xref: /linux/security/ipe/ipe.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
4  */
5 #include <uapi/linux/lsm.h>
6 
7 #include "ipe.h"
8 #include "eval.h"
9 #include "hooks.h"
10 
11 extern const char *const ipe_boot_policy;
12 bool ipe_enabled;
13 
14 static struct lsm_blob_sizes ipe_blobs __ro_after_init = {
15 	.lbs_superblock = sizeof(struct ipe_superblock),
16 #ifdef CONFIG_IPE_PROP_DM_VERITY
17 	.lbs_bdev = sizeof(struct ipe_bdev),
18 #endif /* CONFIG_IPE_PROP_DM_VERITY */
19 #ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
20 	.lbs_inode = sizeof(struct ipe_inode),
21 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
22 };
23 
24 static const struct lsm_id ipe_lsmid = {
25 	.name = "ipe",
26 	.id = LSM_ID_IPE,
27 };
28 
29 struct ipe_superblock *ipe_sb(const struct super_block *sb)
30 {
31 	return sb->s_security + ipe_blobs.lbs_superblock;
32 }
33 
34 #ifdef CONFIG_IPE_PROP_DM_VERITY
35 struct ipe_bdev *ipe_bdev(struct block_device *b)
36 {
37 	return b->bd_security + ipe_blobs.lbs_bdev;
38 }
39 #endif /* CONFIG_IPE_PROP_DM_VERITY */
40 
41 #ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
42 struct ipe_inode *ipe_inode(const struct inode *inode)
43 {
44 	return inode->i_security + ipe_blobs.lbs_inode;
45 }
46 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
47 
48 static struct security_hook_list ipe_hooks[] __ro_after_init = {
49 	LSM_HOOK_INIT(bprm_check_security, ipe_bprm_check_security),
50 	LSM_HOOK_INIT(mmap_file, ipe_mmap_file),
51 	LSM_HOOK_INIT(file_mprotect, ipe_file_mprotect),
52 	LSM_HOOK_INIT(kernel_read_file, ipe_kernel_read_file),
53 	LSM_HOOK_INIT(kernel_load_data, ipe_kernel_load_data),
54 	LSM_HOOK_INIT(initramfs_populated, ipe_unpack_initramfs),
55 #ifdef CONFIG_IPE_PROP_DM_VERITY
56 	LSM_HOOK_INIT(bdev_free_security, ipe_bdev_free_security),
57 	LSM_HOOK_INIT(bdev_setintegrity, ipe_bdev_setintegrity),
58 #endif /* CONFIG_IPE_PROP_DM_VERITY */
59 #ifdef CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG
60 	LSM_HOOK_INIT(inode_setintegrity, ipe_inode_setintegrity),
61 #endif /* CONFIG_IPE_PROP_FS_VERITY_BUILTIN_SIG */
62 };
63 
64 /**
65  * ipe_init() - Entry point of IPE.
66  *
67  * This is called at LSM init, which happens occurs early during kernel
68  * start up. During this phase, IPE registers its hooks and loads the
69  * builtin boot policy.
70  *
71  * Return:
72  * * %0		- OK
73  * * %-ENOMEM	- Out of memory (OOM)
74  */
75 static int __init ipe_init(void)
76 {
77 	struct ipe_policy *p = NULL;
78 
79 	security_add_hooks(ipe_hooks, ARRAY_SIZE(ipe_hooks), &ipe_lsmid);
80 	ipe_enabled = true;
81 
82 	if (ipe_boot_policy) {
83 		p = ipe_new_policy(ipe_boot_policy, strlen(ipe_boot_policy),
84 				   NULL, 0);
85 		if (IS_ERR(p))
86 			return PTR_ERR(p);
87 
88 		rcu_assign_pointer(ipe_active_policy, p);
89 	}
90 
91 	return 0;
92 }
93 
94 DEFINE_LSM(ipe) = {
95 	.name = "ipe",
96 	.init = ipe_init,
97 	.blobs = &ipe_blobs,
98 };
99