Fixed crash issue if no link file binary data for shader. Signed-off-by: Furong Zhang <furong.zhang@intel.com>

diff --git a/media_driver/agnostic/common/vp/hal/vphal_common.h b/media_driver/agnostic/common/vp/hal/vphal_common.h
index d242e47..67e8241 100644
--- a/media_driver/agnostic/common/vp/hal/vphal_common.h
+++ b/media_driver/agnostic/common/vp/hal/vphal_common.h

@@ -546,7 +546,7 @@
 
 typedef enum _VPHAL_SCALING_PREFERENCE
 {
-    VPHAL_SCALING_PREFER_SFC,          // SFC is default
+    VPHAL_SCALING_PREFER_SFC = 0,          // SFC is default
     VPHAL_SCALING_PREFER_COMP,         // For Gen9/10, Composition AVS get better quality than SFC AVS
     VPHAL_SCALING_PREFER_SFC_FOR_VEBOX // if VEBOX is required, use VEBOX + SFC, otherwise use Composistion
 } VPHAL_SCALING_PREFERENCE;

diff --git a/media_driver/agnostic/common/vp/hal/vphal_renderer.cpp b/media_driver/agnostic/common/vp/hal/vphal_renderer.cpp
index 713e987..d7b6d16 100644
--- a/media_driver/agnostic/common/vp/hal/vphal_renderer.cpp
+++ b/media_driver/agnostic/common/vp/hal/vphal_renderer.cpp

@@ -1420,6 +1420,7 @@
                                             m_modifyKdllFunctionPointers);
     if (!pKernelDllState)
     {
+        eStatus = MOS_STATUS_NULL_POINTER;
         VPHAL_RENDER_ASSERTMESSAGE("Failed to allocate KDLL state.");
         goto finish;
     }

diff --git a/media_driver/agnostic/common/vp/kdll/hal_kerneldll.c b/media_driver/agnostic/common/vp/kdll/hal_kerneldll.c
index 5baec43..b763eaf 100644
--- a/media_driver/agnostic/common/vp/kdll/hal_kerneldll.c
+++ b/media_driver/agnostic/common/vp/kdll/hal_kerneldll.c

@@ -3347,7 +3347,8 @@
 
     // Get link file binary data
     pLinkHeader = (Kdll_LinkFileHeader *) pCacheEntry[IDR_VP_LinkFile].pBinary;
-    if (pLinkHeader->dwVersion != IDR_VP_LINKFILE_VERSION ||
+    if (pLinkHeader == nullptr ||
+        pLinkHeader->dwVersion != IDR_VP_LINKFILE_VERSION ||
         sizeof(Kdll_LinkFileHeader) != IDR_VP_LINKFILE_HEADER)
     {
         VPHAL_RENDER_ASSERTMESSAGE("Invalid link file version.");