From 09180fde374270382ef41fca75a0cec65d8a9571 Mon Sep 17 00:00:00 2001
From: Weizhen Wang <wangweizhen@pingcap.com>
Date: Mon, 5 Sep 2022 20:08:55 +0800
Subject: [PATCH] planner: fix show View Privilege behave for view table
 (#37343)

close pingcap/tidb#34326
---
 executor/explain_test.go             | 20 ++++++++++++++++++++
 planner/core/logical_plan_builder.go | 15 ++++++++++++---
 sessionctx/stmtctx/stmtctx.go        |  1 +
 3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/executor/explain_test.go b/executor/explain_test.go
index a05c0e044249c..4899f8a354403 100644
--- a/executor/explain_test.go
+++ b/executor/explain_test.go
@@ -24,6 +24,7 @@ import (
 	"time"
 
 	"github.com/pingcap/tidb/config"
+	"github.com/pingcap/tidb/errno"
 	"github.com/pingcap/tidb/parser/auth"
 	plannercore "github.com/pingcap/tidb/planner/core"
 	"github.com/pingcap/tidb/session"
@@ -66,6 +67,25 @@ func TestExplainPrivileges(t *testing.T) {
 
 	err = tk1.ExecToErr("explain format = 'brief' select * from v")
 	require.Equal(t, plannercore.ErrTableaccessDenied.GenWithStackByArgs("SELECT", "explain", "%", "v").Error(), err.Error())
+
+	// https://github.com/pingcap/tidb/issues/34326
+	tk.MustExec("create table t1 (i int)")
+	tk.MustExec("create table t2 (j int)")
+	tk.MustExec("create table t3 (k int, secret int)")
+
+	tk.MustExec("create view v1 as select * from t1")
+	tk.MustExec("create view v2 as select * from v1, t2")
+	tk.MustExec("create view v3 as select k from t3")
+
+	tk.MustExec("grant select, show view on explaindatabase.v2 to 'explain'@'%'")
+	tk.MustExec("grant         show view on explaindatabase.v1 to 'explain'@'%'")
+	tk.MustExec("grant select, show view on explaindatabase.t3 to 'explain'@'%'")
+	tk.MustExec("grant select, show view on explaindatabase.v3 to 'explain'@'%'")
+
+	tk1.MustGetErrMsg("explain select * from v1", "[planner:1142]SELECT command denied to user 'explain'@'%' for table 'v1'")
+	tk1.MustGetErrCode("explain select * from v2", errno.ErrViewNoExplain)
+	tk1.MustQuery("explain select * from t3")
+	tk1.MustQuery("explain select * from v3")
 }
 
 func TestExplainCartesianJoin(t *testing.T) {
diff --git a/planner/core/logical_plan_builder.go b/planner/core/logical_plan_builder.go
index 50b555db9ad04..e57d951959054 100644
--- a/planner/core/logical_plan_builder.go
+++ b/planner/core/logical_plan_builder.go
@@ -4874,6 +4874,8 @@ func (b *PlanBuilder) checkRecursiveView(dbName model.CIStr, tableName model.CIS
 
 // BuildDataSourceFromView is used to build LogicalPlan from view
 func (b *PlanBuilder) BuildDataSourceFromView(ctx context.Context, dbName model.CIStr, tableInfo *model.TableInfo) (LogicalPlan, error) {
+	viewDepth := b.ctx.GetSessionVars().StmtCtx.ViewDepth
+	b.ctx.GetSessionVars().StmtCtx.ViewDepth++
 	deferFunc, err := b.checkRecursiveView(dbName, tableInfo.Name)
 	if err != nil {
 		return nil, err
@@ -4912,14 +4914,21 @@ func (b *PlanBuilder) BuildDataSourceFromView(ctx context.Context, dbName model.
 			terror.ErrorNotEqual(err, ErrNoSuchTable) &&
 			terror.ErrorNotEqual(err, ErrInternal) &&
 			terror.ErrorNotEqual(err, ErrFieldNotInGroupBy) &&
-			terror.ErrorNotEqual(err, ErrMixOfGroupFuncAndFields) {
+			terror.ErrorNotEqual(err, ErrMixOfGroupFuncAndFields) &&
+			terror.ErrorNotEqual(err, ErrViewNoExplain) {
 			err = ErrViewInvalid.GenWithStackByArgs(dbName.O, tableInfo.Name.O)
 		}
 		return nil, err
 	}
-
+	pm := privilege.GetPrivilegeManager(b.ctx)
+	if viewDepth != 0 &&
+		b.ctx.GetSessionVars().StmtCtx.InExplainStmt &&
+		pm != nil &&
+		!pm.RequestVerification(b.ctx.GetSessionVars().ActiveRoles, dbName.L, tableInfo.Name.L, "", mysql.SelectPriv) {
+		return nil, ErrViewNoExplain
+	}
 	if tableInfo.View.Security == model.SecurityDefiner {
-		if pm := privilege.GetPrivilegeManager(b.ctx); pm != nil {
+		if pm != nil {
 			for _, v := range b.visitInfo {
 				if !pm.RequestVerificationWithUser(v.db, v.table, v.column, v.privilege, tableInfo.View.Definer) {
 					return nil, ErrViewInvalid.GenWithStackByArgs(dbName.O, tableInfo.Name.O)
diff --git a/sessionctx/stmtctx/stmtctx.go b/sessionctx/stmtctx/stmtctx.go
index 7a290b264edc9..18945a9e5fb81 100644
--- a/sessionctx/stmtctx/stmtctx.go
+++ b/sessionctx/stmtctx/stmtctx.go
@@ -145,6 +145,7 @@ type StatementContext struct {
 	// in stmtCtx
 	IsStaleness     bool
 	InRestrictedSQL bool
+	ViewDepth       int32
 	// mu struct holds variables that change during execution.
 	mu struct {
 		sync.Mutex