security/keys/compat.c

   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                 goto err;
  44         if (ret == 0)
  45                 goto no_payload_free;
  46
  47         ret = keyctl_instantiate_key_common(id, iov, ioc, ret, ringid);
  48 err:
  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 }