1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/*
* Check decoding of prctl PR_GET_MDWE/PR_SET_MDWE operations.
*
* Copyright (c) 2021-2023 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#include "scno.h"
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/prctl.h>
static long injected_val;
static long
do_prctl(kernel_ulong_t cmd, kernel_ulong_t arg2, kernel_ulong_t arg3,
kernel_ulong_t arg4, kernel_ulong_t arg5)
{
long rc = syscall(__NR_prctl, cmd, arg2, arg3, arg4, arg5);
if (rc != injected_val) {
error_msg_and_fail("Return value (%ld) differs from expected "
"injected value (%ld)",
rc, injected_val);
}
return rc;
}
int
main(int argc, char **argv)
{
static const kernel_ulong_t bogus_arg2 =
(kernel_ulong_t) 0xdecafeedbeefda7eULL;
static const kernel_ulong_t bogus_arg3 =
(kernel_ulong_t) 0xbadc0dedfacef00dULL;
static const kernel_ulong_t bogus_arg4 =
(kernel_ulong_t) 0xcafeda7efeedbeefULL;
static const kernel_ulong_t bogus_arg5 =
(kernel_ulong_t) 0xfa57beeffacefeedULL;
static const struct {
long arg;
const char *str;
} get_strs[] = {
{-1, ""},
{0, ""},
{1, " (PR_MDWE_REFUSE_EXEC_GAIN)"},
{2, ""},
{3, " (PR_MDWE_REFUSE_EXEC_GAIN|0x2)"},
{0x7ea1cafe, ""},
};
static const struct {
kernel_ulong_t arg;
const char *str;
} set_strs[] = {
{0, "0"},
{1, "PR_MDWE_REFUSE_EXEC_GAIN"},
{2, "0x2 /* PR_MDWE_??? */"},
{3, "PR_MDWE_REFUSE_EXEC_GAIN|0x2"},
{0x7ea1cafe, "0x7ea1cafe /* PR_MDWE_??? */"}
};
long rc;
unsigned long num_skip;
const char *str = NULL;
bool locked = false;
if (argc < 3)
error_msg_and_fail("Usage: %s NUM_SKIP INJECT_RETVAL", argv[0]);
num_skip = strtoul(argv[1], NULL, 0);
injected_val = strtol(argv[2], NULL, 0);
for (size_t i = 0; i < num_skip; i++) {
if ((prctl_marker() != injected_val) ||
((injected_val == -1) && (errno != ENOTTY)))
continue;
locked = true;
break;
}
if (!locked)
error_msg_and_fail("Have not locked on prctl(-1, -2, -3, -4"
", -5) returning %ld", injected_val);
/* PR_GET_MDWE */
for (unsigned int j = 0; j < 2; j++) {
if (j) {
rc = do_prctl(PR_GET_MDWE, bogus_arg2, bogus_arg3,
bogus_arg4, bogus_arg5);
} else {
rc = do_prctl(PR_GET_MDWE, 0, 0, 0, 0);
}
const char *errstr = sprintrc(rc);
for (size_t i = 0; i < ARRAY_SIZE(get_strs); i++) {
if (get_strs[i].arg == rc) {
str = get_strs[i].str;
break;
}
}
if (!str)
error_msg_and_fail("Unknown return value: %ld", rc);
printf("prctl(PR_GET_MDWE, %s) = ", j ?
#if SIZEOF_KERNEL_LONG_T > 4
"0xdecafeedbeefda7e, 0xbadc0dedfacef00d"
", 0xcafeda7efeedbeef, 0xfa57beeffacefeed"
#else
"0xbeefda7e, 0xfacef00d, 0xfeedbeef, 0xfacefeed"
#endif
: "0, 0, 0, 0");
if (rc < 0)
printf("%s", errstr);
else
printf("%#lx", rc);
printf("%s (INJECTED)\n", str);
}
/* PR_SET_FP_MODE */
for (size_t i = 0; i < ARRAY_SIZE(set_strs); i++) {
rc = do_prctl(PR_SET_MDWE, set_strs[i].arg, 0, 0, 0);
printf("prctl(PR_SET_MDWE, %s, 0, 0, 0) = %s (INJECTED)\n",
set_strs[i].str, sprintrc(rc));
rc = do_prctl(PR_SET_MDWE, set_strs[i].arg,
bogus_arg3, bogus_arg4, bogus_arg5);
printf("prctl(PR_SET_MDWE, %s, %s) = %s (INJECTED)\n",
set_strs[i].str,
#if SIZEOF_KERNEL_LONG_T > 4
"0xbadc0dedfacef00d, 0xcafeda7efeedbeef"
", 0xfa57beeffacefeed"
#else
"0xfacef00d, 0xfeedbeef, 0xfacefeed"
#endif
, sprintrc(rc));
}
puts("+++ exited with 0 +++");
return 0;
}
|
