packages/net/fastd/patches/0003-receive-fix-buffer-leak-when-receiving-invalid-packe.patch

From f6a2651fa91c472d04cb34264718f761669c8aa1 Mon Sep 17 00:00:00 2001
Message-Id: <f6a2651fa91c472d04cb34264718f761669c8aa1.1603136280.git.mschiffer@universe-factory.net>
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Mon, 19 Oct 2020 21:08:16 +0200
Subject: [PATCH] receive: fix buffer leak when receiving invalid packets

For fastd versions before v20, this was just a memory leak (which could
still be used for DoS, as it's remotely triggerable). With the new
buffer management of fastd v20, this will trigger an assertion failure
instead as soon as the buffer pool is empty.

(cherry picked from commit 737925113363b6130879729cdff9ccc46c33eaea)
---
 src/receive.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/src/receive.c
+++ b/src/receive.c
@@ -186,6 +186,11 @@ static inline void handle_socket_receive
 
 	case PACKET_HANDSHAKE:
 		fastd_handshake_handle(sock, local_addr, remote_addr, peer, buffer);
+		break;
+
+	default:
+		fastd_buffer_free(buffer);
+		pr_debug("received packet with invalid type from %P[%I]", peer, remote_addr);
 	}
 }
 
@@ -211,6 +216,11 @@ static inline void handle_socket_receive
 
 	case PACKET_HANDSHAKE:
 		fastd_handshake_handle(sock, local_addr, remote_addr, NULL, buffer);
+		break;
+
+	default:
+		fastd_buffer_free(buffer);
+		pr_debug("received packet with invalid type from unknown address %I", remote_addr);
 	}
 }