diff options
| -rw-r--r-- | test/syscalls/linux/open_create.cc | 116 |
1 files changed, 113 insertions, 3 deletions
diff --git a/test/syscalls/linux/open_create.cc b/test/syscalls/linux/open_create.cc index 51eacf3f2..78c36f98f 100644 --- a/test/syscalls/linux/open_create.cc +++ b/test/syscalls/linux/open_create.cc @@ -88,21 +88,21 @@ TEST(CreateTest, CreateExclusively) { SyscallFailsWithErrno(EEXIST)); } -TEST(CreateTeast, CreatWithOTrunc) { +TEST(CreateTest, CreatWithOTrunc) { std::string dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncd"); ASSERT_THAT(mkdir(dirpath.c_str(), 0777), SyscallSucceeds()); ASSERT_THAT(open(dirpath.c_str(), O_CREAT | O_TRUNC, 0666), SyscallFailsWithErrno(EISDIR)); } -TEST(CreateTeast, CreatDirWithOTruncAndReadOnly) { +TEST(CreateTest, CreatDirWithOTruncAndReadOnly) { std::string dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncd"); ASSERT_THAT(mkdir(dirpath.c_str(), 0777), SyscallSucceeds()); ASSERT_THAT(open(dirpath.c_str(), O_CREAT | O_TRUNC | O_RDONLY, 0666), SyscallFailsWithErrno(EISDIR)); } -TEST(CreateTeast, CreatFileWithOTruncAndReadOnly) { +TEST(CreateTest, CreatFileWithOTruncAndReadOnly) { std::string dirpath = JoinPath(GetAbsoluteTestTmpdir(), "truncfile"); int dirfd; ASSERT_THAT(dirfd = open(dirpath.c_str(), O_RDWR | O_CREAT, 0666), @@ -149,6 +149,116 @@ TEST(CreateTest, OpenCreateROThenRW) { EXPECT_THAT(WriteFd(fd2.get(), &c, 1), SyscallSucceedsWithValue(1)); } +TEST(CreateTest, ChmodReadToWriteBetweenOpens_NoRandomSave) { + // Make sure we don't have CAP_DAC_OVERRIDE, since that allows the user to + // override file read/write permissions. CAP_DAC_READ_SEARCH needs to be + // cleared for the same reason. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + const TempPath file = + ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileMode(0400)); + + const FileDescriptor rfd = + ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); + + // Cannot restore after making permissions more restrictive. + const DisableSave ds; + ASSERT_THAT(fchmod(rfd.get(), 0200), SyscallSucceeds()); + + EXPECT_THAT(open(file.path().c_str(), O_RDONLY), + SyscallFailsWithErrno(EACCES)); + + const FileDescriptor wfd = + ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_WRONLY)); + + char c = 'x'; + EXPECT_THAT(write(wfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + c = 0; + EXPECT_THAT(read(rfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + EXPECT_EQ(c, 'x'); +} + +TEST(CreateTest, ChmodWriteToReadBetweenOpens_NoRandomSave) { + // Make sure we don't have CAP_DAC_OVERRIDE, since that allows the user to + // override file read/write permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + + const TempPath file = + ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileMode(0200)); + + const FileDescriptor wfd = + ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_WRONLY)); + + // Cannot restore after making permissions more restrictive. + const DisableSave ds; + ASSERT_THAT(fchmod(wfd.get(), 0400), SyscallSucceeds()); + + EXPECT_THAT(open(file.path().c_str(), O_WRONLY), + SyscallFailsWithErrno(EACCES)); + + const FileDescriptor rfd = + ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); + + char c = 'x'; + EXPECT_THAT(write(wfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + c = 0; + EXPECT_THAT(read(rfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + EXPECT_EQ(c, 'x'); +} + +TEST(CreateTest, CreateWithReadFlagNotAllowedByMode_NoRandomSave) { + // The only time we can open a file with flags forbidden by its permissions + // is when we are creating the file. We cannot re-open with the same flags, + // so we cannot restore an fd obtained from such an operation. + const DisableSave ds; + + // Make sure we don't have CAP_DAC_OVERRIDE, since that allows the user to + // override file read/write permissions. CAP_DAC_READ_SEARCH needs to be + // cleared for the same reason. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + // Create and open a file with read flag but without read permissions. + const std::string path = NewTempAbsPath(); + const FileDescriptor rfd = + ASSERT_NO_ERRNO_AND_VALUE(Open(path, O_CREAT | O_RDONLY, 0222)); + + EXPECT_THAT(open(path.c_str(), O_RDONLY), SyscallFailsWithErrno(EACCES)); + const FileDescriptor wfd = ASSERT_NO_ERRNO_AND_VALUE(Open(path, O_WRONLY)); + + char c = 'x'; + EXPECT_THAT(write(wfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + c = 0; + EXPECT_THAT(read(rfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + EXPECT_EQ(c, 'x'); +} + +TEST(CreateTest, CreateWithWriteFlagNotAllowedByMode_NoRandomSave) { + // The only time we can open a file with flags forbidden by its permissions + // is when we are creating the file. We cannot re-open with the same flags, + // so we cannot restore an fd obtained from such an operation. + const DisableSave ds; + + // Make sure we don't have CAP_DAC_OVERRIDE, since that allows the user to + // override file read/write permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + + // Create and open a file with write flag but without write permissions. + const std::string path = NewTempAbsPath(); + const FileDescriptor wfd = + ASSERT_NO_ERRNO_AND_VALUE(Open(path, O_CREAT | O_WRONLY, 0444)); + + EXPECT_THAT(open(path.c_str(), O_WRONLY), SyscallFailsWithErrno(EACCES)); + const FileDescriptor rfd = ASSERT_NO_ERRNO_AND_VALUE(Open(path, O_RDONLY)); + + char c = 'x'; + EXPECT_THAT(write(wfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + c = 0; + EXPECT_THAT(read(rfd.get(), &c, 1), SyscallSucceedsWithValue(1)); + EXPECT_EQ(c, 'x'); +} + } // namespace } // namespace testing |