struct task_smack *old_tsp = smack_cred(old);
2094 	struct task_smack *new_tsp = smack_cred(new);
2095 
2096 	new_tsp->smk_task = old_tsp->smk_task;
2097 	new_tsp->smk_forked = old_tsp->smk_task;
2098 	mutex_init(&new_tsp->smk_rules_lock);
2099 	INIT_LIST_HEAD(&new_tsp->smk_rules);
2100 
2101 	/* cbs copy rule list */
2102 }
2103 
2104 /**
2105  * smack_cred_getsecid - get the secid corresponding to a creds structure
2106  * @cred: the object creds
2107  * @secid: where to put the result
2108  *
2109  * Sets the secid to contain a u32 version of the smack label.
2110  */
2111 static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
2112 {
2113 	struct smack_known *skp;
2114 
2115 	rcu_read_lock();
2116 	skp = smk_of_task(smack_cred(cred));
2117 	*secid = skp->smk_secid;
2118 	rcu_read_unlock();
2119 }
2120 
2121 /**
2122  * smack_kernel_act_as - Set the subjective context in a set of credentials
2123  * @new: points to the set of credentials to be modified.
2124  * @secid: specifies the security ID to be set
2125  *
2126  * Set the security data for a kernel service.
2127  */
2128 static int smack_kernel_act_as(struct cred *new, u32 secid)
2129 {
2130 	struct task_smack *new_tsp = smack_cred(new);
2131 
2132 	new_tsp->smk_task = smack_from_secid(secid);
2133 	return 0;
2134 }
2135 
2136 /**
2137  * smack_kernel_create_files_as - Set the file creation label in a set of creds
2138  * @new: points to the set of credentials to be modified
2139  * @inode: points to the inode to use as a reference
2140  *
2141  * Set the file creation context in a set of credentials to the same
2142  * as the objective context of the specified inode
2143  */
2144 static int smack_kernel_create_files_as(struct cred *new,
2145 					struct inode *inode)
2146 {
2147 	struct inode_smack *isp = smack_inode(inode);
2148 	struct task_smack *tsp = smack_cred(new);
2149 
2150 	tsp->smk_forked = isp->smk_inode;
2151 	tsp->smk_task = tsp->smk_forked;
2152 	return 0;
2153 }
2154 
2155 /**
2156  * smk_curacc_on_task - helper to log task related access
2157  * @p: the task object
2158  * @access: the access requested
2159  * @caller: name of the calling function for audit
2160  *
2161  * Return 0 if access is permitted
2162  */
2163 static int smk_curacc_on_task(struct task_struct *p, int access,
2164 				const char *caller)
2165 {
2166 	struct smk_audit_info ad;
2167 	struct smack_known *skp = smk_of_task_struct_obj(p);
2168 	int rc;
2169 
2170 	smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
2171 	smk_ad_setfield_u_tsk(&ad, p);
2172 	rc = smk_curacc(skp, access, &ad);
2173 	rc = smk_bu_task(p, access, rc);
2174 	return rc;
2175 }
2176 
2177 /**
2178  * smack_task_setpgid - Smack check on setting pgid
2179  * @p: the task object
2180  * @pgid: unused
2181  *
2182  * Return 0 if write access is permitted
2183  */
2184 static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
2185 {
2186 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2187 }
2188 
2189 /**
2190  * smack_task_getpgid - Smack access check for getpgid
2191  * @p: the object task
2192  *
2193  * Returns 0 if current can read the object task, error code otherwise
2194  */
2195 static int smack_task_getpgid(struct task_struct *p)
2196 {
2197 	return smk_curacc_on_task(p, MAY_READ, __func__);
2198 }
2199 
2200 /**
2201  * smack_task_getsid - Smack access check for getsid
2202  * @p: the object task
2203  *
2204  * Returns 0 if current can read the object task, error code otherwise
2205  */
2206 static int smack_task_getsid(struct task_struct *p)
2207 {
2208 	return smk_curacc_on_task(p, MAY_READ, __func__);
2209 }
2210 
2211 /**
2212  * smack_current_getsecid_subj - get the subjective secid of the current task
2213  * @secid: where to put the result
2214  *
2215  * Sets the secid to contain a u32 version of the task's subjective smack label.
2216  */
2217 static void smack_current_getsecid_subj(u32 *secid)
2218 {
2219 	struct smack_known *skp = smk_of_current();
2220 
2221 	*secid = skp->smk_secid;
2222 }
2223 
2224 /**
2225  * smack_task_getsecid_obj - get the objective secid of the task
2226  * @p: the task
2227  * @secid: where to put the result
2228  *
2229  * Sets the secid to contain a u32 version of the task's objective smack label.
2230  */
2231 static void smack_task_getsecid_obj(struct task_struct *p, u32 *secid)
2232 {
2233 	struct smack_known *skp = smk_of_task_struct_obj(p);
2234 
2235 	*secid = skp->smk_secid;
2236 }
2237 
2238 /**
2239  * smack_task_setnice - Smack check on setting nice
2240  * @p: the task object
2241  * @nice: unused
2242  *
2243  * Return 0 if write access is permitted
2244  */
2245 static int smack_task_setnice(struct task_struct *p, int nice)
2246 {
2247 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2248 }
2249 
2250 /**
2251  * smack_task_setioprio - Smack check on setting ioprio
2252  * @p: the task object
2253  * @ioprio: unused
2254  *
2255  * Return 0 if write access is permitted
2256  */
2257 static int smack_task_setioprio(struct task_struct *p, int ioprio)
2258 {
2259 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2260 }
2261 
2262 /**
2263  * smack_task_getioprio - Smack check on reading ioprio
2264  * @p: the task object
2265  *
2266  * Return 0 if read access is permitted
2267  */
2268 static int smack_task_getioprio(struct task_struct *p)
2269 {
2270 	return smk_curacc_on_task(p, MAY_READ, __func__);
2271 }
2272 
2273 /**
2274  * smack_task_setscheduler - Smack check on setting scheduler
2275  * @p: the task object
2276  *
2277  * Return 0 if read access is permitted
2278  */
2279 static int smack_task_setscheduler(struct task_struct *p)
2280 {
2281 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2282 }
2283 
2284 /**
2285  * smack_task_getscheduler - Smack check on reading scheduler
2286  * @p: the task object
2287  *
2288  * Return 0 if read access is permitted
2289  */
2290 static int smack_task_getscheduler(struct task_struct *p)
2291 {
2292 	return smk_curacc_on_task(p, MAY_READ, __func__);
2293 }
2294 
2295 /**
2296  * smack_task_movememory - Smack check on moving memory
2297  * @p: the task object
2298  *
2299  * Return 0 if write access is permitted
2300  */
2301 static int smack_task_movememory(struct task_struct *p)
2302 {
2303 	return smk_curacc_on_task(p, MAY_WRITE, __func__);
2304 }
2305 
2306 /**
2307  * smack_task_kill - Smack check on signal delivery
2308  * @p: the task object
2309  * @info: unused
2310  * @sig: unused
2311  * @cred: identifies the cred to use in lieu of current's
2312  *
2313  * Return 0 if write access is permitted
2314  *
2315  */
2316 static int smack_task_kill(struct task_struct *p, struct kernel_siginfo *info,
2317 			   int sig, const struct cred *cred)
2318 {
2319 	struct smk_audit_info ad;
2320 	struct smack_known *skp;
2321 	struct smack_known *tkp = smk_of_task_struct_obj(p);
2322 	int rc;
2323 
2324 	if (!sig)
2325 		return 0; /* null signal; existence test */
2326 
2327 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
2328 	smk_ad_setfield_u_tsk(&ad, p);
2329 	/*
2330 	 * Sending a signal requires that the sender
2331 	 * can write the receiver.
2332 	 */
2333 	if (cred == NULL) {
2334 		rc = smk_curacc(tkp, MAY_DELIVER, &ad);
2335 		rc = smk_bu_task(p, MAY_DELIVER, rc);
2336 		return rc;
2337 	}
2338 	/*
2339 	 * If the cred isn't NULL we're dealing with some USB IO
2340 	 * specific behavior. This is not clean. For one thing
2341 	 * we can't take privilege into account.
2342 	 */
2343 	skp = smk_of_task(smack_cred(cred));
2344 	rc = smk_access(skp, tkp, MAY_DELIVER, &ad);
2345 	rc = smk_bu_note("USB signal", skp, tkp, MAY_DELIVER, rc);
2346 	return rc;
2347 }
2348 
2349 /**
2350  * smack_task_to_inode - copy task smack into the inode blob
2351  * @p: task to copy from
2352  * @inode: inode to copy to
2353  *
2354  * Sets the smack pointer in the inode security blob
2355  */
2356 static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
2357 {
2358 	struct inode_smack *isp = smack_inode(inode);
2359 	struct smack_known *skp = smk_of_task_struct_obj(p);
2360 
2361 	isp->smk_inode = skp;
2362 	isp->smk_flags |= SMK_INODE_INSTANT;
2363 }
2364 
2365 /*
2366  * Socket hooks.
2367  */
2368 
2369 /**
2370  * smack_sk_alloc_security - Allocate a socket blob
2371  * @sk: the socket
2372  * @family: unused
2373  * @gfp_flags: memory allocation flags
2374  *
2375  * Assign Smack pointers to current
2376  *
2377  * Returns 0 on success, -ENOMEM is there's no memory
2378  */
2379 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
2380 {
2381 	struct smack_known *skp = smk_of_current();
2382 	struct socket_smack *ssp;
2383 
2384 	ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
2385 	if (ssp == NULL)
2386 		return -ENOMEM;
2387 
2388 	/*
2389 	 * Sockets created by kernel threads receive web label.
2390 	 */
2391 	if (unlikely(current->flags & PF_KTHREAD)) {
2392 		ssp->smk_in = &smack_known_web;
2393 		ssp->smk_out = &smack_known_web;
2394 	} else {
2395 		ssp->smk_in = skp;
2396 		ssp->smk_out = skp;
2397 	}
2398 	ssp->smk_packet = NULL;
2399 
2400 	sk->sk_security = ssp;
2401 
2402 	return 0;
2403 }
2404 
2405 /**
2406  * smack_sk_free_security - Free a socket blob
2407  * @sk: the socket
2408  *
2409  * Clears the blob pointer
2410  */
2411 static void smack_sk_free_security(struct sock *sk)
2412 {
2413 #ifdef SMACK_IPV6_PORT_LABELING
2414 	struct smk_port_label *spp;
2415 
2416 	if (sk->sk_family == PF_INET6) {
2417 		rcu_read_lock();
2418 		list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2419 			if (spp->smk_sock != sk)
2420 				continue;
2421 			spp->smk_can_reuse = 1;
2422 			break;
2423 		}
2424 		rcu_read_unlock();
2425 	}
2426 #endif
2427 	kfree(sk->sk_security);
2428 }
2429 
2430 /**
2431  * smack_sk_clone_security - Copy security context
2432  * @sk: the old socket
2433  * @newsk: the new socket
2434  *
2435  * Copy the security context of the old socket pointer to the cloned
2436  */
2437 static void smack_sk_clone_security(const struct sock *sk, struct sock *newsk)
2438 {
2439 	struct socket_smack *ssp_old = sk->sk_security;
2440 	struct socket_smack *ssp_new = newsk->sk_security;
2441 
2442 	*ssp_new = *ssp_old;
2443 }
2444 
2445 /**
2446 * smack_ipv4host_label - check host based restrictions
2447 * @sip: the object end
2448 *
2449 * looks for host based access restrictions
2450 *
2451 * This version will only be appropriate for really small sets of single label
2452 * hosts.  The caller is responsible for ensuring that the RCU read lock is
2453 * taken before calling this function.
2454 *
2455 * Returns the label of the far end or NULL if it's not special.
2456 */
2457 static struct smack_known *smack_ipv4host_label(struct sockaddr_in *sip)
2458 {
2459 	struct smk_net4addr *snp;
2460 	struct in_addr *siap = &sip->sin_addr;
2461 
2462 	if (siap->s_addr == 0)
2463 		return NULL;
2464 
2465 	list_for_each_entry_rcu(snp, &smk_net4addr_list, list)
2466 		/*
2467 		 * we break after finding the first match because
2468 		 * the list is sorted from longest to shortest mask
2469 		 * so we have found the most specific match
2470 		 */
2471 		if (snp->smk_host.s_addr ==
2472 		    (siap->s_addr & snp->smk_mask.s_addr))
2473 			return snp->smk_label;
2474 
2475 	return NULL;
2476 }
2477 
2478 /*
2479  * smk_ipv6_localhost - Check for local ipv6 host address
2480  * @sip: the address
2481  *
2482  * Returns boolean true if this is the localhost address
2483  */
2484 static bool smk_ipv6_localhost(struct sockaddr_in6 *sip)
2485 {
2486 	__be16 *be16p = (__be16 *)&sip->sin6_addr;
2487 	__be32 *be32p = (__be32 *)&sip->sin6_addr;
2488 
2489 	if (be32p[0] == 0 && be32p[1] == 0 && be32p[2] == 0 && be16p[6] == 0 &&
2490 	    ntohs(be16p[7]) == 1)
2491 		return true;
2492 	return false;
2493 }
2494 
2495 /**
2496 * smack_ipv6host_label - check host based restrictions
2497 * @sip: the object end
2498 *
2499 * looks for host based access restrictions
2500 *
2501 * This version will only be appropriate for really small sets of single label
2502 * hosts.  The caller is responsible for ensuring that the RCU read lock is
2503 * taken before calling this function.
2504 *
2505 * Returns the label of the far end or NULL if it's not special.
2506 */
2507 static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
2508 {
2509 	struct smk_net6addr *snp;
2510 	struct in6_addr *sap = &sip->sin6_addr;
2511 	int i;
2512 	int found = 0;
2513 
2514 	/*
2515 	 * It's local. Don't look for a host label.
2516 	 */
2517 	if (smk_ipv6_localhost(sip))
2518 		return NULL;
2519 
2520 	list_for_each_entry_rcu(snp, &smk_net6addr_list, list) {
2521 		/*
2522 		 * If the label is NULL the entry has
2523 		 * been renounced. Ignore it.
2524 		 */
2525 		if (snp->smk_label == NULL)
2526 			continue;
2527 		/*
2528 		* we break after finding the first match because
2529 		* the list is sorted from longest to shortest mask
2530 		* so we have found the most specific match
2531 		*/
2532 		for (found = 1, i = 0; i < 8; i++) {
2533 			if ((sap->s6_addr16[i] & snp->smk_mask.s6_addr16[i]) !=
2534 			    snp->smk_host.s6_addr16[i]) {
2535 				found = 0;
2536 				break;
2537 			}
2538 		}
2539 		if (found)
2540 			return snp->smk_label;
2541 	}
2542 
2543 	return NULL;
2544 }
2545 
2546 /**
2547  * smack_netlbl_add - Set the secattr on a socket
2548  * @sk: the socket
2549  *
2550  * Attach the outbound smack value (smk_out) to the socket.
2551  *
2552  * Returns 0 on success or an error code
2553  */
2554 static int smack_netlbl_add(struct sock *sk)
2555 {
2556 	struct socket_smack *ssp = sk->sk_security;
2557 	struct smack_known *skp = ssp->smk_out;
2558 	int rc;
2559 
2560 	local_bh_disable();
2561 	bh_lock_sock_nested(sk);
2562 
2563 	rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
2564 	switch (rc) {
2565 	case 0:
2566 		ssp->smk_state = SMK_NETLBL_LABELED;
2567 		break;
2568 	case -EDESTADDRREQ:
2569 		ssp->smk_state = SMK_NETLBL_REQSKB;
2570 		rc = 0;
2571 		break;
2572 	}
2573 
2574 	bh_unlock_sock(sk);
2575 	local_bh_enable();
2576 
2577 	return rc;
2578 }
2579 
2580 /**
2581  * smack_netlbl_delete - Remove the secattr from a socket
2582  * @sk: the socket
2583  *
2584  * Remove the outbound smack value from a socket
2585  */
2586 static void smack_netlbl_delete(struct sock *sk)
2587 {
2588 	struct socket_smack *ssp = sk->sk_security;
2589 
2590 	/*
2591 	 * Take the label off the socket if one is set.
2592 	 */
2593 	if (ssp->smk_state != SMK_NETLBL_LABELED)
2594 		return;
2595 
2596 	local_bh_disable();
2597 	bh_lock_sock_nested(sk);
2598 	netlbl_sock_delattr(sk);
2599 	bh_unlock_sock(sk);
2600 	local_bh_enable();
2601 	ssp->smk_state = SMK_NETLBL_UNLABELED;
2602 }
2603 
2604 /**
2605  * smk_ipv4_check - Perform IPv4 host access checks
2606  * @sk: the socket
2607  * @sap: the destination address
2608  *
2609  * Set the correct secattr for the given socket based on the destination
2610  * address and perform any outbound access checks needed.
2611  *
2612  * Returns 0 on success or an error code.
2613  *
2614  */
2615 static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
2616 {
2617 	struct smack_known *skp;
2618 	int rc = 0;
2619 	struct smack_known *hkp;
2620 	struct socket_smack *ssp = sk->sk_security;
2621 	struct smk_audit_info ad;
2622 
2623 	rcu_read_lock();
2624 	hkp = smack_ipv4host_label(sap);
2625 	if (hkp != NULL) {
2626 #ifdef CONFIG_AUDIT
2627 		struct lsm_network_audit net;
2628 
2629 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2630 		ad.a.u.net->family = sap->sin_family;
2631 		ad.a.u.net->dport = sap->sin_port;
2632 		ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
2633 #endif
2634 		skp = ssp->smk_out;
2635 		rc = smk_access(skp, hkp, MAY_WRITE, &ad);
2636 		rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
2637 		/*
2638 		 * Clear the socket netlabel if it's set.
2639 		 */
2640 		if (!rc)
2641 			smack_netlbl_delete(sk);
2642 	}
2643 	rcu_read_unlock();
2644 
2645 	return rc;
2646 }
2647 
2648 /**
2649  * smk_ipv6_check - check Smack access
2650  * @subject: subject Smack label
2651  * @object: object Smack label
2652  * @address: address
2653  * @act: the action being taken
2654  *
2655  * Check an IPv6 access
2656  */
2657 static int smk_ipv6_check(struct smack_known *subject,
2658 				struct smack_known *object,
2659 				struct sockaddr_in6 *address, int act)
2660 {
2661 #ifdef CONFIG_AUDIT
2662 	struct lsm_network_audit net;
2663 #endif
2664 	struct smk_audit_info ad;
2665 	int rc;
2666 
2667 #ifdef CONFIG_AUDIT
2668 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
2669 	ad.a.u.net->family = PF_INET6;
2670 	ad.a.u.net->dport = address->sin6_port;
2671 	if (act == SMK_RECEIVING)
2672 		ad.a.u.net->v6info.saddr = address->sin6_addr;
2673 	else
2674 		ad.a.u.net->v6info.daddr = address->sin6_addr;
2675 #endif
2676 	rc = smk_access(subject, object, MAY_WRITE, &ad);
2677 	rc = smk_bu_note("IPv6 check", subject, object, MAY_WRITE, rc);
2678 	return rc;
2679 }
2680 
2681 #ifdef SMACK_IPV6_PORT_LABELING
2682 /**
2683  * smk_ipv6_port_label - Smack port access table management
2684  * @sock: socket
2685  * @address: address
2686  *
2687  * Create or update the port list entry
2688  */
2689 static void smk_ipv6_port_label(struct socket *sock, struct sockaddr *address)
2690 {
2691 	struct sock *sk = sock->sk;
2692 	struct sockaddr_in6 *addr6;
2693 	struct socket_smack *ssp = sock->sk->sk_security;
2694 	struct smk_port_label *spp;
2695 	unsigned short port = 0;
2696 
2697 	if (address == NULL) {
2698 		/*
2699 		 * This operation is changing the Smack information
2700 		 * on the bound socket. Take the changes to the port
2701 		 * as well.
2702 		 */
2703 		rcu_read_lock();
2704 		list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2705 			if (sk != spp->smk_sock)
2706 				continue;
2707 			spp->smk_in = ssp->smk_in;
2708 			spp->smk_out = ssp->smk_out;
2709 			rcu_read_unlock();
2710 			return;
2711 		}
2712 		/*
2713 		 * A NULL address is only used for updating existing
2714 		 * bound entries. If there isn't one, it's OK.
2715 		 */
2716 		rcu_read_unlock();
2717 		return;
2718 	}
2719 
2720 	addr6 = (struct sockaddr_in6 *)address;
2721 	port = ntohs(addr6->sin6_port);
2722 	/*
2723 	 * This is a special case that is safely ignored.
2724 	 */
2725 	if (port == 0)
2726 		return;
2727 
2728 	/*
2729 	 * Look for an existing port list entry.
2730 	 * This is an indication that a port is getting reused.
2731 	 */
2732 	rcu_read_lock();
2733 	list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2734 		if (spp->smk_port != port || spp->smk_sock_type != sock->type)
2735 			continue;
2736 		if (spp->smk_can_reuse != 1) {
2737 			rcu_read_unlock();
2738 			return;
2739 		}
2740 		spp->smk_port = port;
2741 		spp->smk_sock = sk;
2742 		spp->smk_in = ssp->smk_in;
2743 		spp->smk_out = ssp->smk_out;
2744 		spp->smk_can_reuse = 0;
2745 		rcu_read_unlock();
2746 		return;
2747 	}
2748 	rcu_read_unlock();
2749 	/*
2750 	 * A new port entry is required.
2751 	 */
2752 	spp = kzalloc(sizeof(*spp), GFP_KERNEL);
2753 	if (spp == NULL)
2754 		return;
2755 
2756 	spp->smk_port = port;
2757 	spp->smk_sock = sk;
2758 	spp->smk_in = ssp->smk_in;
2759 	spp->smk_out = ssp->smk_out;
2760 	spp->smk_sock_type = sock->type;
2761 	spp->smk_can_reuse = 0;
2762 
2763 	mutex_lock(&smack_ipv6_lock);
2764 	list_add_rcu(&spp->list, &smk_ipv6_port_list);
2765 	mutex_unlock(&smack_ipv6_lock);
2766 	return;
2767 }
2768 
2769 /**
2770  * smk_ipv6_port_check - check Smack port access
2771  * @sk: socket
2772  * @address: address
2773  * @act: the action being taken
2774  *
2775  * Create or update the port list entry
2776  */
2777 static int smk_ipv6_port_check(struct sock *sk, struct sockaddr_in6 *address,
2778 				int act)
2779 {
2780 	struct smk_port_label *spp;
2781 	struct socket_smack *ssp = sk->sk_security;
2782 	struct smack_known *skp = NULL;
2783 	unsigned short port;
2784 	struct smack_known *object;
2785 
2786 	if (act == SMK_RECEIVING) {
2787 		skp = smack_ipv6host_label(address);
2788 		object = ssp->smk_in;
2789 	} else {
2790 		skp = ssp->smk_out;
2791 		object = smack_ipv6host_label(address);
2792 	}
2793 
2794 	/*
2795 	 * The other end is a single label host.
2796 	 */
2797 	if (skp != NULL && object != NULL)
2798 		return smk_ipv6_check(skp, object, address, act);
2799 	if (skp == NULL)
2800 		skp = smack_net_ambient;
2801 	if (object == NULL)
2802 		object = smack_net_ambient;
2803 
2804 	/*
2805 	 * It's remote, so port lookup does no good.
2806 	 */
2807 	if (!smk_ipv6_localhost(address))
2808 		return smk_ipv6_check(skp, object, address, act);
2809 
2810 	/*
2811 	 * It's local so the send check has to have passed.
2812 	 */
2813 	if (act == SMK_RECEIVING)
2814 		return 0;
2815 
2816 	port = ntohs(address->sin6_port);
2817 	rcu_read_lock();
2818 	list_for_each_entry_rcu(spp, &smk_ipv6_port_list, list) {
2819 		if (spp->smk_port != port || spp->smk_sock_type != sk->sk_type)
2820 			continue;
2821 		object = spp->smk_in;
2822 		if (act == SMK_CONNECTING)
2823 			ssp->smk_packet = spp->smk_out;
2824 		break;
2825 	}
2826 	rcu_read_unlock();
2827 
2828 	return smk_ipv6_check(skp, object, address, act);
2829 }
2830 #endif
2831 
2832 /**
2833  * smack_inode_setsecurity - set smack xattrs
2834  * @inode: the object
2835  * @name: attribute name
2836  * @value: attribute value
2837  * @size: size of the attribute
2838  * @flags: unused
2839  *
2840  * Sets the named attribute in the appropriate blob
2841  *
2842  * Returns 0 on success, or an error code
2843  */
2844 static int smack_inode_setsecurity(struct inode *inode, const char *name,
2845 				   const void *value, size_t size, int flags)
2846 {
2847 	struct smack_known *skp;
2848 	struct inode_smack *nsp = smack_inode(inode);
2849 	struct socket_smack *ssp;
2850 	struct socket *sock;
2851 	int rc = 0;
2852 
2853 	if (value == NULL || size > SMK_LONGLABEL || size == 0)
2854 		return -EINVAL;
2855 
2856 	skp = smk_import_entry(value, size);
2857 	if (IS_ERR(skp))
2858 		return PTR_ERR(skp);
2859 
2860 	if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
2861 		nsp->smk_inode = skp;
2862 		nsp->smk_flags |= SMK_INODE_INSTANT;
2863 		return 0;
2864 	}
2865 	/*
2866 	 * The rest of the Smack xattrs are only on sockets.
2867 	 */
2868 	if (inode->i_sb->s_magic != SOCKFS_MAGIC)
2869 		return -EOPNOTSUPP;
2870 
2871 	sock = SOCKET_I(inode);
2872 	if (sock == NULL || sock->sk == NULL)
2873 		return -EOPNOTSUPP;
2874 
2875 	ssp = sock->sk->sk_security;
2876 
2877 	if (strcmp(name, XATTR_SMACK_IPIN) == 0)
2878 		ssp->smk_in = skp;
2879 	else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
2880 		ssp->smk_out = skp;
2881 		if (sock->sk->sk_family == PF_INET) {
2882 			rc = smack_netlbl_add(sock->sk);
2883 			if (rc != 0)
2884 				printk(KERN_WARNING
2885 					"Smack: \"%s\" netlbl error %d.\n",
2886 					__func__, -rc);
2887 		}
2888 	} else
2889 		return -EOPNOTSUPP;
2890 
2891 #ifdef SMACK_IPV6_PORT_LABELING
2892 	if (sock->sk->sk_family == PF_INET6)
2893 		smk_ipv6_port_label(sock, NULL);
2894 #endif
2895 
2896 	return 0;
2897 }
2898 
2899 /**
2900  * smack_socket_post_create - finish socket setup
2901  * @sock: the socket
2902  * @family: protocol family
2903  * @type: unused
2904  * @protocol: unused
2905  * @kern: unused
2906  *
2907  * Sets the netlabel information on the socket
2908  *
2909  * Returns 0 on success, and error code otherwise
2910  */
2911 static int smack_socket_post_create(struct socket *sock, int family,
2912 				    int type, int protocol, int kern)
2913 {
2914 	struct socket_smack *ssp;
2915 
2916 	if (sock->sk == NULL)
2917 		return 0;
2918 
2919 	/*
2920 	 * Sockets created by kernel threads receive web label.
2921 	 */
2922 	if (unlikely(current->flags & PF_KTHREAD)) {
2923 		ssp = sock->sk->sk_security;
2924 		ssp->smk_in = &smack_known_web;
2925 		ssp->smk_out = &smack_known_web;
2926 	}
2927 
2928 	if (family != PF_INET)
2929 		return 0;
2930 	/*
2931 	 * Set the outbound netlbl.
2932 	 */
2933 	return smack_netlbl_add(sock->sk);
2934 }
2935 
2936 /**
2937  * smack_socket_socketpair - create socket pair
2938  * @socka: one socket
2939  * @sockb: another socket
2940  *
2941  * Cross reference the peer labels for SO_PEERSEC
2942  *
2943  * Returns 0
2944  */
2945 static int smack_socket_socketpair(struct socket *socka,
2946 		                   struct socket *sockb)
2947 {
2948 	struct socket_smack *asp = socka->sk->sk_security;
2949 	struct socket_smack *bsp = sockb->sk->sk_security;
2950 
2951 	asp->smk_packet = bsp->smk_out;
2952 	bsp->smk_packet = asp->smk_out;
2953 
2954 	return 0;
2955 }
2956 
2957 #ifdef SMACK_IPV6_PORT_LABELING
2958 /**
2959  * smack_socket_bind - record port binding information.
2960  * @sock: the socket
2961  * @address: the port address
2962  * @addrlen: size of the address
2963  *
2964  * Records the label bound to a port.
2965  *
2966  * Returns 0 on success, and error code otherwise
2967  */
2968 static int smack_socket_bind(struct socket *sock, struct sockaddr *address,
2969 				int addrlen)
2970 {
2971 	if (sock->sk != NULL && sock->sk->sk_family == PF_INET6) {
2972 		if (addrlen < SIN6_LEN_RFC2133 ||
2973 		    address->sa_family != AF_INET6)
2974 			return -EINVAL;
2975 		smk_ipv6_port_label(sock, address);
2976 	}
2977 	return 0;
2978 }
2979 #endif /* SMACK_IPV6_PORT_LABELING */
2980 
2981 /**
2982  * smack_socket_connect - connect access check
2983  * @sock: the socket
2984  * @sap: the other end
2985  * @addrlen: size of sap
2986  *
2987  * Verifies that a connection may be possible
2988  *
2989  * Returns 0 on success, and error code otherwise
2990  */
2991 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
2992 				int addrlen)
2993 {
2994 	int rc = 0;
2995 
2996 	if (sock->sk == NULL)
2997 		return 0;
2998 	if (sock->sk->sk_family != PF_INET &&
2999 	    (!IS_ENABLED(CONFIG_IPV6) || sock->sk->sk_family != PF_INET6))
3000 		return 0;
3001 	if (addrlen < offsetofend(struct sockaddr, sa_family))
3002 		return 0;
3003 	if (IS_ENABLED(CONFIG_IPV6) && sap->sa_family == AF_INET6) {
3004 		struct sockaddr_in6 *sip = (struct sockaddr_in6 *)sap;
3005 		struct smack_known *rsp = NULL;
3006 
3007 		if (addrlen < SIN6_LEN_RFC2133)
3008 			return 0;
3009 		if (__is_defined(SMACK_IPV6_SECMARK_LABELING))
3010 			rsp = smack_ipv6host_label(sip);
3011 		if (rsp != NULL) {
3012 			struct socket_smack *ssp = sock->sk->sk_security;
3013 
3014 			rc = smk_ipv6_check(ssp->smk_out, rsp, sip,
3015 					    SMK_CONNECTING);
3016 		}
3017 #ifdef SMACK_IPV6_PORT_LABELING
3018 		rc = smk_ipv6_port_check(sock->sk, sip, SMK_CONNECTING);
3019 #endif
3020 
3021 		return rc;
3022 	}
3023 	if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
3024 		return 0;
3025 	rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
3026 	return rc;
3027 }
3028 
3029 /**
3030  * smack_flags_to_may - convert S_ to MAY_ values
3031  * @flags: the S_ value
3032  *
3033  * Returns the equivalent MAY_ value
3034  */
3035 static int smack_flags_to_may(int flags)
3036 {
3037 	int may = 0;
3038 
3039 	if (flags & S_IRUGO)
3040 		may |= MAY_READ;
3041 	if (flags & S_IWUGO)
3042 		may |= MAY_WRITE;
3043 	if (flags & S_IXUGO)
3044 		may |= MAY_EXEC;
3045 
3046 	return may;
3047 }
3048 
3049 /**
3050  * smack_msg_msg_alloc_security - Set the security blob for msg_msg
3051  * @msg: the object
3052  *
3053  * Returns 0
3054  */
3055 static int smack_msg_msg_alloc_security(struct msg_msg *msg)
3056 {
3057 	struct smack_known **blob = smack_msg_msg(msg);
3058 
3059 	*blob = smk_of_current();
3060 	return 0;
3061 }
3062 
3063 /**
3064  * smack_of_ipc - the smack pointer for the ipc
3065  * @isp: the object
3066  *
3067  * Returns a pointer to the smack value
3068  */
3069 static struct smack_known *smack_of_ipc(struct kern_ipc_perm *isp)
3070 {
3071 	struct smack_known **blob = smack_ipc(isp);
3072 
3073 	return *blob;
3074 }
3075 
3076 /**
3077  * smack_ipc_alloc_security - Set the security blob for ipc
3078  * @isp: the object
3079  *
3080  * Returns 0
3081  */
3082 static int smack_ipc_alloc_security(struct kern_ipc_perm *isp)
3083 {
3084 	struct smack_known **blob = smack_ipc(isp);
3085 
3086 	*blob = smk_of_current();
3087 	return 0;
3088 }
3089 
3090 /**
3091  * smk_curacc_shm : check if current has access on shm
3092  * @isp : the object
3093  * @access : access requested
3094  *
3095  * Returns 0 if current has the requested access, error code otherwise
3096  */
3097 static int smk_curacc_shm(struct kern_ipc_perm *isp, int access)
3098 {
3099 	struct smack_known *ssp = smack_of_ipc(isp);
3100 	struct smk_audit_info ad;
3101 	int rc;
3102 
3103 #ifdef CONFIG_AUDIT
3104 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3105 	ad.a.u.ipc_id = isp->id;
3106 #endif
3107 	rc = smk_curacc(ssp, access, &ad);
3108 	rc = smk_bu_current("shm", ssp, access, rc);
3109 	return rc;
3110 }
3111 
3112 /**
3113  * smack_shm_associate - Smack access check for shm
3114  * @isp: the object
3115  * @shmflg: access requested
3116  *
3117  * Returns 0 if current has the requested access, error code otherwise
3118  */
3119 static int smack_shm_associate(struct kern_ipc_perm *isp, int shmflg)
3120 {
3121 	int may;
3122 
3123 	may = smack_flags_to_may(shmflg);
3124 	return smk_curacc_shm(isp, may);
3125 }
3126 
3127 /**
3128  * smack_shm_shmctl - Smack access check for shm
3129  * @isp: the object
3130  * @cmd: what it wants to do
3131  *
3132  * Returns 0 if current has the requested access, error code otherwise
3133  */
3134 static int smack_shm_shmctl(struct kern_ipc_perm *isp, int cmd)
3135 {
3136 	int may;
3137 
3138 	switch (cmd) {
3139 	case IPC_STAT:
3140 	case SHM_STAT:
3141 	case SHM_STAT_ANY:
3142 		may = MAY_READ;
3143 		break;
3144 	case IPC_SET:
3145 	case SHM_LOCK:
3146 	case SHM_UNLOCK:
3147 	case IPC_RMID:
3148 		may = MAY_READWRITE;
3149 		break;
3150 	case IPC_INFO:
3151 	case SHM_INFO:
3152 		/*
3153 		 * System level information.
3154 		 */
3155 		return 0;
3156 	default:
3157 		return -EINVAL;
3158 	}
3159 	return smk_curacc_shm(isp, may);
3160 }
3161 
3162 /**
3163  * smack_shm_shmat - Smack access for shmat
3164  * @isp: the object
3165  * @shmaddr: unused
3166  * @shmflg: access requested
3167  *
3168  * Returns 0 if current has the requested access, error code otherwise
3169  */
3170 static int smack_shm_shmat(struct kern_ipc_perm *isp, char __user *shmaddr,
3171 			   int shmflg)
3172 {
3173 	int may;
3174 
3175 	may = smack_flags_to_may(shmflg);
3176 	return smk_curacc_shm(isp, may);
3177 }
3178 
3179 /**
3180  * smk_curacc_sem : check if current has access on sem
3181  * @isp : the object
3182  * @access : access requested
3183  *
3184  * Returns 0 if current has the requested access, error code otherwise
3185  */
3186 static int smk_curacc_sem(struct kern_ipc_perm *isp, int access)
3187 {
3188 	struct smack_known *ssp = smack_of_ipc(isp);
3189 	struct smk_audit_info ad;
3190 	int rc;
3191 
3192 #ifdef CONFIG_AUDIT
3193 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3194 	ad.a.u.ipc_id = isp->id;
3195 #endif
3196 	rc = smk_curacc(ssp, access, &ad);
3197 	rc = smk_bu_current("sem", ssp, access, rc);
3198 	return rc;
3199 }
3200 
3201 /**
3202  * smack_sem_associate - Smack access check for sem
3203  * @isp: the object
3204  * @semflg: access requested
3205  *
3206  * Returns 0 if current has the requested access, error code otherwise
3207  */
3208 static int smack_sem_associate(struct kern_ipc_perm *isp, int semflg)
3209 {
3210 	int may;
3211 
3212 	may = smack_flags_to_may(semflg);
3213 	return smk_curacc_sem(isp, may);
3214 }
3215 
3216 /**
3217  * smack_sem_semctl - Smack access check for sem
3218  * @isp: the object
3219  * @cmd: what it wants to do
3220  *
3221  * Returns 0 if current has the requested access, error code otherwise
3222  */
3223 static int smack_sem_semctl(struct kern_ipc_perm *isp, int cmd)
3224 {
3225 	int may;
3226 
3227 	switch (cmd) {
3228 	case GETPID:
3229 	case GETNCNT:
3230 	case GETZCNT:
3231 	case GETVAL:
3232 	case GETALL:
3233 	case IPC_STAT:
3234 	case SEM_STAT:
3235 	case SEM_STAT_ANY:
3236 		may = MAY_READ;
3237 		break;
3238 	case SETVAL:
3239 	case SETALL:
3240 	case IPC_RMID:
3241 	case IPC_SET:
3242 		may = MAY_READWRITE;
3243 		break;
3244 	case IPC_INFO:
3245 	case SEM_INFO:
3246 		/*
3247 		 * System level information
3248 		 */
3249 		return 0;
3250 	default:
3251 		return -EINVAL;
3252 	}
3253 
3254 	return smk_curacc_sem(isp, may);
3255 }
3256 
3257 /**
3258  * smack_sem_semop - Smack checks of semaphore operations
3259  * @isp: the object
3260  * @sops: unused
3261  * @nsops: unused
3262  * @alter: unused
3263  *
3264  * Treated as read and write in all cases.
3265  *
3266  * Returns 0 if access is allowed, error code otherwise
3267  */
3268 static int smack_sem_semop(struct kern_ipc_perm *isp, struct sembuf *sops,
3269 			   unsigned nsops, int alter)
3270 {
3271 	return smk_curacc_sem(isp, MAY_READWRITE);
3272 }
3273 
3274 /**
3275  * smk_curacc_msq : helper to check if current has access on msq
3276  * @isp : the msq
3277  * @access : access requested
3278  *
3279  * return 0 if current has access, error otherwise
3280  */
3281 static int smk_curacc_msq(struct kern_ipc_perm *isp, int access)
3282 {
3283 	struct smack_known *msp = smack_of_ipc(isp);
3284 	struct smk_audit_info ad;
3285 	int rc;
3286 
3287 #ifdef CONFIG_AUDIT
3288 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3289 	ad.a.u.ipc_id = isp->id;
3290 #endif
3291 	rc = smk_curacc(msp, access, &ad);
3292 	rc = smk_bu_current("msq", msp, access, rc);
3293 	return rc;
3294 }
3295 
3296 /**
3297  * smack_msg_queue_associate - Smack access check for msg_queue
3298  * @isp: the object
3299  * @msqflg: access requested
3300  *
3301  * Returns 0 if current has the requested access, error code otherwise
3302  */
3303 static int smack_msg_queue_associate(struct kern_ipc_perm *isp, int msqflg)
3304 {
3305 	int may;
3306 
3307 	may = smack_flags_to_may(msqflg);
3308 	return smk_curacc_msq(isp, may);
3309 }
3310 
3311 /**
3312  * smack_msg_queue_msgctl - Smack access check for msg_queue
3313  * @isp: the object
3314  * @cmd: what it wants to do
3315  *
3316  * Returns 0 if current has the requested access, error code otherwise
3317  */
3318 static int smack_msg_queue_msgctl(struct kern_ipc_perm *isp, int cmd)
3319 {
3320 	int may;
3321 
3322 	switch (cmd) {
3323 	case IPC_STAT:
3324 	case MSG_STAT:
3325 	case MSG_STAT_ANY:
3326 		may = MAY_READ;
3327 		break;
3328 	case IPC_SET:
3329 	case IPC_RMID:
3330 		may = MAY_READWRITE;
3331 		break;
3332 	case IPC_INFO:
3333 	case MSG_INFO:
3334 		/*
3335 		 * System level information
3336 		 */
3337 		return 0;
3338 	default:
3339 		return -EINVAL;
3340 	}
3341 
3342 	return smk_curacc_msq(isp, may);
3343 }
3344 
3345 /**
3346  * smack_msg_queue_msgsnd - Smack access check for msg_queue
3347  * @isp: the object
3348  * @msg: unused
3349  * @msqflg: access requested
3350  *
3351  * Returns 0 if current has the requested access, error code otherwise
3352  */
3353 static int smack_msg_queue_msgsnd(struct kern_ipc_perm *isp, struct msg_msg *msg,
3354 				  int msqflg)
3355 {
3356 	int may;
3357 
3358 	may = smack_flags_to_may(msqflg);
3359 	return smk_curacc_msq(isp, may);
3360 }
3361 
3362 /**
3363  * smack_msg_queue_msgrcv - Smack access check for msg_queue
3364  * @isp: the object
3365  * @msg: unused
3366  * @target: unused
3367  * @type: unused
3368  * @mode: unused
3369  *
3370  * Returns 0 if current has read and write access, error code otherwise
3371  */
3372 static int smack_msg_queue_msgrcv(struct kern_ipc_perm *isp,
3373 				  struct msg_msg *msg,
3374 				  struct task_struct *target, long type,
3375 				  int mode)
3376 {
3377 	return smk_curacc_msq(isp, MAY_READWRITE);
3378 }
3379 
3380 /**
3381  * smack_ipc_permission - Smack access for ipc_permission()
3382  * @ipp: the object permissions
3383  * @flag: access requested
3384  *
3385  * Returns 0 if current has read and write access, error code otherwise
3386  */
3387 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
3388 {
3389 	struct smack_known **blob = smack_ipc(ipp);
3390 	struct smack_known *iskp = *blob;
3391 	int may = smack_flags_to_may(flag);
3392 	struct smk_audit_info ad;
3393 	int rc;
3394 
3395 #ifdef CONFIG_AUDIT
3396 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_IPC);
3397 	ad.a.u.ipc_id = ipp->id;
3398 #endif
3399 	rc = smk_curacc(iskp, may, &ad);
3400 	rc = smk_bu_current("svipc", iskp, may, rc);
3401 	return rc;
3402 }
3403 
3404 /**
3405  * smack_ipc_getsecid - Extract smack security id
3406  * @ipp: the object permissions
3407  * @secid: where result will be saved
3408  */
3409 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
3410 {
3411 	struct smack_known **blob = smack_ipc(ipp);
3412 	struct smack_known *iskp = *blob;
3413 
3414 	*secid = iskp->smk_secid;
3415 }
3416 
3417 /**
3418  * smack_d_instantiate - Make sure the blob is correct on an inode
3419  * @opt_dentry: dentry where inode will be attached
3420  * @inode: the object
3421  *
3422  * Set the inode's security blob if it hasn't been done already.
3423  */
3424 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
3425 {
3426 	struct super_block *sbp;
3427 	struct superblock_smack *sbsp;
3428 	struct inode_smack *isp;
3429 	struct smack_known *skp;
3430 	struct smack_known *ckp = smk_of_current();
3431 	struct smack_known *final;
3432 	char trattr[TRANS_TRUE_SIZE];
3433 	int transflag = 0;
3434 	int rc;
3435 	struct dentry *dp;
3436 
3437 	if (inode == NULL)
3438 		return;
3439 
3440 	isp = smack_inode(inode);
3441 
3442 	/*
3443 	 * If the inode is already instantiated
3444 	 * take the quick way out
3445 	 */
3446 	if (isp->smk_flags & SMK_INODE_INSTANT)
3447 		return;
3448 
3449 	sbp = inode->i_sb;
3450 	sbsp = smack_superblock(sbp);
3451 	/*
3452 	 * We're going to use the superblock default label
3453 	 * if there's no label on the file.
3454 	 */
3455 	final = sbsp->smk_default;
3456 
3457 	/*
3458 	 * If this is the root inode the superblock
3459 	 * may be in the process of initialization.
3460 	 * If that is the case use the root value out
3461 	 * of the superblock.
3462 	 */
3463 	if (opt_dentry->d_parent == opt_dentry) {
3464 		switch (sbp->s_magic) {
3465 		case CGROUP_SUPER_MAGIC:
3466 		case CGROUP2_SUPER_MAGIC:
3467 			/*
3468 			 * The cgroup filesystem is never mounted,
3469 			 * so there's no opportunity to set the mount
3470 			 * options.
3471 			 */
3472 			sbsp->smk_root = &smack_known_star;
3473 			sbsp->smk_default = &smack_known_star;
3474 			isp->smk_inode = sbsp->smk_root;
3475 			break;
3476 		case TMPFS_MAGIC:
3477 			/*
3478 			 * What about shmem/tmpfs anonymous files with dentry
3479 			 * obtained from d_alloc_pseudo()?
3480 			 */
3481 			isp->smk_inode = smk_of_current();
3482 			break;
3483 		case PIPEFS_MAGIC:
3484 			isp->smk_inode = smk_of_current();
3485 			break;
3486 		case SOCKFS_MAGIC:
3487 			/*
3488 			 * Socket access is controlled by the socket
3489 			 * structures associated with the task involved.
3490 			 */
3491 			isp->smk_inode = &smack_known_star;
3492 			break;
3493 		default:
3494 			isp->smk_inode = sbsp->smk_root;
3495 			break;
3496 		}
3497 		isp->smk_flags |= SMK_INODE_INSTANT;
3498 		return;
3499 	}
3500 
3501 	/*
3502 	 * This is pretty hackish.
3503 	 * Casey says that we shouldn't have to do
3504 	 * file system specific code, but it does help
3505 	 * with keeping it simple.
3506 	 */
3507 	switch (sbp->s_magic) {
3508 	case SMACK_MAGIC:
3509 	case CGROUP_SUPER_MAGIC:
3510 	case CGROUP2_SUPER_MAGIC:
3511 		/*
3512 		 * Casey says that it's a little embarrassing
3513 		 * that the smack file system doesn't do
3514 		 * extended attributes.
3515 		 *
3516 		 * Cgroupfs is special
3517 		 */
3518 		final = &smack_known_star;
3519 		break;
3520 	case DEVPTS_SUPER_MAGIC:
3521 		/*
3522 		 * devpts seems content with the label of the task.
3523 		 * Programs that change smack have to treat the
3524 		 * pty with respect.
3525 		 */
3526 		final = ckp;
3527 		break;
3528 	case PROC_SUPER_MAGIC:
3529 		/*
3530 		 * Casey says procfs appears not to care.
3531 		 * The superblock default suffices.
3532 		 */
3533 		break;
3534 	case TMPFS_MAGIC:
3535 		/*
3536 		 * Device labels should come from the filesystem,
3537 		 * but watch out, because they're volitile,
3538 		 * getting recreated on every reboot.
3539 		 */
3540 		final = &smack_known_star;
3541 		/*
3542 		 * If a smack value has been set we want to use it,
3543 		 * but since tmpfs isn't giving us the opportunity
3544 		 * to set mount options simulate setting the
3545 		 * superblock default.
3546 		 */
3547 		fallthrough;
3548 	default:
3549 		/*
3550 		 * This isn't an understood special case.
3551 		 * Get the value from the xattr.
3552 		 */
3553 
3554 		/*
3555 		 * UNIX domain sockets use lower level socket data.
3556 		 */
3557 		if (S_ISSOCK(inode->i_mode)) {
3558 			final = &smack_known_star;
3559 			break;
3560 		}
3561 		/*
3562 		 * No xattr support means, alas, no SMACK label.
3563 		 * Use the aforeapplied default.
3564 		 * It would be curious if the label of the task
3565 		 * does not match that assigned.
3566 		 */
3567 		if (!(inode->i_opflags & IOP_XATTR))
3568 		        break;
3569 		/*
3570 		 * Get the dentry for xattr.
3571 		 */
3572 		dp = dget(opt_dentry);
3573 		skp = smk_fetch(XATTR_NAME_SMACK, inode, dp);
3574 		if (!IS_ERR_OR_NULL(skp))
3575 			final = skp;
3576 
3577 		/*
3578 		 * Transmuting directory
3579 		 */
3580 		if (S_ISDIR(inode->i_mode)) {
3581 			/*
3582 			 * If this is a new directory and the label was
3583 			 * transmuted when the inode was initialized
3584 			 * set the transmute attribute on the directory
3585 			 * and mark the inode.
3586 			 *
3587 			 * If there is a transmute attribute on the
3588 			 * directory mark the inode.
3589 			 */
3590 			rc = __vfs_getxattr(dp, inode,
3591 					    XATTR_NAME_SMACKTRANSMUTE, trattr,
3592 					    TRANS_TRUE_SIZE);
3593 			if (rc >= 0 && strncmp(trattr, TRANS_TRUE,
3594 					       TRANS_TRUE_SIZE) != 0)
3595 				rc = -EINVAL;
3596 			if (rc >= 0)
3597 				transflag = SMK_INODE_TRANSMUTE;
3598 		}
3599 		/*
3600 		 * Don't let the exec or mmap label be "*" or "@".
3601 		 */
3602 		skp = smk_fetch(XATTR_NAME_SMACKEXEC, inode, dp);
3603 		if (IS_ERR(skp) || skp == &smack_known_star ||
3604 		    skp == &smack_known_web)
3605 			skp = NULL;
3606 		isp->smk_task = skp;
3607 
3608 		skp = smk_fetch(XATTR_NAME_SMACKMMAP, inode, dp);
3609 		if (IS_ERR(skp) || skp == &smack_known_star ||
3610 		    skp == &smack_known_web)
3611 			skp = NULL;
3612 		isp->smk_mmap = skp;
3613 
3614 		dput(dp);
3615 		break;
3616 	}
3617 
3618 	if (final == NULL)
3619 		isp->smk_inode = ckp;
3620 	else
3621 		isp->smk_inode = final;
3622 
3623 	isp->smk_flags |= (SMK_INODE_INSTANT | transflag);
3624 
3625 	return;
3626 }
3627 
3628 /**
3629  * smack_getprocattr - Smack process attribute access
3630  * @p: the object task
3631  * @name: the name of the attribute in /proc/.../attr
3632  * @value: where to put the result
3633  *
3634  * Places a copy of the task Smack into value
3635  *
3636  * Returns the length of the smack label or an error code
3637  */
3638 static int smack_getprocattr(struct task_struct *p, const char *name, char **value)
3639 {
3640 	struct smack_known *skp = smk_of_task_struct_obj(p);
3641 	char *cp;
3642 	int slen;
3643 
3644 	if (strcmp(name, "current") != 0)
3645 		return -EINVAL;
3646 
3647 	cp = kstrdup(skp->smk_known, GFP_KERNEL);
3648 	if (cp == NULL)
3649 		return -ENOMEM;
3650 
3651 	slen = strlen(cp);
3652 	*value = cp;
3653 	return slen;
3654 }
3655 
3656 /**
3657  * smack_setprocattr - Smack process attribute setting
3658  * @name: the name of the attribute in /proc/.../attr
3659  * @value: the value to set
3660  * @size: the size of the value
3661  *
3662  * Sets the Smack value of the task. Only setting self
3663  * is permitted and only with privilege
3664  *
3665  * Returns the length of the smack label or an error code
3666  */
3667 static int smack_setprocattr(const char *name, void *value, size_t size)
3668 {
3669 	struct task_smack *tsp = smack_cred(current_cred());
3670 	struct cred *new;
3671 	struct smack_known *skp;
3672 	struct smack_known_list_elem *sklep;
3673 	int rc;
3674 
3675 	if (!smack_privileged(CAP_MAC_ADMIN) && list_empty(&tsp->smk_relabel))
3676 		return -EPERM;
3677 
3678 	if (value == NULL || size == 0 || size >= SMK_LONGLABEL)
3679 		return -EINVAL;
3680 
3681 	if (strcmp(name, "current") != 0)
3682 		return -EINVAL;
3683 
3684 	skp = smk_import_entry(value, size);
3685 	if (IS_ERR(skp))
3686 		return PTR_ERR(skp);
3687 
3688 	/*
3689 	 * No process is ever allowed the web ("@") label
3690 	 * and the star ("*") label.
3691 	 */
3692 	if (skp == &smack_known_web || skp == &smack_known_star)
3693 		return -EINVAL;
3694 
3695 	if (!smack_privileged(CAP_MAC_ADMIN)) {
3696 		rc = -EPERM;
3697 		list_for_each_entry(sklep, &tsp->smk_relabel, list)
3698 			if (sklep->smk_label == skp) {
3699 				rc = 0;
3700 				break;
3701 			}
3702 		if (rc)
3703 			return rc;
3704 	}
3705 
3706 	new = prepare_creds();
3707 	if (new == NULL)
3708 		return -ENOMEM;
3709 
3710 	tsp = smack_cred(new);
3711 	tsp->smk_task = skp;
3712 	/*
3713 	 * process can change its label only once
3714 	 */
3715 	smk_destroy_label_list(&tsp->smk_relabel);
3716 
3717 	commit_creds(new);
3718 	return size;
3719 }
3720 
3721 /**
3722  * smack_unix_stream_connect - Smack access on UDS
3723  * @sock: one sock
3724  * @other: the other sock
3725  * @newsk: unused
3726  *
3727  * Return 0 if a subject with the smack of sock could access
3728  * an object with the smack of other, otherwise an error code
3729  */
3730 static int smack_unix_stream_connect(struct sock *sock,
3731 				     struct sock *other, struct sock *newsk)
3732 {
3733 	struct smack_known *skp;
3734 	struct smack_known *okp;
3735 	struct socket_smack *ssp = sock->sk_security;
3736 	struct socket_smack *osp = other->sk_security;
3737 	struct socket_smack *nsp = newsk->sk_security;
3738 	struct smk_audit_info ad;
3739 	int rc = 0;
3740 #ifdef CONFIG_AUDIT
3741 	struct lsm_network_audit net;
3742 #endif
3743 
3744 	if (!smack_privileged(CAP_MAC_OVERRIDE)) {
3745 		skp = ssp->smk_out;
3746 		okp = osp->smk_in;
3747 #ifdef CONFIG_AUDIT
3748 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3749 		smk_ad_setfield_u_net_sk(&ad, other);
3750 #endif
3751 		rc = smk_access(skp, okp, MAY_WRITE, &ad);
3752 		rc = smk_bu_note("UDS connect", skp, okp, MAY_WRITE, rc);
3753 		if (rc == 0) {
3754 			okp = osp->smk_out;
3755 			skp = ssp->smk_in;
3756 			rc = smk_access(okp, skp, MAY_WRITE, &ad);
3757 			rc = smk_bu_note("UDS connect", okp, skp,
3758 						MAY_WRITE, rc);
3759 		}
3760 	}
3761 
3762 	/*
3763 	 * Cross reference the peer labels for SO_PEERSEC.
3764 	 */
3765 	if (rc == 0) {
3766 		nsp->smk_packet = ssp->smk_out;
3767 		ssp->smk_packet = osp->smk_out;
3768 	}
3769 
3770 	return rc;
3771 }
3772 
3773 /**
3774  * smack_unix_may_send - Smack access on UDS
3775  * @sock: one socket
3776  * @other: the other socket
3777  *
3778  * Return 0 if a subject with the smack of sock could access
3779  * an object with the smack of other, otherwise an error code
3780  */
3781 static int smack_unix_may_send(struct socket *sock, struct socket *other)
3782 {
3783 	struct socket_smack *ssp = sock->sk->sk_security;
3784 	struct socket_smack *osp = other->sk->sk_security;
3785 	struct smk_audit_info ad;
3786 	int rc;
3787 
3788 #ifdef CONFIG_AUDIT
3789 	struct lsm_network_audit net;
3790 
3791 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
3792 	smk_ad_setfield_u_net_sk(&ad, other->sk);
3793 #endif
3794 
3795 	if (smack_privileged(CAP_MAC_OVERRIDE))
3796 		return 0;
3797 
3798 	rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
3799 	rc = smk_bu_note("UDS send", ssp->smk_out, osp->smk_in, MAY_WRITE, rc);
3800 	return rc;
3801 }
3802 
3803 /**
3804  * smack_socket_sendmsg - Smack check based on destination host
3805  * @sock: the socket
3806  * @msg: the message
3807  * @size: the size of the message
3808  *
3809  * Return 0 if the current subject can write to the destination host.
3810  * For IPv4 this is only a question if the destination is a single label host.
3811  * For IPv6 this is a check against the label of the port.
3812  */
3813 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
3814 				int size)
3815 {
3816 	struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name;
3817 #if IS_ENABLED(CONFIG_IPV6)
3818 	struct sockaddr_in6 *sap = (struct sockaddr_in6 *) msg->msg_name;
3819 #endif
3820 #ifdef SMACK_IPV6_SECMARK_LABELING
3821 	struct socket_smack *ssp = sock->sk->sk_security;
3822 	struct smack_known *rsp;
3823 #endif
3824 	int rc = 0;
3825 
3826 	/*
3827 	 * Perfectly reasonable for this to be NULL
3828 	 */
3829 	if (sip == NULL)
3830 		return 0;
3831 
3832 	switch (sock->sk->sk_family) {
3833 	case AF_INET:
3834 		if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
3835 		    sip->sin_family != AF_INET)
3836 			return -EINVAL;
3837 		rc = smk_ipv4_check(sock->sk, sip);
3838 		break;
3839 #if IS_ENABLED(CONFIG_IPV6)
3840 	case AF_INET6:
3841 		if (msg->msg_namelen < SIN6_LEN_RFC2133 ||
3842 		    sap->sin6_family != AF_INET6)
3843 			return -EINVAL;
3844 #ifdef SMACK_IPV6_SECMARK_LABELING
3845 		rsp = smack_ipv6host_label(sap);
3846 		if (rsp != NULL)
3847 			rc = smk_ipv6_check(ssp->smk_out, rsp, sap,
3848 						SMK_CONNECTING);
3849 #endif
3850 #ifdef SMACK_IPV6_PORT_LABELING
3851 		rc = smk_ipv6_port_check(sock->sk, sap, SMK_SENDING);
3852 #endif
3853 #endif /* IS_ENABLED(CONFIG_IPV6) */
3854 		break;
3855 	}
3856 	return rc;
3857 }
3858 
3859 /**
3860  * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
3861  * @sap: netlabel secattr
3862  * @ssp: socket security information
3863  *
3864  * Returns a pointer to a Smack label entry found on the label list.
3865  */
3866 static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
3867 						struct socket_smack *ssp)
3868 {
3869 	struct smack_known *skp;
3870 	int found = 0;
3871 	int acat;
3872 	int kcat;
3873 
3874 	/*
3875 	 * Netlabel found it in the cache.
3876 	 */
3877 	if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
3878 		return (struct smack_known *)sap->cache->data;
3879 
3880 	if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
3881 		/*
3882 		 * Looks like a fallback, which gives us a secid.
3883 		 */
3884 		return smack_from_secid(sap->attr.secid);
3885 
3886 	if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
3887 		/*
3888 		 * Looks like a CIPSO packet.
3889 		 * If there are flags but no level netlabel isn't
3890 		 * behaving the way we expect it to.
3891 		 *
3892 		 * Look it up in the label table
3893 		 * Without guidance regarding the smack value
3894 		 * for the packet fall back on the network
3895 		 * ambient value.
3896 		 */
3897 		rcu_read_lock();
3898 		list_for_each_entry_rcu(skp, &smack_known_list, list) {
3899 			if (sap->attr.mls.lvl != skp->smk_netlabel.attr.mls.lvl)
3900 				continue;
3901 			/*
3902 			 * Compare the catsets. Use the netlbl APIs.
3903 			 */
3904 			if ((sap->flags & NETLBL_SECATTR_MLS_CAT) == 0) {
3905 				if ((skp->smk_netlabel.flags &
3906 				     NETLBL_SECATTR_MLS_CAT) == 0)
3907 					found = 1;
3908 				break;
3909 			}
3910 			for (acat = -1, kcat = -1; acat == kcat; ) {
3911 				acat = netlbl_catmap_walk(sap->attr.mls.cat,
3912 							  acat + 1);
3913 				kcat = netlbl_catmap_walk(
3914 					skp->smk_netlabel.attr.mls.cat,
3915 					kcat + 1);
3916 				if (acat < 0 || kcat < 0)
3917 					break;
3918 			}
3919 			if (acat == kcat) {
3920 				found = 1;
3921 				break;
3922 			}
3923 		}
3924 		rcu_read_unlock();
3925 
3926 		if (found)
3927 			return skp;
3928 
3929 		if (ssp != NULL && ssp->smk_in == &smack_known_star)
3930 			return &smack_known_web;
3931 		return &smack_known_star;
3932 	}
3933 	/*
3934 	 * Without guidance regarding the smack value
3935 	 * for the packet fall back on the network
3936 	 * ambient value.
3937 	 */
3938 	return smack_net_ambient;
3939 }
3940 
3941 #if IS_ENABLED(CONFIG_IPV6)
3942 static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
3943 {
3944 	u8 nexthdr;
3945 	int offset;
3946 	int proto = -EINVAL;
3947 	struct ipv6hdr _ipv6h;
3948 	struct ipv6hdr *ip6;
3949 	__be16 frag_off;
3950 	struct tcphdr _tcph, *th;
3951 	struct udphdr _udph, *uh;
3952 	struct dccp_hdr _dccph, *dh;
3953 
3954 	sip->sin6_port = 0;
3955 
3956 	offset = skb_network_offset(skb);
3957 	ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3958 	if (ip6 == NULL)
3959 		return -EINVAL;
3960 	sip->sin6_addr = ip6->saddr;
3961 
3962 	nexthdr = ip6->nexthdr;
3963 	offset += sizeof(_ipv6h);
3964 	offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3965 	if (offset < 0)
3966 		return -EINVAL;
3967 
3968 	proto = nexthdr;
3969 	switch (proto) {
3970 	case IPPROTO_TCP:
3971 		th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3972 		if (th != NULL)
3973 			sip->sin6_port = th->source;
3974 		break;
3975 	case IPPROTO_UDP:
3976 	case IPPROTO_UDPLITE:
3977 		uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3978 		if (uh != NULL)
3979 			sip->sin6_port = uh->source;
3980 		break;
3981 	case IPPROTO_DCCP:
3982 		dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3983 		if (dh != NULL)
3984 			sip->sin6_port = dh->dccph_sport;
3985 		break;
3986 	}
3987 	return proto;
3988 }
3989 #endif /* CONFIG_IPV6 */
3990 
3991 /**
3992  * smack_from_skb - Smack data from the secmark in an skb
3993  * @skb: packet
3994  *
3995  * Returns smack_known of the secmark or NULL if that won't work.
3996  */
3997 #ifdef CONFIG_NETWORK_SECMARK
3998 static struct smack_known *smack_from_skb(struct sk_buff *skb)
3999 {
4000 	if (skb == NULL || skb->secmark == 0)
4001 		return NULL;
4002 
4003 	return smack_from_secid(skb->secmark);
4004 }
4005 #else
4006 static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
4007 {
4008 	return NULL;
4009 }
4010 #endif
4011 
4012 /**
4013  * smack_from_netlbl - Smack data from the IP options in an skb
4014  * @sk: socket data came in on
4015  * @family: address family
4016  * @skb: packet
4017  *
4018  * Find the Smack label in the IP options. If it hasn't been
4019  * added to the netlabel cache, add it here.
4020  *
4021  * Returns smack_known of the IP options or NULL if that won't work.
4022  */
4023 static struct smack_known *smack_from_netlbl(const struct sock *sk, u16 family,
4024 					     struct sk_buff *skb)
4025 {
4026 	struct netlbl_lsm_secattr secattr;
4027 	struct socket_smack *ssp = NULL;
4028 	struct smack_known *skp = NULL;
4029 
4030 	netlbl_secattr_init(&secattr);
4031 
4032 	if (sk)
4033 		ssp = sk->sk_security;
4034 
4035 	if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
4036 		skp = smack_from_secattr(&secattr, ssp);
4037 		if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
4038 			netlbl_cache_add(skb, family, &skp->smk_netlabel);
4039 	}
4040 
4041 	netlbl_secattr_destroy(&secattr);
4042 
4043 	return skp;
4044 }
4045 
4046 /**
4047  * smack_socket_sock_rcv_skb - Smack packet delivery access check
4048  * @sk: socket
4049  * @skb: packet
4050  *
4051  * Returns 0 if the packet should be delivered, an error code otherwise
4052  */
4053 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4054 {
4055 	struct socket_smack *ssp = sk->sk_security;
4056 	struct smack_known *skp = NULL;
4057 	int rc = 0;
4058 	struct smk_audit_info ad;
4059 	u16 family = sk->sk_family;
4060 #ifdef CONFIG_AUDIT
4061 	struct lsm_network_audit net;
4062 #endif
4063 #if IS_ENABLED(CONFIG_IPV6)
4064 	struct sockaddr_in6 sadd;
4065 	int proto;
4066 
4067 	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4068 		family = PF_INET;
4069 #endif /* CONFIG_IPV6 */
4070 
4071 	switch (family) {
4072 	case PF_INET:
4073 		/*
4074 		 * If there is a secmark use it rather than the CIPSO label.
4075 		 * If there is no secmark fall back to CIPSO.
4076 		 * The secmark is assumed to reflect policy better.
4077 		 */
4078 		skp = smack_from_skb(skb);
4079 		if (skp == NULL) {
4080 			skp = smack_from_netlbl(sk, family, skb);
4081 			if (skp == NULL)
4082 				skp = smack_net_ambient;
4083 		}
4084 
4085 #ifdef CONFIG_AUDIT
4086 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4087 		ad.a.u.net->family = family;
4088 		ad.a.u.net->netif = skb->skb_iif;
4089 		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4090 #endif
4091 		/*
4092 		 * Receiving a packet requires that the other end
4093 		 * be able to write here. Read access is not required.
4094 		 * This is the simplist possible security model
4095 		 * for networking.
4096 		 */
4097 		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4098 		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
4099 					MAY_WRITE, rc);
4100 		if (rc != 0)
4101 			netlbl_skbuff_err(skb, family, rc, 0);
4102 		break;
4103 #if IS_ENABLED(CONFIG_IPV6)
4104 	case PF_INET6:
4105 		proto = smk_skb_to_addr_ipv6(skb, &sadd);
4106 		if (proto != IPPROTO_UDP && proto != IPPROTO_UDPLITE &&
4107 		    proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
4108 			break;
4109 #ifdef SMACK_IPV6_SECMARK_LABELING
4110 		skp = smack_from_skb(skb);
4111 		if (skp == NULL) {
4112 			if (smk_ipv6_localhost(&sadd))
4113 				break;
4114 			skp = smack_ipv6host_label(&sadd);
4115 			if (skp == NULL)
4116 				skp = smack_net_ambient;
4117 		}
4118 #ifdef CONFIG_AUDIT
4119 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4120 		ad.a.u.net->family = family;
4121 		ad.a.u.net->netif = skb->skb_iif;
4122 		ipv6_skb_to_auditdata(skb, &ad.a, NULL);
4123 #endif /* CONFIG_AUDIT */
4124 		rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4125 		rc = smk_bu_note("IPv6 delivery", skp, ssp->smk_in,
4126 					MAY_WRITE, rc);
4127 #endif /* SMACK_IPV6_SECMARK_LABELING */
4128 #ifdef SMACK_IPV6_PORT_LABELING
4129 		rc = smk_ipv6_port_check(sk, &sadd, SMK_RECEIVING);
4130 #endif /* SMACK_IPV6_PORT_LABELING */
4131 		if (rc != 0)
4132 			icmpv6_send(skb, ICMPV6_DEST_UNREACH,
4133 					ICMPV6_ADM_PROHIBITED, 0);
4134 		break;
4135 #endif /* CONFIG_IPV6 */
4136 	}
4137 
4138 	return rc;
4139 }
4140 
4141 /**
4142  * smack_socket_getpeersec_stream - pull in packet label
4143  * @sock: the socket
4144  * @optval: user's destination
4145  * @optlen: size thereof
4146  * @len: max thereof
4147  *
4148  * returns zero on success, an error code otherwise
4149  */
4150 static int smack_socket_getpeersec_stream(struct socket *sock,
4151 					  sockptr_t optval, sockptr_t optlen,
4152 					  unsigned int len)
4153 {
4154 	struct socket_smack *ssp;
4155 	char *rcp = "";
4156 	u32 slen = 1;
4157 	int rc = 0;
4158 
4159 	ssp = sock->sk->sk_security;
4160 	if (ssp->smk_packet != NULL) {
4161 		rcp = ssp->smk_packet->smk_known;
4162 		slen = strlen(rcp) + 1;
4163 	}
4164 	if (slen > len) {
4165 		rc = -ERANGE;
4166 		goto out_len;
4167 	}
4168 
4169 	if (copy_to_sockptr(optval, rcp, slen))
4170 		rc = -EFAULT;
4171 out_len:
4172 	if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
4173 		rc = -EFAULT;
4174 	return rc;
4175 }
4176 
4177 
4178 /**
4179  * smack_socket_getpeersec_dgram - pull in packet label
4180  * @sock: the peer socket
4181  * @skb: packet data
4182  * @secid: pointer to where to put the secid of the packet
4183  *
4184  * Sets the netlabel socket state on sk from parent
4185  */
4186 static int smack_socket_getpeersec_dgram(struct socket *sock,
4187 					 struct sk_buff *skb, u32 *secid)
4188 
4189 {
4190 	struct socket_smack *ssp = NULL;
4191 	struct smack_known *skp;
4192 	struct sock *sk = NULL;
4193 	int family = PF_UNSPEC;
4194 	u32 s = 0;	/* 0 is the invalid secid */
4195 
4196 	if (skb != NULL) {
4197 		if (skb->protocol == htons(ETH_P_IP))
4198 			family = PF_INET;
4199 #if IS_ENABLED(CONFIG_IPV6)
4200 		else if (skb->protocol == htons(ETH_P_IPV6))
4201 			family = PF_INET6;
4202 #endif /* CONFIG_IPV6 */
4203 	}
4204 	if (family == PF_UNSPEC && sock != NULL)
4205 		family = sock->sk->sk_family;
4206 
4207 	switch (family) {
4208 	case PF_UNIX:
4209 		ssp = sock->sk->sk_security;
4210 		s = ssp->smk_out->smk_secid;
4211 		break;
4212 	case PF_INET:
4213 		skp = smack_from_skb(skb);
4214 		if (skp) {
4215 			s = skp->smk_secid;
4216 			break;
4217 		}
4218 		/*
4219 		 * Translate what netlabel gave us.
4220 		 */
4221 		if (sock != NULL)
4222 			sk = sock->sk;
4223 		skp = smack_from_netlbl(sk, family, skb);
4224 		if (skp != NULL)
4225 			s = skp->smk_secid;
4226 		break;
4227 	case PF_INET6:
4228 #ifdef SMACK_IPV6_SECMARK_LABELING
4229 		skp = smack_from_skb(skb);
4230 		if (skp)
4231 			s = skp->smk_secid;
4232 #endif
4233 		break;
4234 	}
4235 	*secid = s;
4236 	if (s == 0)
4237 		return -EINVAL;
4238 	return 0;
4239 }
4240 
4241 /**
4242  * smack_sock_graft - Initialize a newly created socket with an existing sock
4243  * @sk: child sock
4244  * @parent: parent socket
4245  *
4246  * Set the smk_{in,out} state of an existing sock based on the process that
4247  * is creating the new socket.
4248  */
4249 static void smack_sock_graft(struct sock *sk, struct socket *parent)
4250 {
4251 	struct socket_smack *ssp;
4252 	struct smack_known *skp = smk_of_current();
4253 
4254 	if (sk == NULL ||
4255 	    (sk->sk_family != PF_INET && sk->sk_family != PF_INET6))
4256 		return;
4257 
4258 	ssp = sk->sk_security;
4259 	ssp->smk_in = skp;
4260 	ssp->smk_out = skp;
4261 	/* cssp->smk_packet is already set in smack_inet_csk_clone() */
4262 }
4263 
4264 /**
4265  * smack_inet_conn_request - Smack access check on connect
4266  * @sk: socket involved
4267  * @skb: packet
4268  * @req: unused
4269  *
4270  * Returns 0 if a task with the packet label could write to
4271  * the socket, otherwise an error code
4272  */
4273 static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
4274 				   struct request_sock *req)
4275 {
4276 	u16 family = sk->sk_family;
4277 	struct smack_known *skp;
4278 	struct socket_smack *ssp = sk->sk_security;
4279 	struct sockaddr_in addr;
4280 	struct iphdr *hdr;
4281 	struct smack_known *hskp;
4282 	int rc;
4283 	struct smk_audit_info ad;
4284 #ifdef CONFIG_AUDIT
4285 	struct lsm_network_audit net;
4286 #endif
4287 
4288 #if IS_ENABLED(CONFIG_IPV6)
4289 	if (family == PF_INET6) {
4290 		/*
4291 		 * Handle mapped IPv4 packets arriving
4292 		 * via IPv6 sockets. Don't set up netlabel
4293 		 * processing on IPv6.
4294 		 */
4295 		if (skb->protocol == htons(ETH_P_IP))
4296 			family = PF_INET;
4297 		else
4298 			return 0;
4299 	}
4300 #endif /* CONFIG_IPV6 */
4301 
4302 	/*
4303 	 * If there is a secmark use it rather than the CIPSO label.
4304 	 * If there is no secmark fall back to CIPSO.
4305 	 * The secmark is assumed to reflect policy better.
4306 	 */
4307 	skp = smack_from_skb(skb);
4308 	if (skp == NULL) {
4309 		skp = smack_from_netlbl(sk, family, skb);
4310 		if (skp == NULL)
4311 			skp = &smack_known_huh;
4312 	}
4313 
4314 #ifdef CONFIG_AUDIT
4315 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
4316 	ad.a.u.net->family = family;
4317 	ad.a.u.net->netif = skb->skb_iif;
4318 	ipv4_skb_to_auditdata(skb, &ad.a, NULL);
4319 #endif
4320 	/*
4321 	 * Receiving a packet requires that the other end be able to write
4322 	 * here. Read access is not required.
4323 	 */
4324 	rc = smk_access(skp, ssp->smk_in, MAY_WRITE, &ad);
4325 	rc = smk_bu_note("IPv4 connect", skp, ssp->smk_in, MAY_WRITE, rc);
4326 	if (rc != 0)
4327 		return rc;
4328 
4329 	/*
4330 	 * Save the peer's label in the request_sock so we can later setup
4331 	 * smk_packet in the child socket so that SO_PEERCRED can report it.
4332 	 */
4333 	req->peer_secid = skp->smk_secid;
4334 
4335 	/*
4336 	 * We need to decide if we want to label the incoming connection here
4337 	 * if we do we only need to label the request_sock and the stack will
4338 	 * propagate the wire-label to the sock when it is created.
4339 	 */
4340 	hdr = ip_hdr(skb);
4341 	addr.sin_addr.s_addr = hdr->saddr;
4342 	rcu_read_lock();
4343 	hskp = smack_ipv4host_label(&addr);
4344 	rcu_read_unlock();
4345 
4346 	if (hskp == NULL)
4347 		rc = netlbl_req_setattr(req, &skp->smk_netlabel);
4348 	else
4349 		netlbl_req_delattr(req);
4350 
4351 	return rc;
4352 }
4353 
4354 /**
4355  * smack_inet_csk_clone - Copy the connection information to the new socket
4356  * @sk: the new socket
4357  * @req: the connection's request_sock
4358  *
4359  * Transfer the connection's peer label to the newly created socket.
4360  */
4361 static void smack_inet_csk_clone(struct sock *sk,
4362 				 const struct request_sock *req)
4363 {
4364 	struct socket_smack *ssp = sk->sk_security;
4365 	struct smack_known *skp;
4366 
4367 	if (req->peer_secid != 0) {
4368 		skp = smack_from_secid(req->peer_secid);
4369 		ssp->smk_packet = skp;
4370 	} else
4371 		ssp->smk_packet = NULL;
4372 }
4373 
4374 /*
4375  * Key management security hooks
4376  *
4377  * Casey has not tested key support very heavily.
4378  * The permission check is most likely too restrictive.
4379  * If you care about keys please have a look.
4380  */
4381 #ifdef CONFIG_KEYS
4382 
4383 /**
4384  * smack_key_alloc - Set the key security blob
4385  * @key: object
4386  * @cred: the credentials to use
4387  * @flags: unused
4388  *
4389  * No allocation required
4390  *
4391  * Returns 0
4392  */
4393 static int smack_key_alloc(struct key *key, const struct cred *cred,
4394 			   unsigned long flags)
4395 {
4396 	struct smack_known *skp = smk_of_task(smack_cred(cred));
4397 
4398 	key->security = skp;
4399 	return 0;
4400 }
4401 
4402 /**
4403  * smack_key_free - Clear the key security blob
4404  * @key: the object
4405  *
4406  * Clear the blob pointer
4407  */
4408 static void smack_key_free(struct key *key)
4409 {
4410 	key->security = NULL;
4411 }
4412 
4413 /**
4414  * smack_key_permission - Smack access on a key
4415  * @key_ref: gets to the object
4416  * @cred: the credentials to use
4417  * @need_perm: requested key permission
4418  *
4419  * Return 0 if the task has read and write to the object,
4420  * an error code otherwise
4421  */
4422 static int smack_key_permission(key_ref_t key_ref,
4423 				const struct cred *cred,
4424 				enum key_need_perm need_perm)
4425 {
4426 	struct key *keyp;
4427 	struct smk_audit_info ad;
4428 	struct smack_known *tkp = smk_of_task(smack_cred(cred));
4429 	int request = 0;
4430 	int rc;
4431 
4432 	/*
4433 	 * Validate requested permissions
4434 	 */
4435 	switch (need_perm) {
4436 	case KEY_NEED_READ:
4437 	case KEY_NEED_SEARCH:
4438 	case KEY_NEED_VIEW:
4439 		request |= MAY_READ;
4440 		break;
4441 	case KEY_NEED_WRITE:
4442 	case KEY_NEED_LINK:
4443 	case KEY_NEED_SETATTR:
4444 		request |= MAY_WRITE;
4445 		break;
4446 	case KEY_NEED_UNSPECIFIED:
4447 	case KEY_NEED_UNLINK:
4448 	case KEY_SYSADMIN_OVERRIDE:
4449 	case KEY_AUTHTOKEN_OVERRIDE:
4450 	case KEY_DEFER_PERM_CHECK:
4451 		return 0;
4452 	default:
4453 		return -EINVAL;
4454 	}
4455 
4456 	keyp = key_ref_to_ptr(key_ref);
4457 	if (keyp == NULL)
4458 		return -EINVAL;
4459 	/*
4460 	 * If the key hasn't been initialized give it access so that
4461 	 * it may do so.
4462 	 */
4463 	if (keyp->security == NULL)
4464 		return 0;
4465 	/*
4466 	 * This should not occur
4467 	 */
4468 	if (tkp == NULL)
4469 		return -EACCES;
4470 
4471 	if (smack_privileged(CAP_MAC_OVERRIDE))
4472 		return 0;
4473 
4474 #ifdef CONFIG_AUDIT
4475 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4476 	ad.a.u.key_struct.key = keyp->serial;
4477 	ad.a.u.key_struct.key_desc = keyp->description;
4478 #endif
4479 	rc = smk_access(tkp, keyp->security, request, &ad);
4480 	rc = smk_bu_note("key access", tkp, keyp->security, request, rc);
4481 	return rc;
4482 }
4483 
4484 /*
4485  * smack_key_getsecurity - Smack label tagging the key
4486  * @key points to the key to be queried
4487  * @_buffer points to a pointer that should be set to point to the
4488  * resulting string (if no label or an error occurs).
4489  * Return the length of the string (including terminating NUL) or -ve if
4490  * an error.
4491  * May also return 0 (and a NULL buffer pointer) if there is no label.
4492  */
4493 static int smack_key_getsecurity(struct key *key, char **_buffer)
4494 {
4495 	struct smack_known *skp = key->security;
4496 	size_t length;
4497 	char *copy;
4498 
4499 	if (key->security == NULL) {
4500 		*_buffer = NULL;
4501 		return 0;
4502 	}
4503 
4504 	copy = kstrdup(skp->smk_known, GFP_KERNEL);
4505 	if (copy == NULL)
4506 		return -ENOMEM;
4507 	length = strlen(copy) + 1;
4508 
4509 	*_buffer = copy;
4510 	return length;
4511 }
4512 
4513 
4514 #ifdef CONFIG_KEY_NOTIFICATIONS
4515 /**
4516  * smack_watch_key - Smack access to watch a key for notifications.
4517  * @key: The key to be watched
4518  *
4519  * Return 0 if the @watch->cred has permission to read from the key object and
4520  * an error otherwise.
4521  */
4522 static int smack_watch_key(struct key *key)
4523 {
4524 	struct smk_audit_info ad;
4525 	struct smack_known *tkp = smk_of_current();
4526 	int rc;
4527 
4528 	if (key == NULL)
4529 		return -EINVAL;
4530 	/*
4531 	 * If the key hasn't been initialized give it access so that
4532 	 * it may do so.
4533 	 */
4534 	if (key->security == NULL)
4535 		return 0;
4536 	/*
4537 	 * This should not occur
4538 	 */
4539 	if (tkp == NULL)
4540 		return -EACCES;
4541 
4542 	if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4543 		return 0;
4544 
4545 #ifdef CONFIG_AUDIT
4546 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY);
4547 	ad.a.u.key_struct.key = key->serial;
4548 	ad.a.u.key_struct.key_desc = key->description;
4549 #endif
4550 	rc = smk_access(tkp, key->security, MAY_READ, &ad);
4551 	rc = smk_bu_note("key watch", tkp, key->security, MAY_READ, rc);
4552 	return rc;
4553 }
4554 #endif /* CONFIG_KEY_NOTIFICATIONS */
4555 #endif /* CONFIG_KEYS */
4556 
4557 #ifdef CONFIG_WATCH_QUEUE
4558 /**
4559  * smack_post_notification - Smack access to post a notification to a queue
4560  * @w_cred: The credentials of the watcher.
4561  * @cred: The credentials of the event source (may be NULL).
4562  * @n: The notification message to be posted.
4563  */
4564 static int smack_post_notification(const struct cred *w_cred,
4565 				   const struct cred *cred,
4566 				   struct watch_notification *n)
4567 {
4568 	struct smk_audit_info ad;
4569 	struct smack_known *subj, *obj;
4570 	int rc;
4571 
4572 	/* Always let maintenance notifications through. */
4573 	if (n->type == WATCH_TYPE_META)
4574 		return 0;
4575 
4576 	if (!cred)
4577 		return 0;
4578 	subj = smk_of_task(smack_cred(cred));
4579 	obj = smk_of_task(smack_cred(w_cred));
4580 
4581 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NOTIFICATION);
4582 	rc = smk_access(subj, obj, MAY_WRITE, &ad);
4583 	rc = smk_bu_note("notification", subj, obj, MAY_WRITE, rc);
4584 	return rc;
4585 }
4586 #endif /* CONFIG_WATCH_QUEUE */
4587 
4588 /*
4589  * Smack Audit hooks
4590  *
4591  * Audit requires a unique representation of each Smack specific
4592  * rule. This unique representation is used to distinguish the
4593  * object to be audited from remaining kernel objects and also
4594  * works as a glue between the audit hooks.
4595  *
4596  * Since repository entries are added but never deleted, we'll use
4597  * the smack_known label address related to the given audit rule as
4598  * the needed unique representation. This also better fits the smack
4599  * model where nearly everything is a label.
4600  */
4601 #ifdef CONFIG_AUDIT
4602 
4603 /**
4604  * smack_audit_rule_init - Initialize a smack audit rule
4605  * @field: audit rule fields given from user-space (audit.h)
4606  * @op: required testing operator (=, !=, >, <, ...)
4607  * @rulestr: smack label to be audited
4608  * @vrule: pointer to save our own audit rule representation
4609  *
4610  * Prepare to audit cases where (@field @op @rulestr) is true.
4611  * The label to be audited is created if necessay.
4612  */
4613 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
4614 {
4615 	struct smack_known *skp;
4616 	char **rule = (char **)vrule;
4617 	*rule = NULL;
4618 
4619 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4620 		return -EINVAL;
4621 
4622 	if (op != Audit_equal && op != Audit_not_equal)
4623 		return -EINVAL;
4624 
4625 	skp = smk_import_entry(rulestr, 0);
4626 	if (IS_ERR(skp))
4627 		return PTR_ERR(skp);
4628 
4629 	*rule = skp->smk_known;
4630 
4631 	return 0;
4632 }
4633 
4634 /**
4635  * smack_audit_rule_known - Distinguish Smack audit rules
4636  * @krule: rule of interest, in Audit kernel representation format
4637  *
4638  * This is used to filter Smack rules from remaining Audit ones.
4639  * If it's proved that this rule belongs to us, the
4640  * audit_rule_match hook will be called to do the final judgement.
4641  */
4642 static int smack_audit_rule_known(struct audit_krule *krule)
4643 {
4644 	struct audit_field *f;
4645 	int i;
4646 
4647 	for (i = 0; i < krule->field_count; i++) {
4648 		f = &krule->fields[i];
4649 
4650 		if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
4651 			return 1;
4652 	}
4653 
4654 	return 0;
4655 }
4656 
4657 /**
4658  * smack_audit_rule_match - Audit given object ?
4659  * @secid: security id for identifying the object to test
4660  * @field: audit rule flags given from user-space
4661  * @op: required testing operator
4662  * @vrule: smack internal rule presentation
4663  *
4664  * The core Audit hook. It's used to take the decision of
4665  * whether to audit or not to audit a given object.
4666  */
4667 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule)
4668 {
4669 	struct smack_known *skp;
4670 	char *rule = vrule;
4671 
4672 	if (unlikely(!rule)) {
4673 		WARN_ONCE(1, "Smack: missing rule\n");
4674 		return -ENOENT;
4675 	}
4676 
4677 	if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
4678 		return 0;
4679 
4680 	skp = smack_from_secid(secid);
4681 
4682 	/*
4683 	 * No need to do string comparisons. If a match occurs,
4684 	 * both pointers will point to the same smack_known
4685 	 * label.
4686 	 */
4687 	if (op == Audit_equal)
4688 		return (rule == skp->smk_known);
4689 	if (op == Audit_not_equal)
4690 		return (rule != skp->smk_known);
4691 
4692 	return 0;
4693 }
4694 
4695 /*
4696  * There is no need for a smack_audit_rule_free hook.
4697  * No memory was allocated.
4698  */
4699 
4700 #endif /* CONFIG_AUDIT */
4701 
4702 /**
4703  * smack_ismaclabel - check if xattr @name references a smack MAC label
4704  * @name: Full xattr name to check.
4705  */
4706 static int smack_ismaclabel(const char *name)
4707 {
4708 	return (strcmp(name, XATTR_SMACK_SUFFIX) == 0);
4709 }
4710 
4711 
4712 /**
4713  * smack_secid_to_secctx - return the smack label for a secid
4714  * @secid: incoming integer
4715  * @secdata: destination
4716  * @seclen: how long it is
4717  *
4718  * Exists for networking code.
4719  */
4720 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
4721 {
4722 	struct smack_known *skp = smack_from_secid(secid);
4723 
4724 	if (secdata)
4725 		*secdata = skp->smk_known;
4726 	*seclen = strlen(skp->smk_known);
4727 	return 0;
4728 }
4729 
4730 /**
4731  * smack_secctx_to_secid - return the secid for a smack label
4732  * @secdata: smack label
4733  * @seclen: how long result is
4734  * @secid: outgoing integer
4735  *
4736  * Exists for audit and networking code.
4737  */
4738 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
4739 {
4740 	struct smack_known *skp = smk_find_entry(secdata);
4741 
4742 	if (skp)
4743 		*secid = skp->smk_secid;
4744 	else
4745 		*secid = 0;
4746 	return 0;
4747 }
4748 
4749 /*
4750  * There used to be a smack_release_secctx hook
4751  * that did nothing back when hooks were in a vector.
4752  * Now that there's a list such a hook adds cost.
4753  */
4754 
4755 static int smack_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
4756 {
4757 	return smack_inode_setsecurity(inode, XATTR_SMACK_SUFFIX, ctx,
4758 				       ctxlen, 0);
4759 }
4760 
4761 static int smack_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
4762 {
4763 	return __vfs_setxattr_noperm(&nop_mnt_idmap, dentry, XATTR_NAME_SMACK,
4764 				     ctx, ctxlen, 0);
4765 }
4766 
4767 static int smack_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
4768 {
4769 	struct smack_known *skp = smk_of_inode(inode);
4770 
4771 	*ctx = skp->smk_known;
4772 	*ctxlen = strlen(skp->smk_known);
4773 	return 0;
4774 }
4775 
4776 static int smack_inode_copy_up(struct dentry *dentry, struct cred **new)
4777 {
4778 
4779 	struct task_smack *tsp;
4780 	struct smack_known *skp;
4781 	struct inode_smack *isp;
4782 	struct cred *new_creds = *new;
4783 
4784 	if (new_creds == NULL) {
4785 		new_creds = prepare_creds();
4786 		if (new_creds == NULL)
4787 			return -ENOMEM;
4788 	}
4789 
4790 	tsp = smack_cred(new_creds);
4791 
4792 	/*
4793 	 * Get label from overlay inode and set it in create_sid
4794 	 */
4795 	isp = smack_inode(d_inode(dentry));
4796 	skp = isp->smk_inode;
4797 	tsp->smk_task = skp;
4798 	*new = new_creds;
4799 	return 0;
4800 }
4801 
4802 static int smack_inode_copy_up_xattr(const char *name)
4803 {
4804 	/*
4805 	 * Return 1 if this is the smack access Smack attribute.
4806 	 */
4807 	if (strcmp(name, XATTR_NAME_SMACK) == 0)
4808 		return 1;
4809 
4810 	return -EOPNOTSUPP;
4811 }
4812 
4813 static int smack_dentry_create_files_as(struct dentry *dentry, int mode,
4814 					struct qstr *name,
4815 					const struct cred *old,
4816 					struct cred *new)
4817 {
4818 	struct task_smack *otsp = smack_cred(old);
4819 	struct task_smack *ntsp = smack_cred(new);
4820 	struct inode_smack *isp;
4821 	int may;
4822 
4823 	/*
4824 	 * Use the process credential unless all of
4825 	 * the transmuting criteria are met
4826 	 */
4827 	ntsp->smk_task = otsp->smk_task;
4828 
4829 	/*
4830 	 * the attribute of the containing directory
4831 	 */
4832 	isp = smack_inode(d_inode(dentry->d_parent));
4833 
4834 	if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
4835 		rcu_read_lock();
4836 		may = smk_access_entry(otsp->smk_task->smk_known,
4837 				       isp->smk_inode->smk_known,
4838 				       &otsp->smk_task->smk_rules);
4839 		rcu_read_unlock();
4840 
4841 		/*
4842 		 * If the directory is transmuting and the rule
4843 		 * providing access is transmuting use the containing
4844 		 * directory label instead of the process label.
4845 		 */
4846 		if (may > 0 && (may & MAY_TRANSMUTE)) {
4847 			ntsp->smk_task = isp->smk_inode;
4848 			ntsp->smk_transmuted = ntsp->smk_task;
4849 		}
4850 	}
4851 	return 0;
4852 }
4853 
4854 #ifdef CONFIG_IO_URING
4855 /**
4856  * smack_uring_override_creds - Is io_uring cred override allowed?
4857  * @new: the target creds
4858  *
4859  * Check to see if the current task is allowed to override it's credentials
4860  * to service an io_uring operation.
4861  */
4862 static int smack_uring_override_creds(const struct cred *new)
4863 {
4864 	struct task_smack *tsp = smack_cred(current_cred());
4865 	struct task_smack *nsp = smack_cred(new);
4866 
4867 	/*
4868 	 * Allow the degenerate case where the new Smack value is
4869 	 * the same as the current Smack value.
4870 	 */
4871 	if (tsp->smk_task == nsp->smk_task)
4872 		return 0;
4873 
4874 	if (smack_privileged_cred(CAP_MAC_OVERRIDE, current_cred()))
4875 		return 0;
4876 
4877 	return -EPERM;
4878 }
4879 
4880 /**
4881  * smack_uring_sqpoll - check if a io_uring polling thread can be created
4882  *
4883  * Check to see if the current task is allowed to create a new io_uring
4884  * kernel polling thread.
4885  */
4886 static int smack_uring_sqpoll(void)
4887 {
4888 	if (smack_privileged_cred(CAP_MAC_ADMIN, current_cred()))
4889 		return 0;
4890 
4891 	return -EPERM;
4892 }
4893 
4894 /**
4895  * smack_uring_cmd - check on file operations for io_uring
4896  * @ioucmd: the command in question
4897  *
4898  * Make a best guess about whether a io_uring "command" should
4899  * be allowed. Use the same logic used for determining if the
4900  * file could be opened for read in the absence of better criteria.
4901  */
4902 static int smack_uring_cmd(struct io_uring_cmd *ioucmd)
4903 {
4904 	struct file *file = ioucmd->file;
4905 	struct smk_audit_info ad;
4906 	struct task_smack *tsp;
4907 	struct inode *inode;
4908 	int rc;
4909 
4910 	if (!file)
4911 		return -EINVAL;
4912 
4913 	tsp = smack_cred(file->f_cred);
4914 	inode = file_inode(file);
4915 
4916 	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
4917 	smk_ad_setfield_u_fs_path(&ad, file->f_path);
4918 	rc = smk_tskacc(tsp, smk_of_inode(inode), MAY_READ, &ad);
4919 	rc = smk_bu_credfile(file->f_cred, file, MAY_READ, rc);
4920 
4921 	return rc;
4922 }
4923 
4924 #endif /* CONFIG_IO_URING */
4925 
4926 struct lsm_blob_sizes smack_blob_sizes __ro_after_init = {
4927 	.lbs_cred = sizeof(struct task_smack),
4928 	.lbs_file = sizeof(struct smack_known *),
4929 	.lbs_inode = sizeof(struct inode_smack),
4930 	.lbs_ipc = sizeof(struct smack_known *),
4931 	.lbs_msg_msg = sizeof(struct smack_known *),
4932 	.lbs_superblock = sizeof(struct superblock_smack),
4933 	.lbs_xattr_count = SMACK_INODE_INIT_XATTRS,
4934 };
4935 
4936 static struct security_hook_list smack_hooks[] __ro_after_init = {
4937 	LSM_HOOK_INIT(ptrace_access_check, smack_ptrace_access_check),
4938 	LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
4939 	LSM_HOOK_INIT(syslog, smack_syslog),
4940 
4941 	LSM_HOOK_INIT(fs_context_submount, smack_fs_context_submount),
4942 	LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
4943 	LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),
4944 
4945 	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
4946 	LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
4947 	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
4948 	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
4949 	LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
4950 
4951 	LSM_HOOK_INIT(bprm_creds_for_exec, smack_bprm_creds_for_exec),
4952 
4953 	LSM_HOOK_INIT(inode_alloc_security, smack_inode_alloc_security),
4954 	LSM_HOOK_INIT(inode_init_security, smack_inode_init_security),
4955 	LSM_HOOK_INIT(inode_link, smack_inode_link),
4956 	LSM_HOOK_INIT(inode_unlink, smack_inode_unlink),
4957 	LSM_HOOK_INIT(inode_rmdir, smack_inode_rmdir),
4958 	LSM_HOOK_INIT(inode_rename, smack_inode_rename),
4959 	LSM_HOOK_INIT(inode_permission, smack_inode_permission),
4960 	LSM_HOOK_INIT(inode_setattr, smack_inode_setattr),
4961 	LSM_HOOK_INIT(inode_getattr, smack_inode_getattr),
4962 	LSM_HOOK_INIT(inode_setxattr, smack_inode_setxattr),
4963 	LSM_HOOK_INIT(inode_post_setxattr, smack_inode_post_setxattr),
4964 	LSM_HOOK_INIT(inode_getxattr, smack_inode_getxattr),
4965 	LSM_HOOK_INIT(inode_removexattr, smack_inode_removexattr),
4966 	LSM_HOOK_INIT(inode_set_acl, smack_inode_set_acl),
4967 	LSM_HOOK_INIT(inode_get_acl, smack_inode_get_acl),
4968 	LSM_HOOK_INIT(inode_remove_acl, smack_inode_remove_acl),
4969 	LSM_HOOK_INIT(inode_getsecurity, smack_inode_getsecurity),
4970 	LSM_HOOK_INIT(inode_setsecurity, smack_inode_setsecurity),
4971 	LSM_HOOK_INIT(inode_listsecurity, smack_inode_listsecurity),
4972 	LSM_HOOK_INIT(inode_getsecid, smack_inode_getsecid),
4973 
4974 	LSM_HOOK_INIT(file_alloc_security, smack_file_alloc_security),
4975 	LSM_HOOK_INIT(file_ioctl, smack_file_ioctl),
4976 	LSM_HOOK_INIT(file_ioctl_compat, smack_file_ioctl),
4977 	LSM_HOOK_INIT(file_lock, smack_file_lock),
4978 	LSM_HOOK_INIT(file_fcntl, smack_file_fcntl),
4979 	LSM_HOOK_INIT(mmap_file, smack_mmap_file),
4980 	LSM_HOOK_INIT(mmap_addr, cap_mmap_addr),
4981 	LSM_HOOK_INIT(file_set_fowner, smack_file_set_fowner),
4982 	LSM_HOOK_INIT(file_send_sigiotask, smack_file_send_sigiotask),
4983 	LSM_HOOK_INIT(file_receive, smack_file_receive),
4984 
4985 	LSM_HOOK_INIT(file_open, smack_file_open),
4986 
4987 	LSM_HOOK_INIT(cred_alloc_blank, smack_cred_alloc_blank),
4988 	LSM_HOOK_INIT(cred_free, smack_cred_free),
4989 	LSM_HOOK_INIT(cred_prepare, smack_cred_prepare),
4990 	LSM_HOOK_INIT(cred_transfer, smack_cred_transfer),
4991 	LSM_HOOK_INIT(cred_getsecid, smack_cred_getsecid),
4992 	LSM_HOOK_INIT(kernel_act_as, smack_kernel_act_as),
4993 	LSM_HOOK_INIT(kernel_create_files_as, smack_kernel_create_files_as),
4994 	LSM_HOOK_INIT(task_setpgid, smack_task_setpgid),
4995 	LSM_HOOK_INIT(task_getpgid, smack_task_getpgid),
4996 	LSM_HOOK_INIT(task_getsid, smack_task_getsid),
4997 	LSM_HOOK_INIT(current_getsecid_subj, smack_current_getsecid_subj),
4998 	LSM_HOOK_INIT(task_getsecid_obj, smack_task_getsecid_obj),
4999 	LSM_HOOK_INIT(task_setnice, smack_task_setnice),
5000 	LSM_HOOK_INIT(task_setioprio, smack_task_setioprio),
5001 	LSM_HOOK_INIT(task_getioprio, smack_task_getioprio),
5002 	LSM_HOOK_INIT(task_setscheduler, smack_task_setscheduler),
5003 	LSM_HOOK_INIT(task_getscheduler, smack_task_getscheduler),
5004 	LSM_HOOK_INIT(task_movememory, smack_task_movememory),
5005 	LSM_HOOK_INIT(task_kill, smack_task_kill),
5006 	LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
5007 
5008 	LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
5009 	LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
5010 
5011 	LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
5012 
5013 	LSM_HOOK_INIT(msg_queue_alloc_security, smack_ipc_alloc_security),
5014 	LSM_HOOK_INIT(msg_queue_associate, smack_msg_queue_associate),
5015 	LSM_HOOK_INIT(msg_queue_msgctl, smack_msg_queue_msgctl),
5016 	LSM_HOOK_INIT(msg_queue_msgsnd, smack_msg_queue_msgsnd),
5017 	LSM_HOOK_INIT(msg_queue_msgrcv, smack_msg_queue_msgrcv),
5018 
5019 	LSM_HOOK_INIT(shm_alloc_security, smack_ipc_alloc_security),
5020 	LSM_HOOK_INIT(shm_associate, smack_shm_associate),
5021 	LSM_HOOK_INIT(shm_shmctl, smack_shm_shmctl),
5022 	LSM_HOOK_INIT(shm_shmat, smack_shm_shmat),
5023 
5024 	LSM_HOOK_INIT(sem_alloc_security, smack_ipc_alloc_security),
5025 	LSM_HOOK_INIT(sem_associate, smack_sem_associate),
5026 	LSM_HOOK_INIT(sem_semctl, smack_sem_semctl),
5027 	LSM_HOOK_INIT(sem_semop, smack_sem_semop),
5028 
5029 	LSM_HOOK_INIT(d_instantiate, smack_d_instantiate),
5030 
5031 	LSM_HOOK_INIT(getprocattr, smack_getprocattr),
5032 	LSM_HOOK_INIT(setprocattr, smack_setprocattr),
5033 
5034 	LSM_HOOK_INIT(unix_stream_connect, smack_unix_stream_connect),
5035 	LSM_HOOK_INIT(unix_may_send, smack_unix_may_send),
5036 
5037 	LSM_HOOK_INIT(socket_post_create, smack_socket_post_create),
5038 	LSM_HOOK_INIT(socket_socketpair, smack_socket_socketpair),
5039 #ifdef SMACK_IPV6_PORT_LABELING
5040 	LSM_HOOK_INIT(socket_bind, smack_socket_bind),
5041 #endif
5042 	LSM_HOOK_INIT(socket_connect, smack_socket_connect),
5043 	LSM_HOOK_INIT(socket_sendmsg, smack_socket_sendmsg),
5044 	LSM_HOOK_INIT(socket_sock_rcv_skb, smack_socket_sock_rcv_skb),
5045 	LSM_HOOK_INIT(socket_getpeersec_stream, smack_socket_getpeersec_stream),
5046 	LSM_HOOK_INIT(socket_getpeersec_dgram, smack_socket_getpeersec_dgram),
5047 	LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
5048 	LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
5049 	LSM_HOOK_INIT(sk_clone_security, smack_sk_clone_security),
5050 	LSM_HOOK_INIT(sock_graft, smack_sock_graft),
5051 	LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
5052 	LSM_HOOK_INIT(inet_csk_clone, smack_inet_csk_clone),
5053 
5054  /* key management security hooks */
5055 #ifdef CONFIG_KEYS
5056 	LSM_HOOK_INIT(key_alloc, smack_key_alloc),
5057 	LSM_HOOK_INIT(key_free, smack_key_free),
5058 	LSM_HOOK_INIT(key_permission, smack_key_permission),
5059 	LSM_HOOK_INIT(key_getsecurity, smack_key_getsecurity),
5060 #ifdef CONFIG_KEY_NOTIFICATIONS
5061 	LSM_HOOK_INIT(watch_key, smack_watch_key),
5062 #endif
5063 #endif /* CONFIG_KEYS */
5064 
5065 #ifdef CONFIG_WATCH_QUEUE
5066 	LSM_HOOK_INIT(post_notification, smack_post_notification),
5067 #endif
5068 
5069  /* Audit hooks */
5070 #ifdef CONFIG_AUDIT
5071 	LSM_HOOK_INIT(audit_rule_init, smack_audit_rule_init),
5072 	LSM_HOOK_INIT(audit_rule_known, smack_audit_rule_known),
5073 	LSM_HOOK_INIT(audit_rule_match, smack_audit_rule_match),
5074 #endif /* CONFIG_AUDIT */
5075 
5076 	LSM_HOOK_INIT(ismaclabel, smack_ismaclabel),
5077 	LSM_HOOK_INIT(secid_to_secctx, smack_secid_to_secctx),
5078 	LSM_HOOK_INIT(secctx_to_secid, smack_secctx_to_secid),
5079 	LSM_HOOK_INIT(inode_notifysecctx, smack_inode_notifysecctx),
5080 	LSM_HOOK_INIT(inode_setsecctx, smack_inode_setsecctx),
5081 	LSM_HOOK_INIT(inode_getsecctx, smack_inode_getsecctx),
5082 	LSM_HOOK_INIT(inode_copy_up, smack_inode_copy_up),
5083 	LSM_HOOK_INIT(inode_copy_up_xattr, smack_inode_copy_up_xattr),
5084 	LSM_HOOK_INIT(dentry_create_files_as, smack_dentry_create_files_as),
5085 #ifdef CONFIG_IO_URING
5086 	LSM_HOOK_INIT(uring_override_creds, smack_uring_override_creds),
5087 	LSM_HOOK_INIT(uring_sqpoll, smack_uring_sqpoll),
5088 	LSM_HOOK_INIT(uring_cmd, smack_uring_cmd),
5089 #endif
5090 };
5091 
5092 
5093 static __init void init_smack_known_list(void)
5094 {
5095 	/*
5096 	 * Initialize rule list locks
5097 	 */
5098 	mutex_init(&smack_known_huh.smk_rules_lock);
5099 	mutex_init(&smack_known_hat.smk_rules_lock);
5100 	mutex_init(&smack_known_floor.smk_rules_lock);
5101 	mutex_init(&smack_known_star.smk_rules_lock);
5102 	mutex_init(&smack_known_web.smk_rules_lock);
5103 	/*
5104 	 * Initialize rule lists
5105 	 */
5106 	INIT_LIST_HEAD(&smack_known_huh.smk_rules);
5107 	INIT_LIST_HEAD(&smack_known_hat.smk_rules);
5108 	INIT_LIST_HEAD(&smack_known_star.smk_rules);
5109 	INIT_LIST_HEAD(&smack_known_floor.smk_rules);
5110 	INIT_LIST_HEAD(&smack_known_web.smk_rules);
5111 	/*
5112 	 * Create the known labels list
5113 	 */
5114 	smk_insert_entry(&smack_known_huh);
5115 	smk_insert_entry(&smack_known_hat);
5116 	smk_insert_entry(&smack_known_star);
5117 	smk_insert_entry(&smack_known_floor);
5118 	smk_insert_entry(&smack_known_web);
5119 }
5120 
5121 /**
5122  * smack_init - initialize the smack system
5123  *
5124  * Returns 0 on success, -ENOMEM is there's no memory
5125  */
5126 static __init int smack_init(void)
5127 {
5128 	struct cred *cred = (struct cred *) current->cred;
5129 	struct task_smack *tsp;
5130 
5131 	smack_rule_cache = KMEM_CACHE(smack_rule, 0);
5132 	if (!smack_rule_cache)
5133 		return -ENOMEM;
5134 
5135 	/*
5136 	 * Set the security state for the initial task.
5137 	 */
5138 	tsp = smack_cred(cred);
5139 	init_task_smack(tsp, &smack_known_floor, &smack_known_floor);
5140 
5141 	/*
5142 	 * Register with LSM
5143 	 */
5144 	security_add_hooks(smack_hooks, ARRAY_SIZE(smack_hooks), "smack");
5145 	smack_enabled = 1;
5146 
5147 	pr_info("Smack:  Initializing.\n");
5148 #ifdef CONFIG_SECURITY_SMACK_NETFILTER
5149 	pr_info("Smack:  Netfilter enabled.\n");
5150 #endif
5151 #ifdef SMACK_IPV6_PORT_LABELING
5152 	pr_info("Smack:  IPv6 port labeling enabled.\n");
5153 #endif
5154 #ifdef SMACK_IPV6_SECMARK_LABELING
5155 	pr_info("Smack:  IPv6 Netfilter enabled.\n");
5156 #endif
5157 
5158 	/* initialize the smack_known_list */
5159 	init_smack_known_list();
5160 
5161 	return 0;
5162 }
5163 
5164 /*
5165  * Smack requires early initialization in order to label
5166  * all processes and objects when they are created.
5167  */
5168 DEFINE_LSM(smack) = {
5169 	.name = "smack",
5170 	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
5171 	.blobs = &smack_blob_sizes,
5172 	.init = smack_init,
5173 };
5174