1 /* SPDX-License-Identifier: GPL-2.0-only */ 1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* 2 /*
3 * Landlock LSM - Filesystem management and ho 3 * Landlock LSM - Filesystem management and hooks
4 * 4 *
5 * Copyright © 2017-2020 Mickaël Salaün <mi 5 * Copyright © 2017-2020 Mickaël Salaün <mic@digikod.net>
6 * Copyright © 2018-2020 ANSSI 6 * Copyright © 2018-2020 ANSSI
7 */ 7 */
8 8
9 #ifndef _SECURITY_LANDLOCK_FS_H 9 #ifndef _SECURITY_LANDLOCK_FS_H
10 #define _SECURITY_LANDLOCK_FS_H 10 #define _SECURITY_LANDLOCK_FS_H
11 11
12 #include <linux/fs.h> 12 #include <linux/fs.h>
13 #include <linux/init.h> 13 #include <linux/init.h>
14 #include <linux/rcupdate.h> 14 #include <linux/rcupdate.h>
15 15
16 #include "ruleset.h" 16 #include "ruleset.h"
17 #include "setup.h" 17 #include "setup.h"
18 18
19 /** 19 /**
20 * struct landlock_inode_security - Inode secu 20 * struct landlock_inode_security - Inode security blob
21 * 21 *
22 * Enable to reference a &struct landlock_obje 22 * Enable to reference a &struct landlock_object tied to an inode (i.e.
23 * underlying object). 23 * underlying object).
24 */ 24 */
25 struct landlock_inode_security { 25 struct landlock_inode_security {
26 /** 26 /**
27 * @object: Weak pointer to an allocat 27 * @object: Weak pointer to an allocated object. All assignments of a
28 * new object are protected by the und 28 * new object are protected by the underlying inode->i_lock. However,
29 * atomically disassociating @object f 29 * atomically disassociating @object from the inode is only protected
30 * by @object->lock, from the time @ob 30 * by @object->lock, from the time @object's usage refcount drops to
31 * zero to the time this pointer is nu 31 * zero to the time this pointer is nulled out (cf. release_inode() and
32 * hook_sb_delete()). Indeed, such di 32 * hook_sb_delete()). Indeed, such disassociation doesn't require
33 * inode->i_lock thanks to the careful 33 * inode->i_lock thanks to the careful rcu_access_pointer() check
34 * performed by get_inode_object(). 34 * performed by get_inode_object().
35 */ 35 */
36 struct landlock_object __rcu *object; 36 struct landlock_object __rcu *object;
37 }; 37 };
38 38
39 /** 39 /**
40 * struct landlock_file_security - File securi <<
41 * <<
42 * This information is populated when opening <<
43 * tracks the relevant Landlock access rights <<
44 * of opening the file. Other LSM hooks use th <<
45 * operations on already opened files. <<
46 */ <<
47 struct landlock_file_security { <<
48 /** <<
49 * @allowed_access: Access rights that <<
50 * opening the file. This is not neces <<
51 * rights available at that time, but <<
52 * needed to authorize later operation <<
53 */ <<
54 access_mask_t allowed_access; <<
55 /** <<
56 * @fown_domain: Domain of the task th <<
57 * signal e.g., SIGURG when writing MS <<
58 * This pointer is protected by the re <<
59 * fown_struct's members: pid, uid, an <<
60 */ <<
61 struct landlock_ruleset *fown_domain; <<
62 }; <<
63 <<
64 /** <<
65 * struct landlock_superblock_security - Super 40 * struct landlock_superblock_security - Superblock security blob
66 * 41 *
67 * Enable hook_sb_delete() to wait for concurr 42 * Enable hook_sb_delete() to wait for concurrent calls to release_inode().
68 */ 43 */
69 struct landlock_superblock_security { 44 struct landlock_superblock_security {
70 /** 45 /**
71 * @inode_refs: Number of pending inod 46 * @inode_refs: Number of pending inodes (from this superblock) that
72 * are being released by release_inode 47 * are being released by release_inode().
73 * Cf. struct super_block->s_fsnotify_ 48 * Cf. struct super_block->s_fsnotify_inode_refs .
74 */ 49 */
75 atomic_long_t inode_refs; 50 atomic_long_t inode_refs;
76 }; 51 };
77 <<
78 static inline struct landlock_file_security * <<
79 landlock_file(const struct file *const file) <<
80 { <<
81 return file->f_security + landlock_blo <<
82 } <<
83 52
84 static inline struct landlock_inode_security * 53 static inline struct landlock_inode_security *
85 landlock_inode(const struct inode *const inode 54 landlock_inode(const struct inode *const inode)
86 { 55 {
87 return inode->i_security + landlock_bl 56 return inode->i_security + landlock_blob_sizes.lbs_inode;
88 } 57 }
89 58
90 static inline struct landlock_superblock_secur 59 static inline struct landlock_superblock_security *
91 landlock_superblock(const struct super_block * 60 landlock_superblock(const struct super_block *const superblock)
92 { 61 {
93 return superblock->s_security + landlo 62 return superblock->s_security + landlock_blob_sizes.lbs_superblock;
94 } 63 }
95 64
96 __init void landlock_add_fs_hooks(void); 65 __init void landlock_add_fs_hooks(void);
97 66
98 int landlock_append_fs_rule(struct landlock_ru 67 int landlock_append_fs_rule(struct landlock_ruleset *const ruleset,
99 const struct path 68 const struct path *const path,
100 access_mask_t acce 69 access_mask_t access_hierarchy);
101 70
102 #endif /* _SECURITY_LANDLOCK_FS_H */ 71 #endif /* _SECURITY_LANDLOCK_FS_H */
103 72
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