[PATCH] MdeModulePkg/SdDxe: Potential NULL pointer on Token

["GuoMinJ" <newexplorerj@gmail.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2286

Token pointer may be NULL, it is should be check before use it.

Signed-off-by: GuoMinJ <newexplorerj@gmail.com>
---
 MdeModulePkg/Bus/Sd/SdDxe/SdBlockIo.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/MdeModulePkg/Bus/Sd/SdDxe/SdBlockIo.c b/MdeModulePkg/Bus/Sd/SdDxe/SdBlockIo.c
index 9f42abe7e2..25ab5abb2d 100644
--- a/MdeModulePkg/Bus/Sd/SdDxe/SdBlockIo.c
+++ b/MdeModulePkg/Bus/Sd/SdDxe/SdBlockIo.c
@@ -1367,7 +1367,12 @@ SdEraseBlocks (
     return Status;
   }
 
-  DEBUG ((EFI_D_ERROR, "SdEraseBlocks(): Lba 0x%x BlkNo 0x%x Event %p with %r\n", Lba, BlockNum, Token->Event, Status));
+  DEBUG ((DEBUG_ERROR, "SdEraseBlocks(): Lba 0x%x BlkNo 0x%x with %r, ", Lba, BlockNum, Status));
+  if ((Token != NULL) && (Token->Event != NULL)) {
+    DEBUG ((DEBUG_ERROR, "Event pointer is %p\n", Token->Event));
+  else {
+    DEBUG ((DEBUG_ERROR, "Event is meaningless\n"));
+  }
 
   return Status;
 }
-- 
2.17.1