core/rawdb: add sanity-limit to header accessor (#29534)

Author: holiman

core/rawdb/accessors_chain.go

@@ -316,8 +316,8 @@ func ReadHeaderRange(db ethdb.Reader, number uint64, count uint64) []rlp.RawValu
 	if count == 0 {
 		return rlpHeaders
 	}
-	// read remaining from ancients
-	data, err := db.AncientRange(ChainFreezerHeaderTable, i+1-count, count, 0)
+	// read remaining from ancients, cap at 2M
+	data, err := db.AncientRange(ChainFreezerHeaderTable, i+1-count, count, 2*1024*1024)
 	if err != nil {
 		log.Error("Failed to read headers from freezer", "err", err)
 		return rlpHeaders