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Diffstat (limited to 'test/syscalls/linux/chmod.cc')
| -rw-r--r-- | test/syscalls/linux/chmod.cc | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/test/syscalls/linux/chmod.cc b/test/syscalls/linux/chmod.cc new file mode 100644 index 000000000..a06b5cfd6 --- /dev/null +++ b/test/syscalls/linux/chmod.cc @@ -0,0 +1,264 @@ +// Copyright 2018 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include <fcntl.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include <string> + +#include "gtest/gtest.h" +#include "test/util/capability_util.h" +#include "test/util/file_descriptor.h" +#include "test/util/fs_util.h" +#include "test/util/temp_path.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +TEST(ChmodTest, ChmodFileSucceeds) { + // Drop capabilities that allow us to override file permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + + auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + + ASSERT_THAT(chmod(file.path().c_str(), 0466), SyscallSucceeds()); + EXPECT_THAT(open(file.path().c_str(), O_RDWR), SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, ChmodDirSucceeds) { + // Drop capabilities that allow us to override file and directory permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); + const std::string fileInDir = NewTempAbsPathInDir(dir.path()); + + ASSERT_THAT(chmod(dir.path().c_str(), 0466), SyscallSucceeds()); + EXPECT_THAT(open(fileInDir.c_str(), O_RDONLY), SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, FchmodFileSucceeds_NoRandomSave) { + // Drop capabilities that allow us to file directory permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + + auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileMode(0666)); + int fd; + ASSERT_THAT(fd = open(file.path().c_str(), O_RDWR), SyscallSucceeds()); + + { + const DisableSave ds; // File permissions are reduced. + ASSERT_THAT(fchmod(fd, 0444), SyscallSucceeds()); + EXPECT_THAT(close(fd), SyscallSucceeds()); + } + + EXPECT_THAT(open(file.path().c_str(), O_RDWR), SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, FchmodDirSucceeds_NoRandomSave) { + // Drop capabilities that allow us to override file and directory permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); + int fd; + ASSERT_THAT(fd = open(dir.path().c_str(), O_RDONLY | O_DIRECTORY), + SyscallSucceeds()); + + { + const DisableSave ds; // File permissions are reduced. + ASSERT_THAT(fchmod(fd, 0), SyscallSucceeds()); + EXPECT_THAT(close(fd), SyscallSucceeds()); + } + + EXPECT_THAT(open(dir.path().c_str(), O_RDONLY), + SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, FchmodBadF) { + ASSERT_THAT(fchmod(-1, 0444), SyscallFailsWithErrno(EBADF)); +} + +TEST(ChmodTest, FchmodatBadF) { + ASSERT_THAT(fchmodat(-1, "foo", 0444, 0), SyscallFailsWithErrno(EBADF)); +} + +TEST(ChmodTest, FchmodatNotDir) { + ASSERT_THAT(fchmodat(-1, "", 0444, 0), SyscallFailsWithErrno(ENOENT)); +} + +TEST(ChmodTest, FchmodatFileAbsolutePath) { + // Drop capabilities that allow us to override file permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + + auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + + ASSERT_THAT(fchmodat(-1, file.path().c_str(), 0444, 0), SyscallSucceeds()); + EXPECT_THAT(open(file.path().c_str(), O_RDWR), SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, FchmodatDirAbsolutePath) { + // Drop capabilities that allow us to override file and directory permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); + + int fd; + ASSERT_THAT(fd = open(dir.path().c_str(), O_RDONLY | O_DIRECTORY), + SyscallSucceeds()); + EXPECT_THAT(close(fd), SyscallSucceeds()); + + ASSERT_THAT(fchmodat(-1, dir.path().c_str(), 0, 0), SyscallSucceeds()); + EXPECT_THAT(open(dir.path().c_str(), O_RDONLY), + SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, FchmodatFile) { + // Drop capabilities that allow us to override file permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + + auto temp_file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + + int parent_fd; + ASSERT_THAT( + parent_fd = open(GetAbsoluteTestTmpdir().c_str(), O_RDONLY | O_DIRECTORY), + SyscallSucceeds()); + + ASSERT_THAT( + fchmodat(parent_fd, std::string(Basename(temp_file.path())).c_str(), 0444, + 0), + SyscallSucceeds()); + EXPECT_THAT(close(parent_fd), SyscallSucceeds()); + + EXPECT_THAT(open(temp_file.path().c_str(), O_RDWR), + SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, FchmodatDir) { + // Drop capabilities that allow us to override file and directory permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + auto dir = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); + + int parent_fd; + ASSERT_THAT( + parent_fd = open(GetAbsoluteTestTmpdir().c_str(), O_RDONLY | O_DIRECTORY), + SyscallSucceeds()); + + int fd; + ASSERT_THAT(fd = open(dir.path().c_str(), O_RDONLY | O_DIRECTORY), + SyscallSucceeds()); + EXPECT_THAT(close(fd), SyscallSucceeds()); + + ASSERT_THAT( + fchmodat(parent_fd, std::string(Basename(dir.path())).c_str(), 0, 0), + SyscallSucceeds()); + EXPECT_THAT(close(parent_fd), SyscallSucceeds()); + + EXPECT_THAT(open(dir.path().c_str(), O_RDONLY | O_DIRECTORY), + SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, ChmodDowngradeWritability_NoRandomSave) { + auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileMode(0666)); + + int fd; + ASSERT_THAT(fd = open(file.path().c_str(), O_RDWR), SyscallSucceeds()); + + const DisableSave ds; // Permissions are dropped. + ASSERT_THAT(chmod(file.path().c_str(), 0444), SyscallSucceeds()); + EXPECT_THAT(write(fd, "hello", 5), SyscallSucceedsWithValue(5)); + + EXPECT_THAT(close(fd), SyscallSucceeds()); +} + +TEST(ChmodTest, ChmodFileToNoPermissionsSucceeds) { + // Drop capabilities that allow us to override file permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileMode(0666)); + + ASSERT_THAT(chmod(file.path().c_str(), 0), SyscallSucceeds()); + + EXPECT_THAT(open(file.path().c_str(), O_RDONLY), + SyscallFailsWithErrno(EACCES)); +} + +TEST(ChmodTest, FchmodDowngradeWritability_NoRandomSave) { + auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile()); + + int fd; + ASSERT_THAT(fd = open(file.path().c_str(), O_RDWR | O_CREAT, 0666), + SyscallSucceeds()); + + const DisableSave ds; // Permissions are dropped. + ASSERT_THAT(fchmod(fd, 0444), SyscallSucceeds()); + EXPECT_THAT(write(fd, "hello", 5), SyscallSucceedsWithValue(5)); + + EXPECT_THAT(close(fd), SyscallSucceeds()); +} + +TEST(ChmodTest, FchmodFileToNoPermissionsSucceeds_NoRandomSave) { + // Drop capabilities that allow us to override file permissions. + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_OVERRIDE, false)); + ASSERT_NO_ERRNO(SetCapability(CAP_DAC_READ_SEARCH, false)); + + auto file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileMode(0666)); + + int fd; + ASSERT_THAT(fd = open(file.path().c_str(), O_RDWR), SyscallSucceeds()); + + { + const DisableSave ds; // Permissions are dropped. + ASSERT_THAT(fchmod(fd, 0), SyscallSucceeds()); + EXPECT_THAT(close(fd), SyscallSucceeds()); + } + + EXPECT_THAT(open(file.path().c_str(), O_RDONLY), + SyscallFailsWithErrno(EACCES)); +} + +// Verify that we can get a RW FD after chmod, even if a RO fd is left open. +TEST(ChmodTest, ChmodWritableWithOpenFD) { + // FIXME(b/72455313): broken on hostfs. + if (IsRunningOnGvisor()) { + return; + } + + TempPath file = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFileMode(0444)); + + FileDescriptor fd1 = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDONLY)); + + ASSERT_THAT(fchmod(fd1.get(), 0644), SyscallSucceeds()); + + // This FD is writable, even though fd1 has a read-only reference to the file. + FileDescriptor fd2 = ASSERT_NO_ERRNO_AND_VALUE(Open(file.path(), O_RDWR)); + + // fd1 is not writable, but fd2 is. + char c = 'a'; + EXPECT_THAT(WriteFd(fd1.get(), &c, 1), SyscallFailsWithErrno(EBADF)); + EXPECT_THAT(WriteFd(fd2.get(), &c, 1), SyscallSucceedsWithValue(1)); +} + +} // namespace + +} // namespace testing +} // namespace gvisor |