diff -up smartmontools-5.39.1/os_linux.cpp.megaraid smartmontools-5.39.1/os_linux.cpp
--- smartmontools-5.39.1/os_linux.cpp.megaraid	2010-01-28 21:24:32.000000000 +0100
+++ smartmontools-5.39.1/os_linux.cpp	2010-11-15 12:58:56.648181400 +0100
@@ -1095,17 +1095,21 @@ bool linux_megaraid_device::megasas_cmd(
   pthru->cdb_len = cdbLen;
   pthru->timeout = 0;
   pthru->flags = MFI_FRAME_DIR_READ;
-  pthru->sge_count = 1;
-  pthru->data_xfer_len = dataLen;
-  pthru->sgl.sge32[0].phys_addr = (intptr_t)data;
-  pthru->sgl.sge32[0].length = (uint32_t)dataLen;
+  if (dataLen > 0) {
+    pthru->sge_count = 1;
+    pthru->data_xfer_len = dataLen;
+    pthru->sgl.sge32[0].phys_addr = (intptr_t)data;
+    pthru->sgl.sge32[0].length = (uint32_t)dataLen;
+  }
   memcpy(pthru->cdb, cdb, cdbLen);
 
   uio.host_no = m_hba;
-  uio.sge_count = 1;
-  uio.sgl_off = offsetof(struct megasas_pthru_frame, sgl);
-  uio.sgl[0].iov_base = data;
-  uio.sgl[0].iov_len = dataLen;
+  if (dataLen > 0) {
+    uio.sge_count = 1;
+    uio.sgl_off = offsetof(struct megasas_pthru_frame, sgl);
+    uio.sgl[0].iov_base = data;
+    uio.sgl[0].iov_len = dataLen;
+  }
 
   rc = 0;
   errno = 0;