From b16a5f03fe1a42c5c35bdf04732cd5671e765adf Mon Sep 17 00:00:00 2001
From: vemneyy <wllamsmth1@gmail.com>
Date: Thu, 20 Nov 2025 15:21:22 +0300
Subject: [PATCH] Socks: Fix buffer full panic when encoding large UDP packets
 (#5252)
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Co-authored-by: 风扇滑翔翼 <Fangliding.fshxy@outlook.com>
---
 proxy/socks/protocol.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/proxy/socks/protocol.go b/proxy/socks/protocol.go
index 9bccf607..76ceb47c 100644
--- a/proxy/socks/protocol.go
+++ b/proxy/socks/protocol.go
@@ -353,6 +353,11 @@ func EncodeUDPPacket(request *protocol.RequestHeader, data []byte) (*buf.Buffer,
 		b.Release()
 		return nil, err
 	}
+	// if data is too large, return an empty buffer (drop too big data)
+	if b.Available() < int32(len(data)) {
+		b.Clear()
+		return b, nil
+	}
 	common.Must2(b.Write(data))
 	return b, nil
 }