790503 - On Mac Mini, defaultCalibration reads outside of sensors[]

Status: RESOLVED FIXED

(Core :: Hardware Abstraction Layer (HAL), defect)

Description

[Jesse Ruderman]

Attachment: testcase

1. Build Firefox with Address Sanitizer.
  https://developer.mozilla.org/en-US/docs/Building_Firefox_with_Address_Sanitizer

2. Run Firefox on a Mac without a sudden motion sensor, such as a Mac Mini.
3. Load the testcase.

Result: ASan reports that defaultCalibration in smslib.mm reads past the end of sensors[].

After the loop in smsStartup finds no sensors, sensorNum is SENSOR_COUNT.  smsStartup returns |failure_result|, but EnableSensorNotifications ignores this return value.

Comment 1

[Jesse Ruderman]

Attachment: stack trace from ASan

Comment 2

[Jesse Ruderman]

Attachment: stack trace from gdb

Comment 3

[Doug Turner (:dougt)]

Attachment: patch v.1

I haven't tested/compiled this, but it should probably work.

Comment 4

[Jesse Ruderman]

Comment on attachment 660311 [details] [diff] [review]
patch v.1

This fixes the bug for me.  But I think you should get code review from a peer. And remove the trailing whitespace.

Comment 5

[Doug Turner (:dougt)]

Comment on attachment 660311 [details] [diff] [review]
patch v.1

Review of attachment 660311 [details] [diff] [review]:
-----------------------------------------------------------------

i'll get the whitespace before I check-in.

Comment 6

[Doug Turner (:dougt)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/bae96aa5f1ad

Comment 7

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/bae96aa5f1ad