1  // SPDX-License-Identifier: GPL-2.0-only
2  /*
3   * AppArmor security module
4   *
5   * This file contains AppArmor LSM hooks.
6   *
7   * Copyright (C) 1998-2008 Novell/SUSE
8   * Copyright 2009-2010 Canonical Ltd.
9   */
10  
11  #include <linux/lsm_hooks.h>
12  #include <linux/moduleparam.h>
13  #include <linux/mm.h>
14  #include <linux/mman.h>
15  #include <linux/mount.h>
16  #include <linux/namei.h>
17  #include <linux/ptrace.h>
18  #include <linux/ctype.h>
19  #include <linux/sysctl.h>
20  #include <linux/audit.h>
21  #include <linux/user_namespace.h>
22  #include <linux/netfilter_ipv4.h>
23  #include <linux/netfilter_ipv6.h>
24  #include <linux/zstd.h>
25  #include <net/sock.h>
26  #include <uapi/linux/mount.h>
27  #include <uapi/linux/lsm.h>
28  
29  #include "include/apparmor.h"
30  #include "include/apparmorfs.h"
31  #include "include/audit.h"
32  #include "include/capability.h"
33  #include "include/cred.h"
34  #include "include/file.h"
35  #include "include/ipc.h"
36  #include "include/net.h"
37  #include "include/path.h"
38  #include "include/label.h"
39  #include "include/policy.h"
40  #include "include/policy_ns.h"
41  #include "include/procattr.h"
42  #include "include/mount.h"
43  #include "include/secid.h"
44  
45  /* Flag indicating whether initialization completed */
46  int apparmor_initialized;
47  
48  union aa_buffer {
49  	struct list_head list;
50  	DECLARE_FLEX_ARRAY(char, buffer);
51  };
52  
53  struct aa_local_cache {
54  	unsigned int hold;
55  	unsigned int count;
56  	struct list_head head;
57  };
58  
59  #define RESERVE_COUNT 2
60  static int reserve_count = RESERVE_COUNT;
61  static int buffer_count;
62  
63  static LIST_HEAD(aa_global_buffers);
64  static DEFINE_SPINLOCK(aa_buffers_lock);
65  static DEFINE_PER_CPU(struct aa_local_cache, aa_local_buffers);
66  
67  /*
68   * LSM hook functions
69   */
70  
71  /*
72   * put the associated labels
73   */
apparmor_cred_free(struct cred * cred)74  static void apparmor_cred_free(struct cred *cred)
75  {
76  	aa_put_label(cred_label(cred));
77  	set_cred_label(cred, NULL);
78  }
79  
80  /*
81   * allocate the apparmor part of blank credentials
82   */
apparmor_cred_alloc_blank(struct cred * cred,gfp_t gfp)83  static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp)
84  {
85  	set_cred_label(cred, NULL);
86  	return 0;
87  }
88  
89  /*
90   * prepare new cred label for modification by prepare_cred block
91   */
apparmor_cred_prepare(struct cred * new,const struct cred * old,gfp_t gfp)92  static int apparmor_cred_prepare(struct cred *new, const struct cred *old,
93  				 gfp_t gfp)
94  {
95  	set_cred_label(new, aa_get_newest_label(cred_label(old)));
96  	return 0;
97  }
98  
99  /*
100   * transfer the apparmor data to a blank set of creds
101   */
apparmor_cred_transfer(struct cred * new,const struct cred * old)102  static void apparmor_cred_transfer(struct cred *new, const struct cred *old)
103  {
104  	set_cred_label(new, aa_get_newest_label(cred_label(old)));
105  }
106  
apparmor_task_free(struct task_struct * task)107  static void apparmor_task_free(struct task_struct *task)
108  {
109  
110  	aa_free_task_ctx(task_ctx(task));
111  }
112  
apparmor_task_alloc(struct task_struct * task,unsigned long clone_flags)113  static int apparmor_task_alloc(struct task_struct *task,
114  			       unsigned long clone_flags)
115  {
116  	struct aa_task_ctx *new = task_ctx(task);
117  
118  	aa_dup_task_ctx(new, task_ctx(current));
119  
120  	return 0;
121  }
122  
apparmor_ptrace_access_check(struct task_struct * child,unsigned int mode)123  static int apparmor_ptrace_access_check(struct task_struct *child,
124  					unsigned int mode)
125  {
126  	struct aa_label *tracer, *tracee;
127  	const struct cred *cred;
128  	int error;
129  
130  	cred = get_task_cred(child);
131  	tracee = cred_label(cred);	/* ref count on cred */
132  	tracer = __begin_current_label_crit_section();
133  	error = aa_may_ptrace(current_cred(), tracer, cred, tracee,
134  			(mode & PTRACE_MODE_READ) ? AA_PTRACE_READ
135  						  : AA_PTRACE_TRACE);
136  	__end_current_label_crit_section(tracer);
137  	put_cred(cred);
138  
139  	return error;
140  }
141  
apparmor_ptrace_traceme(struct task_struct * parent)142  static int apparmor_ptrace_traceme(struct task_struct *parent)
143  {
144  	struct aa_label *tracer, *tracee;
145  	const struct cred *cred;
146  	int error;
147  
148  	tracee = __begin_current_label_crit_section();
149  	cred = get_task_cred(parent);
150  	tracer = cred_label(cred);	/* ref count on cred */
151  	error = aa_may_ptrace(cred, tracer, current_cred(), tracee,
152  			      AA_PTRACE_TRACE);
153  	put_cred(cred);
154  	__end_current_label_crit_section(tracee);
155  
156  	return error;
157  }
158  
159  /* Derived from security/commoncap.c:cap_capget */
apparmor_capget(const struct task_struct * target,kernel_cap_t * effective,kernel_cap_t * inheritable,kernel_cap_t * permitted)160  static int apparmor_capget(const struct task_struct *target, kernel_cap_t *effective,
161  			   kernel_cap_t *inheritable, kernel_cap_t *permitted)
162  {
163  	struct aa_label *label;
164  	const struct cred *cred;
165  
166  	rcu_read_lock();
167  	cred = __task_cred(target);
168  	label = aa_get_newest_cred_label(cred);
169  
170  	/*
171  	 * cap_capget is stacked ahead of this and will
172  	 * initialize effective and permitted.
173  	 */
174  	if (!unconfined(label)) {
175  		struct aa_profile *profile;
176  		struct label_it i;
177  
178  		label_for_each_confined(i, label, profile) {
179  			struct aa_ruleset *rules;
180  			if (COMPLAIN_MODE(profile))
181  				continue;
182  			rules = list_first_entry(&profile->rules,
183  						 typeof(*rules), list);
184  			*effective = cap_intersect(*effective,
185  						   rules->caps.allow);
186  			*permitted = cap_intersect(*permitted,
187  						   rules->caps.allow);
188  		}
189  	}
190  	rcu_read_unlock();
191  	aa_put_label(label);
192  
193  	return 0;
194  }
195  
apparmor_capable(const struct cred * cred,struct user_namespace * ns,int cap,unsigned int opts)196  static int apparmor_capable(const struct cred *cred, struct user_namespace *ns,
197  			    int cap, unsigned int opts)
198  {
199  	struct aa_label *label;
200  	int error = 0;
201  
202  	label = aa_get_newest_cred_label(cred);
203  	if (!unconfined(label))
204  		error = aa_capable(cred, label, cap, opts);
205  	aa_put_label(label);
206  
207  	return error;
208  }
209  
210  /**
211   * common_perm - basic common permission check wrapper fn for paths
212   * @op: operation being checked
213   * @path: path to check permission of  (NOT NULL)
214   * @mask: requested permissions mask
215   * @cond: conditional info for the permission request  (NOT NULL)
216   *
217   * Returns: %0 else error code if error or permission denied
218   */
common_perm(const char * op,const struct path * path,u32 mask,struct path_cond * cond)219  static int common_perm(const char *op, const struct path *path, u32 mask,
220  		       struct path_cond *cond)
221  {
222  	struct aa_label *label;
223  	int error = 0;
224  
225  	label = __begin_current_label_crit_section();
226  	if (!unconfined(label))
227  		error = aa_path_perm(op, current_cred(), label, path, 0, mask,
228  				     cond);
229  	__end_current_label_crit_section(label);
230  
231  	return error;
232  }
233  
234  /**
235   * common_perm_cond - common permission wrapper around inode cond
236   * @op: operation being checked
237   * @path: location to check (NOT NULL)
238   * @mask: requested permissions mask
239   *
240   * Returns: %0 else error code if error or permission denied
241   */
common_perm_cond(const char * op,const struct path * path,u32 mask)242  static int common_perm_cond(const char *op, const struct path *path, u32 mask)
243  {
244  	vfsuid_t vfsuid = i_uid_into_vfsuid(mnt_idmap(path->mnt),
245  					    d_backing_inode(path->dentry));
246  	struct path_cond cond = {
247  		vfsuid_into_kuid(vfsuid),
248  		d_backing_inode(path->dentry)->i_mode
249  	};
250  
251  	if (!path_mediated_fs(path->dentry))
252  		return 0;
253  
254  	return common_perm(op, path, mask, &cond);
255  }
256  
257  /**
258   * common_perm_dir_dentry - common permission wrapper when path is dir, dentry
259   * @op: operation being checked
260   * @dir: directory of the dentry  (NOT NULL)
261   * @dentry: dentry to check  (NOT NULL)
262   * @mask: requested permissions mask
263   * @cond: conditional info for the permission request  (NOT NULL)
264   *
265   * Returns: %0 else error code if error or permission denied
266   */
common_perm_dir_dentry(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,struct path_cond * cond)267  static int common_perm_dir_dentry(const char *op, const struct path *dir,
268  				  struct dentry *dentry, u32 mask,
269  				  struct path_cond *cond)
270  {
271  	struct path path = { .mnt = dir->mnt, .dentry = dentry };
272  
273  	return common_perm(op, &path, mask, cond);
274  }
275  
276  /**
277   * common_perm_rm - common permission wrapper for operations doing rm
278   * @op: operation being checked
279   * @dir: directory that the dentry is in  (NOT NULL)
280   * @dentry: dentry being rm'd  (NOT NULL)
281   * @mask: requested permission mask
282   *
283   * Returns: %0 else error code if error or permission denied
284   */
common_perm_rm(const char * op,const struct path * dir,struct dentry * dentry,u32 mask)285  static int common_perm_rm(const char *op, const struct path *dir,
286  			  struct dentry *dentry, u32 mask)
287  {
288  	struct inode *inode = d_backing_inode(dentry);
289  	struct path_cond cond = { };
290  	vfsuid_t vfsuid;
291  
292  	if (!inode || !path_mediated_fs(dentry))
293  		return 0;
294  
295  	vfsuid = i_uid_into_vfsuid(mnt_idmap(dir->mnt), inode);
296  	cond.uid = vfsuid_into_kuid(vfsuid);
297  	cond.mode = inode->i_mode;
298  
299  	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
300  }
301  
302  /**
303   * common_perm_create - common permission wrapper for operations doing create
304   * @op: operation being checked
305   * @dir: directory that dentry will be created in  (NOT NULL)
306   * @dentry: dentry to create   (NOT NULL)
307   * @mask: request permission mask
308   * @mode: created file mode
309   *
310   * Returns: %0 else error code if error or permission denied
311   */
common_perm_create(const char * op,const struct path * dir,struct dentry * dentry,u32 mask,umode_t mode)312  static int common_perm_create(const char *op, const struct path *dir,
313  			      struct dentry *dentry, u32 mask, umode_t mode)
314  {
315  	struct path_cond cond = { current_fsuid(), mode };
316  
317  	if (!path_mediated_fs(dir->dentry))
318  		return 0;
319  
320  	return common_perm_dir_dentry(op, dir, dentry, mask, &cond);
321  }
322  
apparmor_path_unlink(const struct path * dir,struct dentry * dentry)323  static int apparmor_path_unlink(const struct path *dir, struct dentry *dentry)
324  {
325  	return common_perm_rm(OP_UNLINK, dir, dentry, AA_MAY_DELETE);
326  }
327  
apparmor_path_mkdir(const struct path * dir,struct dentry * dentry,umode_t mode)328  static int apparmor_path_mkdir(const struct path *dir, struct dentry *dentry,
329  			       umode_t mode)
330  {
331  	return common_perm_create(OP_MKDIR, dir, dentry, AA_MAY_CREATE,
332  				  S_IFDIR);
333  }
334  
apparmor_path_rmdir(const struct path * dir,struct dentry * dentry)335  static int apparmor_path_rmdir(const struct path *dir, struct dentry *dentry)
336  {
337  	return common_perm_rm(OP_RMDIR, dir, dentry, AA_MAY_DELETE);
338  }
339  
apparmor_path_mknod(const struct path * dir,struct dentry * dentry,umode_t mode,unsigned int dev)340  static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
341  			       umode_t mode, unsigned int dev)
342  {
343  	return common_perm_create(OP_MKNOD, dir, dentry, AA_MAY_CREATE, mode);
344  }
345  
apparmor_path_truncate(const struct path * path)346  static int apparmor_path_truncate(const struct path *path)
347  {
348  	return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_SETATTR);
349  }
350  
apparmor_file_truncate(struct file * file)351  static int apparmor_file_truncate(struct file *file)
352  {
353  	return apparmor_path_truncate(&file->f_path);
354  }
355  
apparmor_path_symlink(const struct path * dir,struct dentry * dentry,const char * old_name)356  static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
357  				 const char *old_name)
358  {
359  	return common_perm_create(OP_SYMLINK, dir, dentry, AA_MAY_CREATE,
360  				  S_IFLNK);
361  }
362  
apparmor_path_link(struct dentry * old_dentry,const struct path * new_dir,struct dentry * new_dentry)363  static int apparmor_path_link(struct dentry *old_dentry, const struct path *new_dir,
364  			      struct dentry *new_dentry)
365  {
366  	struct aa_label *label;
367  	int error = 0;
368  
369  	if (!path_mediated_fs(old_dentry))
370  		return 0;
371  
372  	label = begin_current_label_crit_section();
373  	if (!unconfined(label))
374  		error = aa_path_link(current_cred(), label, old_dentry, new_dir,
375  				     new_dentry);
376  	end_current_label_crit_section(label);
377  
378  	return error;
379  }
380  
apparmor_path_rename(const struct path * old_dir,struct dentry * old_dentry,const struct path * new_dir,struct dentry * new_dentry,const unsigned int flags)381  static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_dentry,
382  				const struct path *new_dir, struct dentry *new_dentry,
383  				const unsigned int flags)
384  {
385  	struct aa_label *label;
386  	int error = 0;
387  
388  	if (!path_mediated_fs(old_dentry))
389  		return 0;
390  	if ((flags & RENAME_EXCHANGE) && !path_mediated_fs(new_dentry))
391  		return 0;
392  
393  	label = begin_current_label_crit_section();
394  	if (!unconfined(label)) {
395  		struct mnt_idmap *idmap = mnt_idmap(old_dir->mnt);
396  		vfsuid_t vfsuid;
397  		struct path old_path = { .mnt = old_dir->mnt,
398  					 .dentry = old_dentry };
399  		struct path new_path = { .mnt = new_dir->mnt,
400  					 .dentry = new_dentry };
401  		struct path_cond cond = {
402  			.mode = d_backing_inode(old_dentry)->i_mode
403  		};
404  		vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
405  		cond.uid = vfsuid_into_kuid(vfsuid);
406  
407  		if (flags & RENAME_EXCHANGE) {
408  			struct path_cond cond_exchange = {
409  				.mode = d_backing_inode(new_dentry)->i_mode,
410  			};
411  			vfsuid = i_uid_into_vfsuid(idmap, d_backing_inode(old_dentry));
412  			cond_exchange.uid = vfsuid_into_kuid(vfsuid);
413  
414  			error = aa_path_perm(OP_RENAME_SRC, current_cred(),
415  					     label, &new_path, 0,
416  					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
417  					     AA_MAY_SETATTR | AA_MAY_DELETE,
418  					     &cond_exchange);
419  			if (!error)
420  				error = aa_path_perm(OP_RENAME_DEST, current_cred(),
421  						     label, &old_path,
422  						     0, MAY_WRITE | AA_MAY_SETATTR |
423  						     AA_MAY_CREATE, &cond_exchange);
424  		}
425  
426  		if (!error)
427  			error = aa_path_perm(OP_RENAME_SRC, current_cred(),
428  					     label, &old_path, 0,
429  					     MAY_READ | AA_MAY_GETATTR | MAY_WRITE |
430  					     AA_MAY_SETATTR | AA_MAY_DELETE,
431  					     &cond);
432  		if (!error)
433  			error = aa_path_perm(OP_RENAME_DEST, current_cred(),
434  					     label, &new_path,
435  					     0, MAY_WRITE | AA_MAY_SETATTR |
436  					     AA_MAY_CREATE, &cond);
437  
438  	}
439  	end_current_label_crit_section(label);
440  
441  	return error;
442  }
443  
apparmor_path_chmod(const struct path * path,umode_t mode)444  static int apparmor_path_chmod(const struct path *path, umode_t mode)
445  {
446  	return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
447  }
448  
apparmor_path_chown(const struct path * path,kuid_t uid,kgid_t gid)449  static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
450  {
451  	return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
452  }
453  
apparmor_inode_getattr(const struct path * path)454  static int apparmor_inode_getattr(const struct path *path)
455  {
456  	return common_perm_cond(OP_GETATTR, path, AA_MAY_GETATTR);
457  }
458  
apparmor_file_open(struct file * file)459  static int apparmor_file_open(struct file *file)
460  {
461  	struct aa_file_ctx *fctx = file_ctx(file);
462  	struct aa_label *label;
463  	int error = 0;
464  	bool needput;
465  
466  	if (!path_mediated_fs(file->f_path.dentry))
467  		return 0;
468  
469  	/* If in exec, permission is handled by bprm hooks.
470  	 * Cache permissions granted by the previous exec check, with
471  	 * implicit read and executable mmap which are required to
472  	 * actually execute the image.
473  	 *
474  	 * Illogically, FMODE_EXEC is in f_flags, not f_mode.
475  	 */
476  	if (file->f_flags & __FMODE_EXEC) {
477  		fctx->allow = MAY_EXEC | MAY_READ | AA_EXEC_MMAP;
478  		return 0;
479  	}
480  
481  	label = aa_get_newest_cred_label_condref(file->f_cred, &needput);
482  	if (!unconfined(label)) {
483  		struct mnt_idmap *idmap = file_mnt_idmap(file);
484  		struct inode *inode = file_inode(file);
485  		vfsuid_t vfsuid;
486  		struct path_cond cond = {
487  			.mode = inode->i_mode,
488  		};
489  		vfsuid = i_uid_into_vfsuid(idmap, inode);
490  		cond.uid = vfsuid_into_kuid(vfsuid);
491  
492  		error = aa_path_perm(OP_OPEN, file->f_cred,
493  				     label, &file->f_path, 0,
494  				     aa_map_file_to_perms(file), &cond);
495  		/* todo cache full allowed permissions set and state */
496  		fctx->allow = aa_map_file_to_perms(file);
497  	}
498  	aa_put_label_condref(label, needput);
499  
500  	return error;
501  }
502  
apparmor_file_alloc_security(struct file * file)503  static int apparmor_file_alloc_security(struct file *file)
504  {
505  	struct aa_file_ctx *ctx = file_ctx(file);
506  	struct aa_label *label = begin_current_label_crit_section();
507  
508  	spin_lock_init(&ctx->lock);
509  	rcu_assign_pointer(ctx->label, aa_get_label(label));
510  	end_current_label_crit_section(label);
511  	return 0;
512  }
513  
apparmor_file_free_security(struct file * file)514  static void apparmor_file_free_security(struct file *file)
515  {
516  	struct aa_file_ctx *ctx = file_ctx(file);
517  
518  	if (ctx)
519  		aa_put_label(rcu_access_pointer(ctx->label));
520  }
521  
common_file_perm(const char * op,struct file * file,u32 mask,bool in_atomic)522  static int common_file_perm(const char *op, struct file *file, u32 mask,
523  			    bool in_atomic)
524  {
525  	struct aa_label *label;
526  	int error = 0;
527  
528  	/* don't reaudit files closed during inheritance */
529  	if (file->f_path.dentry == aa_null.dentry)
530  		return -EACCES;
531  
532  	label = __begin_current_label_crit_section();
533  	error = aa_file_perm(op, current_cred(), label, file, mask, in_atomic);
534  	__end_current_label_crit_section(label);
535  
536  	return error;
537  }
538  
apparmor_file_receive(struct file * file)539  static int apparmor_file_receive(struct file *file)
540  {
541  	return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file),
542  				false);
543  }
544  
apparmor_file_permission(struct file * file,int mask)545  static int apparmor_file_permission(struct file *file, int mask)
546  {
547  	return common_file_perm(OP_FPERM, file, mask, false);
548  }
549  
apparmor_file_lock(struct file * file,unsigned int cmd)550  static int apparmor_file_lock(struct file *file, unsigned int cmd)
551  {
552  	u32 mask = AA_MAY_LOCK;
553  
554  	if (cmd == F_WRLCK)
555  		mask |= MAY_WRITE;
556  
557  	return common_file_perm(OP_FLOCK, file, mask, false);
558  }
559  
common_mmap(const char * op,struct file * file,unsigned long prot,unsigned long flags,bool in_atomic)560  static int common_mmap(const char *op, struct file *file, unsigned long prot,
561  		       unsigned long flags, bool in_atomic)
562  {
563  	int mask = 0;
564  
565  	if (!file || !file_ctx(file))
566  		return 0;
567  
568  	if (prot & PROT_READ)
569  		mask |= MAY_READ;
570  	/*
571  	 * Private mappings don't require write perms since they don't
572  	 * write back to the files
573  	 */
574  	if ((prot & PROT_WRITE) && !(flags & MAP_PRIVATE))
575  		mask |= MAY_WRITE;
576  	if (prot & PROT_EXEC)
577  		mask |= AA_EXEC_MMAP;
578  
579  	return common_file_perm(op, file, mask, in_atomic);
580  }
581  
apparmor_mmap_file(struct file * file,unsigned long reqprot,unsigned long prot,unsigned long flags)582  static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
583  			      unsigned long prot, unsigned long flags)
584  {
585  	return common_mmap(OP_FMMAP, file, prot, flags, GFP_ATOMIC);
586  }
587  
apparmor_file_mprotect(struct vm_area_struct * vma,unsigned long reqprot,unsigned long prot)588  static int apparmor_file_mprotect(struct vm_area_struct *vma,
589  				  unsigned long reqprot, unsigned long prot)
590  {
591  	return common_mmap(OP_FMPROT, vma->vm_file, prot,
592  			   !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0,
593  			   false);
594  }
595  
596  #ifdef CONFIG_IO_URING
audit_uring_mask(u32 mask)597  static const char *audit_uring_mask(u32 mask)
598  {
599  	if (mask & AA_MAY_CREATE_SQPOLL)
600  		return "sqpoll";
601  	if (mask & AA_MAY_OVERRIDE_CRED)
602  		return "override_creds";
603  	return "";
604  }
605  
audit_uring_cb(struct audit_buffer * ab,void * va)606  static void audit_uring_cb(struct audit_buffer *ab, void *va)
607  {
608  	struct apparmor_audit_data *ad = aad_of_va(va);
609  
610  	if (ad->request & AA_URING_PERM_MASK) {
611  		audit_log_format(ab, " requested=\"%s\"",
612  				 audit_uring_mask(ad->request));
613  		if (ad->denied & AA_URING_PERM_MASK) {
614  			audit_log_format(ab, " denied=\"%s\"",
615  					 audit_uring_mask(ad->denied));
616  		}
617  	}
618  	if (ad->uring.target) {
619  		audit_log_format(ab, " tcontext=");
620  		aa_label_xaudit(ab, labels_ns(ad->subj_label),
621  				ad->uring.target,
622  				FLAGS_NONE, GFP_ATOMIC);
623  	}
624  }
625  
profile_uring(struct aa_profile * profile,u32 request,struct aa_label * new,int cap,struct apparmor_audit_data * ad)626  static int profile_uring(struct aa_profile *profile, u32 request,
627  			 struct aa_label *new, int cap,
628  			 struct apparmor_audit_data *ad)
629  {
630  	unsigned int state;
631  	struct aa_ruleset *rules;
632  	int error = 0;
633  
634  	AA_BUG(!profile);
635  
636  	rules = list_first_entry(&profile->rules, typeof(*rules), list);
637  	state = RULE_MEDIATES(rules, AA_CLASS_IO_URING);
638  	if (state) {
639  		struct aa_perms perms = { };
640  
641  		if (new) {
642  			aa_label_match(profile, rules, new, state,
643  				       false, request, &perms);
644  		} else {
645  			perms = *aa_lookup_perms(rules->policy, state);
646  		}
647  		aa_apply_modes_to_perms(profile, &perms);
648  		error = aa_check_perms(profile, &perms, request, ad,
649  				       audit_uring_cb);
650  	}
651  
652  	return error;
653  }
654  
655  /**
656   * apparmor_uring_override_creds - check the requested cred override
657   * @new: the target creds
658   *
659   * Check to see if the current task is allowed to override it's credentials
660   * to service an io_uring operation.
661   */
apparmor_uring_override_creds(const struct cred * new)662  static int apparmor_uring_override_creds(const struct cred *new)
663  {
664  	struct aa_profile *profile;
665  	struct aa_label *label;
666  	int error;
667  	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
668  			  OP_URING_OVERRIDE);
669  
670  	ad.uring.target = cred_label(new);
671  	label = __begin_current_label_crit_section();
672  	error = fn_for_each(label, profile,
673  			profile_uring(profile, AA_MAY_OVERRIDE_CRED,
674  				      cred_label(new), CAP_SYS_ADMIN, &ad));
675  	__end_current_label_crit_section(label);
676  
677  	return error;
678  }
679  
680  /**
681   * apparmor_uring_sqpoll - check if a io_uring polling thread can be created
682   *
683   * Check to see if the current task is allowed to create a new io_uring
684   * kernel polling thread.
685   */
apparmor_uring_sqpoll(void)686  static int apparmor_uring_sqpoll(void)
687  {
688  	struct aa_profile *profile;
689  	struct aa_label *label;
690  	int error;
691  	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_IO_URING,
692  			  OP_URING_SQPOLL);
693  
694  	label = __begin_current_label_crit_section();
695  	error = fn_for_each(label, profile,
696  			profile_uring(profile, AA_MAY_CREATE_SQPOLL,
697  				      NULL, CAP_SYS_ADMIN, &ad));
698  	__end_current_label_crit_section(label);
699  
700  	return error;
701  }
702  #endif /* CONFIG_IO_URING */
703  
apparmor_sb_mount(const char * dev_name,const struct path * path,const char * type,unsigned long flags,void * data)704  static int apparmor_sb_mount(const char *dev_name, const struct path *path,
705  			     const char *type, unsigned long flags, void *data)
706  {
707  	struct aa_label *label;
708  	int error = 0;
709  
710  	/* Discard magic */
711  	if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
712  		flags &= ~MS_MGC_MSK;
713  
714  	flags &= ~AA_MS_IGNORE_MASK;
715  
716  	label = __begin_current_label_crit_section();
717  	if (!unconfined(label)) {
718  		if (flags & MS_REMOUNT)
719  			error = aa_remount(current_cred(), label, path, flags,
720  					   data);
721  		else if (flags & MS_BIND)
722  			error = aa_bind_mount(current_cred(), label, path,
723  					      dev_name, flags);
724  		else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE |
725  				  MS_UNBINDABLE))
726  			error = aa_mount_change_type(current_cred(), label,
727  						     path, flags);
728  		else if (flags & MS_MOVE)
729  			error = aa_move_mount_old(current_cred(), label, path,
730  						  dev_name);
731  		else
732  			error = aa_new_mount(current_cred(), label, dev_name,
733  					     path, type, flags, data);
734  	}
735  	__end_current_label_crit_section(label);
736  
737  	return error;
738  }
739  
apparmor_move_mount(const struct path * from_path,const struct path * to_path)740  static int apparmor_move_mount(const struct path *from_path,
741  			       const struct path *to_path)
742  {
743  	struct aa_label *label;
744  	int error = 0;
745  
746  	label = __begin_current_label_crit_section();
747  	if (!unconfined(label))
748  		error = aa_move_mount(current_cred(), label, from_path,
749  				      to_path);
750  	__end_current_label_crit_section(label);
751  
752  	return error;
753  }
754  
apparmor_sb_umount(struct vfsmount * mnt,int flags)755  static int apparmor_sb_umount(struct vfsmount *mnt, int flags)
756  {
757  	struct aa_label *label;
758  	int error = 0;
759  
760  	label = __begin_current_label_crit_section();
761  	if (!unconfined(label))
762  		error = aa_umount(current_cred(), label, mnt, flags);
763  	__end_current_label_crit_section(label);
764  
765  	return error;
766  }
767  
apparmor_sb_pivotroot(const struct path * old_path,const struct path * new_path)768  static int apparmor_sb_pivotroot(const struct path *old_path,
769  				 const struct path *new_path)
770  {
771  	struct aa_label *label;
772  	int error = 0;
773  
774  	label = aa_get_current_label();
775  	if (!unconfined(label))
776  		error = aa_pivotroot(current_cred(), label, old_path, new_path);
777  	aa_put_label(label);
778  
779  	return error;
780  }
781  
apparmor_getselfattr(unsigned int attr,struct lsm_ctx __user * lx,u32 * size,u32 flags)782  static int apparmor_getselfattr(unsigned int attr, struct lsm_ctx __user *lx,
783  				u32 *size, u32 flags)
784  {
785  	int error = -ENOENT;
786  	struct aa_task_ctx *ctx = task_ctx(current);
787  	struct aa_label *label = NULL;
788  	char *value = NULL;
789  
790  	switch (attr) {
791  	case LSM_ATTR_CURRENT:
792  		label = aa_get_newest_label(cred_label(current_cred()));
793  		break;
794  	case LSM_ATTR_PREV:
795  		if (ctx->previous)
796  			label = aa_get_newest_label(ctx->previous);
797  		break;
798  	case LSM_ATTR_EXEC:
799  		if (ctx->onexec)
800  			label = aa_get_newest_label(ctx->onexec);
801  		break;
802  	default:
803  		error = -EOPNOTSUPP;
804  		break;
805  	}
806  
807  	if (label) {
808  		error = aa_getprocattr(label, &value, false);
809  		if (error > 0)
810  			error = lsm_fill_user_ctx(lx, size, value, error,
811  						  LSM_ID_APPARMOR, 0);
812  		kfree(value);
813  	}
814  
815  	aa_put_label(label);
816  
817  	if (error < 0)
818  		return error;
819  	return 1;
820  }
821  
apparmor_getprocattr(struct task_struct * task,const char * name,char ** value)822  static int apparmor_getprocattr(struct task_struct *task, const char *name,
823  				char **value)
824  {
825  	int error = -ENOENT;
826  	/* released below */
827  	const struct cred *cred = get_task_cred(task);
828  	struct aa_task_ctx *ctx = task_ctx(current);
829  	struct aa_label *label = NULL;
830  
831  	if (strcmp(name, "current") == 0)
832  		label = aa_get_newest_label(cred_label(cred));
833  	else if (strcmp(name, "prev") == 0  && ctx->previous)
834  		label = aa_get_newest_label(ctx->previous);
835  	else if (strcmp(name, "exec") == 0 && ctx->onexec)
836  		label = aa_get_newest_label(ctx->onexec);
837  	else
838  		error = -EINVAL;
839  
840  	if (label)
841  		error = aa_getprocattr(label, value, true);
842  
843  	aa_put_label(label);
844  	put_cred(cred);
845  
846  	return error;
847  }
848  
do_setattr(u64 attr,void * value,size_t size)849  static int do_setattr(u64 attr, void *value, size_t size)
850  {
851  	char *command, *largs = NULL, *args = value;
852  	size_t arg_size;
853  	int error;
854  	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_NONE,
855  			  OP_SETPROCATTR);
856  
857  	if (size == 0)
858  		return -EINVAL;
859  
860  	/* AppArmor requires that the buffer must be null terminated atm */
861  	if (args[size - 1] != '\0') {
862  		/* null terminate */
863  		largs = args = kmalloc(size + 1, GFP_KERNEL);
864  		if (!args)
865  			return -ENOMEM;
866  		memcpy(args, value, size);
867  		args[size] = '\0';
868  	}
869  
870  	error = -EINVAL;
871  	args = strim(args);
872  	command = strsep(&args, " ");
873  	if (!args)
874  		goto out;
875  	args = skip_spaces(args);
876  	if (!*args)
877  		goto out;
878  
879  	arg_size = size - (args - (largs ? largs : (char *) value));
880  	if (attr == LSM_ATTR_CURRENT) {
881  		if (strcmp(command, "changehat") == 0) {
882  			error = aa_setprocattr_changehat(args, arg_size,
883  							 AA_CHANGE_NOFLAGS);
884  		} else if (strcmp(command, "permhat") == 0) {
885  			error = aa_setprocattr_changehat(args, arg_size,
886  							 AA_CHANGE_TEST);
887  		} else if (strcmp(command, "changeprofile") == 0) {
888  			error = aa_change_profile(args, AA_CHANGE_NOFLAGS);
889  		} else if (strcmp(command, "permprofile") == 0) {
890  			error = aa_change_profile(args, AA_CHANGE_TEST);
891  		} else if (strcmp(command, "stack") == 0) {
892  			error = aa_change_profile(args, AA_CHANGE_STACK);
893  		} else
894  			goto fail;
895  	} else if (attr == LSM_ATTR_EXEC) {
896  		if (strcmp(command, "exec") == 0)
897  			error = aa_change_profile(args, AA_CHANGE_ONEXEC);
898  		else if (strcmp(command, "stack") == 0)
899  			error = aa_change_profile(args, (AA_CHANGE_ONEXEC |
900  							 AA_CHANGE_STACK));
901  		else
902  			goto fail;
903  	} else
904  		/* only support the "current" and "exec" process attributes */
905  		goto fail;
906  
907  	if (!error)
908  		error = size;
909  out:
910  	kfree(largs);
911  	return error;
912  
913  fail:
914  	ad.subj_label = begin_current_label_crit_section();
915  	if (attr == LSM_ATTR_CURRENT)
916  		ad.info = "current";
917  	else if (attr == LSM_ATTR_EXEC)
918  		ad.info = "exec";
919  	else
920  		ad.info = "invalid";
921  	ad.error = error = -EINVAL;
922  	aa_audit_msg(AUDIT_APPARMOR_DENIED, &ad, NULL);
923  	end_current_label_crit_section(ad.subj_label);
924  	goto out;
925  }
926  
apparmor_setselfattr(unsigned int attr,struct lsm_ctx * ctx,u32 size,u32 flags)927  static int apparmor_setselfattr(unsigned int attr, struct lsm_ctx *ctx,
928  				u32 size, u32 flags)
929  {
930  	int rc;
931  
932  	if (attr != LSM_ATTR_CURRENT && attr != LSM_ATTR_EXEC)
933  		return -EOPNOTSUPP;
934  
935  	rc = do_setattr(attr, ctx->ctx, ctx->ctx_len);
936  	if (rc > 0)
937  		return 0;
938  	return rc;
939  }
940  
apparmor_setprocattr(const char * name,void * value,size_t size)941  static int apparmor_setprocattr(const char *name, void *value,
942  				size_t size)
943  {
944  	int attr = lsm_name_to_attr(name);
945  
946  	if (attr)
947  		return do_setattr(attr, value, size);
948  	return -EINVAL;
949  }
950  
951  /**
952   * apparmor_bprm_committing_creds - do task cleanup on committing new creds
953   * @bprm: binprm for the exec  (NOT NULL)
954   */
apparmor_bprm_committing_creds(const struct linux_binprm * bprm)955  static void apparmor_bprm_committing_creds(const struct linux_binprm *bprm)
956  {
957  	struct aa_label *label = aa_current_raw_label();
958  	struct aa_label *new_label = cred_label(bprm->cred);
959  
960  	/* bail out if unconfined or not changing profile */
961  	if ((new_label->proxy == label->proxy) ||
962  	    (unconfined(new_label)))
963  		return;
964  
965  	aa_inherit_files(bprm->cred, current->files);
966  
967  	current->pdeath_signal = 0;
968  
969  	/* reset soft limits and set hard limits for the new label */
970  	__aa_transition_rlimits(label, new_label);
971  }
972  
973  /**
974   * apparmor_bprm_committed_creds() - do cleanup after new creds committed
975   * @bprm: binprm for the exec  (NOT NULL)
976   */
apparmor_bprm_committed_creds(const struct linux_binprm * bprm)977  static void apparmor_bprm_committed_creds(const struct linux_binprm *bprm)
978  {
979  	/* clear out temporary/transitional state from the context */
980  	aa_clear_task_ctx_trans(task_ctx(current));
981  
982  	return;
983  }
984  
apparmor_current_getsecid_subj(u32 * secid)985  static void apparmor_current_getsecid_subj(u32 *secid)
986  {
987  	struct aa_label *label = __begin_current_label_crit_section();
988  	*secid = label->secid;
989  	__end_current_label_crit_section(label);
990  }
991  
apparmor_task_getsecid_obj(struct task_struct * p,u32 * secid)992  static void apparmor_task_getsecid_obj(struct task_struct *p, u32 *secid)
993  {
994  	struct aa_label *label = aa_get_task_label(p);
995  	*secid = label->secid;
996  	aa_put_label(label);
997  }
998  
apparmor_task_setrlimit(struct task_struct * task,unsigned int resource,struct rlimit * new_rlim)999  static int apparmor_task_setrlimit(struct task_struct *task,
1000  		unsigned int resource, struct rlimit *new_rlim)
1001  {
1002  	struct aa_label *label = __begin_current_label_crit_section();
1003  	int error = 0;
1004  
1005  	if (!unconfined(label))
1006  		error = aa_task_setrlimit(current_cred(), label, task,
1007  					  resource, new_rlim);
1008  	__end_current_label_crit_section(label);
1009  
1010  	return error;
1011  }
1012  
apparmor_task_kill(struct task_struct * target,struct kernel_siginfo * info,int sig,const struct cred * cred)1013  static int apparmor_task_kill(struct task_struct *target, struct kernel_siginfo *info,
1014  			      int sig, const struct cred *cred)
1015  {
1016  	const struct cred *tc;
1017  	struct aa_label *cl, *tl;
1018  	int error;
1019  
1020  	tc = get_task_cred(target);
1021  	tl = aa_get_newest_cred_label(tc);
1022  	if (cred) {
1023  		/*
1024  		 * Dealing with USB IO specific behavior
1025  		 */
1026  		cl = aa_get_newest_cred_label(cred);
1027  		error = aa_may_signal(cred, cl, tc, tl, sig);
1028  		aa_put_label(cl);
1029  	} else {
1030  		cl = __begin_current_label_crit_section();
1031  		error = aa_may_signal(current_cred(), cl, tc, tl, sig);
1032  		__end_current_label_crit_section(cl);
1033  	}
1034  	aa_put_label(tl);
1035  	put_cred(tc);
1036  
1037  	return error;
1038  }
1039  
apparmor_userns_create(const struct cred * cred)1040  static int apparmor_userns_create(const struct cred *cred)
1041  {
1042  	struct aa_label *label;
1043  	struct aa_profile *profile;
1044  	int error = 0;
1045  	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_TASK, AA_CLASS_NS,
1046  			  OP_USERNS_CREATE);
1047  
1048  	ad.subj_cred = current_cred();
1049  
1050  	label = begin_current_label_crit_section();
1051  	if (!unconfined(label)) {
1052  		error = fn_for_each(label, profile,
1053  				    aa_profile_ns_perm(profile, &ad,
1054  						       AA_USERNS_CREATE));
1055  	}
1056  	end_current_label_crit_section(label);
1057  
1058  	return error;
1059  }
1060  
apparmor_sk_free_security(struct sock * sk)1061  static void apparmor_sk_free_security(struct sock *sk)
1062  {
1063  	struct aa_sk_ctx *ctx = aa_sock(sk);
1064  
1065  	aa_put_label(ctx->label);
1066  	aa_put_label(ctx->peer);
1067  }
1068  
1069  /**
1070   * apparmor_sk_clone_security - clone the sk_security field
1071   * @sk: sock to have security cloned
1072   * @newsk: sock getting clone
1073   */
apparmor_sk_clone_security(const struct sock * sk,struct sock * newsk)1074  static void apparmor_sk_clone_security(const struct sock *sk,
1075  				       struct sock *newsk)
1076  {
1077  	struct aa_sk_ctx *ctx = aa_sock(sk);
1078  	struct aa_sk_ctx *new = aa_sock(newsk);
1079  
1080  	if (new->label)
1081  		aa_put_label(new->label);
1082  	new->label = aa_get_label(ctx->label);
1083  
1084  	if (new->peer)
1085  		aa_put_label(new->peer);
1086  	new->peer = aa_get_label(ctx->peer);
1087  }
1088  
apparmor_socket_create(int family,int type,int protocol,int kern)1089  static int apparmor_socket_create(int family, int type, int protocol, int kern)
1090  {
1091  	struct aa_label *label;
1092  	int error = 0;
1093  
1094  	AA_BUG(in_interrupt());
1095  
1096  	label = begin_current_label_crit_section();
1097  	if (!(kern || unconfined(label)))
1098  		error = af_select(family,
1099  				  create_perm(label, family, type, protocol),
1100  				  aa_af_perm(current_cred(), label,
1101  					     OP_CREATE, AA_MAY_CREATE,
1102  					     family, type, protocol));
1103  	end_current_label_crit_section(label);
1104  
1105  	return error;
1106  }
1107  
1108  /**
1109   * apparmor_socket_post_create - setup the per-socket security struct
1110   * @sock: socket that is being setup
1111   * @family: family of socket being created
1112   * @type: type of the socket
1113   * @protocol: protocol of the socket
1114   * @kern: socket is a special kernel socket
1115   *
1116   * Note:
1117   * -   kernel sockets labeled kernel_t used to use unconfined
1118   * -   socket may not have sk here if created with sock_create_lite or
1119   *     sock_alloc. These should be accept cases which will be handled in
1120   *     sock_graft.
1121   */
apparmor_socket_post_create(struct socket * sock,int family,int type,int protocol,int kern)1122  static int apparmor_socket_post_create(struct socket *sock, int family,
1123  				       int type, int protocol, int kern)
1124  {
1125  	struct aa_label *label;
1126  
1127  	if (kern) {
1128  		label = aa_get_label(kernel_t);
1129  	} else
1130  		label = aa_get_current_label();
1131  
1132  	if (sock->sk) {
1133  		struct aa_sk_ctx *ctx = aa_sock(sock->sk);
1134  
1135  		aa_put_label(ctx->label);
1136  		ctx->label = aa_get_label(label);
1137  	}
1138  	aa_put_label(label);
1139  
1140  	return 0;
1141  }
1142  
apparmor_socket_bind(struct socket * sock,struct sockaddr * address,int addrlen)1143  static int apparmor_socket_bind(struct socket *sock,
1144  				struct sockaddr *address, int addrlen)
1145  {
1146  	AA_BUG(!sock);
1147  	AA_BUG(!sock->sk);
1148  	AA_BUG(!address);
1149  	AA_BUG(in_interrupt());
1150  
1151  	return af_select(sock->sk->sk_family,
1152  			 bind_perm(sock, address, addrlen),
1153  			 aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk));
1154  }
1155  
apparmor_socket_connect(struct socket * sock,struct sockaddr * address,int addrlen)1156  static int apparmor_socket_connect(struct socket *sock,
1157  				   struct sockaddr *address, int addrlen)
1158  {
1159  	AA_BUG(!sock);
1160  	AA_BUG(!sock->sk);
1161  	AA_BUG(!address);
1162  	AA_BUG(in_interrupt());
1163  
1164  	return af_select(sock->sk->sk_family,
1165  			 connect_perm(sock, address, addrlen),
1166  			 aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk));
1167  }
1168  
apparmor_socket_listen(struct socket * sock,int backlog)1169  static int apparmor_socket_listen(struct socket *sock, int backlog)
1170  {
1171  	AA_BUG(!sock);
1172  	AA_BUG(!sock->sk);
1173  	AA_BUG(in_interrupt());
1174  
1175  	return af_select(sock->sk->sk_family,
1176  			 listen_perm(sock, backlog),
1177  			 aa_sk_perm(OP_LISTEN, AA_MAY_LISTEN, sock->sk));
1178  }
1179  
1180  /*
1181   * Note: while @newsock is created and has some information, the accept
1182   *       has not been done.
1183   */
apparmor_socket_accept(struct socket * sock,struct socket * newsock)1184  static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
1185  {
1186  	AA_BUG(!sock);
1187  	AA_BUG(!sock->sk);
1188  	AA_BUG(!newsock);
1189  	AA_BUG(in_interrupt());
1190  
1191  	return af_select(sock->sk->sk_family,
1192  			 accept_perm(sock, newsock),
1193  			 aa_sk_perm(OP_ACCEPT, AA_MAY_ACCEPT, sock->sk));
1194  }
1195  
aa_sock_msg_perm(const char * op,u32 request,struct socket * sock,struct msghdr * msg,int size)1196  static int aa_sock_msg_perm(const char *op, u32 request, struct socket *sock,
1197  			    struct msghdr *msg, int size)
1198  {
1199  	AA_BUG(!sock);
1200  	AA_BUG(!sock->sk);
1201  	AA_BUG(!msg);
1202  	AA_BUG(in_interrupt());
1203  
1204  	return af_select(sock->sk->sk_family,
1205  			 msg_perm(op, request, sock, msg, size),
1206  			 aa_sk_perm(op, request, sock->sk));
1207  }
1208  
apparmor_socket_sendmsg(struct socket * sock,struct msghdr * msg,int size)1209  static int apparmor_socket_sendmsg(struct socket *sock,
1210  				   struct msghdr *msg, int size)
1211  {
1212  	return aa_sock_msg_perm(OP_SENDMSG, AA_MAY_SEND, sock, msg, size);
1213  }
1214  
apparmor_socket_recvmsg(struct socket * sock,struct msghdr * msg,int size,int flags)1215  static int apparmor_socket_recvmsg(struct socket *sock,
1216  				   struct msghdr *msg, int size, int flags)
1217  {
1218  	return aa_sock_msg_perm(OP_RECVMSG, AA_MAY_RECEIVE, sock, msg, size);
1219  }
1220  
1221  /* revaliation, get/set attr, shutdown */
aa_sock_perm(const char * op,u32 request,struct socket * sock)1222  static int aa_sock_perm(const char *op, u32 request, struct socket *sock)
1223  {
1224  	AA_BUG(!sock);
1225  	AA_BUG(!sock->sk);
1226  	AA_BUG(in_interrupt());
1227  
1228  	return af_select(sock->sk->sk_family,
1229  			 sock_perm(op, request, sock),
1230  			 aa_sk_perm(op, request, sock->sk));
1231  }
1232  
apparmor_socket_getsockname(struct socket * sock)1233  static int apparmor_socket_getsockname(struct socket *sock)
1234  {
1235  	return aa_sock_perm(OP_GETSOCKNAME, AA_MAY_GETATTR, sock);
1236  }
1237  
apparmor_socket_getpeername(struct socket * sock)1238  static int apparmor_socket_getpeername(struct socket *sock)
1239  {
1240  	return aa_sock_perm(OP_GETPEERNAME, AA_MAY_GETATTR, sock);
1241  }
1242  
1243  /* revaliation, get/set attr, opt */
aa_sock_opt_perm(const char * op,u32 request,struct socket * sock,int level,int optname)1244  static int aa_sock_opt_perm(const char *op, u32 request, struct socket *sock,
1245  			    int level, int optname)
1246  {
1247  	AA_BUG(!sock);
1248  	AA_BUG(!sock->sk);
1249  	AA_BUG(in_interrupt());
1250  
1251  	return af_select(sock->sk->sk_family,
1252  			 opt_perm(op, request, sock, level, optname),
1253  			 aa_sk_perm(op, request, sock->sk));
1254  }
1255  
apparmor_socket_getsockopt(struct socket * sock,int level,int optname)1256  static int apparmor_socket_getsockopt(struct socket *sock, int level,
1257  				      int optname)
1258  {
1259  	return aa_sock_opt_perm(OP_GETSOCKOPT, AA_MAY_GETOPT, sock,
1260  				level, optname);
1261  }
1262  
apparmor_socket_setsockopt(struct socket * sock,int level,int optname)1263  static int apparmor_socket_setsockopt(struct socket *sock, int level,
1264  				      int optname)
1265  {
1266  	return aa_sock_opt_perm(OP_SETSOCKOPT, AA_MAY_SETOPT, sock,
1267  				level, optname);
1268  }
1269  
apparmor_socket_shutdown(struct socket * sock,int how)1270  static int apparmor_socket_shutdown(struct socket *sock, int how)
1271  {
1272  	return aa_sock_perm(OP_SHUTDOWN, AA_MAY_SHUTDOWN, sock);
1273  }
1274  
1275  #ifdef CONFIG_NETWORK_SECMARK
1276  /**
1277   * apparmor_socket_sock_rcv_skb - check perms before associating skb to sk
1278   * @sk: sk to associate @skb with
1279   * @skb: skb to check for perms
1280   *
1281   * Note: can not sleep may be called with locks held
1282   *
1283   * dont want protocol specific in __skb_recv_datagram()
1284   * to deny an incoming connection  socket_sock_rcv_skb()
1285   */
apparmor_socket_sock_rcv_skb(struct sock * sk,struct sk_buff * skb)1286  static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
1287  {
1288  	struct aa_sk_ctx *ctx = aa_sock(sk);
1289  
1290  	if (!skb->secmark)
1291  		return 0;
1292  
1293  	/*
1294  	 * If reach here before socket_post_create hook is called, in which
1295  	 * case label is null, drop the packet.
1296  	 */
1297  	if (!ctx->label)
1298  		return -EACCES;
1299  
1300  	return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
1301  				      skb->secmark, sk);
1302  }
1303  #endif
1304  
1305  
sk_peer_label(struct sock * sk)1306  static struct aa_label *sk_peer_label(struct sock *sk)
1307  {
1308  	struct aa_sk_ctx *ctx = aa_sock(sk);
1309  
1310  	if (ctx->peer)
1311  		return ctx->peer;
1312  
1313  	return ERR_PTR(-ENOPROTOOPT);
1314  }
1315  
1316  /**
1317   * apparmor_socket_getpeersec_stream - get security context of peer
1318   * @sock: socket that we are trying to get the peer context of
1319   * @optval: output - buffer to copy peer name to
1320   * @optlen: output - size of copied name in @optval
1321   * @len: size of @optval buffer
1322   * Returns: 0 on success, -errno of failure
1323   *
1324   * Note: for tcp only valid if using ipsec or cipso on lan
1325   */
apparmor_socket_getpeersec_stream(struct socket * sock,sockptr_t optval,sockptr_t optlen,unsigned int len)1326  static int apparmor_socket_getpeersec_stream(struct socket *sock,
1327  					     sockptr_t optval, sockptr_t optlen,
1328  					     unsigned int len)
1329  {
1330  	char *name = NULL;
1331  	int slen, error = 0;
1332  	struct aa_label *label;
1333  	struct aa_label *peer;
1334  
1335  	label = begin_current_label_crit_section();
1336  	peer = sk_peer_label(sock->sk);
1337  	if (IS_ERR(peer)) {
1338  		error = PTR_ERR(peer);
1339  		goto done;
1340  	}
1341  	slen = aa_label_asxprint(&name, labels_ns(label), peer,
1342  				 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS |
1343  				 FLAG_HIDDEN_UNCONFINED, GFP_KERNEL);
1344  	/* don't include terminating \0 in slen, it breaks some apps */
1345  	if (slen < 0) {
1346  		error = -ENOMEM;
1347  		goto done;
1348  	}
1349  	if (slen > len) {
1350  		error = -ERANGE;
1351  		goto done_len;
1352  	}
1353  
1354  	if (copy_to_sockptr(optval, name, slen))
1355  		error = -EFAULT;
1356  done_len:
1357  	if (copy_to_sockptr(optlen, &slen, sizeof(slen)))
1358  		error = -EFAULT;
1359  done:
1360  	end_current_label_crit_section(label);
1361  	kfree(name);
1362  	return error;
1363  }
1364  
1365  /**
1366   * apparmor_socket_getpeersec_dgram - get security label of packet
1367   * @sock: the peer socket
1368   * @skb: packet data
1369   * @secid: pointer to where to put the secid of the packet
1370   *
1371   * Sets the netlabel socket state on sk from parent
1372   */
apparmor_socket_getpeersec_dgram(struct socket * sock,struct sk_buff * skb,u32 * secid)1373  static int apparmor_socket_getpeersec_dgram(struct socket *sock,
1374  					    struct sk_buff *skb, u32 *secid)
1375  
1376  {
1377  	/* TODO: requires secid support */
1378  	return -ENOPROTOOPT;
1379  }
1380  
1381  /**
1382   * apparmor_sock_graft - Initialize newly created socket
1383   * @sk: child sock
1384   * @parent: parent socket
1385   *
1386   * Note: could set off of SOCK_CTX(parent) but need to track inode and we can
1387   *       just set sk security information off of current creating process label
1388   *       Labeling of sk for accept case - probably should be sock based
1389   *       instead of task, because of the case where an implicitly labeled
1390   *       socket is shared by different tasks.
1391   */
apparmor_sock_graft(struct sock * sk,struct socket * parent)1392  static void apparmor_sock_graft(struct sock *sk, struct socket *parent)
1393  {
1394  	struct aa_sk_ctx *ctx = aa_sock(sk);
1395  
1396  	if (!ctx->label)
1397  		ctx->label = aa_get_current_label();
1398  }
1399  
1400  #ifdef CONFIG_NETWORK_SECMARK
apparmor_inet_conn_request(const struct sock * sk,struct sk_buff * skb,struct request_sock * req)1401  static int apparmor_inet_conn_request(const struct sock *sk, struct sk_buff *skb,
1402  				      struct request_sock *req)
1403  {
1404  	struct aa_sk_ctx *ctx = aa_sock(sk);
1405  
1406  	if (!skb->secmark)
1407  		return 0;
1408  
1409  	return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
1410  				      skb->secmark, sk);
1411  }
1412  #endif
1413  
1414  /*
1415   * The cred blob is a pointer to, not an instance of, an aa_label.
1416   */
1417  struct lsm_blob_sizes apparmor_blob_sizes __ro_after_init = {
1418  	.lbs_cred = sizeof(struct aa_label *),
1419  	.lbs_file = sizeof(struct aa_file_ctx),
1420  	.lbs_task = sizeof(struct aa_task_ctx),
1421  	.lbs_sock = sizeof(struct aa_sk_ctx),
1422  };
1423  
1424  static const struct lsm_id apparmor_lsmid = {
1425  	.name = "apparmor",
1426  	.id = LSM_ID_APPARMOR,
1427  };
1428  
1429  static struct security_hook_list apparmor_hooks[] __ro_after_init = {
1430  	LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
1431  	LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
1432  	LSM_HOOK_INIT(capget, apparmor_capget),
1433  	LSM_HOOK_INIT(capable, apparmor_capable),
1434  
1435  	LSM_HOOK_INIT(move_mount, apparmor_move_mount),
1436  	LSM_HOOK_INIT(sb_mount, apparmor_sb_mount),
1437  	LSM_HOOK_INIT(sb_umount, apparmor_sb_umount),
1438  	LSM_HOOK_INIT(sb_pivotroot, apparmor_sb_pivotroot),
1439  
1440  	LSM_HOOK_INIT(path_link, apparmor_path_link),
1441  	LSM_HOOK_INIT(path_unlink, apparmor_path_unlink),
1442  	LSM_HOOK_INIT(path_symlink, apparmor_path_symlink),
1443  	LSM_HOOK_INIT(path_mkdir, apparmor_path_mkdir),
1444  	LSM_HOOK_INIT(path_rmdir, apparmor_path_rmdir),
1445  	LSM_HOOK_INIT(path_mknod, apparmor_path_mknod),
1446  	LSM_HOOK_INIT(path_rename, apparmor_path_rename),
1447  	LSM_HOOK_INIT(path_chmod, apparmor_path_chmod),
1448  	LSM_HOOK_INIT(path_chown, apparmor_path_chown),
1449  	LSM_HOOK_INIT(path_truncate, apparmor_path_truncate),
1450  	LSM_HOOK_INIT(inode_getattr, apparmor_inode_getattr),
1451  
1452  	LSM_HOOK_INIT(file_open, apparmor_file_open),
1453  	LSM_HOOK_INIT(file_receive, apparmor_file_receive),
1454  	LSM_HOOK_INIT(file_permission, apparmor_file_permission),
1455  	LSM_HOOK_INIT(file_alloc_security, apparmor_file_alloc_security),
1456  	LSM_HOOK_INIT(file_free_security, apparmor_file_free_security),
1457  	LSM_HOOK_INIT(mmap_file, apparmor_mmap_file),
1458  	LSM_HOOK_INIT(file_mprotect, apparmor_file_mprotect),
1459  	LSM_HOOK_INIT(file_lock, apparmor_file_lock),
1460  	LSM_HOOK_INIT(file_truncate, apparmor_file_truncate),
1461  
1462  	LSM_HOOK_INIT(getselfattr, apparmor_getselfattr),
1463  	LSM_HOOK_INIT(setselfattr, apparmor_setselfattr),
1464  	LSM_HOOK_INIT(getprocattr, apparmor_getprocattr),
1465  	LSM_HOOK_INIT(setprocattr, apparmor_setprocattr),
1466  
1467  	LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
1468  	LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
1469  
1470  	LSM_HOOK_INIT(socket_create, apparmor_socket_create),
1471  	LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
1472  	LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
1473  	LSM_HOOK_INIT(socket_connect, apparmor_socket_connect),
1474  	LSM_HOOK_INIT(socket_listen, apparmor_socket_listen),
1475  	LSM_HOOK_INIT(socket_accept, apparmor_socket_accept),
1476  	LSM_HOOK_INIT(socket_sendmsg, apparmor_socket_sendmsg),
1477  	LSM_HOOK_INIT(socket_recvmsg, apparmor_socket_recvmsg),
1478  	LSM_HOOK_INIT(socket_getsockname, apparmor_socket_getsockname),
1479  	LSM_HOOK_INIT(socket_getpeername, apparmor_socket_getpeername),
1480  	LSM_HOOK_INIT(socket_getsockopt, apparmor_socket_getsockopt),
1481  	LSM_HOOK_INIT(socket_setsockopt, apparmor_socket_setsockopt),
1482  	LSM_HOOK_INIT(socket_shutdown, apparmor_socket_shutdown),
1483  #ifdef CONFIG_NETWORK_SECMARK
1484  	LSM_HOOK_INIT(socket_sock_rcv_skb, apparmor_socket_sock_rcv_skb),
1485  #endif
1486  	LSM_HOOK_INIT(socket_getpeersec_stream,
1487  		      apparmor_socket_getpeersec_stream),
1488  	LSM_HOOK_INIT(socket_getpeersec_dgram,
1489  		      apparmor_socket_getpeersec_dgram),
1490  	LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
1491  #ifdef CONFIG_NETWORK_SECMARK
1492  	LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),
1493  #endif
1494  
1495  	LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
1496  	LSM_HOOK_INIT(cred_free, apparmor_cred_free),
1497  	LSM_HOOK_INIT(cred_prepare, apparmor_cred_prepare),
1498  	LSM_HOOK_INIT(cred_transfer, apparmor_cred_transfer),
1499  
1500  	LSM_HOOK_INIT(bprm_creds_for_exec, apparmor_bprm_creds_for_exec),
1501  	LSM_HOOK_INIT(bprm_committing_creds, apparmor_bprm_committing_creds),
1502  	LSM_HOOK_INIT(bprm_committed_creds, apparmor_bprm_committed_creds),
1503  
1504  	LSM_HOOK_INIT(task_free, apparmor_task_free),
1505  	LSM_HOOK_INIT(task_alloc, apparmor_task_alloc),
1506  	LSM_HOOK_INIT(current_getsecid_subj, apparmor_current_getsecid_subj),
1507  	LSM_HOOK_INIT(task_getsecid_obj, apparmor_task_getsecid_obj),
1508  	LSM_HOOK_INIT(task_setrlimit, apparmor_task_setrlimit),
1509  	LSM_HOOK_INIT(task_kill, apparmor_task_kill),
1510  	LSM_HOOK_INIT(userns_create, apparmor_userns_create),
1511  
1512  #ifdef CONFIG_AUDIT
1513  	LSM_HOOK_INIT(audit_rule_init, aa_audit_rule_init),
1514  	LSM_HOOK_INIT(audit_rule_known, aa_audit_rule_known),
1515  	LSM_HOOK_INIT(audit_rule_match, aa_audit_rule_match),
1516  	LSM_HOOK_INIT(audit_rule_free, aa_audit_rule_free),
1517  #endif
1518  
1519  	LSM_HOOK_INIT(secid_to_secctx, apparmor_secid_to_secctx),
1520  	LSM_HOOK_INIT(secctx_to_secid, apparmor_secctx_to_secid),
1521  	LSM_HOOK_INIT(release_secctx, apparmor_release_secctx),
1522  
1523  #ifdef CONFIG_IO_URING
1524  	LSM_HOOK_INIT(uring_override_creds, apparmor_uring_override_creds),
1525  	LSM_HOOK_INIT(uring_sqpoll, apparmor_uring_sqpoll),
1526  #endif
1527  };
1528  
1529  /*
1530   * AppArmor sysfs module parameters
1531   */
1532  
1533  static int param_set_aabool(const char *val, const struct kernel_param *kp);
1534  static int param_get_aabool(char *buffer, const struct kernel_param *kp);
1535  #define param_check_aabool param_check_bool
1536  static const struct kernel_param_ops param_ops_aabool = {
1537  	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1538  	.set = param_set_aabool,
1539  	.get = param_get_aabool
1540  };
1541  
1542  static int param_set_aauint(const char *val, const struct kernel_param *kp);
1543  static int param_get_aauint(char *buffer, const struct kernel_param *kp);
1544  #define param_check_aauint param_check_uint
1545  static const struct kernel_param_ops param_ops_aauint = {
1546  	.set = param_set_aauint,
1547  	.get = param_get_aauint
1548  };
1549  
1550  static int param_set_aacompressionlevel(const char *val,
1551  					const struct kernel_param *kp);
1552  static int param_get_aacompressionlevel(char *buffer,
1553  					const struct kernel_param *kp);
1554  #define param_check_aacompressionlevel param_check_int
1555  static const struct kernel_param_ops param_ops_aacompressionlevel = {
1556  	.set = param_set_aacompressionlevel,
1557  	.get = param_get_aacompressionlevel
1558  };
1559  
1560  static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp);
1561  static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp);
1562  #define param_check_aalockpolicy param_check_bool
1563  static const struct kernel_param_ops param_ops_aalockpolicy = {
1564  	.flags = KERNEL_PARAM_OPS_FL_NOARG,
1565  	.set = param_set_aalockpolicy,
1566  	.get = param_get_aalockpolicy
1567  };
1568  
1569  static int param_set_audit(const char *val, const struct kernel_param *kp);
1570  static int param_get_audit(char *buffer, const struct kernel_param *kp);
1571  
1572  static int param_set_mode(const char *val, const struct kernel_param *kp);
1573  static int param_get_mode(char *buffer, const struct kernel_param *kp);
1574  
1575  /* Flag values, also controllable via /sys/module/apparmor/parameters
1576   * We define special types as we want to do additional mediation.
1577   */
1578  
1579  /* AppArmor global enforcement switch - complain, enforce, kill */
1580  enum profile_mode aa_g_profile_mode = APPARMOR_ENFORCE;
1581  module_param_call(mode, param_set_mode, param_get_mode,
1582  		  &aa_g_profile_mode, S_IRUSR | S_IWUSR);
1583  
1584  /* whether policy verification hashing is enabled */
1585  bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT);
1586  #ifdef CONFIG_SECURITY_APPARMOR_HASH
1587  module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR);
1588  #endif
1589  
1590  /* whether policy exactly as loaded is retained for debug and checkpointing */
1591  bool aa_g_export_binary = IS_ENABLED(CONFIG_SECURITY_APPARMOR_EXPORT_BINARY);
1592  #ifdef CONFIG_SECURITY_APPARMOR_EXPORT_BINARY
1593  module_param_named(export_binary, aa_g_export_binary, aabool, 0600);
1594  #endif
1595  
1596  /* policy loaddata compression level */
1597  int aa_g_rawdata_compression_level = AA_DEFAULT_CLEVEL;
1598  module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level,
1599  		   aacompressionlevel, 0400);
1600  
1601  /* Debug mode */
1602  bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES);
1603  module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR);
1604  
1605  /* Audit mode */
1606  enum audit_mode aa_g_audit;
1607  module_param_call(audit, param_set_audit, param_get_audit,
1608  		  &aa_g_audit, S_IRUSR | S_IWUSR);
1609  
1610  /* Determines if audit header is included in audited messages.  This
1611   * provides more context if the audit daemon is not running
1612   */
1613  bool aa_g_audit_header = true;
1614  module_param_named(audit_header, aa_g_audit_header, aabool,
1615  		   S_IRUSR | S_IWUSR);
1616  
1617  /* lock out loading/removal of policy
1618   * TODO: add in at boot loading of policy, which is the only way to
1619   *       load policy, if lock_policy is set
1620   */
1621  bool aa_g_lock_policy;
1622  module_param_named(lock_policy, aa_g_lock_policy, aalockpolicy,
1623  		   S_IRUSR | S_IWUSR);
1624  
1625  /* Syscall logging mode */
1626  bool aa_g_logsyscall;
1627  module_param_named(logsyscall, aa_g_logsyscall, aabool, S_IRUSR | S_IWUSR);
1628  
1629  /* Maximum pathname length before accesses will start getting rejected */
1630  unsigned int aa_g_path_max = 2 * PATH_MAX;
1631  module_param_named(path_max, aa_g_path_max, aauint, S_IRUSR);
1632  
1633  /* Determines how paranoid loading of policy is and how much verification
1634   * on the loaded policy is done.
1635   * DEPRECATED: read only as strict checking of load is always done now
1636   * that none root users (user namespaces) can load policy.
1637   */
1638  bool aa_g_paranoid_load = IS_ENABLED(CONFIG_SECURITY_APPARMOR_PARANOID_LOAD);
1639  module_param_named(paranoid_load, aa_g_paranoid_load, aabool, S_IRUGO);
1640  
1641  static int param_get_aaintbool(char *buffer, const struct kernel_param *kp);
1642  static int param_set_aaintbool(const char *val, const struct kernel_param *kp);
1643  #define param_check_aaintbool param_check_int
1644  static const struct kernel_param_ops param_ops_aaintbool = {
1645  	.set = param_set_aaintbool,
1646  	.get = param_get_aaintbool
1647  };
1648  /* Boot time disable flag */
1649  static int apparmor_enabled __ro_after_init = 1;
1650  module_param_named(enabled, apparmor_enabled, aaintbool, 0444);
1651  
apparmor_enabled_setup(char * str)1652  static int __init apparmor_enabled_setup(char *str)
1653  {
1654  	unsigned long enabled;
1655  	int error = kstrtoul(str, 0, &enabled);
1656  	if (!error)
1657  		apparmor_enabled = enabled ? 1 : 0;
1658  	return 1;
1659  }
1660  
1661  __setup("apparmor=", apparmor_enabled_setup);
1662  
1663  /* set global flag turning off the ability to load policy */
param_set_aalockpolicy(const char * val,const struct kernel_param * kp)1664  static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp)
1665  {
1666  	if (!apparmor_enabled)
1667  		return -EINVAL;
1668  	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1669  		return -EPERM;
1670  	return param_set_bool(val, kp);
1671  }
1672  
param_get_aalockpolicy(char * buffer,const struct kernel_param * kp)1673  static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp)
1674  {
1675  	if (!apparmor_enabled)
1676  		return -EINVAL;
1677  	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1678  		return -EPERM;
1679  	return param_get_bool(buffer, kp);
1680  }
1681  
param_set_aabool(const char * val,const struct kernel_param * kp)1682  static int param_set_aabool(const char *val, const struct kernel_param *kp)
1683  {
1684  	if (!apparmor_enabled)
1685  		return -EINVAL;
1686  	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1687  		return -EPERM;
1688  	return param_set_bool(val, kp);
1689  }
1690  
param_get_aabool(char * buffer,const struct kernel_param * kp)1691  static int param_get_aabool(char *buffer, const struct kernel_param *kp)
1692  {
1693  	if (!apparmor_enabled)
1694  		return -EINVAL;
1695  	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1696  		return -EPERM;
1697  	return param_get_bool(buffer, kp);
1698  }
1699  
param_set_aauint(const char * val,const struct kernel_param * kp)1700  static int param_set_aauint(const char *val, const struct kernel_param *kp)
1701  {
1702  	int error;
1703  
1704  	if (!apparmor_enabled)
1705  		return -EINVAL;
1706  	/* file is ro but enforce 2nd line check */
1707  	if (apparmor_initialized)
1708  		return -EPERM;
1709  
1710  	error = param_set_uint(val, kp);
1711  	aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer));
1712  	pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
1713  
1714  	return error;
1715  }
1716  
param_get_aauint(char * buffer,const struct kernel_param * kp)1717  static int param_get_aauint(char *buffer, const struct kernel_param *kp)
1718  {
1719  	if (!apparmor_enabled)
1720  		return -EINVAL;
1721  	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1722  		return -EPERM;
1723  	return param_get_uint(buffer, kp);
1724  }
1725  
1726  /* Can only be set before AppArmor is initialized (i.e. on boot cmdline). */
param_set_aaintbool(const char * val,const struct kernel_param * kp)1727  static int param_set_aaintbool(const char *val, const struct kernel_param *kp)
1728  {
1729  	struct kernel_param kp_local;
1730  	bool value;
1731  	int error;
1732  
1733  	if (apparmor_initialized)
1734  		return -EPERM;
1735  
1736  	/* Create local copy, with arg pointing to bool type. */
1737  	value = !!*((int *)kp->arg);
1738  	memcpy(&kp_local, kp, sizeof(kp_local));
1739  	kp_local.arg = &value;
1740  
1741  	error = param_set_bool(val, &kp_local);
1742  	if (!error)
1743  		*((int *)kp->arg) = *((bool *)kp_local.arg);
1744  	return error;
1745  }
1746  
1747  /*
1748   * To avoid changing /sys/module/apparmor/parameters/enabled from Y/N to
1749   * 1/0, this converts the "int that is actually bool" back to bool for
1750   * display in the /sys filesystem, while keeping it "int" for the LSM
1751   * infrastructure.
1752   */
param_get_aaintbool(char * buffer,const struct kernel_param * kp)1753  static int param_get_aaintbool(char *buffer, const struct kernel_param *kp)
1754  {
1755  	struct kernel_param kp_local;
1756  	bool value;
1757  
1758  	/* Create local copy, with arg pointing to bool type. */
1759  	value = !!*((int *)kp->arg);
1760  	memcpy(&kp_local, kp, sizeof(kp_local));
1761  	kp_local.arg = &value;
1762  
1763  	return param_get_bool(buffer, &kp_local);
1764  }
1765  
param_set_aacompressionlevel(const char * val,const struct kernel_param * kp)1766  static int param_set_aacompressionlevel(const char *val,
1767  					const struct kernel_param *kp)
1768  {
1769  	int error;
1770  
1771  	if (!apparmor_enabled)
1772  		return -EINVAL;
1773  	if (apparmor_initialized)
1774  		return -EPERM;
1775  
1776  	error = param_set_int(val, kp);
1777  
1778  	aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level,
1779  					       AA_MIN_CLEVEL, AA_MAX_CLEVEL);
1780  	pr_info("AppArmor: policy rawdata compression level set to %d\n",
1781  		aa_g_rawdata_compression_level);
1782  
1783  	return error;
1784  }
1785  
param_get_aacompressionlevel(char * buffer,const struct kernel_param * kp)1786  static int param_get_aacompressionlevel(char *buffer,
1787  					const struct kernel_param *kp)
1788  {
1789  	if (!apparmor_enabled)
1790  		return -EINVAL;
1791  	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1792  		return -EPERM;
1793  	return param_get_int(buffer, kp);
1794  }
1795  
param_get_audit(char * buffer,const struct kernel_param * kp)1796  static int param_get_audit(char *buffer, const struct kernel_param *kp)
1797  {
1798  	if (!apparmor_enabled)
1799  		return -EINVAL;
1800  	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1801  		return -EPERM;
1802  	return sprintf(buffer, "%s", audit_mode_names[aa_g_audit]);
1803  }
1804  
param_set_audit(const char * val,const struct kernel_param * kp)1805  static int param_set_audit(const char *val, const struct kernel_param *kp)
1806  {
1807  	int i;
1808  
1809  	if (!apparmor_enabled)
1810  		return -EINVAL;
1811  	if (!val)
1812  		return -EINVAL;
1813  	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1814  		return -EPERM;
1815  
1816  	i = match_string(audit_mode_names, AUDIT_MAX_INDEX, val);
1817  	if (i < 0)
1818  		return -EINVAL;
1819  
1820  	aa_g_audit = i;
1821  	return 0;
1822  }
1823  
param_get_mode(char * buffer,const struct kernel_param * kp)1824  static int param_get_mode(char *buffer, const struct kernel_param *kp)
1825  {
1826  	if (!apparmor_enabled)
1827  		return -EINVAL;
1828  	if (apparmor_initialized && !aa_current_policy_view_capable(NULL))
1829  		return -EPERM;
1830  
1831  	return sprintf(buffer, "%s", aa_profile_mode_names[aa_g_profile_mode]);
1832  }
1833  
param_set_mode(const char * val,const struct kernel_param * kp)1834  static int param_set_mode(const char *val, const struct kernel_param *kp)
1835  {
1836  	int i;
1837  
1838  	if (!apparmor_enabled)
1839  		return -EINVAL;
1840  	if (!val)
1841  		return -EINVAL;
1842  	if (apparmor_initialized && !aa_current_policy_admin_capable(NULL))
1843  		return -EPERM;
1844  
1845  	i = match_string(aa_profile_mode_names, APPARMOR_MODE_NAMES_MAX_INDEX,
1846  			 val);
1847  	if (i < 0)
1848  		return -EINVAL;
1849  
1850  	aa_g_profile_mode = i;
1851  	return 0;
1852  }
1853  
aa_get_buffer(bool in_atomic)1854  char *aa_get_buffer(bool in_atomic)
1855  {
1856  	union aa_buffer *aa_buf;
1857  	struct aa_local_cache *cache;
1858  	bool try_again = true;
1859  	gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
1860  
1861  	/* use per cpu cached buffers first */
1862  	cache = get_cpu_ptr(&aa_local_buffers);
1863  	if (!list_empty(&cache->head)) {
1864  		aa_buf = list_first_entry(&cache->head, union aa_buffer, list);
1865  		list_del(&aa_buf->list);
1866  		cache->hold--;
1867  		cache->count--;
1868  		put_cpu_ptr(&aa_local_buffers);
1869  		return &aa_buf->buffer[0];
1870  	}
1871  	put_cpu_ptr(&aa_local_buffers);
1872  
1873  	if (!spin_trylock(&aa_buffers_lock)) {
1874  		cache = get_cpu_ptr(&aa_local_buffers);
1875  		cache->hold += 1;
1876  		put_cpu_ptr(&aa_local_buffers);
1877  		spin_lock(&aa_buffers_lock);
1878  	} else {
1879  		cache = get_cpu_ptr(&aa_local_buffers);
1880  		put_cpu_ptr(&aa_local_buffers);
1881  	}
1882  retry:
1883  	if (buffer_count > reserve_count ||
1884  	    (in_atomic && !list_empty(&aa_global_buffers))) {
1885  		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1886  					  list);
1887  		list_del(&aa_buf->list);
1888  		buffer_count--;
1889  		spin_unlock(&aa_buffers_lock);
1890  		return aa_buf->buffer;
1891  	}
1892  	if (in_atomic) {
1893  		/*
1894  		 * out of reserve buffers and in atomic context so increase
1895  		 * how many buffers to keep in reserve
1896  		 */
1897  		reserve_count++;
1898  		flags = GFP_ATOMIC;
1899  	}
1900  	spin_unlock(&aa_buffers_lock);
1901  
1902  	if (!in_atomic)
1903  		might_sleep();
1904  	aa_buf = kmalloc(aa_g_path_max, flags);
1905  	if (!aa_buf) {
1906  		if (try_again) {
1907  			try_again = false;
1908  			spin_lock(&aa_buffers_lock);
1909  			goto retry;
1910  		}
1911  		pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
1912  		return NULL;
1913  	}
1914  	return aa_buf->buffer;
1915  }
1916  
aa_put_buffer(char * buf)1917  void aa_put_buffer(char *buf)
1918  {
1919  	union aa_buffer *aa_buf;
1920  	struct aa_local_cache *cache;
1921  
1922  	if (!buf)
1923  		return;
1924  	aa_buf = container_of(buf, union aa_buffer, buffer[0]);
1925  
1926  	cache = get_cpu_ptr(&aa_local_buffers);
1927  	if (!cache->hold) {
1928  		put_cpu_ptr(&aa_local_buffers);
1929  
1930  		if (spin_trylock(&aa_buffers_lock)) {
1931  			/* put back on global list */
1932  			list_add(&aa_buf->list, &aa_global_buffers);
1933  			buffer_count++;
1934  			spin_unlock(&aa_buffers_lock);
1935  			cache = get_cpu_ptr(&aa_local_buffers);
1936  			put_cpu_ptr(&aa_local_buffers);
1937  			return;
1938  		}
1939  		/* contention on global list, fallback to percpu */
1940  		cache = get_cpu_ptr(&aa_local_buffers);
1941  		cache->hold += 1;
1942  	}
1943  
1944  	/* cache in percpu list */
1945  	list_add(&aa_buf->list, &cache->head);
1946  	cache->count++;
1947  	put_cpu_ptr(&aa_local_buffers);
1948  }
1949  
1950  /*
1951   * AppArmor init functions
1952   */
1953  
1954  /**
1955   * set_init_ctx - set a task context and profile on the first task.
1956   *
1957   * TODO: allow setting an alternate profile than unconfined
1958   */
set_init_ctx(void)1959  static int __init set_init_ctx(void)
1960  {
1961  	struct cred *cred = (__force struct cred *)current->real_cred;
1962  
1963  	set_cred_label(cred, aa_get_label(ns_unconfined(root_ns)));
1964  
1965  	return 0;
1966  }
1967  
destroy_buffers(void)1968  static void destroy_buffers(void)
1969  {
1970  	union aa_buffer *aa_buf;
1971  
1972  	spin_lock(&aa_buffers_lock);
1973  	while (!list_empty(&aa_global_buffers)) {
1974  		aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
1975  					 list);
1976  		list_del(&aa_buf->list);
1977  		spin_unlock(&aa_buffers_lock);
1978  		kfree(aa_buf);
1979  		spin_lock(&aa_buffers_lock);
1980  	}
1981  	spin_unlock(&aa_buffers_lock);
1982  }
1983  
alloc_buffers(void)1984  static int __init alloc_buffers(void)
1985  {
1986  	union aa_buffer *aa_buf;
1987  	int i, num;
1988  
1989  	/*
1990  	 * per cpu set of cached allocated buffers used to help reduce
1991  	 * lock contention
1992  	 */
1993  	for_each_possible_cpu(i) {
1994  		per_cpu(aa_local_buffers, i).hold = 0;
1995  		per_cpu(aa_local_buffers, i).count = 0;
1996  		INIT_LIST_HEAD(&per_cpu(aa_local_buffers, i).head);
1997  	}
1998  	/*
1999  	 * A function may require two buffers at once. Usually the buffers are
2000  	 * used for a short period of time and are shared. On UP kernel buffers
2001  	 * two should be enough, with more CPUs it is possible that more
2002  	 * buffers will be used simultaneously. The preallocated pool may grow.
2003  	 * This preallocation has also the side-effect that AppArmor will be
2004  	 * disabled early at boot if aa_g_path_max is extremly high.
2005  	 */
2006  	if (num_online_cpus() > 1)
2007  		num = 4 + RESERVE_COUNT;
2008  	else
2009  		num = 2 + RESERVE_COUNT;
2010  
2011  	for (i = 0; i < num; i++) {
2012  
2013  		aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL |
2014  				 __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
2015  		if (!aa_buf) {
2016  			destroy_buffers();
2017  			return -ENOMEM;
2018  		}
2019  		aa_put_buffer(aa_buf->buffer);
2020  	}
2021  	return 0;
2022  }
2023  
2024  #ifdef CONFIG_SYSCTL
apparmor_dointvec(const struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)2025  static int apparmor_dointvec(const struct ctl_table *table, int write,
2026  			     void *buffer, size_t *lenp, loff_t *ppos)
2027  {
2028  	if (!aa_current_policy_admin_capable(NULL))
2029  		return -EPERM;
2030  	if (!apparmor_enabled)
2031  		return -EINVAL;
2032  
2033  	return proc_dointvec(table, write, buffer, lenp, ppos);
2034  }
2035  
2036  static struct ctl_table apparmor_sysctl_table[] = {
2037  #ifdef CONFIG_USER_NS
2038  	{
2039  		.procname       = "unprivileged_userns_apparmor_policy",
2040  		.data           = &unprivileged_userns_apparmor_policy,
2041  		.maxlen         = sizeof(int),
2042  		.mode           = 0600,
2043  		.proc_handler   = apparmor_dointvec,
2044  	},
2045  #endif /* CONFIG_USER_NS */
2046  	{
2047  		.procname       = "apparmor_display_secid_mode",
2048  		.data           = &apparmor_display_secid_mode,
2049  		.maxlen         = sizeof(int),
2050  		.mode           = 0600,
2051  		.proc_handler   = apparmor_dointvec,
2052  	},
2053  	{
2054  		.procname       = "apparmor_restrict_unprivileged_unconfined",
2055  		.data           = &aa_unprivileged_unconfined_restricted,
2056  		.maxlen         = sizeof(int),
2057  		.mode           = 0600,
2058  		.proc_handler   = apparmor_dointvec,
2059  	},
2060  };
2061  
apparmor_init_sysctl(void)2062  static int __init apparmor_init_sysctl(void)
2063  {
2064  	return register_sysctl("kernel", apparmor_sysctl_table) ? 0 : -ENOMEM;
2065  }
2066  #else
apparmor_init_sysctl(void)2067  static inline int apparmor_init_sysctl(void)
2068  {
2069  	return 0;
2070  }
2071  #endif /* CONFIG_SYSCTL */
2072  
2073  #if defined(CONFIG_NETFILTER) && defined(CONFIG_NETWORK_SECMARK)
apparmor_ip_postroute(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)2074  static unsigned int apparmor_ip_postroute(void *priv,
2075  					  struct sk_buff *skb,
2076  					  const struct nf_hook_state *state)
2077  {
2078  	struct aa_sk_ctx *ctx;
2079  	struct sock *sk;
2080  
2081  	if (!skb->secmark)
2082  		return NF_ACCEPT;
2083  
2084  	sk = skb_to_full_sk(skb);
2085  	if (sk == NULL)
2086  		return NF_ACCEPT;
2087  
2088  	ctx = aa_sock(sk);
2089  	if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
2090  				    skb->secmark, sk))
2091  		return NF_ACCEPT;
2092  
2093  	return NF_DROP_ERR(-ECONNREFUSED);
2094  
2095  }
2096  
2097  static const struct nf_hook_ops apparmor_nf_ops[] = {
2098  	{
2099  		.hook =         apparmor_ip_postroute,
2100  		.pf =           NFPROTO_IPV4,
2101  		.hooknum =      NF_INET_POST_ROUTING,
2102  		.priority =     NF_IP_PRI_SELINUX_FIRST,
2103  	},
2104  #if IS_ENABLED(CONFIG_IPV6)
2105  	{
2106  		.hook =         apparmor_ip_postroute,
2107  		.pf =           NFPROTO_IPV6,
2108  		.hooknum =      NF_INET_POST_ROUTING,
2109  		.priority =     NF_IP6_PRI_SELINUX_FIRST,
2110  	},
2111  #endif
2112  };
2113  
apparmor_nf_register(struct net * net)2114  static int __net_init apparmor_nf_register(struct net *net)
2115  {
2116  	return nf_register_net_hooks(net, apparmor_nf_ops,
2117  				    ARRAY_SIZE(apparmor_nf_ops));
2118  }
2119  
apparmor_nf_unregister(struct net * net)2120  static void __net_exit apparmor_nf_unregister(struct net *net)
2121  {
2122  	nf_unregister_net_hooks(net, apparmor_nf_ops,
2123  				ARRAY_SIZE(apparmor_nf_ops));
2124  }
2125  
2126  static struct pernet_operations apparmor_net_ops = {
2127  	.init = apparmor_nf_register,
2128  	.exit = apparmor_nf_unregister,
2129  };
2130  
apparmor_nf_ip_init(void)2131  static int __init apparmor_nf_ip_init(void)
2132  {
2133  	int err;
2134  
2135  	if (!apparmor_enabled)
2136  		return 0;
2137  
2138  	err = register_pernet_subsys(&apparmor_net_ops);
2139  	if (err)
2140  		panic("Apparmor: register_pernet_subsys: error %d\n", err);
2141  
2142  	return 0;
2143  }
2144  __initcall(apparmor_nf_ip_init);
2145  #endif
2146  
2147  static char nulldfa_src[] = {
2148  	#include "nulldfa.in"
2149  };
2150  static struct aa_dfa *nulldfa;
2151  
2152  static char stacksplitdfa_src[] = {
2153  	#include "stacksplitdfa.in"
2154  };
2155  struct aa_dfa *stacksplitdfa;
2156  struct aa_policydb *nullpdb;
2157  
aa_setup_dfa_engine(void)2158  static int __init aa_setup_dfa_engine(void)
2159  {
2160  	int error = -ENOMEM;
2161  
2162  	nullpdb = aa_alloc_pdb(GFP_KERNEL);
2163  	if (!nullpdb)
2164  		return -ENOMEM;
2165  
2166  	nulldfa = aa_dfa_unpack(nulldfa_src, sizeof(nulldfa_src),
2167  			    TO_ACCEPT1_FLAG(YYTD_DATA32) |
2168  			    TO_ACCEPT2_FLAG(YYTD_DATA32));
2169  	if (IS_ERR(nulldfa)) {
2170  		error = PTR_ERR(nulldfa);
2171  		goto fail;
2172  	}
2173  	nullpdb->dfa = aa_get_dfa(nulldfa);
2174  	nullpdb->perms = kcalloc(2, sizeof(struct aa_perms), GFP_KERNEL);
2175  	if (!nullpdb->perms)
2176  		goto fail;
2177  	nullpdb->size = 2;
2178  
2179  	stacksplitdfa = aa_dfa_unpack(stacksplitdfa_src,
2180  				      sizeof(stacksplitdfa_src),
2181  				      TO_ACCEPT1_FLAG(YYTD_DATA32) |
2182  				      TO_ACCEPT2_FLAG(YYTD_DATA32));
2183  	if (IS_ERR(stacksplitdfa)) {
2184  		error = PTR_ERR(stacksplitdfa);
2185  		goto fail;
2186  	}
2187  
2188  	return 0;
2189  
2190  fail:
2191  	aa_put_pdb(nullpdb);
2192  	aa_put_dfa(nulldfa);
2193  	nullpdb = NULL;
2194  	nulldfa = NULL;
2195  	stacksplitdfa = NULL;
2196  
2197  	return error;
2198  }
2199  
aa_teardown_dfa_engine(void)2200  static void __init aa_teardown_dfa_engine(void)
2201  {
2202  	aa_put_dfa(stacksplitdfa);
2203  	aa_put_dfa(nulldfa);
2204  	aa_put_pdb(nullpdb);
2205  	nullpdb = NULL;
2206  	stacksplitdfa = NULL;
2207  	nulldfa = NULL;
2208  }
2209  
apparmor_init(void)2210  static int __init apparmor_init(void)
2211  {
2212  	int error;
2213  
2214  	error = aa_setup_dfa_engine();
2215  	if (error) {
2216  		AA_ERROR("Unable to setup dfa engine\n");
2217  		goto alloc_out;
2218  	}
2219  
2220  	error = aa_alloc_root_ns();
2221  	if (error) {
2222  		AA_ERROR("Unable to allocate default profile namespace\n");
2223  		goto alloc_out;
2224  	}
2225  
2226  	error = apparmor_init_sysctl();
2227  	if (error) {
2228  		AA_ERROR("Unable to register sysctls\n");
2229  		goto alloc_out;
2230  
2231  	}
2232  
2233  	error = alloc_buffers();
2234  	if (error) {
2235  		AA_ERROR("Unable to allocate work buffers\n");
2236  		goto alloc_out;
2237  	}
2238  
2239  	error = set_init_ctx();
2240  	if (error) {
2241  		AA_ERROR("Failed to set context on init task\n");
2242  		aa_free_root_ns();
2243  		goto buffers_out;
2244  	}
2245  	security_add_hooks(apparmor_hooks, ARRAY_SIZE(apparmor_hooks),
2246  				&apparmor_lsmid);
2247  
2248  	/* Report that AppArmor successfully initialized */
2249  	apparmor_initialized = 1;
2250  	if (aa_g_profile_mode == APPARMOR_COMPLAIN)
2251  		aa_info_message("AppArmor initialized: complain mode enabled");
2252  	else if (aa_g_profile_mode == APPARMOR_KILL)
2253  		aa_info_message("AppArmor initialized: kill mode enabled");
2254  	else
2255  		aa_info_message("AppArmor initialized");
2256  
2257  	return error;
2258  
2259  buffers_out:
2260  	destroy_buffers();
2261  alloc_out:
2262  	aa_destroy_aafs();
2263  	aa_teardown_dfa_engine();
2264  
2265  	apparmor_enabled = false;
2266  	return error;
2267  }
2268  
2269  DEFINE_LSM(apparmor) = {
2270  	.name = "apparmor",
2271  	.flags = LSM_FLAG_LEGACY_MAJOR | LSM_FLAG_EXCLUSIVE,
2272  	.enabled = &apparmor_enabled,
2273  	.blobs = &apparmor_blob_sizes,
2274  	.init = apparmor_init,
2275  };
2276