From 2227d801a5fab7c3018f54d5f0f82ac23267df11 Mon Sep 17 00:00:00 2001
From: tangcong <tangcong506@gmail.com>
Date: Wed, 20 May 2020 12:35:25 +0800
Subject: [PATCH] wal: fix crc mismatch crash bug

---
 wal/wal.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/wal/wal.go b/wal/wal.go
index 5d0be5585a69..0f6fe64cfd4c 100644
--- a/wal/wal.go
+++ b/wal/wal.go
@@ -567,6 +567,14 @@ func ValidSnapshotEntries(lg *zap.Logger, walDir string) ([]walpb.Snapshot, erro
 			snaps = append(snaps, loadedSnap)
 		case stateType:
 			state = mustUnmarshalState(rec.Data)
+		case crcType:
+			crc := decoder.crc.Sum32()
+			// current crc of decoder must match the crc of the record.
+			// do no need to match 0 crc, since the decoder is a new one at this case.
+			if crc != 0 && rec.Validate(crc) != nil {
+				return nil,ErrCRCMismatch
+			}
+			decoder.updateCRC(rec.Crc)
 		}
 	}
 	// We do not have to read out all the WAL entries