1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/fs/ext4/xattr_security.c
4  * Handler for storing security labels as extended attributes.
5  */
6 
7 #include <linux/string.h>
8 #include <linux/fs.h>
9 #include <linux/security.h>
10 #include <linux/slab.h>
11 #include "ext4_jbd2.h"
12 #include "ext4.h"
13 #include "xattr.h"
14 
15 static int
ext4_xattr_security_get(const struct xattr_handler * handler,struct dentry * unused,struct inode * inode,const char * name,void * buffer,size_t size)16 ext4_xattr_security_get(const struct xattr_handler *handler,
17 			struct dentry *unused, struct inode *inode,
18 			const char *name, void *buffer, size_t size)
19 {
20 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY,
21 			      name, buffer, size);
22 }
23 
24 static int
ext4_xattr_security_set(const struct xattr_handler * handler,struct user_namespace * mnt_userns,struct dentry * unused,struct inode * inode,const char * name,const void * value,size_t size,int flags)25 ext4_xattr_security_set(const struct xattr_handler *handler,
26 			struct user_namespace *mnt_userns,
27 			struct dentry *unused, struct inode *inode,
28 			const char *name, const void *value,
29 			size_t size, int flags)
30 {
31 	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_SECURITY,
32 			      name, value, size, flags);
33 }
34 
35 static int
ext4_initxattrs(struct inode * inode,const struct xattr * xattr_array,void * fs_info)36 ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array,
37 		void *fs_info)
38 {
39 	const struct xattr *xattr;
40 	handle_t *handle = fs_info;
41 	int err = 0;
42 
43 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
44 		err = ext4_xattr_set_handle(handle, inode,
45 					    EXT4_XATTR_INDEX_SECURITY,
46 					    xattr->name, xattr->value,
47 					    xattr->value_len, XATTR_CREATE);
48 		if (err < 0)
49 			break;
50 	}
51 	return err;
52 }
53 
54 int
ext4_init_security(handle_t * handle,struct inode * inode,struct inode * dir,const struct qstr * qstr)55 ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
56 		   const struct qstr *qstr)
57 {
58 	return security_inode_init_security(inode, dir, qstr,
59 					    &ext4_initxattrs, handle);
60 }
61 
62 const struct xattr_handler ext4_xattr_security_handler = {
63 	.prefix	= XATTR_SECURITY_PREFIX,
64 	.get	= ext4_xattr_security_get,
65 	.set	= ext4_xattr_security_set,
66 };
67