From f6855314eae6e8ea655d58607986020c4da9019e Mon Sep 17 00:00:00 2001
From: Meo597 <197331664+Meo597@users.noreply.github.com>
Date: Mon, 26 Oct 2026 08:56:18 +0800
Subject: [PATCH] limit the file size for downloads

---
 app/geodata/download.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/app/geodata/download.go b/app/geodata/download.go
index 11218e7fa..8d9789f7a 100644
--- a/app/geodata/download.go
+++ b/app/geodata/download.go
@@ -22,6 +22,7 @@ import (
 )
 
 const idleTimeout = 30 * time.Second
+const maxDownloadSize int64 = 256 * 1024 * 1024
 
 // DO NOT EDIT. Ignored by geodata, rejected by Lua.
 const luaGuardHeader = "\x12\x01\x00"
@@ -216,14 +217,19 @@ func (d *downloader) fetch(rawURL string, writer io.Writer) error {
 	defer resp.Body.Close()
 
 	if resp.StatusCode < http.StatusOK || resp.StatusCode >= http.StatusMultipleChoices {
-		io.Copy(io.Discard, resp.Body)
 		return errors.New("unexpected status code: ", resp.StatusCode)
 	}
+	if resp.ContentLength > maxDownloadSize {
+		return errors.New("geodata download exceeds 256 MiB")
+	}
 
-	n, err := io.Copy(writer, resp.Body)
+	n, err := io.Copy(writer, io.LimitReader(resp.Body, maxDownloadSize+1))
 	if err != nil {
 		return err
 	}
+	if n > maxDownloadSize {
+		return errors.New("geodata download exceeds 256 MiB")
+	}
 	if n == 0 {
 		return errors.New("empty response body")
 	}