File ffmpeg-CVE-2021-38171.patch of Package ffmpeg-4.27507

From 9ffa49496d1aae4cbbb387aac28a9e061a6ab0a6 Mon Sep 17 00:00:00 2001
From: maryam ebrahimzadeh <me22bee@outlook.com>
Date: Wed, 4 Aug 2021 16:15:18 -0400
Subject: [PATCH] avformat/adtsenc: return value check for init_get_bits in
 adts_decode_extradata

As the second argument for init_get_bits (buf) can be crafted, a return value check for this function call is necessary.
'buf' is  part of  'AVPacket pkt'.
replace init_get_bits with init_get_bits8.

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavformat/adtsenc.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libavformat/adtsenc.c b/libavformat/adtsenc.c
index ba15c0a724..3924e678d9 100644
--- a/libavformat/adtsenc.c
+++ b/libavformat/adtsenc.c
@@ -53,9 +53,11 @@ static int adts_decode_extradata(AVFormatContext *s, ADTSContext *adts, const ui
     GetBitContext gb;
     PutBitContext pb;
     MPEG4AudioConfig m4ac;
-    int off;
+    int off, ret;
 
-    init_get_bits(&gb, buf, size * 8);
+    ret = init_get_bits8(&gb, buf, size);
+    if (ret < 0)
+        return ret;
     off = avpriv_mpeg4audio_get_config2(&m4ac, buf, size, 1, s);
     if (off < 0)
         return off;
-- 
2.33.0