From 4bdf24a689b52364a58cb7587b572a80515422b8 Mon Sep 17 00:00:00 2001 From: sungtae kim <sungtae@messagebird.com> Date: Sun, 3 Mar 2019 16:20:24 +0100 Subject: [PATCH] res/res_rtp_asterisk.c: Fixing possible divide by zero Currently, when the Asterisk calculates rtp statistics, it uses sample_count as a unsigned integer parameter. This would be fine for most of cases, but in case of large enough number of sample_count, this might be causing the divide by zero error. ASTERISK-28321 Change-Id: If7e0629abaceddd2166eb012456c53033ea26249 --- res/res_rtp_asterisk.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c index c5d557ec1e..909d82a816 100644 --- a/res/res_rtp_asterisk.c +++ b/res/res_rtp_asterisk.c @@ -2755,6 +2755,14 @@ static double normdev_compute(double normdev, double sample, unsigned int sample normdev = normdev * sample_count + sample; sample_count++; + /* + It's possible the sample_count hits the maximum value and back to 0. + Set to 1 to prevent the divide by zero crash if the sample_count is 0. + */ + if (sample_count == 0) { + sample_count = 1; + } + return normdev / sample_count; } @@ -2771,6 +2779,14 @@ static double stddev_compute(double stddev, double sample, double normdev, doubl stddev = sample_count * stddev; sample_count++; + /* + It's possible the sample_count hits the maximum value and back to 0. + Set to 1 to prevent the divide by zero crash if the sample_count is 0. + */ + if (sample_count == 0) { + sample_count = 1; + } + return stddev + ( sample_count * SQUARE( (sample - normdev) / sample_count ) ) + ( SQUARE(sample - normdev_curent) / sample_count ); -- GitLab