Added boundary check for array access as a short-term way of fixing the bug of out-of-bounds reads …

webrtc/modules/audio_processing/aec/aec_core.c

Index: webrtc/modules/audio_processing/aec/aec_core.c
diff --git a/webrtc/modules/audio_processing/aec/aec_core.c b/webrtc/modules/audio_processing/aec/aec_core.c
index 063201586ad48d7d3af34508c4d1874cb5363b8b..4c610220ee9d16f2bcc2e242675de126610fedb5 100644
--- a/webrtc/modules/audio_processing/aec/aec_core.c
+++ b/webrtc/modules/audio_processing/aec/aec_core.c
@@ -820,8 +820,11 @@ static void UpdateDelayMetrics(AecCore* self) {
   // negative (anti-causal system) or larger than the AEC filter length.
   {
     int num_delays_out_of_bounds = self->num_delay_values;
+    const int histogram_length = sizeof( self->delay_histogram ) /

[hlundin-webrtc, 2015/09/14 07:17:43]

No spaces inside parentheses. (3 places.)
http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Horizontal_Wh...

[peah-webrtc, 2015/09/14 07:27:19]

Acknowledged.

+      sizeof( self->delay_histogram[0] );
     for (i = lookahead; i < lookahead + self->num_partitions; ++i) {
-      num_delays_out_of_bounds -= self->delay_histogram[i];
+      if ( i < histogram_length )

[hlundin-webrtc, 2015/09/14 07:17:43]

Why not make this part of the loop criterion? Once i >= histogram_length, all
subsequent iterations in the loop will be no-op => might just as well exit the
loop.

[peah-webrtc, 2015/09/14 07:27:20]

Acknowledged.

+        num_delays_out_of_bounds -= self->delay_histogram[i];
     }
     self->fraction_poor_delays = (float)num_delays_out_of_bounds /
         self->num_delay_values;