From 3164e22f9b323d31384010f6c3d09a86aeeba7ae Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Fri, 10 Sep 2021 03:06:32 +0200
Subject: [PATCH] Kernel: Fix null dereference in
 IPv4Socket::receive_packet_buffered()

This was a mistake in the move away from KBuffer-as-a-value type.
We need to check `packet` here, not `packet->data`.

Regressed in b300f9aa2fd11796e63b5029008b33a1ae735928.

Fixes #9888.
---
 Kernel/Net/IPv4Socket.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Kernel/Net/IPv4Socket.cpp b/Kernel/Net/IPv4Socket.cpp
index d8e7922ee0..3f2704ec29 100644
--- a/Kernel/Net/IPv4Socket.cpp
+++ b/Kernel/Net/IPv4Socket.cpp
@@ -312,7 +312,8 @@ KResultOr<size_t> IPv4Socket::receive_packet_buffered(OpenFileDescription& descr
                 m_receive_queue.size());
         }
     }
-    if (!packet->data) {
+
+    if (!packet) {
         if (protocol_is_disconnected()) {
             dbgln("IPv4Socket({}) is protocol-disconnected, returning 0 in recvfrom!", this);
             return 0;