KernelSU: SUS_SU: Initiate path with 0 and no memset is needed

1. kernel & KernelSU: More optimization for SUS_SU mode 2 (Experimental)

2. Always flag zygote spawned isolated service as non-root user app process and no su allowed process

3. Change susfs_fake_qstr_name, shorter length

4. KernelSU: SUS_SU: Initiate path with 0 and no memset is needed

Co-authored-by: simonpunk <simonpunk2016@gmail.com>

kernel/core_hook.c

@@ -1224,17 +1224,29 @@ int ksu_handle_setuid(struct cred *new, const struct cred *old)
 		return 0;
 	}
 
-#ifdef CONFIG_KSU_SUSFS_SUS_MOUNT
+#ifdef CONFIG_KSU_SUSFS
 	// check if current process is zygote
 	bool is_zygote_child = susfs_is_sid_equal(old->security, susfs_zygote_sid);
+#endif // #ifdef CONFIG_KSU_SUSFS
 	if (likely(is_zygote_child)) {
 		// if spawned process is non user app process
 		if (unlikely(new_uid.val < 10000 && new_uid.val >= 1000)) {
+#ifdef CONFIG_KSU_SUSFS_SUS_SU
+			// set flag if zygote spawned system process is allowed for root access
+			if (!ksu_is_allow_uid(new_uid.val)) {
+				task_lock(current);
+				susfs_set_current_proc_su_not_allowed();
+				task_unlock(current);
+			}
+#endif // #ifdef CONFIG_KSU_SUSFS_SUS_SU
+#ifdef CONFIG_KSU_SUSFS_SUS_MOUNT
 			// umount for the system process if path DATA_ADB_UMOUNT_FOR_ZYGOTE_SYSTEM_PROCESS exists
 			if (susfs_is_umount_for_zygote_system_process_enabled) {
 				goto out_ksu_try_umount;
 			}
+#endif // #ifdef CONFIG_KSU_SUSFS_SUS_MOUNT
 		}
+#ifdef CONFIG_KSU_SUSFS
 		// - here we check if uid is a isolated service spawned by zygote directly
 		// - Apps that do not use "useAppZyogte" to start a isolated service will be directly
 		//   spawned by zygote which KSU will ignore it by default, the only fix for now is to
@@ -1242,14 +1254,21 @@ int ksu_handle_setuid(struct cred *new, const struct cred *old)
 		// - Therefore make sure your root app doesn't use isolated service for root access
 		// - Kudos to ThePedroo, the author and maintainer of Rezygisk for finding and reporting
 		//   the detection, really big helps here!
-		else if (new_uid.val >= 90000 && new_uid.val < 1000000 && susfs_is_umount_for_zygote_iso_service_enabled) {
+		else if (new_uid.val >= 90000 && new_uid.val < 1000000) {
 			task_lock(current);
 			susfs_set_current_non_root_user_app_proc();
+#ifdef CONFIG_KSU_SUSFS_SUS_SU
+			susfs_set_current_proc_su_not_allowed();
+#endif
 			task_unlock(current);
+#ifdef CONFIG_KSU_SUSFS_SUS_MOUNT
+			if (susfs_is_umount_for_zygote_iso_service_enabled) {
 			goto out_susfs_try_umount_all;
 		}
+	#endif // #ifdef CONFIG_KSU_SUSFS_SUS_MOUNT
+		}
 	}
-#endif
+#endif // #ifdef CONFIG_KSU_SUSFS
 
 	if (!is_appuid(new_uid) || is_unsupported_uid(new_uid.val)) {
 		// pr_info("handle setuid ignore non application or isolated uid: %d\n", new_uid.val);
@@ -1264,9 +1283,12 @@ int ksu_handle_setuid(struct cred *new, const struct cred *old)
 	else {
 		task_lock(current);
 		susfs_set_current_non_root_user_app_proc();
+#ifdef CONFIG_KSU_SUSFS_SUS_SU
+		susfs_set_current_proc_su_not_allowed();
+#endif // #ifdef CONFIG_KSU_SUSFS_SUS_SU
 		task_unlock(current);
 	}
-#endif
+#endif // #ifdef CONFIG_KSU_SUSFS
 
 #ifdef CONFIG_KSU_SUSFS_SUS_MOUNT
 out_ksu_try_umount:
@@ -1278,7 +1300,7 @@ out_ksu_try_umount:
 		pr_info("uid: %d should not umount!\n", current_uid().val);
 #endif
 	}
-#ifndef CONFIG_KSU_SUSFS_SUS_MOUNT
+#ifndef CONFIG_KSU_SUSFS
  	// check old process's selinux context, if it is not zygote, ignore it!
  	// because some su apps may setuid to untrusted_app but they are in global mount namespace
  	// when we umount for such process, that is a disaster!

kernel/sucompat.c

@@ -65,12 +65,18 @@ int ksu_handle_faccessat(int *dfd, const char __user **filename_user, int *mode,
 	}
 #endif
 
+#ifndef CONFIG_KSU_SUSFS_SUS_SU
 	if (!ksu_is_allow_uid(current_uid().val)) {
 		return 0;
 	}
+#endif
 
+#ifdef CONFIG_KSU_SUSFS_SUS_SU
+	char path[sizeof(su)] = {0};
+#else
 	char path[sizeof(su) + 1];
 	memset(path, 0, sizeof(path));
+#endif
 	ksu_strncpy_from_user_nofault(path, *filename_user, sizeof(path));
 
 	if (unlikely(!memcmp(path, su, sizeof(su)))) {
@@ -89,10 +95,6 @@ struct filename* susfs_ksu_handle_stat(int *dfd, const char __user **filename_us
 		return name;
 	}
 
-	if (!ksu_is_allow_uid(current_uid().val)) {
-		return name;
-	}
-
 	if (likely(memcmp(name->name, su, sizeof(su)))) {
 		return name;
 	}
@@ -113,16 +115,22 @@ int ksu_handle_stat(int *dfd, const char __user **filename_user, int *flags)
 	}
 #endif
 
+#ifndef CONFIG_KSU_SUSFS_SUS_SU
 	if (!ksu_is_allow_uid(current_uid().val)) {
 		return 0;
 	}
+#endif
 
 	if (unlikely(!filename_user)) {
 		return 0;
 	}
 
+#ifdef CONFIG_KSU_SUSFS_SUS_SU
+	char path[sizeof(su)] = {0};
+#else
 	char path[sizeof(su) + 1];
 	memset(path, 0, sizeof(path));
+#endif
 // Remove this later!! we use syscall hook, so this will never happen!!!!!
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 18, 0) && 0
 	// it becomes a `struct filename *` after 5.18
@@ -172,8 +180,10 @@ int ksu_handle_execveat_sucompat(int *fd, struct filename **filename_ptr,
 	if (likely(memcmp(filename->name, su, sizeof(su))))
 		return 0;
 
+#ifndef CONFIG_KSU_SUSFS_SUS_SU
 	if (!ksu_is_allow_uid(current_uid().val))
 		return 0;
+#endif
 
 	pr_info("do_execveat_common su found\n");
 	memcpy((void *)filename->name, ksud_path, sizeof(ksud_path));
@@ -187,8 +197,12 @@ int ksu_handle_execve_sucompat(int *fd, const char __user **filename_user,
 			       void *__never_use_argv, void *__never_use_envp,
 			       int *__never_use_flags)
 {
-	// const char su[] = SU_PATH;
+	//const char su[] = SU_PATH;
+#ifdef CONFIG_KSU_SUSFS_SUS_SU
+	char path[sizeof(su)] = {0};
+#else
 	char path[sizeof(su) + 1];
+#endif
 
 #ifndef CONFIG_KSU_KPROBES_HOOK
 	if (!ksu_sucompat_hook_state) {
@@ -215,7 +229,6 @@ int ksu_handle_execve_sucompat(int *fd, const char __user **filename_user,
 	long len = strncpy_from_user(path, *filename_user, sizeof(path));
 	if (len <= 0 || len > sizeof(path))
 		return 0;
-
 	// strncpy_from_user_nofault does this too
 	path[sizeof(path) - 1] = '\0';