From 711fa7400dbc836e46cb0a977654595f61139cf5 Mon Sep 17 00:00:00 2001
From: David Cermak <cermak@espressif.com>
Date: Wed, 15 Apr 2026 09:27:46 +0200
Subject: [PATCH] fix(lwip): Trim to max packet size in dhcp server

---
 components/lwip/apps/dhcpserver/dhcpserver.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/components/lwip/apps/dhcpserver/dhcpserver.c b/components/lwip/apps/dhcpserver/dhcpserver.c
index 6b4830a5f1c..a8067a6834a 100644
--- a/components/lwip/apps/dhcpserver/dhcpserver.c
+++ b/components/lwip/apps/dhcpserver/dhcpserver.c
@@ -1173,7 +1173,7 @@ static void handle_dhcp(void *arg,
 {
     struct dhcps_t *dhcps = arg;
     struct dhcps_msg *pmsg_dhcps = NULL;
-    s16_t tlen, malloc_len;
+    u16_t tlen, malloc_len;
     u16_t i;
     u16_t dhcps_msg_cnt = 0;
     u8_t *p_dhcps_msg = NULL;
@@ -1188,6 +1188,11 @@ static void handle_dhcp(void *arg,
         return;
     }
 
+    if (p->tot_len > 1500) {
+        pbuf_free(p);
+        return;
+    }
+
     malloc_len = sizeof(struct dhcps_msg);
 #if DHCPS_DEBUG
     DHCPS_LOG("dhcps: handle_dhcp malloc_len=%d rx_len=%d", malloc_len, p->tot_len);