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Update kernel/ksud.c
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@longhuan1999 @tiann
longhuan1999 authored and tiann committed Oct 2, 2023
1 parent d98aa32 commit 0e3b6b7
Showing 1 changed file with 64 additions and 62 deletions.
126 changes: 64 additions & 62 deletions kernel/ksud.c
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Original file line number Diff line number Diff line change
Expand Up @@ -103,44 +103,6 @@ static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
return native;
}

static const bool get_env_bool(struct user_arg_ptr envp, const char *name) {
const char __user *const __user *env;

// Traverse the list of environment variables
for (env = envp.ptr.native; *env != NULL; env++) {
const char __user *entry = *env;
char buf[256];

// Reading environment variable strings from user space
if (ksu_strncpy_from_user_nofault(buf, entry, sizeof(buf)) < 0)
continue;

// Parsing environment variable names and values
char *env_name = buf;
char *env_value = strchr(buf, '=');
if (env_value == NULL)
continue;

// Replace equal sign with string terminator
*env_value = '\0';
env_value++;

// pr_info("env %s=%s\n", env_name, env_value);
// Check if the environment variable names are matching
if (strcmp(env_name, name) == 0) {
// If matched, returns a Boolean value based on the environment variable's value
if (strcmp(env_value, "1") == 0 || strcmp(env_value, "true") == 0)
return true;
else
return false;
}
}

// If the specified environment variable is not found, return the default value
pr_info("not found env %s\n", name);
return false;
}

/*
* count() counts the number of strings in array ARGV.
*/
Expand Down Expand Up @@ -178,7 +140,7 @@ static int __maybe_unused count(struct user_arg_ptr argv, int max)

// the call from execve_handler_pre won't provided correct value for __never_use_argument, use them after fix execve_handler_pre, keeping them for consistence for manually patched code
int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr,
struct user_arg_ptr *argv, struct user_arg_ptr *envp, int *__never_use_flags)
struct user_arg_ptr *argv, struct user_arg_ptr *envp, int *__never_use_flags)
{
#ifndef CONFIG_KPROBES
if (!ksu_execveat_hook) {
Expand All @@ -190,9 +152,9 @@ int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr,
static const char app_process[] = "/system/bin/app_process";
static bool first_app_process = true;

/* This applies to Android 10 and above versions */
/* This applies to versions Android 10+ */
static const char system_bin_init[] = "/system/bin/init";
/* This applies to versions between Android 6 and Android 9 */
/* This applies to versions between Android 6 ~ 9 */
static const char old_system_init[] = "/init";
static bool init_second_stage_executed = false;

Expand All @@ -204,44 +166,84 @@ int ksu_handle_execveat_ksud(int *fd, struct filename **filename_ptr,
return 0;
}

if (unlikely(!memcmp(filename->name, system_bin_init,
sizeof(system_bin_init) - 1)) ||
unlikely(!memcmp(filename->name, old_system_init,
sizeof(old_system_init) - 1))) {
// init executed
if (unlikely(!memcmp(filename->name, system_bin_init,
sizeof(system_bin_init) - 1))) {
// /system/bin/init executed
int argc = count(*argv, MAX_ARG_STRINGS);
pr_info("init argc: %d\n", argc);
pr_info("/system/bin/init argc: %d\n", argc);
if (argc > 1 && !init_second_stage_executed) {
const char __user *p = get_user_arg_ptr(*argv, 1);
/* This applies to versions Android 6 ~ 7 and Android 10+ */
if (p && !IS_ERR(p)) {
char first_arg[16];
ksu_strncpy_from_user_nofault(first_arg, p, sizeof(first_arg));
pr_info("init first arg: %s\n", first_arg);
if (!strcmp(first_arg, "second_stage") || !strcmp(first_arg, "--second-stage")) {
pr_info("init second_stage executed\n");
ksu_strncpy_from_user_nofault(first_arg, p, sizeof(first_arg));
pr_info("/system/bin/init first arg: %s\n", first_arg);
if (!strcmp(first_arg, "second_stage")) {
pr_info("/system/bin/init second_stage executed\n");
apply_kernelsu_rules();
init_second_stage_executed = true;
ksu_android_ns_fs_check();
}
} else {
pr_err("init parse args err!\n");
pr_err("/system/bin/init parse args err!\n");
}
}
} else if (unlikely(!memcmp(filename->name, old_system_init,
sizeof(old_system_init) - 1))) {
// /init executed
int argc = count(*argv, MAX_ARG_STRINGS);
pr_info("/init argc: %d\n", argc);
if (argc > 1 && !init_second_stage_executed) {
/* This applies to versions between Android 6 ~ 7 */
const char __user *p = get_user_arg_ptr(*argv, 1);
if (p && !IS_ERR(p)) {
char first_arg[16];
ksu_strncpy_from_user_nofault(first_arg, p, sizeof(first_arg));
pr_info("/init first arg: %s\n", first_arg);
if (!strcmp(first_arg, "--second-stage")) {
pr_info("/init second_stage executed\n");
apply_kernelsu_rules();
init_second_stage_executed = true;
ksu_android_ns_fs_check();
}
} else {
pr_err("/init parse args err!\n");
}
} else if (argc == 1 && !init_second_stage_executed) {
/* This applies to versions between Android 8 and Android 9 */
const bool init_second_stage = get_env_bool(*envp, "INIT_SECOND_STAGE");
pr_info("init env INIT_SECOND_STAGE = %s\n", init_second_stage ? "true" : "false");
if (init_second_stage) {
pr_info("init second_stage executed\n");
apply_kernelsu_rules();
init_second_stage_executed = true;
ksu_android_ns_fs_check();
/* This applies to versions between Android 8 ~ 9 */
int envc = count(*envp, MAX_ARG_STRINGS);
if (envc > 0) {
int n;
for (n = 1; n <= envc; n++) {
const char __user *p = get_user_arg_ptr(*envp, n);
if (!p || IS_ERR(p)) {
continue;
}
char env[256];
// Reading environment variable strings from user space
if (ksu_strncpy_from_user_nofault(env, p, sizeof(env)) < 0)
continue;
// Parsing environment variable names and values
char *env_name = env;
char *env_value = strchr(env, '=');
if (env_value == NULL)
continue;
// Replace equal sign with string terminator
*env_value = '\0';
env_value++;
// Check if the environment variable name and value are matching
if (!strcmp(env_name, "INIT_SECOND_STAGE") && (!strcmp(env_value, "1") || !strcmp(env_value, "true"))) {
pr_info("/init second_stage executed\n");
apply_kernelsu_rules();
init_second_stage_executed = true;
ksu_android_ns_fs_check();
}
}
}
}
}

if (unlikely(first_app_process &&
!memcmp(filename->name, app_process, sizeof(app_process) - 1))) {
!memcmp(filename->name, app_process, sizeof(app_process) - 1))) {
first_app_process = false;
pr_info("exec app_process, /data prepared, second_stage: %d\n", init_second_stage_executed);
on_post_fs_data(); // we keep this for old ksud
Expand Down

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