diff options
Diffstat (limited to 'test/syscalls/linux')
-rw-r--r-- | test/syscalls/linux/BUILD | 18 | ||||
-rw-r--r-- | test/syscalls/linux/verity_ioctl.cc | 103 | ||||
-rw-r--r-- | test/syscalls/linux/verity_mmap.cc | 158 |
3 files changed, 177 insertions, 102 deletions
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index efed4aeb0..729b4c63b 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -1024,6 +1024,7 @@ cc_binary( "//test/util:temp_path", "//test/util:test_main", "//test/util:test_util", + "//test/util:verity_util", ], ) @@ -1294,6 +1295,23 @@ cc_binary( ) cc_binary( + name = "verity_mmap_test", + testonly = 1, + srcs = ["verity_mmap.cc"], + linkstatic = 1, + deps = [ + "//test/util:capability_util", + gtest, + "//test/util:fs_util", + "//test/util:memory_util", + "//test/util:temp_path", + "//test/util:test_main", + "//test/util:test_util", + "//test/util:verity_util", + ], +) + +cc_binary( name = "mount_test", testonly = 1, srcs = ["mount.cc"], diff --git a/test/syscalls/linux/verity_ioctl.cc b/test/syscalls/linux/verity_ioctl.cc index 822e16f3c..be91b23d0 100644 --- a/test/syscalls/linux/verity_ioctl.cc +++ b/test/syscalls/linux/verity_ioctl.cc @@ -28,40 +28,13 @@ #include "test/util/mount_util.h" #include "test/util/temp_path.h" #include "test/util/test_util.h" +#include "test/util/verity_util.h" namespace gvisor { namespace testing { namespace { -#ifndef FS_IOC_ENABLE_VERITY -#define FS_IOC_ENABLE_VERITY 1082156677 -#endif - -#ifndef FS_IOC_MEASURE_VERITY -#define FS_IOC_MEASURE_VERITY 3221513862 -#endif - -#ifndef FS_VERITY_FL -#define FS_VERITY_FL 1048576 -#endif - -#ifndef FS_IOC_GETFLAGS -#define FS_IOC_GETFLAGS 2148034049 -#endif - -struct fsverity_digest { - __u16 digest_algorithm; - __u16 digest_size; /* input/output */ - __u8 digest[]; -}; - -constexpr int kMaxDigestSize = 64; -constexpr int kDefaultDigestSize = 32; -constexpr char kContents[] = "foobarbaz"; -constexpr char kMerklePrefix[] = ".merkle.verity."; -constexpr char kMerkleRootPrefix[] = ".merkleroot.verity."; - class IoctlTest : public ::testing::Test { protected: void SetUp() override { @@ -85,80 +58,6 @@ class IoctlTest : public ::testing::Test { std::string filename_; }; -// Provide a function to convert bytes to hex string, since -// absl::BytesToHexString does not seem to be compatible with golang -// hex.DecodeString used in verity due to zero-padding. -std::string BytesToHexString(uint8_t bytes[], int size) { - std::stringstream ss; - ss << std::hex; - for (int i = 0; i < size; ++i) { - ss << std::setw(2) << std::setfill('0') << static_cast<int>(bytes[i]); - } - return ss.str(); -} - -std::string MerklePath(absl::string_view path) { - return JoinPath(Dirname(path), - std::string(kMerklePrefix) + std::string(Basename(path))); -} - -std::string MerkleRootPath(absl::string_view path) { - return JoinPath(Dirname(path), - std::string(kMerkleRootPrefix) + std::string(Basename(path))); -} - -// Flip a random bit in the file represented by fd. -PosixError FlipRandomBit(int fd, int size) { - // Generate a random offset in the file. - srand(time(nullptr)); - unsigned int seed = 0; - int random_offset = rand_r(&seed) % size; - - // Read a random byte and flip a bit in it. - char buf[1]; - RETURN_ERROR_IF_SYSCALL_FAIL(PreadFd(fd, buf, 1, random_offset)); - buf[0] ^= 1; - RETURN_ERROR_IF_SYSCALL_FAIL(PwriteFd(fd, buf, 1, random_offset)); - return NoError(); -} - -// Mount a verity on the tmpfs and enable both the file and the direcotry. Then -// mount a new verity with measured root hash. -PosixErrorOr<std::string> MountVerity(std::string tmpfs_dir, - std::string filename) { - // Mount a verity fs on the existing tmpfs mount. - std::string mount_opts = "lower_path=" + tmpfs_dir; - ASSIGN_OR_RETURN_ERRNO(TempPath verity_dir, TempPath::CreateDir()); - RETURN_ERROR_IF_SYSCALL_FAIL( - mount("", verity_dir.path().c_str(), "verity", 0, mount_opts.c_str())); - - // Enable both the file and the directory. - ASSIGN_OR_RETURN_ERRNO( - auto fd, Open(JoinPath(verity_dir.path(), filename), O_RDONLY, 0777)); - RETURN_ERROR_IF_SYSCALL_FAIL(ioctl(fd.get(), FS_IOC_ENABLE_VERITY)); - ASSIGN_OR_RETURN_ERRNO(auto dir_fd, Open(verity_dir.path(), O_RDONLY, 0777)); - RETURN_ERROR_IF_SYSCALL_FAIL(ioctl(dir_fd.get(), FS_IOC_ENABLE_VERITY)); - - // Measure the root hash. - uint8_t digest_array[sizeof(struct fsverity_digest) + kMaxDigestSize] = {0}; - struct fsverity_digest* digest = - reinterpret_cast<struct fsverity_digest*>(digest_array); - digest->digest_size = kMaxDigestSize; - RETURN_ERROR_IF_SYSCALL_FAIL( - ioctl(dir_fd.get(), FS_IOC_MEASURE_VERITY, digest)); - - // Mount a verity fs with specified root hash. - mount_opts += - ",root_hash=" + BytesToHexString(digest->digest, digest->digest_size); - ASSIGN_OR_RETURN_ERRNO(TempPath verity_with_hash_dir, TempPath::CreateDir()); - RETURN_ERROR_IF_SYSCALL_FAIL(mount("", verity_with_hash_dir.path().c_str(), - "verity", 0, mount_opts.c_str())); - // Verity directories should not be deleted. Release the TempPath objects to - // prevent those directories from being deleted by the destructor. - verity_dir.release(); - return verity_with_hash_dir.release(); -} - TEST_F(IoctlTest, Enable) { // Mount a verity fs on the existing tmpfs mount. std::string mount_opts = "lower_path=" + tmpfs_dir_.path(); diff --git a/test/syscalls/linux/verity_mmap.cc b/test/syscalls/linux/verity_mmap.cc new file mode 100644 index 000000000..dde74cc91 --- /dev/null +++ b/test/syscalls/linux/verity_mmap.cc @@ -0,0 +1,158 @@ +// Copyright 2021 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 <stdint.h> +#include <stdlib.h> +#include <sys/mman.h> +#include <sys/mount.h> + +#include <string> + +#include "gmock/gmock.h" +#include "gtest/gtest.h" +#include "test/util/capability_util.h" +#include "test/util/fs_util.h" +#include "test/util/memory_util.h" +#include "test/util/temp_path.h" +#include "test/util/test_util.h" +#include "test/util/verity_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +class MmapTest : public ::testing::Test { + protected: + void SetUp() override { + // Verity is implemented in VFS2. + SKIP_IF(IsRunningWithVFS1()); + + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN))); + // Mount a tmpfs file system, to be wrapped by a verity fs. + tmpfs_dir_ = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateDir()); + ASSERT_THAT(mount("", tmpfs_dir_.path().c_str(), "tmpfs", 0, ""), + SyscallSucceeds()); + + // Create a new file in the tmpfs mount. + file_ = ASSERT_NO_ERRNO_AND_VALUE( + TempPath::CreateFileWith(tmpfs_dir_.path(), kContents, 0777)); + filename_ = Basename(file_.path()); + } + + TempPath tmpfs_dir_; + TempPath file_; + std::string filename_; +}; + +TEST_F(MmapTest, MmapRead) { + std::string verity_dir = + ASSERT_NO_ERRNO_AND_VALUE(MountVerity(tmpfs_dir_.path(), filename_)); + + // Make sure the file can be open and mmapped in the mounted verity fs. + auto const verity_fd = ASSERT_NO_ERRNO_AND_VALUE( + Open(JoinPath(verity_dir, filename_), O_RDONLY, 0777)); + + Mapping const m = + ASSERT_NO_ERRNO_AND_VALUE(Mmap(nullptr, sizeof(kContents) - 1, PROT_READ, + MAP_SHARED, verity_fd.get(), 0)); + EXPECT_THAT(std::string(m.view()), ::testing::StrEq(kContents)); +} + +TEST_F(MmapTest, ModifiedBeforeMmap) { + std::string verity_dir = + ASSERT_NO_ERRNO_AND_VALUE(MountVerity(tmpfs_dir_.path(), filename_)); + + // Modify the file and check verification failure upon mmapping. + auto const fd = ASSERT_NO_ERRNO_AND_VALUE( + Open(JoinPath(tmpfs_dir_.path(), filename_), O_RDWR, 0777)); + ASSERT_NO_ERRNO(FlipRandomBit(fd.get(), sizeof(kContents) - 1)); + + auto const verity_fd = ASSERT_NO_ERRNO_AND_VALUE( + Open(JoinPath(verity_dir, filename_), O_RDONLY, 0777)); + Mapping const m = + ASSERT_NO_ERRNO_AND_VALUE(Mmap(nullptr, sizeof(kContents) - 1, PROT_READ, + MAP_SHARED, verity_fd.get(), 0)); + + // Memory fault is expected when Translate fails. + EXPECT_EXIT(std::string(m.view()), ::testing::KilledBySignal(SIGSEGV), ""); +} + +TEST_F(MmapTest, ModifiedAfterMmap) { + std::string verity_dir = + ASSERT_NO_ERRNO_AND_VALUE(MountVerity(tmpfs_dir_.path(), filename_)); + + auto const verity_fd = ASSERT_NO_ERRNO_AND_VALUE( + Open(JoinPath(verity_dir, filename_), O_RDONLY, 0777)); + Mapping const m = + ASSERT_NO_ERRNO_AND_VALUE(Mmap(nullptr, sizeof(kContents) - 1, PROT_READ, + MAP_SHARED, verity_fd.get(), 0)); + + // Modify the file after mapping and check verification failure upon mmapping. + auto const fd = ASSERT_NO_ERRNO_AND_VALUE( + Open(JoinPath(tmpfs_dir_.path(), filename_), O_RDWR, 0777)); + ASSERT_NO_ERRNO(FlipRandomBit(fd.get(), sizeof(kContents) - 1)); + + // Memory fault is expected when Translate fails. + EXPECT_EXIT(std::string(m.view()), ::testing::KilledBySignal(SIGSEGV), ""); +} + +class MmapParamTest + : public MmapTest, + public ::testing::WithParamInterface<std::tuple<int, int>> { + protected: + int prot() const { return std::get<0>(GetParam()); } + int flags() const { return std::get<1>(GetParam()); } +}; + +INSTANTIATE_TEST_SUITE_P( + WriteExecNoneSharedPrivate, MmapParamTest, + ::testing::Combine(::testing::ValuesIn({ + PROT_WRITE, + PROT_EXEC, + PROT_NONE, + }), + ::testing::ValuesIn({MAP_SHARED, MAP_PRIVATE}))); + +TEST_P(MmapParamTest, Mmap) { + std::string verity_dir = + ASSERT_NO_ERRNO_AND_VALUE(MountVerity(tmpfs_dir_.path(), filename_)); + + // Make sure the file can be open and mmapped in the mounted verity fs. + auto const verity_fd = ASSERT_NO_ERRNO_AND_VALUE( + Open(JoinPath(verity_dir, filename_), O_RDONLY, 0777)); + + if (prot() == PROT_WRITE && flags() == MAP_SHARED) { + // Verity file system is read-only. + EXPECT_THAT( + reinterpret_cast<intptr_t>(mmap(nullptr, sizeof(kContents) - 1, prot(), + flags(), verity_fd.get(), 0)), + SyscallFailsWithErrno(EACCES)); + } else { + Mapping const m = ASSERT_NO_ERRNO_AND_VALUE(Mmap( + nullptr, sizeof(kContents) - 1, prot(), flags(), verity_fd.get(), 0)); + if (prot() == PROT_NONE) { + // Memory mapped by MAP_NONE cannot be accessed. + EXPECT_EXIT(std::string(m.view()), ::testing::KilledBySignal(SIGSEGV), + ""); + } else { + EXPECT_THAT(std::string(m.view()), ::testing::StrEq(kContents)); + } + } +} + +} // namespace + +} // namespace testing +} // namespace gvisor |