biometrics: fingerprint: add locking to default impl
There exists the following race condition:
a). thread A receives setNotify and sets the callback to some object
b). thread B of the wrapped implementation calls
BiometricsFingerprint::notify which it was given a handle to. Thread B
executes past the nullptr check:
c). thread A receives setNotify and sets the callback to some other
object (or nullptr)
d). thread B resumes in notify with unknown state
Add mutex to protect access to mClientCallback.
Change-Id: I9163204ff5802e9246056caeb2a7857e6138531c
Fixes: 64802340
Test: VtsHalBiometricsFingerprintV2_1IfaceFuzzer
diff --git a/biometrics/fingerprint/2.1/default/BiometricsFingerprint.h b/biometrics/fingerprint/2.1/default/BiometricsFingerprint.h
index 5923c84..6d64e3d 100644
--- a/biometrics/fingerprint/2.1/default/BiometricsFingerprint.h
+++ b/biometrics/fingerprint/2.1/default/BiometricsFingerprint.h
@@ -69,6 +69,7 @@
static FingerprintAcquiredInfo VendorAcquiredFilter(int32_t error, int32_t* vendorCode);
static BiometricsFingerprint* sInstance;
+ std::mutex mClientCallbackMutex;
sp<IBiometricsFingerprintClientCallback> mClientCallback;
fingerprint_device_t *mDevice;
};