From fb2ad3ec7bd9e10916a47088f29907f607738869 Mon Sep 17 00:00:00 2001 From: ShirkNeko <109797057+ShirkNeko@users.noreply.github.com> Date: Sun, 14 Sep 2025 17:38:25 +0800 Subject: [PATCH] kernel: keep legacy throne tracker as an option kernel: keep legacy throne tracker as an option This change restores older throne tracker that uses packages.list scanning to track app UIDs. It's intended for ultra-legacy Linux 3.X kernels that experience deadlocks or crashes with the newer implementation due to issues in user_data_actor(). We have to remember that the whole iterate_dir, and filldir subsystem is way different on 3.X. Changes: - CONFIG_KSU_THRONE_TRACKER_LEGACY in Kconfig - conditional compilation in Makefile - throne_tracker_legacy.c which keeps the old implementation Enable this option if newer throne tracker (tiann #2757crashes on you.) Co-authored-by: backslashxx <118538522+backslashxx@users.noreply.github.com> --- kernel/Kconfig | 9 + kernel/Makefile | 7 +- kernel/throne_tracker_legacy.c | 412 +++++++++++++++++++++++++++++++++ 3 files changed, 427 insertions(+), 1 deletion(-) create mode 100644 kernel/throne_tracker_legacy.c diff --git a/kernel/Kconfig b/kernel/Kconfig index 927dcfff..92ffdc20 100644 --- a/kernel/Kconfig +++ b/kernel/Kconfig @@ -8,6 +8,15 @@ config KSU To compile as a module, choose M here: the module will be called kernelsu. +config KSU_THRONE_TRACKER_LEGACY + bool "Use legacy throne tracker (packages.list scanning)" + depends on KSU + default n + help + Use legacy throne tracker that scans packages.list for app UIDs. + This is kept for Ultra-Legacy Linux 3.X kernels which are prone to deadlocks. + Enable this if default scanning deadlocks/crashes on you. + config KSU_DEBUG bool "KernelSU debug mode" depends on KSU diff --git a/kernel/Makefile b/kernel/Makefile index 53fd770f..f26d0093 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -3,7 +3,6 @@ kernelsu-objs += allowlist.o kernelsu-objs += dynamic_manager.o kernelsu-objs += apk_sign.o kernelsu-objs += sucompat.o -kernelsu-objs += throne_tracker.o kernelsu-objs += core_hook.o kernelsu-objs += ksud.o kernelsu-objs += embed_ksud.o @@ -17,6 +16,12 @@ kernelsu-objs += selinux/selinux.o kernelsu-objs += selinux/sepolicy.o kernelsu-objs += selinux/rules.o +ifeq ($(CONFIG_KSU_THRONE_TRACKER_LEGACY),y) + kernelsu-objs += throne_tracker_legacy.o +else + kernelsu-objs += throne_tracker.o +endif + ccflags-y += -I$(srctree)/security/selinux -I$(srctree)/security/selinux/include ccflags-y += -I$(objtree)/security/selinux -include $(srctree)/include/uapi/asm-generic/errno.h diff --git a/kernel/throne_tracker_legacy.c b/kernel/throne_tracker_legacy.c new file mode 100644 index 00000000..9b603273 --- /dev/null +++ b/kernel/throne_tracker_legacy.c @@ -0,0 +1,412 @@ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "allowlist.h" +#include "klog.h" // IWYU pragma: keep +#include "ksu.h" +#include "manager.h" +#include "throne_tracker.h" +#include "kernel_compat.h" + +// legacy throne tracker +// this is kept for UL purposes +// reason: can't solve deadlock on user_data_actor() +// xx - 20200914 + +uid_t ksu_manager_uid = KSU_INVALID_UID; + +#define SYSTEM_PACKAGES_LIST_PATH "/data/system/packages.list.tmp" + +struct uid_data { + struct list_head list; + u32 uid; + char package[KSU_MAX_PACKAGE_NAME]; +}; + +static int get_pkg_from_apk_path(char *pkg, const char *path) +{ + int len = strlen(path); + if (len >= KSU_MAX_PACKAGE_NAME || len < 1) + return -1; + + const char *last_slash = NULL; + const char *second_last_slash = NULL; + + int i; + for (i = len - 1; i >= 0; i--) { + if (path[i] == '/') { + if (!last_slash) { + last_slash = &path[i]; + } else { + second_last_slash = &path[i]; + break; + } + } + } + + if (!last_slash || !second_last_slash) + return -1; + + const char *last_hyphen = strchr(second_last_slash, '-'); + if (!last_hyphen || last_hyphen > last_slash) + return -1; + + int pkg_len = last_hyphen - second_last_slash - 1; + if (pkg_len >= KSU_MAX_PACKAGE_NAME || pkg_len <= 0) + return -1; + + // Copying the package name + strncpy(pkg, second_last_slash + 1, pkg_len); + pkg[pkg_len] = '\0'; + + return 0; +} + +static void crown_manager(const char *apk, struct list_head *uid_data) +{ + char pkg[KSU_MAX_PACKAGE_NAME]; + if (get_pkg_from_apk_path(pkg, apk) < 0) { + pr_err("Failed to get package name from apk path: %s\n", apk); + return; + } + + pr_info("manager pkg: %s\n", pkg); + +#ifdef KSU_MANAGER_PACKAGE + // pkg is `/` + if (strncmp(pkg, KSU_MANAGER_PACKAGE, sizeof(KSU_MANAGER_PACKAGE))) { + pr_info("manager package is inconsistent with kernel build: %s\n", + KSU_MANAGER_PACKAGE); + return; + } +#endif + struct list_head *list = (struct list_head *)uid_data; + struct uid_data *np; + + list_for_each_entry (np, list, list) { + if (strncmp(np->package, pkg, KSU_MAX_PACKAGE_NAME) == 0) { + pr_info("Crowning manager: %s(uid=%d)\n", pkg, np->uid); + ksu_set_manager_uid(np->uid); + break; + } + } +} + +#define DATA_PATH_LEN 384 // 384 is enough for /data/app//base.apk + +struct data_path { + char dirpath[DATA_PATH_LEN]; + int depth; + struct list_head list; +}; + +struct apk_path_hash { + unsigned int hash; + bool exists; + struct list_head list; +}; + +static struct list_head apk_path_hash_list = LIST_HEAD_INIT(apk_path_hash_list); + +struct my_dir_context { + struct dir_context ctx; + struct list_head *data_path_list; + char *parent_dir; + void *private_data; + int depth; + int *stop; +}; +// https://docs.kernel.org/filesystems/porting.html +// filldir_t (readdir callbacks) calling conventions have changed. Instead of returning 0 or -E... it returns bool now. false means "no more" (as -E... used to) and true - "keep going" (as 0 in old calling conventions). Rationale: callers never looked at specific -E... values anyway. -> iterate_shared() instances require no changes at all, all filldir_t ones in the tree converted. +#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 1, 0) +#define FILLDIR_RETURN_TYPE bool +#define FILLDIR_ACTOR_CONTINUE true +#define FILLDIR_ACTOR_STOP false +#else +#define FILLDIR_RETURN_TYPE int +#define FILLDIR_ACTOR_CONTINUE 0 +#define FILLDIR_ACTOR_STOP -EINVAL +#endif + +FILLDIR_RETURN_TYPE my_actor(struct dir_context *ctx, const char *name, + int namelen, loff_t off, u64 ino, + unsigned int d_type) +{ + struct my_dir_context *my_ctx = + container_of(ctx, struct my_dir_context, ctx); + char dirpath[DATA_PATH_LEN]; + + if (!my_ctx) { + pr_err("Invalid context\n"); + return FILLDIR_ACTOR_STOP; + } + if (my_ctx->stop && *my_ctx->stop) { + pr_info("Stop searching\n"); + return FILLDIR_ACTOR_STOP; + } + + if (!strncmp(name, "..", namelen) || !strncmp(name, ".", namelen)) + return FILLDIR_ACTOR_CONTINUE; // Skip "." and ".." + + if (d_type == DT_DIR && namelen >= 8 && !strncmp(name, "vmdl", 4) && + !strncmp(name + namelen - 4, ".tmp", 4)) { + pr_info("Skipping directory: %.*s\n", namelen, name); + return FILLDIR_ACTOR_CONTINUE; // Skip staging package + } + + if (snprintf(dirpath, DATA_PATH_LEN, "%s/%.*s", my_ctx->parent_dir, + namelen, name) >= DATA_PATH_LEN) { + pr_err("Path too long: %s/%.*s\n", my_ctx->parent_dir, namelen, + name); + return FILLDIR_ACTOR_CONTINUE; + } + + if (d_type == DT_DIR && my_ctx->depth > 0 && + (my_ctx->stop && !*my_ctx->stop)) { + struct data_path *data = kmalloc(sizeof(struct data_path), GFP_ATOMIC); + + if (!data) { + pr_err("Failed to allocate memory for %s\n", dirpath); + return FILLDIR_ACTOR_CONTINUE; + } + + strscpy(data->dirpath, dirpath, DATA_PATH_LEN); + data->depth = my_ctx->depth - 1; + list_add_tail(&data->list, my_ctx->data_path_list); + } else { + if ((namelen == 8) && (strncmp(name, "base.apk", namelen) == 0)) { + struct apk_path_hash *pos, *n; + unsigned int hash = full_name_hash(NULL, dirpath, strlen(dirpath)); + list_for_each_entry(pos, &apk_path_hash_list, list) { + if (hash == pos->hash) { + pos->exists = true; + return FILLDIR_ACTOR_CONTINUE; + } + } + + bool is_manager = is_manager_apk(dirpath); + pr_info("Found new base.apk at path: %s, is_manager: %d\n", + dirpath, is_manager); + if (is_manager) { + crown_manager(dirpath, my_ctx->private_data); + *my_ctx->stop = 1; + + // Manager found, clear APK cache list + list_for_each_entry_safe(pos, n, &apk_path_hash_list, list) { + list_del(&pos->list); + kfree(pos); + } + } else { + struct apk_path_hash *apk_data = kmalloc(sizeof(struct apk_path_hash), GFP_ATOMIC); + apk_data->hash = hash; + apk_data->exists = true; + list_add_tail(&apk_data->list, &apk_path_hash_list); + } + } + } + + return FILLDIR_ACTOR_CONTINUE; +} + +void search_manager(const char *path, int depth, struct list_head *uid_data) +{ + int i, stop = 0; + struct list_head data_path_list; + INIT_LIST_HEAD(&data_path_list); + unsigned long data_app_magic = 0; + + // Initialize APK cache list + struct apk_path_hash *pos, *n; + list_for_each_entry(pos, &apk_path_hash_list, list) { + pos->exists = false; + } + + // First depth + struct data_path data; + strscpy(data.dirpath, path, DATA_PATH_LEN); + data.depth = depth; + list_add_tail(&data.list, &data_path_list); + + for (i = depth; i >= 0; i--) { + struct data_path *pos, *n; + + list_for_each_entry_safe(pos, n, &data_path_list, list) { + struct my_dir_context ctx = { .ctx.actor = my_actor, + .data_path_list = &data_path_list, + .parent_dir = pos->dirpath, + .private_data = uid_data, + .depth = pos->depth, + .stop = &stop }; + struct file *file; + + if (!stop) { + file = ksu_filp_open_compat(pos->dirpath, O_RDONLY | O_NOFOLLOW, 0); + if (IS_ERR(file)) { + pr_err("Failed to open directory: %s, err: %ld\n", pos->dirpath, PTR_ERR(file)); + goto skip_iterate; + } + + // grab magic on first folder, which is /data/app + if (!data_app_magic) { + if (file->f_inode->i_sb->s_magic) { + data_app_magic = file->f_inode->i_sb->s_magic; + pr_info("%s: dir: %s got magic! 0x%lx\n", __func__, pos->dirpath, data_app_magic); + } else { + filp_close(file, NULL); + goto skip_iterate; + } + } + + if (file->f_inode->i_sb->s_magic != data_app_magic) { + pr_info("%s: skip: %s magic: 0x%lx expected: 0x%lx\n", __func__, pos->dirpath, + file->f_inode->i_sb->s_magic, data_app_magic); + filp_close(file, NULL); + goto skip_iterate; + } + + iterate_dir(file, &ctx.ctx); + filp_close(file, NULL); + } +skip_iterate: + list_del(&pos->list); + if (pos != &data) + kfree(pos); + } + } + + // Remove stale cached APK entries + list_for_each_entry_safe(pos, n, &apk_path_hash_list, list) { + if (!pos->exists) { + list_del(&pos->list); + kfree(pos); + } + } +} + +static bool is_uid_exist(uid_t uid, char *package, void *data) +{ + struct list_head *list = (struct list_head *)data; + struct uid_data *np; + + bool exist = false; + list_for_each_entry (np, list, list) { + if (np->uid == uid % 100000 && + strncmp(np->package, package, KSU_MAX_PACKAGE_NAME) == 0) { + exist = true; + break; + } + } + return exist; +} + +void track_throne() +{ + struct file *fp = + ksu_filp_open_compat(SYSTEM_PACKAGES_LIST_PATH, O_RDONLY, 0); + if (IS_ERR(fp)) { + pr_err("%s: open " SYSTEM_PACKAGES_LIST_PATH " failed: %ld\n", + __func__, PTR_ERR(fp)); + return; + } + + struct list_head uid_list; + INIT_LIST_HEAD(&uid_list); + + char chr = 0; + loff_t pos = 0; + loff_t line_start = 0; + char buf[KSU_MAX_PACKAGE_NAME]; + for (;;) { + ssize_t count = + ksu_kernel_read_compat(fp, &chr, sizeof(chr), &pos); + if (count != sizeof(chr)) + break; + if (chr != '\n') + continue; + + count = ksu_kernel_read_compat(fp, buf, sizeof(buf), + &line_start); + + struct uid_data *data = + kzalloc(sizeof(struct uid_data), GFP_ATOMIC); + if (!data) { + filp_close(fp, 0); + goto out; + } + + char *tmp = buf; + const char *delim = " "; + char *package = strsep(&tmp, delim); + char *uid = strsep(&tmp, delim); + if (!uid || !package) { + pr_err("update_uid: package or uid is NULL!\n"); + break; + } + + u32 res; + if (kstrtou32(uid, 10, &res)) { + pr_err("update_uid: uid parse err\n"); + break; + } + data->uid = res; + strncpy(data->package, package, KSU_MAX_PACKAGE_NAME); + list_add_tail(&data->list, &uid_list); + // reset line start + line_start = pos; + } + filp_close(fp, 0); + + // now update uid list + struct uid_data *np; + struct uid_data *n; + + // first, check if manager_uid exist! + bool manager_exist = false; + list_for_each_entry (np, &uid_list, list) { + // if manager is installed in work profile, the uid in packages.list is still equals main profile + // don't delete it in this case! + int manager_uid = ksu_get_manager_uid() % 100000; + if (np->uid == manager_uid) { + manager_exist = true; + break; + } + } + + if (!manager_exist) { + if (ksu_is_manager_uid_valid()) { + pr_info("manager is uninstalled, invalidate it!\n"); + ksu_invalidate_manager_uid(); + goto prune; + } + pr_info("Searching manager...\n"); + search_manager("/data/app", 2, &uid_list); + pr_info("Search manager finished\n"); + } + +prune: + // then prune the allowlist + ksu_prune_allowlist(is_uid_exist, &uid_list); +out: + // free uid_list + list_for_each_entry_safe (np, n, &uid_list, list) { + list_del(&np->list); + kfree(np); + } +} + +void ksu_throne_tracker_init() +{ + // nothing to do +} + +void ksu_throne_tracker_exit() +{ + // nothing to do +}