YT-18571: fix UB in TryDeserializeProtoWithEnvelope()

commit_hash:f7f428c98fde0d9283df07abc1085a3bd4ba8c81

1 files changed, 3 insertions, 1 deletions

diff --git a/yt/yt/core/misc/protobuf_helpers.cpp b/yt/yt/core/misc/protobuf_helpers.cpp
index 2ed1448c919..62c0050cc2e 100644
--- a/yt/yt/core/misc/protobuf_helpers.cpp
+++ b/yt/yt/core/misc/protobuf_helpers.cpp
@@ -182,7 +182,9 @@ bool TryDeserializeProtoWithEnvelope(
         return false;
     }
 
-    const auto* fixedHeader = reinterpret_cast<const TEnvelopeFixedHeader*>(data.Begin());
+    TEnvelopeFixedHeader fixedHeaderStorage;
+    ::memcpy(&fixedHeaderStorage, data.Begin(), sizeof(fixedHeaderStorage));
+    const auto* fixedHeader = &fixedHeaderStorage;
     const char* sourceHeader = data.Begin() + sizeof(TEnvelopeFixedHeader);
     if (fixedHeader->EnvelopeSize + sizeof(*fixedHeader) > data.Size()) {
         return false;