1 // SPDX-License-Identifier: GPL-2.0
2 #include "reiserfs.h"
3 #include <linux/errno.h>
4 #include <linux/fs.h>
5 #include <linux/pagemap.h>
6 #include <linux/xattr.h>
7 #include <linux/slab.h>
8 #include "xattr.h"
9 #include <linux/security.h>
10 #include <linux/uaccess.h>
11
12 static int
security_get(const struct xattr_handler * handler,struct dentry * unused,struct inode * inode,const char * name,void * buffer,size_t size)13 security_get(const struct xattr_handler *handler, struct dentry *unused,
14 struct inode *inode, const char *name, void *buffer, size_t size)
15 {
16 if (IS_PRIVATE(inode))
17 return -EPERM;
18
19 return reiserfs_xattr_get(inode, xattr_full_name(handler, name),
20 buffer, size);
21 }
22
23 static int
security_set(const struct xattr_handler * handler,struct user_namespace * mnt_userns,struct dentry * unused,struct inode * inode,const char * name,const void * buffer,size_t size,int flags)24 security_set(const struct xattr_handler *handler,
25 struct user_namespace *mnt_userns, struct dentry *unused,
26 struct inode *inode, const char *name, const void *buffer,
27 size_t size, int flags)
28 {
29 if (IS_PRIVATE(inode))
30 return -EPERM;
31
32 return reiserfs_xattr_set(inode,
33 xattr_full_name(handler, name),
34 buffer, size, flags);
35 }
36
security_list(struct dentry * dentry)37 static bool security_list(struct dentry *dentry)
38 {
39 return !IS_PRIVATE(d_inode(dentry));
40 }
41
42 /* Initializes the security context for a new inode and returns the number
43 * of blocks needed for the transaction. If successful, reiserfs_security
44 * must be released using reiserfs_security_free when the caller is done. */
reiserfs_security_init(struct inode * dir,struct inode * inode,const struct qstr * qstr,struct reiserfs_security_handle * sec)45 int reiserfs_security_init(struct inode *dir, struct inode *inode,
46 const struct qstr *qstr,
47 struct reiserfs_security_handle *sec)
48 {
49 int blocks = 0;
50 int error;
51
52 sec->name = NULL;
53
54 /* Don't add selinux attributes on xattrs - they'll never get used */
55 if (IS_PRIVATE(dir))
56 return 0;
57
58 error = security_old_inode_init_security(inode, dir, qstr, &sec->name,
59 &sec->value, &sec->length);
60 if (error) {
61 if (error == -EOPNOTSUPP)
62 error = 0;
63
64 sec->name = NULL;
65 sec->value = NULL;
66 sec->length = 0;
67 return error;
68 }
69
70 if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
71 blocks = reiserfs_xattr_jcreate_nblocks(inode) +
72 reiserfs_xattr_nblocks(inode, sec->length);
73 /* We don't want to count the directories twice if we have
74 * a default ACL. */
75 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
76 }
77 return blocks;
78 }
79
reiserfs_security_write(struct reiserfs_transaction_handle * th,struct inode * inode,struct reiserfs_security_handle * sec)80 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
81 struct inode *inode,
82 struct reiserfs_security_handle *sec)
83 {
84 int error;
85 if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
86 return -EINVAL;
87
88 error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
89 sec->length, XATTR_CREATE);
90 if (error == -ENODATA || error == -EOPNOTSUPP)
91 error = 0;
92
93 return error;
94 }
95
reiserfs_security_free(struct reiserfs_security_handle * sec)96 void reiserfs_security_free(struct reiserfs_security_handle *sec)
97 {
98 kfree(sec->name);
99 kfree(sec->value);
100 sec->name = NULL;
101 sec->value = NULL;
102 }
103
104 const struct xattr_handler reiserfs_xattr_security_handler = {
105 .prefix = XATTR_SECURITY_PREFIX,
106 .get = security_get,
107 .set = security_set,
108 .list = security_list,
109 };
110