1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2019 Xiao Yang <ice_yangxiao@163.com>
4 *
5 * Description:
6 * Check various errnos for futex(FUTEX_CMP_REQUEUE).
7 * 1) futex(FUTEX_CMP_REQUEUE) with invalid val returns EINVAL.
8 * 2) futex(FUTEX_CMP_REQUEUE) with invalid val2 returns EINVAL.
9 * 3) futex(FUTEX_CMP_REQUEUE) with mismatched val3 returns EAGAIN.
10 *
11 * It's also a regression test for CVE-2018-6927:
12 * fbe0e839d1e2 ("futex: Prevent overflow by strengthen input validation")
13 */
14
15 #include <errno.h>
16 #include <sys/time.h>
17
18 #include "tst_test.h"
19 #include "futextest.h"
20 #include "lapi/futex.h"
21
22 static futex_t *futexes;
23
24 static struct tcase {
25 int set_wakes;
26 int set_requeues;
27 int exp_val;
28 int exp_errno;
29 } tcases[] = {
30 {1, -1, FUTEX_INITIALIZER, EINVAL},
31 {-1, 1, FUTEX_INITIALIZER, EINVAL},
32 {1, 1, FUTEX_INITIALIZER + 1, EAGAIN},
33 };
34
35 static struct futex_test_variants variants[] = {
36 #if (__NR_futex != __LTP__NR_INVALID_SYSCALL)
37 { .fntype = FUTEX_FN_FUTEX, .desc = "syscall with old kernel spec"},
38 #endif
39
40 #if (__NR_futex_time64 != __LTP__NR_INVALID_SYSCALL)
41 { .fntype = FUTEX_FN_FUTEX64, .desc = "syscall time64 with kernel spec"},
42 #endif
43 };
44
verify_futex_cmp_requeue(unsigned int n)45 static void verify_futex_cmp_requeue(unsigned int n)
46 {
47 struct futex_test_variants *tv = &variants[tst_variant];
48 struct tcase *tc = &tcases[n];
49
50 TEST(futex_cmp_requeue(tv->fntype, &futexes[0], tc->exp_val,
51 &futexes[1], tc->set_wakes, tc->set_requeues, 0));
52 if (TST_RET != -1) {
53 tst_res(TFAIL, "futex_cmp_requeue() succeeded unexpectedly");
54 return;
55 }
56
57 if (TST_ERR != tc->exp_errno) {
58 tst_res(TFAIL | TTERRNO,
59 "futex_cmp_requeue() failed unexpectedly, expected %s",
60 tst_strerrno(tc->exp_errno));
61 return;
62 }
63
64 tst_res(TPASS | TTERRNO, "futex_cmp_requeue() failed as expected");
65 }
66
setup(void)67 static void setup(void)
68 {
69 struct futex_test_variants *tv = &variants[tst_variant];
70
71 tst_res(TINFO, "Testing variant: %s", tv->desc);
72 futex_supported_by_kernel(tv->fntype);
73
74 futexes = SAFE_MMAP(NULL, sizeof(futex_t) * 2, PROT_READ | PROT_WRITE,
75 MAP_ANONYMOUS | MAP_SHARED, -1, 0);
76
77 futexes[0] = FUTEX_INITIALIZER;
78 futexes[1] = FUTEX_INITIALIZER + 1;
79 }
80
cleanup(void)81 static void cleanup(void)
82 {
83 if (futexes)
84 SAFE_MUNMAP((void *)futexes, sizeof(futex_t) * 2);
85 }
86
87 static struct tst_test test = {
88 .setup = setup,
89 .cleanup = cleanup,
90 .test = verify_futex_cmp_requeue,
91 .tcnt = ARRAY_SIZE(tcases),
92 .test_variants = ARRAY_SIZE(variants),
93 .tags = (const struct tst_tag[]) {
94 {"CVE", "2018-6927"},
95 {"linux-git", "fbe0e839d1e2"},
96 {}
97 }
98 };
99