From dbfde45901ecc299256ec66c43df838ccca7134b Mon Sep 17 00:00:00 2001
From: mohammadmseet-hue <mohammadmseet@gmail.com>
Date: Sat, 11 Apr 2026 18:57:02 +0200
Subject: [PATCH] Fix panic on malformed PrismHeader packets

Add minimum data length check and validate PrismHeader.Length against
actual data length before using it for slicing. Malformed packets with
short data or inflated Length fields caused slice bounds panics.
---
 layers/prism.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/layers/prism.go b/layers/prism.go
index e1711e7f5..f53479075 100644
--- a/layers/prism.go
+++ b/layers/prism.go
@@ -11,6 +11,7 @@ package layers
 import (
 	"encoding/binary"
 	"errors"
+	"fmt"
 
 	"github.com/google/gopacket"
 )
@@ -113,8 +114,16 @@ type PrismHeader struct {
 func (m *PrismHeader) LayerType() gopacket.LayerType { return LayerTypePrismHeader }
 
 func (m *PrismHeader) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 24 {
+		df.SetTruncated()
+		return errors.New("PrismHeader too short")
+	}
 	m.Code = binary.LittleEndian.Uint16(data[0:4])
 	m.Length = binary.LittleEndian.Uint16(data[4:8])
+	if int(m.Length) > len(data) {
+		df.SetTruncated()
+		return fmt.Errorf("PrismHeader length %d exceeds data length %d", m.Length, len(data))
+	}
 	m.DeviceName = string(data[8:24])
 	m.BaseLayer = BaseLayer{Contents: data[:m.Length], Payload: data[m.Length:len(data)]}