From 2e312791d6a4da2bb543f7dbbc98a37a32029717 Mon Sep 17 00:00:00 2001 From: Kevin Chyn Date: Thu, 18 Jul 2019 13:37:23 -0700 Subject: [PATCH] Biometric HAL death should invoke handleError on the handler All client lifecycle is modified on the handler. When the HAL dies, serviceDied comes in on the main thread and will race with the rest of client lifecycle manipulation. We need to guarantee this is in order, otherwise it's possible for BiometricService to receive the following order of events 1) BiometricService requests auth 2) Face/FingerprintService is ready to start auth 3) HAL dies in the middle of 2), and sends onError to BiometricService 4) onReadyForAuthentication is sent to BiometricService, causing NPE With this change, it will guarantee that 3) occurs after 4), which will avoid A) BiometricService receiving events out of order, and more importantly B) allow BiometricPrompt to show the HW_UNAVAILABLE error instead of crashing system server. Fixes: 137800315 Test: Authentication with BiometricPromptDemo while killing the HAL Change-Id: Iae2d5b39dd494123f274b47edcc44c3afc1fff8c --- .../android/server/biometrics/BiometricServiceBase.java | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/services/core/java/com/android/server/biometrics/BiometricServiceBase.java b/services/core/java/com/android/server/biometrics/BiometricServiceBase.java index f08423eb2016c..20eb6180832ca 100644 --- a/services/core/java/com/android/server/biometrics/BiometricServiceBase.java +++ b/services/core/java/com/android/server/biometrics/BiometricServiceBase.java @@ -665,8 +665,12 @@ public abstract class BiometricServiceBase extends SystemService mMetricsLogger.count(getConstants().tagHalDied(), 1); mHALDeathCount++; mCurrentUserId = UserHandle.USER_NULL; - handleError(getHalDeviceId(), BiometricConstants.BIOMETRIC_ERROR_HW_UNAVAILABLE, - 0 /*vendorCode */); + + // All client lifecycle must be managed on the handler. + mHandler.post(() -> { + handleError(getHalDeviceId(), BiometricConstants.BIOMETRIC_ERROR_HW_UNAVAILABLE, + 0 /*vendorCode */); + }); StatsLog.write(StatsLog.BIOMETRIC_SYSTEM_HEALTH_ISSUE_DETECTED, statsModality(), BiometricsProtoEnums.ISSUE_HAL_DEATH);