[vold] Add argument verification to IncFS methods
+ Get rid of an extra string copy in path validation function
Bug: 152349257
Test: atest vold_tests
Change-Id: I03a8cab0dd6abd7d5c9dcbbc2acb651e818e6cd8
Merged-In: I03a8cab0dd6abd7d5c9dcbbc2acb651e818e6cd8
diff --git a/Android.bp b/Android.bp
index 9d87f68..81a2f0f 100644
--- a/Android.bp
+++ b/Android.bp
@@ -130,6 +130,7 @@
"ScryptParameters.cpp",
"Utils.cpp",
"VoldNativeService.cpp",
+ "VoldNativeServiceValidation.cpp",
"VoldUtil.cpp",
"VolumeManager.cpp",
"cryptfs.cpp",
diff --git a/VoldNativeService.cpp b/VoldNativeService.cpp
index cbe4b45..e894909 100644
--- a/VoldNativeService.cpp
+++ b/VoldNativeService.cpp
@@ -26,6 +26,7 @@
#include "MetadataCrypt.h"
#include "MoveStorage.h"
#include "Process.h"
+#include "VoldNativeServiceValidation.h"
#include "VoldUtil.h"
#include "VolumeManager.h"
#include "cryptfs.h"
@@ -45,6 +46,7 @@
using android::base::StringPrintf;
using std::endl;
+using namespace std::literals;
namespace android {
namespace vold {
@@ -53,14 +55,6 @@
constexpr const char* kDump = "android.permission.DUMP";
-static binder::Status ok() {
- return binder::Status::ok();
-}
-
-static binder::Status exception(uint32_t code, const std::string& msg) {
- return binder::Status::fromExceptionCode(code, String8(msg.c_str()));
-}
-
static binder::Status error(const std::string& msg) {
PLOG(ERROR) << msg;
return binder::Status::fromServiceSpecificError(errno, String8(msg.c_str()));
@@ -82,77 +76,9 @@
}
}
-binder::Status checkPermission(const char* permission) {
- pid_t pid;
- uid_t uid;
-
- if (checkCallingPermission(String16(permission), reinterpret_cast<int32_t*>(&pid),
- reinterpret_cast<int32_t*>(&uid))) {
- return ok();
- } else {
- return exception(binder::Status::EX_SECURITY,
- StringPrintf("UID %d / PID %d lacks permission %s", uid, pid, permission));
- }
-}
-
-binder::Status checkUidOrRoot(uid_t expectedUid) {
- uid_t uid = IPCThreadState::self()->getCallingUid();
- if (uid == expectedUid || uid == AID_ROOT) {
- return ok();
- } else {
- return exception(binder::Status::EX_SECURITY,
- StringPrintf("UID %d is not expected UID %d", uid, expectedUid));
- }
-}
-
-binder::Status checkArgumentId(const std::string& id) {
- if (id.empty()) {
- return exception(binder::Status::EX_ILLEGAL_ARGUMENT, "Missing ID");
- }
- for (const char& c : id) {
- if (!std::isalnum(c) && c != ':' && c != ',') {
- return exception(binder::Status::EX_ILLEGAL_ARGUMENT,
- StringPrintf("ID %s is malformed", id.c_str()));
- }
- }
- return ok();
-}
-
-binder::Status checkArgumentPath(const std::string& path) {
- if (path.empty()) {
- return exception(binder::Status::EX_ILLEGAL_ARGUMENT, "Missing path");
- }
- if (path[0] != '/') {
- return exception(binder::Status::EX_ILLEGAL_ARGUMENT,
- StringPrintf("Path %s is relative", path.c_str()));
- }
- if ((path + '/').find("/../") != std::string::npos) {
- return exception(binder::Status::EX_ILLEGAL_ARGUMENT,
- StringPrintf("Path %s is shady", path.c_str()));
- }
- for (const char& c : path) {
- if (c == '\0' || c == '\n') {
- return exception(binder::Status::EX_ILLEGAL_ARGUMENT,
- StringPrintf("Path %s is malformed", path.c_str()));
- }
- }
- return ok();
-}
-
-binder::Status checkArgumentHex(const std::string& hex) {
- // Empty hex strings are allowed
- for (const char& c : hex) {
- if (!std::isxdigit(c) && c != ':' && c != '-') {
- return exception(binder::Status::EX_ILLEGAL_ARGUMENT,
- StringPrintf("Hex %s is malformed", hex.c_str()));
- }
- }
- return ok();
-}
-
#define ENFORCE_SYSTEM_OR_ROOT \
{ \
- binder::Status status = checkUidOrRoot(AID_SYSTEM); \
+ binder::Status status = CheckUidOrRoot(AID_SYSTEM); \
if (!status.isOk()) { \
return status; \
} \
@@ -160,7 +86,7 @@
#define CHECK_ARGUMENT_ID(id) \
{ \
- binder::Status status = checkArgumentId((id)); \
+ binder::Status status = CheckArgumentId((id)); \
if (!status.isOk()) { \
return status; \
} \
@@ -168,7 +94,7 @@
#define CHECK_ARGUMENT_PATH(path) \
{ \
- binder::Status status = checkArgumentPath((path)); \
+ binder::Status status = CheckArgumentPath((path)); \
if (!status.isOk()) { \
return status; \
} \
@@ -176,7 +102,7 @@
#define CHECK_ARGUMENT_HEX(hex) \
{ \
- binder::Status status = checkArgumentHex((hex)); \
+ binder::Status status = CheckArgumentHex((hex)); \
if (!status.isOk()) { \
return status; \
} \
@@ -206,7 +132,7 @@
status_t VoldNativeService::dump(int fd, const Vector<String16>& /* args */) {
auto out = std::fstream(StringPrintf("/proc/self/fd/%d", fd));
- const binder::Status dump_permission = checkPermission(kDump);
+ const binder::Status dump_permission = CheckPermission(kDump);
if (!dump_permission.isOk()) {
out << dump_permission.toString8() << endl;
return PERMISSION_DENIED;
@@ -214,7 +140,6 @@
ACQUIRE_LOCK;
out << "vold is happy!" << endl;
- out.flush();
return NO_ERROR;
}
@@ -224,7 +149,7 @@
ACQUIRE_LOCK;
VolumeManager::Instance()->setListener(listener);
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::monitor() {
@@ -234,7 +159,7 @@
{ ACQUIRE_LOCK; }
{ ACQUIRE_CRYPT_LOCK; }
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::reset() {
@@ -281,12 +206,12 @@
binder::Status VoldNativeService::addAppIds(const std::vector<std::string>& packageNames,
const std::vector<int32_t>& appIds) {
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::addSandboxIds(const std::vector<int32_t>& appIds,
const std::vector<std::string>& sandboxIds) {
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::onSecureKeyguardStateChanged(bool isShowing) {
@@ -398,7 +323,7 @@
return error("Volume " + volId + " missing path");
}
}
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::benchmark(
@@ -412,7 +337,7 @@
if (!status.isOk()) return status;
std::thread([=]() { android::vold::Benchmark(path, listener); }).detach();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::checkEncryption(const std::string& volId) {
@@ -443,7 +368,7 @@
}
std::thread([=]() { android::vold::MoveStorage(fromVol, toVol, listener); }).detach();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::remountUid(int32_t uid, int32_t remountMode) {
@@ -510,7 +435,7 @@
ACQUIRE_LOCK;
std::thread([=]() { android::vold::Trim(listener); }).detach();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::runIdleMaint(
@@ -519,7 +444,7 @@
ACQUIRE_LOCK;
std::thread([=]() { android::vold::RunIdleMaint(listener); }).detach();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::abortIdleMaint(
@@ -528,7 +453,7 @@
ACQUIRE_LOCK;
std::thread([=]() { android::vold::AbortIdleMaint(listener); }).detach();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::mountAppFuse(int32_t uid, int32_t mountId,
@@ -560,7 +485,7 @@
}
*_aidl_return = android::base::unique_fd(fd);
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::fdeCheckPassword(const std::string& password) {
@@ -577,7 +502,7 @@
// Spawn as thread so init can issue commands back to vold without
// causing deadlock, usually as a result of prep_data_fs.
std::thread(&cryptfs_restart).detach();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::fdeComplete(int32_t* _aidl_return) {
@@ -585,7 +510,7 @@
ACQUIRE_CRYPT_LOCK;
*_aidl_return = cryptfs_crypto_complete();
- return ok();
+ return Ok();
}
static int fdeEnableInternal(int32_t passwordType, const std::string& password,
@@ -625,7 +550,7 @@
// Spawn as thread so init can issue commands back to vold without
// causing deadlock, usually as a result of prep_data_fs.
std::thread(&fdeEnableInternal, passwordType, password, encryptionFlags).detach();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::fdeChangePassword(int32_t passwordType,
@@ -652,7 +577,7 @@
return error(StringPrintf("Failed to read field %s", key.c_str()));
} else {
*_aidl_return = buf;
- return ok();
+ return Ok();
}
}
@@ -668,7 +593,7 @@
ACQUIRE_CRYPT_LOCK;
*_aidl_return = cryptfs_get_password_type();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::fdeGetPassword(std::string* _aidl_return) {
@@ -679,7 +604,7 @@
if (res != nullptr) {
*_aidl_return = res;
}
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::fdeClearPassword() {
@@ -687,7 +612,7 @@
ACQUIRE_CRYPT_LOCK;
cryptfs_clear_password();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::fbeEnable() {
@@ -706,7 +631,7 @@
// causing deadlock, usually as a result of prep_data_fs.
std::thread(&cryptfs_mount_default_encrypted).detach();
}
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::initUser0() {
@@ -721,7 +646,7 @@
ACQUIRE_CRYPT_LOCK;
*_aidl_return = cryptfs_isConvertibleToFBE() != 0;
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::mountFstab(const std::string& blkDevice,
@@ -821,13 +746,13 @@
binder::Status VoldNativeService::prepareSandboxForApp(const std::string& packageName,
int32_t appId, const std::string& sandboxId,
int32_t userId) {
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::destroySandboxForApp(const std::string& packageName,
const std::string& sandboxId,
int32_t userId) {
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::startCheckpoint(int32_t retry) {
@@ -842,7 +767,7 @@
ACQUIRE_LOCK;
*_aidl_return = cp_needsRollback();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::needsCheckpoint(bool* _aidl_return) {
@@ -850,7 +775,7 @@
ACQUIRE_LOCK;
*_aidl_return = cp_needsCheckpoint();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::commitChanges() {
@@ -895,7 +820,7 @@
ACQUIRE_LOCK;
cp_abortChanges(message, retry);
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::supportsCheckpoint(bool* _aidl_return) {
@@ -924,17 +849,23 @@
ACQUIRE_LOCK;
cp_resetCheckpoint();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::incFsEnabled(bool* _aidl_return) {
+ ENFORCE_SYSTEM_OR_ROOT;
+
*_aidl_return = IncFs_IsEnabled();
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::mountIncFs(
const std::string& backingPath, const std::string& targetDir, int32_t flags,
::android::os::incremental::IncrementalFileSystemControlParcel* _aidl_return) {
+ ENFORCE_SYSTEM_OR_ROOT;
+ CHECK_ARGUMENT_PATH(backingPath);
+ CHECK_ARGUMENT_PATH(targetDir);
+
auto result = IncFs_Mount(backingPath.c_str(), targetDir.c_str(),
{.flags = IncFsMountFlags(flags),
.defaultReadTimeoutMs = INCFS_DEFAULT_READ_TIMEOUT_MS,
@@ -948,15 +879,22 @@
if (result.logs >= 0) {
_aidl_return->log.emplace(unique_fd(result.logs));
}
- return ok();
+ return Ok();
}
binder::Status VoldNativeService::unmountIncFs(const std::string& dir) {
+ ENFORCE_SYSTEM_OR_ROOT;
+ CHECK_ARGUMENT_PATH(dir);
+
return translate(IncFs_Unmount(dir.c_str()));
}
binder::Status VoldNativeService::bindMount(const std::string& sourceDir,
const std::string& targetDir) {
+ ENFORCE_SYSTEM_OR_ROOT;
+ CHECK_ARGUMENT_PATH(sourceDir);
+ CHECK_ARGUMENT_PATH(targetDir);
+
return translate(IncFs_BindMount(sourceDir.c_str(), targetDir.c_str()));
}
diff --git a/VoldNativeServiceValidation.cpp b/VoldNativeServiceValidation.cpp
new file mode 100644
index 0000000..61d8981
--- /dev/null
+++ b/VoldNativeServiceValidation.cpp
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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 "VoldNativeServiceValidation.h"
+
+#include <android-base/stringprintf.h>
+#include <android-base/strings.h>
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+#include <private/android_filesystem_config.h>
+
+#include <cctype>
+#include <string_view>
+
+using android::base::StringPrintf;
+using namespace std::literals;
+
+namespace android::vold {
+
+binder::Status Ok() {
+ return binder::Status::ok();
+}
+
+binder::Status Exception(uint32_t code, const std::string& msg) {
+ return binder::Status::fromExceptionCode(code, String8(msg.c_str()));
+}
+
+binder::Status CheckPermission(const char* permission) {
+ pid_t pid;
+ uid_t uid;
+
+ if (checkCallingPermission(String16(permission), reinterpret_cast<int32_t*>(&pid),
+ reinterpret_cast<int32_t*>(&uid))) {
+ return Ok();
+ } else {
+ return Exception(binder::Status::EX_SECURITY,
+ StringPrintf("UID %d / PID %d lacks permission %s", uid, pid, permission));
+ }
+}
+
+binder::Status CheckUidOrRoot(uid_t expectedUid) {
+ uid_t uid = IPCThreadState::self()->getCallingUid();
+ if (uid == expectedUid || uid == AID_ROOT) {
+ return Ok();
+ } else {
+ return Exception(binder::Status::EX_SECURITY,
+ StringPrintf("UID %d is not expected UID %d", uid, expectedUid));
+ }
+}
+
+binder::Status CheckArgumentId(const std::string& id) {
+ if (id.empty()) {
+ return Exception(binder::Status::EX_ILLEGAL_ARGUMENT, "Missing ID");
+ }
+ for (const char& c : id) {
+ if (!std::isalnum(c) && c != ':' && c != ',') {
+ return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
+ StringPrintf("ID %s is malformed", id.c_str()));
+ }
+ }
+ return Ok();
+}
+
+binder::Status CheckArgumentPath(const std::string& path) {
+ if (path.empty()) {
+ return Exception(binder::Status::EX_ILLEGAL_ARGUMENT, "Missing path");
+ }
+ if (path[0] != '/') {
+ return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
+ StringPrintf("Path %s is relative", path.c_str()));
+ }
+ if (path.find("/../"sv) != path.npos || android::base::EndsWith(path, "/.."sv)) {
+ return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
+ StringPrintf("Path %s is shady", path.c_str()));
+ }
+ for (const char& c : path) {
+ if (c == '\0' || c == '\n') {
+ return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
+ StringPrintf("Path %s is malformed", path.c_str()));
+ }
+ }
+ return Ok();
+}
+
+binder::Status CheckArgumentHex(const std::string& hex) {
+ // Empty hex strings are allowed
+ for (const char& c : hex) {
+ if (!std::isxdigit(c) && c != ':' && c != '-') {
+ return Exception(binder::Status::EX_ILLEGAL_ARGUMENT,
+ StringPrintf("Hex %s is malformed", hex.c_str()));
+ }
+ }
+ return Ok();
+}
+
+} // namespace android::vold
diff --git a/VoldNativeServiceValidation.h b/VoldNativeServiceValidation.h
new file mode 100644
index 0000000..d2fc9e0
--- /dev/null
+++ b/VoldNativeServiceValidation.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#pragma once
+
+#include <binder/Status.h>
+
+#include <string>
+
+#include <stdint.h>
+#include <sys/types.h>
+
+namespace android::vold {
+
+binder::Status Ok();
+binder::Status Exception(uint32_t code, const std::string& msg);
+
+binder::Status CheckPermission(const char* permission);
+binder::Status CheckUidOrRoot(uid_t expectedUid);
+binder::Status CheckArgumentId(const std::string& id);
+binder::Status CheckArgumentPath(const std::string& path);
+binder::Status CheckArgumentHex(const std::string& hex);
+
+} // namespace android::vold
diff --git a/tests/Android.bp b/tests/Android.bp
index 4731d0a..b90de3a 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -7,7 +7,9 @@
srcs: [
"Utils_test.cpp",
+ "VoldNativeServiceValidation_test.cpp",
"cryptfs_test.cpp",
],
static_libs: ["libvold"],
+ shared_libs: ["libbinder"]
}
diff --git a/tests/VoldNativeServiceValidation_test.cpp b/tests/VoldNativeServiceValidation_test.cpp
new file mode 100644
index 0000000..b057b82
--- /dev/null
+++ b/tests/VoldNativeServiceValidation_test.cpp
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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 "../VoldNativeServiceValidation.h"
+
+#include <gtest/gtest.h>
+
+#include <string_view>
+
+using namespace std::literals;
+
+namespace android::vold {
+
+class VoldNativeServiceValidationTest : public testing::Test {};
+
+TEST_F(VoldNativeServiceValidationTest, CheckArgumentPathTest) {
+ EXPECT_TRUE(CheckArgumentPath("/").isOk());
+ EXPECT_TRUE(CheckArgumentPath("/1/2").isOk());
+ EXPECT_TRUE(CheckArgumentPath("/1/2/").isOk());
+ EXPECT_TRUE(CheckArgumentPath("/1/2/./3").isOk());
+ EXPECT_TRUE(CheckArgumentPath("/1/2/./3/.").isOk());
+ EXPECT_TRUE(CheckArgumentPath(
+ "/very long path with some/ spaces and quite/ uncommon names /in\1 it/")
+ .isOk());
+
+ EXPECT_FALSE(CheckArgumentPath("").isOk());
+ EXPECT_FALSE(CheckArgumentPath("relative/path").isOk());
+ EXPECT_FALSE(CheckArgumentPath("../data/..").isOk());
+ EXPECT_FALSE(CheckArgumentPath("/../data/..").isOk());
+ EXPECT_FALSE(CheckArgumentPath("/data/../system").isOk());
+ EXPECT_FALSE(CheckArgumentPath("/data/..trick/../system").isOk());
+ EXPECT_FALSE(CheckArgumentPath("/data/..").isOk());
+ EXPECT_FALSE(CheckArgumentPath("/data/././../apex").isOk());
+ EXPECT_FALSE(CheckArgumentPath(std::string("/data/strange\0one"sv)).isOk());
+ EXPECT_FALSE(CheckArgumentPath(std::string("/data/strange\ntwo"sv)).isOk());
+}
+
+} // namespace android::vold