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Merge Android 24Q1 Release (ab/11220357)
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Bug: 319669529
Merged-In: I856c812d22363cc1d1e8aa88706d4d3b89044f52
Change-Id: I9ef2aa7496bbf81f7f0da6b0ea46dc2157ad91f1
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@delphij
delphij committed Jan 30, 2024
2 parents f471877 + 823e0bf commit 7f41fd4
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Showing 2 changed files with 89 additions and 49 deletions.
109 changes: 64 additions & 45 deletions init/property_service.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -58,6 +58,7 @@
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <fs_mgr.h>
#include <private/android_filesystem_config.h>
#include <property_info_parser/property_info_parser.h>
#include <property_info_serializer/property_info_serializer.h>
#include <selinux/android.h>
Expand Down Expand Up @@ -117,12 +118,13 @@ constexpr auto DIGEST_SIZE_USED = 8;

static bool persistent_properties_loaded = false;

static int property_set_fd = -1;
static int from_init_socket = -1;
static int init_socket = -1;
static bool accept_messages = false;
static std::mutex accept_messages_lock;
static std::mutex selinux_check_access_lock;
static std::thread property_service_thread;
static std::thread property_service_for_system_thread;

static std::unique_ptr<PersistWriteThread> persist_write_thread;

Expand Down Expand Up @@ -167,6 +169,7 @@ bool CanReadProperty(const std::string& source_context, const std::string& name)
ucred cr = {.pid = 0, .uid = 0, .gid = 0};
audit_data.cr = &cr;

auto lock = std::lock_guard{selinux_check_access_lock};
return selinux_check_access(source_context.c_str(), target_context, "file", "read",
&audit_data) == 0;
}
Expand All @@ -182,10 +185,9 @@ static bool CheckMacPerms(const std::string& name, const char* target_context,
audit_data.name = name.c_str();
audit_data.cr = &cr;

bool has_access = (selinux_check_access(source_context, target_context, "property_service",
"set", &audit_data) == 0);

return has_access;
auto lock = std::lock_guard{selinux_check_access_lock};
return selinux_check_access(source_context, target_context, "property_service", "set",
&audit_data) == 0;
}

void NotifyPropertyChange(const std::string& name, const std::string& value) {
Expand Down Expand Up @@ -400,30 +402,38 @@ static std::optional<uint32_t> PropertySet(const std::string& name, const std::s
return {PROP_ERROR_INVALID_VALUE};
}

prop_info* pi = (prop_info*)__system_property_find(name.c_str());
if (pi != nullptr) {
// ro.* properties are actually "write-once".
if (StartsWith(name, "ro.")) {
*error = "Read-only property was already set";
return {PROP_ERROR_READ_ONLY_PROPERTY};
}

__system_property_update(pi, value.c_str(), valuelen);
if (name == "sys.powerctl") {
// No action here - NotifyPropertyChange will trigger the appropriate action, and since this
// can come to the second thread, we mustn't call out to the __system_property_* functions
// which support multiple readers but only one mutator.
} else {
int rc = __system_property_add(name.c_str(), name.size(), value.c_str(), valuelen);
if (rc < 0) {
*error = "__system_property_add failed";
return {PROP_ERROR_SET_FAILED};
prop_info* pi = (prop_info*)__system_property_find(name.c_str());
if (pi != nullptr) {
// ro.* properties are actually "write-once".
if (StartsWith(name, "ro.")) {
*error = "Read-only property was already set";
return {PROP_ERROR_READ_ONLY_PROPERTY};
}

__system_property_update(pi, value.c_str(), valuelen);
} else {
int rc = __system_property_add(name.c_str(), name.size(), value.c_str(), valuelen);
if (rc < 0) {
*error = "__system_property_add failed";
return {PROP_ERROR_SET_FAILED};
}
}
}

bool need_persist = StartsWith(name, "persist.") || StartsWith(name, "next_boot.");
if (socket && persistent_properties_loaded && need_persist) {
if (persist_write_thread) {
persist_write_thread->Write(name, value, std::move(*socket));
return {};
// Don't write properties to disk until after we have read all default
// properties to prevent them from being overwritten by default values.
bool need_persist = StartsWith(name, "persist.") || StartsWith(name, "next_boot.");
if (socket && persistent_properties_loaded && need_persist) {
if (persist_write_thread) {
persist_write_thread->Write(name, value, std::move(*socket));
return {};
}
WritePersistentProperty(name, value);
}
WritePersistentProperty(name, value);
}

NotifyPropertyChange(name, value);
Expand Down Expand Up @@ -584,10 +594,10 @@ uint32_t HandlePropertySetNoSocket(const std::string& name, const std::string& v
return *ret;
}

static void handle_property_set_fd() {
static void handle_property_set_fd(int fd) {
static constexpr uint32_t kDefaultSocketTimeout = 2000; /* ms */

int s = accept4(property_set_fd, nullptr, nullptr, SOCK_CLOEXEC);
int s = accept4(fd, nullptr, nullptr, SOCK_CLOEXEC);
if (s == -1) {
return;
}
Expand Down Expand Up @@ -1294,7 +1304,7 @@ void CreateSerializedPropertyInfo() {
mkdir(APPCOMPAT_OVERRIDE_PROP_FOLDERNAME, S_IRWXU | S_IXGRP | S_IXOTH);
if (!WriteStringToFile(serialized_contexts, APPCOMPAT_OVERRIDE_PROP_TREE_FILE, 0444, 0, 0,
false)) {
PLOG(ERROR) << "Unable to write vendor overrides to file";
PLOG(ERROR) << "Unable to write appcompat override property infos to file";
}
selinux_android_restorecon(APPCOMPAT_OVERRIDE_PROP_TREE_FILE, 0);
}
Expand Down Expand Up @@ -1431,19 +1441,21 @@ static void HandleInitSocket() {
}
}

static void PropertyServiceThread() {
static void PropertyServiceThread(int fd, bool listen_init) {
Epoll epoll;
if (auto result = epoll.Open(); !result.ok()) {
LOG(FATAL) << result.error();
}

if (auto result = epoll.RegisterHandler(property_set_fd, handle_property_set_fd);
if (auto result = epoll.RegisterHandler(fd, std::bind(handle_property_set_fd, fd));
!result.ok()) {
LOG(FATAL) << result.error();
}

if (auto result = epoll.RegisterHandler(init_socket, HandleInitSocket); !result.ok()) {
LOG(FATAL) << result.error();
if (listen_init) {
if (auto result = epoll.RegisterHandler(init_socket, HandleInitSocket); !result.ok()) {
LOG(FATAL) << result.error();
}
}

while (true) {
Expand Down Expand Up @@ -1492,6 +1504,23 @@ void PersistWriteThread::Write(std::string name, std::string value, SocketConnec
cv_.notify_all();
}

void StartThread(const char* name, int mode, int gid, std::thread& t, bool listen_init) {
int fd = -1;
if (auto result = CreateSocket(name, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
/*passcred=*/false, /*should_listen=*/false, mode, /*uid=*/0,
/*gid=*/gid, /*socketcon=*/{});
result.ok()) {
fd = *result;
} else {
LOG(FATAL) << "start_property_service socket creation failed: " << result.error();
}

listen(fd, 8);

auto new_thread = std::thread(PropertyServiceThread, fd, listen_init);
t.swap(new_thread);
}

void StartPropertyService(int* epoll_socket) {
InitPropertySet("ro.property_service.version", "2");

Expand All @@ -1503,19 +1532,9 @@ void StartPropertyService(int* epoll_socket) {
init_socket = sockets[1];
StartSendingMessages();

if (auto result = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
/*passcred=*/false, /*should_listen=*/false, 0666, /*uid=*/0,
/*gid=*/0, /*socketcon=*/{});
result.ok()) {
property_set_fd = *result;
} else {
LOG(FATAL) << "start_property_service socket creation failed: " << result.error();
}

listen(property_set_fd, 8);

auto new_thread = std::thread{PropertyServiceThread};
property_service_thread.swap(new_thread);
StartThread(PROP_SERVICE_FOR_SYSTEM_NAME, 0660, AID_SYSTEM, property_service_for_system_thread,
true);
StartThread(PROP_SERVICE_NAME, 0666, 0, property_service_thread, false);

auto async_persist_writes =
android::base::GetBoolProperty("ro.property_service.async_persist_writes", false);
Expand Down
29 changes: 25 additions & 4 deletions libcutils/ashmem-dev.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -301,6 +301,12 @@ static int memfd_create_region(const char* name, size_t size) {
return -1;
}

// forbid size changes to match ashmem behaviour
if (fcntl(fd, F_ADD_SEALS, F_SEAL_GROW | F_SEAL_SHRINK) == -1) {
ALOGE("memfd_create(%s, %zd) F_ADD_SEALS failed: %m", name, size);
return -1;
}

if (debug_log) {
ALOGE("memfd_create(%s, %zd) success. fd=%d\n", name, size, fd.get());
}
Expand Down Expand Up @@ -352,14 +358,29 @@ int ashmem_create_region(const char *name, size_t size)
}

static int memfd_set_prot_region(int fd, int prot) {
/* Only proceed if an fd needs to be write-protected */
int seals = fcntl(fd, F_GET_SEALS);
if (seals == -1) {
ALOGE("memfd_set_prot_region(%d, %d): F_GET_SEALS failed: %s\n", fd, prot, strerror(errno));
return -1;
}

if (prot & PROT_WRITE) {
/* Now we want the buffer to be read-write, let's check if the buffer
* has been previously marked as read-only before, if so return error
*/
if (seals & F_SEAL_FUTURE_WRITE) {
ALOGE("memfd_set_prot_region(%d, %d): region is write protected\n", fd, prot);
errno = EINVAL; // inline with ashmem error code, if already in
// read-only mode
return -1;
}
return 0;
}

if (fcntl(fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE) == -1) {
ALOGE("memfd_set_prot_region(%d, %d): F_SEAL_FUTURE_WRITE seal failed: %s\n", fd, prot,
strerror(errno));
/* We would only allow read-only for any future file operations */
if (fcntl(fd, F_ADD_SEALS, F_SEAL_FUTURE_WRITE | F_SEAL_SEAL) == -1) {
ALOGE("memfd_set_prot_region(%d, %d): F_SEAL_FUTURE_WRITE | F_SEAL_SEAL seal failed: %s\n",
fd, prot, strerror(errno));
return -1;
}

Expand Down

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