1 /*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <inttypes.h>
18 #include <limits.h>
19 #include <stdio.h>
20 #include <sys/capability.h>
21 #include <sys/mman.h>
22 #include <sys/prctl.h>
23 #include <sys/utsname.h>
24 #include <unistd.h>
25
26 #include <string>
27 #include <vector>
28
29 #include <gtest/gtest.h>
30
31 #include "android-base/file.h"
32 #include "android-base/strings.h"
33
34 // http://b/20017123.
TEST(sys_prctl,bug_20017123)35 TEST(sys_prctl, bug_20017123) {
36 #if defined(PR_SET_VMA) // PR_SET_VMA is only available in Android kernels.
37 size_t page_size = static_cast<size_t>(sysconf(_SC_PAGESIZE));
38 void* p = mmap(NULL, page_size * 3, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
39 ASSERT_NE(MAP_FAILED, p);
40 ASSERT_EQ(0, mprotect(p, page_size, PROT_NONE));
41 ASSERT_NE(-1, prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, p, page_size * 3, "anonymous map space"));
42 // Now read the maps and verify that there are no overlapped maps.
43 std::string file_data;
44 ASSERT_TRUE(android::base::ReadFileToString("/proc/self/maps", &file_data));
45
46 uintptr_t last_end = 0;
47 std::vector<std::string> lines = android::base::Split(file_data, "\n");
48 for (size_t i = 0; i < lines.size(); i++) {
49 if (lines[i].empty()) {
50 continue;
51 }
52 uintptr_t start;
53 uintptr_t end;
54 ASSERT_EQ(2, sscanf(lines[i].c_str(), "%" SCNxPTR "-%" SCNxPTR " ", &start, &end))
55 << "Failed to parse line: " << lines[i];
56 // This will never fail on the first line, so no need to do any special checking.
57 ASSERT_GE(start, last_end)
58 << "Overlapping map detected:\n" << lines[i -1] << '\n' << lines[i] << '\n';
59 last_end = end;
60 }
61
62 ASSERT_EQ(0, munmap(p, page_size * 3));
63 #else
64 GTEST_SKIP() << "PR_SET_VMA not available";
65 #endif
66 }
67
TEST(sys_prctl,pr_cap_ambient)68 TEST(sys_prctl, pr_cap_ambient) {
69 // PR_CAP_AMBIENT was introduced in v4.3. Android devices should always
70 // have a backport, but we can't guarantee it's available on the host.
71 #if defined(__ANDROID__) || defined(PR_CAP_AMBIENT)
72 const std::string caps_sha =
73 "https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/"
74 "?id=58319057b7847667f0c9585b9de0e8932b0fdb08";
75 const std::string caps_typo_sha =
76 "https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/"
77 "?id=b7f76ea2ef6739ee484a165ffbac98deb855d3d3";
78
79 utsname u = {};
80 ASSERT_EQ(0, uname(&u));
81
82 errno = 0;
83 auto err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0);
84 EXPECT_EQ(0, err);
85 // EINVAL -> unrecognized prctl option
86 ASSERT_NE(EINVAL, errno) << "kernel (" << u.release << ") missing required commits:\n"
87 << caps_sha << "\n"
88 << caps_typo_sha << "\n";
89
90 // Unprivileged processes shouldn't be able to raise CAP_SYS_ADMIN,
91 // but they can check or lower it
92 err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, CAP_SYS_ADMIN, 0, 0);
93 EXPECT_EQ(-1, err);
94 EXPECT_EQ(EPERM, errno);
95
96 err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_SYS_ADMIN, 0, 0);
97 EXPECT_EQ(0, err);
98
99 err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_LOWER, CAP_SYS_ADMIN, 0, 0);
100 EXPECT_EQ(0, err);
101
102 // ULONG_MAX isn't a legal cap
103 err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, ULONG_MAX, 0, 0);
104 EXPECT_EQ(-1, err);
105 EXPECT_EQ(EINVAL, errno);
106
107 err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, ULONG_MAX, 0, 0);
108 EXPECT_EQ(-1, err);
109 EXPECT_EQ(EINVAL, errno);
110
111 err = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_LOWER, ULONG_MAX, 0, 0);
112 EXPECT_EQ(-1, err);
113 EXPECT_EQ(EINVAL, errno);
114 #else
115 GTEST_SKIP() << "PR_CAP_AMBIENT not available";
116 #endif
117 }
118