mds: skip the buffer in UnknownPayload::decode()

If it receiving an unknown type of metric, it should skip the buffer
when dropping it. Or it will cause corruption.

Fixes: https://tracker.ceph.com/issues/49972
Signed-off-by: Xiubo Li <xiubli@redhat.com>
(cherry picked from commit fb782d4512be1ea130a5953f6067901a939e467d)

diff --git a/src/include/cephfs/metrics/Types.h b/src/include/cephfs/metrics/Types.h
index 3f2b642fdb3d54e9c16d736339796a20355b9958..5843a1ed0fb737e861e5ead9b8ff794452472f5b 100644 (file)
--- a/src/include/cephfs/metrics/Types.h
+++ b/src/include/cephfs/metrics/Types.h
@@ -367,6 +367,10 @@ struct UnknownPayload {
   }
 
   void decode(bufferlist::const_iterator &iter) {
+    using ceph::decode;
+    DECODE_START(254, iter);
+    iter.seek(struct_len);
+    DECODE_FINISH(iter);
   }
 
   void dump(Formatter *f) const {