diff --git a/client/server/server.go b/client/server/server.go index d1dafa518..de6870ff2 100644 --- a/client/server/server.go +++ b/client/server/server.go @@ -2634,6 +2634,15 @@ func (s *Server) authorizeAndPrepareLogin(callerCtx context.Context, msg *proto. return nil, nil, err } + // The update-settings decision is re-taken here for the same reason as the + // privilege one: Login's earlier check ran outside this lock, so the stored + // config it compared against could have moved since. This one is the + // authoritative check, and it is the last read before persistLoginOverrides + // writes. + if s.checkUpdateSettingsDisabled() && configChangeRequested(stored, loginOverridesInput(msg)) { + return nil, nil, gstatus.Errorf(codes.Unavailable, errUpdateSettingsDisabled) + } + s.mutex.Lock() if s.actCancel != nil { s.actCancel() diff --git a/client/server/update_settings_gate_test.go b/client/server/update_settings_gate_test.go index 2972ec415..d9dc41b13 100644 --- a/client/server/update_settings_gate_test.go +++ b/client/server/update_settings_gate_test.go @@ -292,3 +292,52 @@ func TestLogin_RestatingTheStoredConfigPassesTheGate(t *testing.T) { "the gate refused a login that changes nothing: %v", err) } } + +// The value-aware decision has the same synchronization problem as the +// privileged-change one: Login's first check runs outside guardedConfigMu, so +// the stored config it compared against can move before the write. A login that +// was a no-op when it was checked must not be written once it has become a +// change. +func TestLogin_ChangeThatAppearsMidRequestIsRefused(t *testing.T) { + s, _, _, username, _ := setupServerWithProfile(t) + s.updateSettingsDisabled = true + s.rootCtx = internal.CtxInitState(context.Background()) + + target := "moved-under-us" + targetPath := filepath.Join(profilemanager.DefaultConfigPathDir, target+".json") + _, err := profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{ + ConfigPath: targetPath, + ManagementURL: storedManagementURL, + }) + require.NoError(t, err) + + cancelled := false + s.actCancel = func() { cancelled = true } + + // Stand in for a concurrent writer that repoints the profile between the two + // checks, which is the interleaving the lock has to make safe. The login + // restates the URL the profile held when it was checked, so the first check + // sees a no-op and lets it through. + afterLoginPreCheck = func() { + _, err := profilemanager.UpdateOrCreateConfig(profilemanager.ConfigInput{ + ConfigPath: targetPath, + ManagementURL: "https://mgmt.elsewhere.example:443", + }) + require.NoError(t, err) + } + t.Cleanup(func() { afterLoginPreCheck = nil }) + + _, err = s.Login(userCtx(), &proto.LoginRequest{ + ProfileName: &target, + Username: &username, + ManagementUrl: storedManagementURL, + }) + require.Error(t, err, "the login became a settings change before it was written") + require.Equal(t, codes.Unavailable, gstatus.Code(err), "want the update-settings refusal, got %v", err) + require.False(t, cancelled, "the refused login cancelled the login already in progress") + + stored, err := profilemanager.PeekConfig(targetPath) + require.NoError(t, err) + require.Equal(t, "https://mgmt.elsewhere.example:443", stored.ManagementURL.String(), + "the refused login wrote the management URL it was asked for") +}