From 888c4a0117bfa9753ac4b1ffd1ea81c09867e335 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?colin=20axn=C3=A9r?=
 <25233464+colin-axner@users.noreply.github.com>
Date: Tue, 20 Sep 2022 15:32:30 +0200
Subject: [PATCH] fix: add nil checks for controller and host keeper services
 (#2308)

## Description



closes: #XXXX

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

- [ ] Targeted PR against correct branch (see [CONTRIBUTING.md](https://github.com/cosmos/ibc-go/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
- [ ] Code follows the [module structure standards](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules/structure.md).
- [ ] Wrote unit and integration [tests](https://github.com/cosmos/ibc-go/blob/master/CONTRIBUTING.md#testing)
- [ ] Updated relevant documentation (`docs/`) or specification (`x/<module>/spec/`)
- [ ] Added relevant `godoc` [comments](https://blog.golang.org/godoc-documenting-go-code).
- [ ] Added a relevant changelog entry to the `Unreleased` section in `CHANGELOG.md`
- [ ] Re-reviewed `Files changed` in the Github PR explorer
- [ ] Review `Codecov Report` in the comment section below once CI passes
---
 CHANGELOG.md                                  |  1 +
 .../controller/keeper/migrations.go           | 26 ++++++++++---------
 modules/apps/27-interchain-accounts/module.go | 12 ++++++---
 3 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5c555e6e586..2b281b590a7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -105,6 +105,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Bug Fixes
 
+* (27-interchain-accounts) [\#2308](https://github.com/cosmos/ibc-go/pull/2308) Nil checks have been added to ensure services are not registered for nil host or controller keepers.
 * (makefile) [\#1785](https://github.com/cosmos/ibc-go/pull/1785) Fetch the correct versions of protocol buffers dependencies from tendermint, cosmos-sdk, and ics23.
 * (light-clients/solomachine) [#1839](https://github.com/cosmos/ibc-go/issues/1839) Fixed usage of the new diversifier in validation of changing diversifiers for the solo machine. The current diversifier must sign over the new diversifier.
 * (light-clients/07-tendermint) [\#1674](https://github.com/cosmos/ibc-go/pull/1674) Submitted ClientState is zeroed out before checking the proof in order to prevent the proposal from containing information governance is not actually voting on.
diff --git a/modules/apps/27-interchain-accounts/controller/keeper/migrations.go b/modules/apps/27-interchain-accounts/controller/keeper/migrations.go
index ffe86e9f6e7..f5a28bcf4aa 100644
--- a/modules/apps/27-interchain-accounts/controller/keeper/migrations.go
+++ b/modules/apps/27-interchain-accounts/controller/keeper/migrations.go
@@ -22,19 +22,21 @@ func NewMigrator(keeper *Keeper) Migrator {
 // AssertChannelCapabilityMigrations checks that all channel capabilities generated using the interchain accounts controller port prefix
 // are owned by the controller submodule and ibc.
 func (m Migrator) AssertChannelCapabilityMigrations(ctx sdk.Context) error {
-	for _, ch := range m.keeper.GetAllActiveChannels(ctx) {
-		name := host.ChannelCapabilityPath(ch.PortId, ch.ChannelId)
-		cap, found := m.keeper.scopedKeeper.GetCapability(ctx, name)
-		if !found {
-			return sdkerrors.Wrapf(capabilitytypes.ErrCapabilityNotFound, "failed to find capability: %s", name)
+	if m.keeper != nil {
+		for _, ch := range m.keeper.GetAllActiveChannels(ctx) {
+			name := host.ChannelCapabilityPath(ch.PortId, ch.ChannelId)
+			cap, found := m.keeper.scopedKeeper.GetCapability(ctx, name)
+			if !found {
+				return sdkerrors.Wrapf(capabilitytypes.ErrCapabilityNotFound, "failed to find capability: %s", name)
+			}
+
+			isAuthenticated := m.keeper.scopedKeeper.AuthenticateCapability(ctx, cap, name)
+			if !isAuthenticated {
+				return sdkerrors.Wrapf(capabilitytypes.ErrCapabilityNotOwned, "expected capability owner: %s", types.SubModuleName)
+			}
+
+			m.keeper.SetMiddlewareEnabled(ctx, ch.PortId, ch.ChannelId)
 		}
-
-		isAuthenticated := m.keeper.scopedKeeper.AuthenticateCapability(ctx, cap, name)
-		if !isAuthenticated {
-			return sdkerrors.Wrapf(capabilitytypes.ErrCapabilityNotOwned, "expected capability owner: %s", types.SubModuleName)
-		}
-
-		m.keeper.SetMiddlewareEnabled(ctx, ch.PortId, ch.ChannelId)
 	}
 
 	return nil
diff --git a/modules/apps/27-interchain-accounts/module.go b/modules/apps/27-interchain-accounts/module.go
index 616de1a4a3b..37b92577c6d 100644
--- a/modules/apps/27-interchain-accounts/module.go
+++ b/modules/apps/27-interchain-accounts/module.go
@@ -76,6 +76,7 @@ func (AppModuleBasic) RegisterGRPCGatewayRoutes(clientCtx client.Context, mux *r
 	if err != nil {
 		panic(err)
 	}
+
 	err = hosttypes.RegisterQueryHandlerClient(context.Background(), mux, hosttypes.NewQueryClient(clientCtx))
 	if err != nil {
 		panic(err)
@@ -150,9 +151,14 @@ func (am AppModule) LegacyQuerierHandler(legacyQuerierCdc *codec.LegacyAmino) sd
 
 // RegisterServices registers module services
 func (am AppModule) RegisterServices(cfg module.Configurator) {
-	controllertypes.RegisterMsgServer(cfg.MsgServer(), controllerkeeper.NewMsgServerImpl(am.controllerKeeper))
-	controllertypes.RegisterQueryServer(cfg.QueryServer(), am.controllerKeeper)
-	hosttypes.RegisterQueryServer(cfg.QueryServer(), am.hostKeeper)
+	if am.controllerKeeper != nil {
+		controllertypes.RegisterMsgServer(cfg.MsgServer(), controllerkeeper.NewMsgServerImpl(am.controllerKeeper))
+		controllertypes.RegisterQueryServer(cfg.QueryServer(), am.controllerKeeper)
+	}
+
+	if am.hostKeeper != nil {
+		hosttypes.RegisterQueryServer(cfg.QueryServer(), am.hostKeeper)
+	}
 
 	m := controllerkeeper.NewMigrator(am.controllerKeeper)
 	if err := cfg.RegisterMigration(types.ModuleName, 1, m.AssertChannelCapabilityMigrations); err != nil {