1 /*
2  * Copyright (C) 2018 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 <gtest/gtest.h>
18 
19 #include "BionicDeathTest.h"
20 
21 #include <dirent.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <stdlib.h>
25 #include <sys/types.h>
26 #include <unistd.h>
27 
28 #if defined(__BIONIC__)
29 #include <android/fdsan.h>
30 #endif
31 
32 #include <unordered_map>
33 
34 #include <android-base/unique_fd.h>
35 
36 #define FDSAN_TEST(test_name) TEST_F(FdsanTest, test_name)
37 #define EXPECT_FDSAN_DEATH(expression, regex)                                                \
38   EXPECT_DEATH((android_fdsan_set_error_level(ANDROID_FDSAN_ERROR_LEVEL_FATAL), expression), \
39                (regex))
40 
41 struct FdsanTest : public ::testing::Test {
SetUpFdsanTest42   void SetUp() override {
43 #if defined(__BIONIC__)
44     // The bionic unit test running forks for each test by default, which turns
45     // fdsan off as a side-effect, so we need to turn it back on.
46     android_fdsan_set_error_level(ANDROID_FDSAN_ERROR_LEVEL_FATAL);
47 #endif
48   }
49 };
50 
TEST_F(FdsanTest,unowned_untagged_close)51 TEST_F(FdsanTest, unowned_untagged_close) {
52 #if defined(__BIONIC__)
53   int fd = open("/dev/null", O_RDONLY);
54   ASSERT_EQ(0, close(fd));
55 #endif
56 }
57 
TEST_F(FdsanTest,unowned_tagged_close)58 TEST_F(FdsanTest, unowned_tagged_close) {
59 #if defined(__BIONIC__)
60   int fd = open("/dev/null", O_RDONLY);
61   ASSERT_EQ(0, android_fdsan_close_with_tag(fd, 0));
62 #endif
63 }
64 
TEST_F(FdsanTest,unowned_improperly_tagged_close)65 TEST_F(FdsanTest, unowned_improperly_tagged_close) {
66 #if defined(__BIONIC__)
67   int fd = open("/dev/null", O_RDONLY);
68   EXPECT_FDSAN_DEATH(android_fdsan_close_with_tag(fd, 0xdeadbeef), "actually unowned");
69 #endif
70 }
71 
TEST_F(FdsanTest,unowned_incorrect_exchange)72 TEST_F(FdsanTest, unowned_incorrect_exchange) {
73 #if defined(__BIONIC__)
74   int fd = open("/dev/null", O_RDONLY);
75   EXPECT_FDSAN_DEATH(android_fdsan_exchange_owner_tag(fd, 0xbadc0de, 0xdeadbeef),
76                      "failed to exchange ownership");
77 #endif
78 }
79 
TEST_F(FdsanTest,owned_untagged_close)80 TEST_F(FdsanTest, owned_untagged_close) {
81 #if defined(__BIONIC__)
82   int fd = open("/dev/null", O_RDONLY);
83   android_fdsan_exchange_owner_tag(fd, 0, 0xdeadbeef);
84   EXPECT_FDSAN_DEATH(close(fd), "expected to be unowned, actually owned");
85 #endif
86 }
87 
TEST_F(FdsanTest,owned_tagged_close)88 TEST_F(FdsanTest, owned_tagged_close) {
89 #if defined(__BIONIC__)
90   int fd = open("/dev/null", O_RDONLY);
91   android_fdsan_exchange_owner_tag(fd, 0, 0xdeadbeef);
92   ASSERT_EQ(0, android_fdsan_close_with_tag(fd, 0xdeadbeef));
93 #endif
94 }
95 
TEST_F(FdsanTest,owned_improperly_tagged_close)96 TEST_F(FdsanTest, owned_improperly_tagged_close) {
97 #if defined(__BIONIC__)
98   int fd = open("/dev/null", O_RDONLY);
99   android_fdsan_exchange_owner_tag(fd, 0, 0xdeadbeef);
100   EXPECT_FDSAN_DEATH(android_fdsan_close_with_tag(fd, 0xdeadc0de), "expected to be owned");
101 #endif
102 }
103 
TEST_F(FdsanTest,owned_incorrect_exchange)104 TEST_F(FdsanTest, owned_incorrect_exchange) {
105 #if defined(__BIONIC__)
106   int fd = open("/dev/null", O_RDONLY);
107   android_fdsan_exchange_owner_tag(fd, 0, 0xdeadbeef);
108   EXPECT_FDSAN_DEATH(android_fdsan_exchange_owner_tag(fd, 0xbadc0de, 0xdeadbeef),
109                      "failed to exchange");
110 #endif
111 }
112 
TEST_F(FdsanTest,fopen)113 TEST_F(FdsanTest, fopen) {
114 #if defined(__BIONIC__)
115   FILE* f = fopen("/dev/null", "r");
116   ASSERT_TRUE(f);
117   EXPECT_FDSAN_DEATH(close(fileno(f)), "actually owned by FILE");
118 #endif
119 }
120 
TEST_F(FdsanTest,closedir)121 TEST_F(FdsanTest, closedir) {
122 #if defined(__BIONIC__)
123   DIR* dir = opendir("/dev/");
124   ASSERT_TRUE(dir);
125   EXPECT_FDSAN_DEATH(close(dirfd(dir)), "actually owned by DIR");
126 #endif
127 }
128 
TEST_F(FdsanTest,overflow)129 TEST_F(FdsanTest, overflow) {
130 #if defined(__BIONIC__)
131   std::unordered_map<int, uint64_t> fds;
132   for (int i = 0; i < 4096; ++i) {
133     int fd = open("/dev/null", O_RDONLY);
134     auto tag = 0xdead00000000ULL | i;
135     android_fdsan_exchange_owner_tag(fd, 0, tag);
136     fds[fd] = tag;
137   }
138 
139   for (auto [fd, tag] : fds) {
140     android_fdsan_close_with_tag(fd, tag);
141   }
142 #endif
143 }
144 
TEST_F(FdsanTest,owner_value_high)145 TEST_F(FdsanTest, owner_value_high) {
146 #if defined(__BIONIC__)
147   int fd = open("/dev/null", O_RDONLY);
148   uint64_t tag = android_fdsan_create_owner_tag(ANDROID_FDSAN_OWNER_TYPE_UNIQUE_FD, ~0ULL);
149   android_fdsan_exchange_owner_tag(fd, 0, tag);
150   EXPECT_FDSAN_DEATH(android_fdsan_exchange_owner_tag(fd, 0xbadc0de, 0xdeadbeef),
151                      "0xffffffffffffffff");
152 #endif
153 }
154 
TEST_F(FdsanTest,owner_value_low)155 TEST_F(FdsanTest, owner_value_low) {
156 #if defined(__BIONIC__)
157   int fd = open("/dev/null", O_RDONLY);
158   uint64_t tag = android_fdsan_create_owner_tag(ANDROID_FDSAN_OWNER_TYPE_UNIQUE_FD, 1);
159   android_fdsan_exchange_owner_tag(fd, 0, tag);
160   EXPECT_FDSAN_DEATH(android_fdsan_exchange_owner_tag(fd, 0xbadc0de, 0xdeadbeef),
161                      "0x1");
162 #endif
163 }
164 
TEST_F(FdsanTest,unique_fd_unowned_close)165 TEST_F(FdsanTest, unique_fd_unowned_close) {
166 #if defined(__BIONIC__)
167   android::base::unique_fd fd(open("/dev/null", O_RDONLY));
168   android_fdsan_set_error_level(ANDROID_FDSAN_ERROR_LEVEL_FATAL);
169   EXPECT_FDSAN_DEATH(close(fd.get()), "expected to be unowned, actually owned by unique_fd");
170 #endif
171 }
172 
TEST_F(FdsanTest,unique_fd_untag_on_release)173 TEST_F(FdsanTest, unique_fd_untag_on_release) {
174   android::base::unique_fd fd(open("/dev/null", O_RDONLY));
175   close(fd.release());
176 }
177 
TEST_F(FdsanTest,unique_fd_move)178 TEST_F(FdsanTest, unique_fd_move) {
179   android::base::unique_fd fd(open("/dev/null", O_RDONLY));
180   android::base::unique_fd fd_moved = std::move(fd);
181   ASSERT_EQ(-1, fd.get());
182   ASSERT_GT(fd_moved.get(), -1);
183 }
184 
TEST_F(FdsanTest,unique_fd_unowned_close_after_move)185 TEST_F(FdsanTest, unique_fd_unowned_close_after_move) {
186 #if defined(__BIONIC__)
187   android::base::unique_fd fd(open("/dev/null", O_RDONLY));
188   android::base::unique_fd fd_moved = std::move(fd);
189   ASSERT_EQ(-1, fd.get());
190   ASSERT_GT(fd_moved.get(), -1);
191 
192   android_fdsan_set_error_level(ANDROID_FDSAN_ERROR_LEVEL_FATAL);
193   EXPECT_FDSAN_DEATH(close(fd_moved.get()), "expected to be unowned, actually owned by unique_fd");
194 #endif
195 }
196 
TEST_F(FdsanTest,vfork)197 TEST_F(FdsanTest, vfork) {
198   android::base::unique_fd fd(open("/dev/null", O_RDONLY));
199 
200   pid_t rc = vfork();
201   ASSERT_NE(-1, rc);
202 
203   if (rc == 0) {
204     close(fd.get());
205     _exit(0);
206   }
207 
208   int status;
209   pid_t wait_result = waitpid(rc, &status, 0);
210   ASSERT_EQ(wait_result, rc);
211   ASSERT_TRUE(WIFEXITED(status));
212   ASSERT_EQ(0, WEXITSTATUS(status));
213 }
214