fix: exempted fds not being added to fds_to_ignore

This commit fixes the issue that when `fds_to_ignore` is NULL. Instead of creating an array and adding the exempted fds to it when NULL, it would ignore. Not only leading to issues in modules, but could even crashes if the module closes some fd that is now owned by Zygote. This only affects "nativeForkAndSpecialize", which is usually used by Chrome/WebView for isolation.

Author: ThePedroo

loader/src/injector/hook.c

@@ -808,8 +808,8 @@ static void rz_sanitize_fds(struct zygisk_context *ctx) {
     jintArray fdsToIgnore = ctx->args.app->fds_to_ignore ? *ctx->args.app->fds_to_ignore : NULL;
     mark_fds_allowed(ctx, ctx->env, fdsToIgnore);
 
-    if (fdsToIgnore && ctx->exempted_fds_count > 0) {
-      jint len = (*ctx->env)->GetArrayLength(ctx->env, fdsToIgnore);
+    if (ctx->exempted_fds_count > 0) {
+      jint len = fdsToIgnore ? (*ctx->env)->GetArrayLength(ctx->env, fdsToIgnore) : 0;
       jintArray newArray = (*ctx->env)->NewIntArray(ctx->env, (jsize)(len + ctx->exempted_fds_count));
       if (newArray) {
         if (fdsToIgnore && len > 0) {