xref: /linux/security/keys/compat.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /* 32-bit compatibility syscall for 64-bit systems
2  *
3  * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/syscalls.h>
13 #include <linux/keyctl.h>
14 #include <linux/compat.h>
15 #include <linux/slab.h>
16 #include "internal.h"
17 
18 /*
19  * Instantiate a key with the specified compatibility multipart payload and
20  * link the key into the destination keyring if one is given.
21  *
22  * The caller must have the appropriate instantiation permit set for this to
23  * work (see keyctl_assume_authority).  No other permissions are required.
24  *
25  * If successful, 0 will be returned.
26  */
27 static long compat_keyctl_instantiate_key_iov(
28 	key_serial_t id,
29 	const struct compat_iovec __user *_payload_iov,
30 	unsigned ioc,
31 	key_serial_t ringid)
32 {
33 	struct iovec iovstack[UIO_FASTIOV], *iov = iovstack;
34 	long ret;
35 
36 	if (!_payload_iov || !ioc)
37 		goto no_payload;
38 
39 	ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc,
40 					   ARRAY_SIZE(iovstack),
41 					   iovstack, &iov);
42 	if (ret < 0)
43 		return ret;
44 	if (ret == 0)
45 		goto no_payload_free;
46 
47 	ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
48 
49 	if (iov != iovstack)
50 		kfree(iov);
51 	return ret;
52 
53 no_payload_free:
54 	if (iov != iovstack)
55 		kfree(iov);
56 no_payload:
57 	return keyctl_instantiate_key_common(id, NULL, 0, 0, ringid);
58 }
59 
60 /*
61  * The key control system call, 32-bit compatibility version for 64-bit archs
62  *
63  * This should only be called if the 64-bit arch uses weird pointers in 32-bit
64  * mode or doesn't guarantee that the top 32-bits of the argument registers on
65  * taking a 32-bit syscall are zero.  If you can, you should call sys_keyctl()
66  * directly.
67  */
68 asmlinkage long compat_sys_keyctl(u32 option,
69 				  u32 arg2, u32 arg3, u32 arg4, u32 arg5)
70 {
71 	switch (option) {
72 	case KEYCTL_GET_KEYRING_ID:
73 		return keyctl_get_keyring_ID(arg2, arg3);
74 
75 	case KEYCTL_JOIN_SESSION_KEYRING:
76 		return keyctl_join_session_keyring(compat_ptr(arg2));
77 
78 	case KEYCTL_UPDATE:
79 		return keyctl_update_key(arg2, compat_ptr(arg3), arg4);
80 
81 	case KEYCTL_REVOKE:
82 		return keyctl_revoke_key(arg2);
83 
84 	case KEYCTL_DESCRIBE:
85 		return keyctl_describe_key(arg2, compat_ptr(arg3), arg4);
86 
87 	case KEYCTL_CLEAR:
88 		return keyctl_keyring_clear(arg2);
89 
90 	case KEYCTL_LINK:
91 		return keyctl_keyring_link(arg2, arg3);
92 
93 	case KEYCTL_UNLINK:
94 		return keyctl_keyring_unlink(arg2, arg3);
95 
96 	case KEYCTL_SEARCH:
97 		return keyctl_keyring_search(arg2, compat_ptr(arg3),
98 					     compat_ptr(arg4), arg5);
99 
100 	case KEYCTL_READ:
101 		return keyctl_read_key(arg2, compat_ptr(arg3), arg4);
102 
103 	case KEYCTL_CHOWN:
104 		return keyctl_chown_key(arg2, arg3, arg4);
105 
106 	case KEYCTL_SETPERM:
107 		return keyctl_setperm_key(arg2, arg3);
108 
109 	case KEYCTL_INSTANTIATE:
110 		return keyctl_instantiate_key(arg2, compat_ptr(arg3), arg4,
111 					      arg5);
112 
113 	case KEYCTL_NEGATE:
114 		return keyctl_negate_key(arg2, arg3, arg4);
115 
116 	case KEYCTL_SET_REQKEY_KEYRING:
117 		return keyctl_set_reqkey_keyring(arg2);
118 
119 	case KEYCTL_SET_TIMEOUT:
120 		return keyctl_set_timeout(arg2, arg3);
121 
122 	case KEYCTL_ASSUME_AUTHORITY:
123 		return keyctl_assume_authority(arg2);
124 
125 	case KEYCTL_GET_SECURITY:
126 		return keyctl_get_security(arg2, compat_ptr(arg3), arg4);
127 
128 	case KEYCTL_SESSION_TO_PARENT:
129 		return keyctl_session_to_parent();
130 
131 	case KEYCTL_REJECT:
132 		return keyctl_reject_key(arg2, arg3, arg4, arg5);
133 
134 	case KEYCTL_INSTANTIATE_IOV:
135 		return compat_keyctl_instantiate_key_iov(
136 			arg2, compat_ptr(arg3), arg4, arg5);
137 
138 	case KEYCTL_INVALIDATE:
139 		return keyctl_invalidate_key(arg2);
140 
141 	default:
142 		return -EOPNOTSUPP;
143 	}
144 }
145