From 287a93a2a4de7e7e9e487ee96f3261a669b52b6f Mon Sep 17 00:00:00 2001
From: Gunnar Beutner <gunnar@beutner.name>
Date: Mon, 12 Apr 2021 16:44:04 +0200
Subject: [PATCH] LibC: Validate the len argument for inet_ntop()

---
 Userland/Libraries/LibC/arpa/inet.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Userland/Libraries/LibC/arpa/inet.cpp b/Userland/Libraries/LibC/arpa/inet.cpp
index 3cf7cc48a4..30ef7f6d46 100644
--- a/Userland/Libraries/LibC/arpa/inet.cpp
+++ b/Userland/Libraries/LibC/arpa/inet.cpp
@@ -37,6 +37,10 @@ const char* inet_ntop(int af, const void* src, char* dst, socklen_t len)
         errno = EAFNOSUPPORT;
         return nullptr;
     }
+    if (len < 4) {
+        errno = ENOSPC;
+        return nullptr;
+    }
     auto* bytes = (const unsigned char*)src;
     snprintf(dst, len, "%u.%u.%u.%u", bytes[0], bytes[1], bytes[2], bytes[3]);
     return (const char*)dst;