From 29d968bd4cf5d17cddf02806b3d96049a6a7c463 Mon Sep 17 00:00:00 2001
From: Yash Patil <yash.patil@ittiam.com>
Date: Fri, 1 Sep 2023 16:04:23 +0530
Subject: [PATCH] Fix for undefined shift in ducker_apply

These changes handle the Undefined-shift
runtime error reported because value of Q factor
calculated was negative when denominator is zero in division operation.

Bug: ossFuzz:61698
Test: poc in bug
---
 decoder/ixheaacd_mps_decorr.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/decoder/ixheaacd_mps_decorr.c b/decoder/ixheaacd_mps_decorr.c
index 00a0271..5c0a55c 100644
--- a/decoder/ixheaacd_mps_decorr.c
+++ b/decoder/ixheaacd_mps_decorr.c
@@ -837,6 +837,9 @@ static VOID ixheaacd_ducker_apply(
       if (ixheaacd_mps_comp(temp3, temp_1, &qtemp, qtemp1)) {
         temp_2 = ixheaacd_mps_div_32(temp3, temp_1, &qtemp2);
         qtemp2 = qtemp2 + qtemp - qtemp1;
+        if (temp_1 == 0) {
+          qtemp2 = qtemp;
+        }
         temp3 = qtemp2 > 28 ? MAX_32 : 4 << qtemp2;
 
         if (temp_2 > temp3) {