From 0d472c19533a0c13ea8b79e84bcff49230179519 Mon Sep 17 00:00:00 2001
From: Antoine Poinsot <darosior@protonmail.com>
Date: Wed, 22 Jan 2025 11:49:33 -0500
Subject: [PATCH] fuzz: never return an uninitialized sockaddr in
 FuzzedSock::GetSockName

The fuzz provider's `ConsumeData` may return less data than necessary
to fill the sockaddr struct and still return success. Fix this to avoid
the caller using uninitialized memory.
---
 src/test/fuzz/util/net.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/test/fuzz/util/net.cpp b/src/test/fuzz/util/net.cpp
index a134e5ad4f7..669f4438717 100644
--- a/src/test/fuzz/util/net.cpp
+++ b/src/test/fuzz/util/net.cpp
@@ -357,7 +357,9 @@ int FuzzedSock::GetSockName(sockaddr* name, socklen_t* name_len) const
         SetFuzzedErrNo(m_fuzzed_data_provider, getsockname_errnos);
         return -1;
     }
+    assert(name_len);
     *name_len = m_fuzzed_data_provider.ConsumeData(name, *name_len);
+    if (*name_len < (int)sizeof(sockaddr)) return -1;
     return 0;
 }