From 32ffc69bdde364fc851762a3497e5cfa158d22be Mon Sep 17 00:00:00 2001
From: daichuan <daichuan@xiaomi.com>
Date: Wed, 14 Jan 2026 15:34:26 +0800
Subject: [PATCH] net/icmp: Fix devif_loopback dead loop when unrecognized ICMP
 packet received

When an unrecognized ICMP (type=3, code=2) packet is received, the ICMP flow does not set dev->d_len to 0, causing a devif_loopback dead loop.

Therefore, in ICMP input processing, when an ICMP_DEST_UNREACHABLE message is received, if it is not ICMP_FRAG_NEEDED code, jump to typeerr for error handling.

Signed-off-by: daichuan <daichuan@xiaomi.com>
---
 net/icmp/icmp_input.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/icmp/icmp_input.c b/net/icmp/icmp_input.c
index 8bca6325ede..69b5e76ff8a 100644
--- a/net/icmp/icmp_input.c
+++ b/net/icmp/icmp_input.c
@@ -443,6 +443,10 @@ void icmp_input(FAR struct net_driver_s *dev)
 
           goto icmp_send_nothing;
         }
+      else
+        {
+          goto typeerr;
+        }
     }
 #endif
   else if (icmp->type == ICMP_TIMESTAMP_REQUEST)