planner/core: fix nil pointer dereference tidb_decode_key() (#33018)

close #33015
pingcap · Mar 12, 2022 · b4c4b83 · b4c4b83
1 parent 5170f2f
commit b4c4b83
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Showing 2 changed files with 25 additions and 14 deletions.
diff --git a/expression/integration_test.go b/expression/integration_test.go
@@ -2816,7 +2816,7 @@ func TestTiDBDecodeKeyFunc(t *testing.T) {
 	result.Check(testkit.Rows("7480000000000000FF2E5F728000000011FFE1A3000000000000"))
 	warns := tk.Session().GetSessionVars().StmtCtx.GetWarnings()
 	require.Len(t, warns, 1)
-	require.Error(t, warns[0].Err, "invalid record/index key: 7480000000000000FF2E5F728000000011FFE1A3000000000000")
+	require.EqualError(t, warns[0].Err, "invalid key: 7480000000000000FF2E5F728000000011FFE1A3000000000000")
 
 	// Test in real tables.
 	tk.MustExec("use test;")
@@ -2879,10 +2879,15 @@ func TestTiDBDecodeKeyFunc(t *testing.T) {
 	result.Check(testkit.Rows(rs))
 
 	// https://github.com/pingcap/tidb/issues/27434.
-	hexKey = "7480000000000000375F69800000000000000103800000000001D4C1023B6458"
-	sql = fmt.Sprintf("select tidb_decode_key( '%s' )", hexKey)
+	hexKey = "7480000000000100375F69800000000000000103800000000001D4C1023B6458"
+	sql = fmt.Sprintf("select tidb_decode_key('%s')", hexKey)
 	tk.MustQuery(sql).Check(testkit.Rows(hexKey))
 
+	// https://github.com/pingcap/tidb/issues/33015.
+	hexKey = "74800000000000012B5F72800000000000A5D3"
+	sql = fmt.Sprintf("select tidb_decode_key('%s')", hexKey)
+	tk.MustQuery(sql).Check(testkit.Rows(`{"_tidb_rowid":42451,"table_id":"299"}`))
+
 	// Test the table with the nonclustered index.
 	const rowID = 10
 	tk.MustExec("drop table if exists t;")

diff --git a/planner/core/expression_rewriter.go b/planner/core/expression_rewriter.go
@@ -2043,9 +2043,10 @@ func hasCurrentDatetimeDefault(col *table.Column) bool {
 }
 
 func decodeKeyFromString(ctx sessionctx.Context, s string) string {
+	sc := ctx.GetSessionVars().StmtCtx
 	key, err := hex.DecodeString(s)
 	if err != nil {
-		ctx.GetSessionVars().StmtCtx.AppendWarning(errors.Errorf("invalid record/index key: %X", key))
+		sc.AppendWarning(errors.Errorf("invalid key: %X", key))
 		return s
 	}
 	// Auto decode byte if needed.
@@ -2055,39 +2056,44 @@ func decodeKeyFromString(ctx sessionctx.Context, s string) string {
 	}
 	tableID := tablecodec.DecodeTableID(key)
 	if tableID == 0 {
-		ctx.GetSessionVars().StmtCtx.AppendWarning(errors.Errorf("invalid record/index key: %X", key))
+		sc.AppendWarning(errors.Errorf("invalid key: %X", key))
 		return s
 	}
 	dm := domain.GetDomain(ctx)
 	if dm == nil {
-		ctx.GetSessionVars().StmtCtx.AppendWarning(errors.Errorf("domain not found when decoding record/index key: %X", key))
+		sc.AppendWarning(errors.Errorf("domain not found when decoding key: %X", key))
 		return s
 	}
-	tbl, _ := dm.InfoSchema().TableByID(tableID)
+	is := dm.InfoSchema()
+	if is == nil {
+		sc.AppendWarning(errors.Errorf("infoschema not found when decoding key: %X", key))
+		return s
+	}
+	tbl, _ := is.TableByID(tableID)
 	loc := ctx.GetSessionVars().Location()
 	if tablecodec.IsRecordKey(key) {
 		ret, err := decodeRecordKey(key, tableID, tbl, loc)
 		if err != nil {
-			ctx.GetSessionVars().StmtCtx.AppendWarning(err)
+			sc.AppendWarning(err)
 			return s
 		}
 		return ret
 	} else if tablecodec.IsIndexKey(key) {
 		ret, err := decodeIndexKey(key, tableID, tbl, loc)
 		if err != nil {
-			ctx.GetSessionVars().StmtCtx.AppendWarning(err)
+			sc.AppendWarning(err)
 			return s
 		}
 		return ret
 	} else if tablecodec.IsTableKey(key) {
-		ret, err := decodeTableKey(key, tableID, tbl, loc)
+		ret, err := decodeTableKey(key, tableID)
 		if err != nil {
-			ctx.GetSessionVars().StmtCtx.AppendWarning(err)
+			sc.AppendWarning(err)
 			return s
 		}
 		return ret
 	}
-	ctx.GetSessionVars().StmtCtx.AppendWarning(errors.Errorf("invalid record/index key: %X", key))
+	sc.AppendWarning(errors.Errorf("invalid key: %X", key))
 	return s
 }
 
@@ -2100,7 +2106,7 @@ func decodeRecordKey(key []byte, tableID int64, tbl table.Table, loc *time.Locat
 		ret := make(map[string]interface{})
 		ret["table_id"] = strconv.FormatInt(tableID, 10)
 		// When the clustered index is enabled, we should show the PK name.
-		if tbl.Meta().HasClusteredIndex() {
+		if tbl != nil && tbl.Meta().HasClusteredIndex() {
 			ret[tbl.Meta().GetPkName().String()] = handle.IntValue()
 		} else {
 			ret["_tidb_rowid"] = handle.IntValue()
@@ -2235,7 +2241,7 @@ func decodeIndexKey(key []byte, tableID int64, tbl table.Table, loc *time.Locati
 	return string(retStr), nil
 }
 
-func decodeTableKey(key []byte, tableID int64, tbl table.Table, loc *time.Location) (string, error) {
+func decodeTableKey(key []byte, tableID int64) (string, error) {
 	ret := map[string]int64{"table_id": tableID}
 	retStr, err := json.Marshal(ret)
 	if err != nil {