Refine prctl access check, allow /product/bin/su

Author: nampud

kernel/core_hook.c

@@ -253,9 +253,8 @@ static bool is_system_bin_su() {
 	if (mm && mm->exe_file) {
 		pathname = d_path(&mm->exe_file->f_path, path_buf, sizeof(path_buf));
 		if (!IS_ERR(pathname)) {
-			if (strcmp(pathname, "/system/bin/su") == 0) {
-				return true;
-			}
+			if (strcmp(pathname, "/system/bin/su") == 0) return true;
+			if (strcmp(pathname, "/product/bin/su") == 0) return true;
 		}
 	}
 	return false;
@@ -277,9 +276,9 @@ int ksu_handle_prctl(int option, unsigned long arg2, unsigned long arg3,
 	}
 
 	bool from_root = 0 == current_uid().val;
-	bool from_manager = is_manager() || (is_allow_su() && is_system_bin_su());
+	bool from_manager = is_manager();
 
-	if (!from_root && !from_manager) {
+	if (!from_root && !from_manager && !(is_allow_su() && arg2 == CMD_GRANT_ROOT && is_system_bin_su())) {
 		// only root or manager can access this interface
 		return 0;
 	}
@@ -430,7 +429,7 @@ int ksu_handle_prctl(int option, unsigned long arg2, unsigned long arg3,
 	}
 
 	// all other cmds are for 'root manager'
-	if (!from_manager) {
+	if (!from_manager && arg2 != CMD_ENABLE_SU) {
 		return 0;
 	}