From 1603661523e37940ec98e320e631886fca48fd87 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michael@niedermayer.cc>
Date: Tue, 18 Jun 2019 23:55:56 +0200
Subject: [PATCH] avcodec/utils: Check bits_per_coded_sample

This avoids the need for each decoder separately having to handle this case

Fixes: shift exponent -100663046 is negative
Fixes: out of array access
Fixes: 15270/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_IFF_ILBM_fuzzer-5727829913763840

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit d33414d2ad27a5d2193c9ab0948ba7a282c2f910)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/utils.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 1661d48b90..e82cb43dbb 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -958,6 +958,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
             ret = AVERROR(EINVAL);
             goto free_and_end;
         }
+        if (avctx->bits_per_coded_sample < 0) {
+            ret = AVERROR(EINVAL);
+            goto free_and_end;
+        }
         if (avctx->sub_charenc) {
             if (avctx->codec_type != AVMEDIA_TYPE_SUBTITLE) {
                 av_log(avctx, AV_LOG_ERROR, "Character encoding is only "