diff --git a/src/core/common/message.cpp b/src/core/common/message.cpp
index ae623bc40..9c402022d 100644
--- a/src/core/common/message.cpp
+++ b/src/core/common/message.cpp
@@ -331,6 +331,8 @@ otError Message::SetLength(uint16_t aLength)
     uint16_t totalLengthCurrent = GetReserved() + GetLength();
     int      bufs               = 0;
 
+    VerifyOrExit(totalLengthRequest >= GetReserved(), error = OT_ERROR_INVALID_ARGS);
+
     if (totalLengthRequest > kHeadBufferDataSize)
     {
         bufs = (((totalLengthRequest - kHeadBufferDataSize) - 1) / kBufferDataSize) + 1;