Avoid buffer over-read in AEC2 by zeroing memory instead of copying.

Set memory to all-zero floats in ExtractExtendedBlock in AEC2 if buffer is empty.

This avoids a memcopy call which may corrupt audio handling and, in rare cases, crash WebRTC with a buffer over-read.

BUG=webrtc:7845
Review-Url: https://codereview.webrtc.org/2980723002
Cr-Commit-Position: refs/heads/master@{#18984}
Committed: https://chromium.googlesource.com/external/webrtc/+/f91b0b49f911a3c3996b19e7e6b31f5e982af650

[saza WebRTC, 2017-07-12 07:51:12]

Description was changed from

==========
Set memory to 0 in ExtractExtendedBlock if buffer is empty.

BUG=
==========

to

==========
Set memory to 0 in ExtractExtendedBlock if buffer is empty.

BUG=7845
==========

[saza WebRTC, 2017-07-12 07:51:13]

saza@webrtc.org changed reviewers:
+ peah@chromium.org

[saza WebRTC, 2017-07-12 08:09:22]

Description was changed from

==========
Set memory to 0 in ExtractExtendedBlock if buffer is empty.

BUG=7845
==========

to

==========
Set memory to all-zero floats in ExtractExtendedBlock in AEC2 if buffer is
empty.

This avoids a memcopy call which may corrupt audio handling and, in rare cases,
crash WebRTC with a buffer over-read.

BUG=webrtc:7845
==========

[saza WebRTC, 2017-07-12 08:09:40]

ptal

[peah-webrtc, 2017-07-12 08:13:09]

peah@webrtc.org changed reviewers:
+ peah@webrtc.org

[peah-webrtc, 2017-07-12 08:13:09]

Awesome!
lgtm

[saza WebRTC, 2017-07-12 08:17:56]

The CQ bit was checked by saza@webrtc.org

[commit-bot: I haz the power, 2017-07-12 08:18:04]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.webrtc.org/...

[commit-bot: I haz the power, 2017-07-12 08:43:17]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1499847476689900, "parent_rev":
"10b0d0367346419cce329a4a4ba198e22a4d7015", "commit_rev":
"f91b0b49f911a3c3996b19e7e6b31f5e982af650"}

[commit-bot: I haz the power, 2017-07-12 08:43:21]

Description was changed from

==========
Set memory to all-zero floats in ExtractExtendedBlock in AEC2 if buffer is
empty.

This avoids a memcopy call which may corrupt audio handling and, in rare cases,
crash WebRTC with a buffer over-read.

BUG=webrtc:7845
==========

to

==========
Set memory to all-zero floats in ExtractExtendedBlock in AEC2 if buffer is
empty.

This avoids a memcopy call which may corrupt audio handling and, in rare cases,
crash WebRTC with a buffer over-read.

BUG=webrtc:7845

Review-Url: https://codereview.webrtc.org/2980723002
Cr-Commit-Position: refs/heads/master@{#18984}
Committed:
https://chromium.googlesource.com/external/webrtc/+/f91b0b49f911a3c3996b19e7e...
==========

[commit-bot: I haz the power, 2017-07-12 08:43:22]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/external/webrtc/+/f91b0b49f911a3c3996b19e7e...