Isolated processes might still be hide-able

This commit is contained in:
topjohnwu 2021-01-15 20:22:49 -08:00
parent 20be99ec8a
commit 13fbf397d1
3 changed files with 47 additions and 59 deletions

View File

@ -337,6 +337,32 @@ void auto_start_magiskhide(bool late_props) {
}
}
bool is_hide_target(int uid, string_view process) {
mutex_guard lock(hide_state_lock);
if (uid % 100000 >= 90000) {
// Isolated processes
auto it = uid_proc_map.find(-1);
if (it == uid_proc_map.end())
return false;
for (auto &s : it->second) {
if (str_starts(process, s))
return true;
}
} else {
auto it = uid_proc_map.find(uid);
if (it == uid_proc_map.end())
return false;
for (auto &s : it->second) {
if (s == process)
return true;
}
}
return false;
}
#if !ENABLE_INJECT
void test_proc_monitor() {
if (procfp == nullptr && (procfp = opendir("/proc")) == nullptr)
@ -347,35 +373,11 @@ void test_proc_monitor() {
#if ENABLE_INJECT
int check_uid_map(int client) {
mutex_guard lock(hide_state_lock);
if (!hide_state)
if (!hide_enabled())
return 0;
int uid = read_int(client);
string process = read_string(client);
if (uid % 100000 > 90000) {
// Isolated process
auto it = uid_proc_map.find(-1);
if (it == uid_proc_map.end())
return 0;
for (auto &s : it->second) {
if (str_starts(process, s))
return 1;
}
} else {
auto it = uid_proc_map.find(uid);
if (it == uid_proc_map.end())
return 0;
for (auto &s : it->second) {
if (process == s)
return 1;
}
}
return 0;
return is_hide_target(uid, process) ? 1 : 0;
}
#endif

View File

@ -35,6 +35,7 @@ void crawl_procfs(const std::function<bool (int)> &fn);
void crawl_procfs(DIR *dir, const std::function<bool (int)> &fn);
bool hide_enabled();
void update_uid_map();
bool is_hide_target(int uid, std::string_view process);
// Hide policies
void hide_daemon(int pid);

View File

@ -183,8 +183,10 @@ static bool check_pid(int pid) {
return true;
}
int uid = st.st_uid;
// UID hasn't changed
if (st.st_uid == 0)
if (uid == 0)
return false;
sprintf(path, "/proc/%d/cmdline", pid);
@ -200,25 +202,10 @@ static bool check_pid(int pid) {
cmdline == "usap32"sv || cmdline == "usap64"sv)
return false;
int uid = st.st_uid;
// Start accessing uid_proc_map
mutex_guard lock(hide_state_lock);
auto it = uid_proc_map.end();
if (uid % 100000 > 90000) {
// No way to handle isolated process
if (!is_hide_target(uid, cmdline))
goto not_target;
}
it = uid_proc_map.find(uid);
if (it == uid_proc_map.end())
goto not_target;
for (auto &s : it->second) {
if (s != cmdline)
continue;
// Check if ns is separated (could be app zygote)
// Ensure ns is separated
read_ns(pid, &st);
for (auto &zit : zygote_map) {
if (zit.second.st_ino == st.st_ino &&
@ -228,14 +215,12 @@ static bool check_pid(int pid) {
}
}
// Finally this is our target!
// Detach from ptrace but should still remain stopped.
// The hide daemon will resume the process.
// Detach but the process should still remain stopped
// The hide daemon will resume the process after hiding it
LOGI("proc_monitor: [%s] PID=[%d] UID=[%d]\n", cmdline, pid, uid);
detach_pid(pid, SIGSTOP);
hide_daemon(pid);
return true;
}
not_target:
PTRACE_LOG("[%s] is not our target\n", cmdline);