ffmpeg: fix CVE-2021-38171

backport from upstream

(From OE-Core rev: 3cb40cabc79e4c9b4ffaf99543368b0c57d18df1)

Signed-off-by: Kiran Surendran <kiran.surendran@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-multimedia/ffmpeg/ffmpeg/fix-CVE-2021-38171.patch

@@ -0,0 +1,42 @@
+CVE: CVE-2021-38171
+Upstream-Status: Backport
+Signed-off-by: Kiran Surendran <kiran.surendran@windriver.com>
+
+From fb993619d1035fa9646506925ea70fb122038999 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>
+(cherry picked from commit 9ffa49496d1aae4cbbb387aac28a9e061a6ab0a6)
+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 3595cb3bb2..c35a12a628 100644
+--- a/libavformat/adtsenc.c
++++ b/libavformat/adtsenc.c
+@@ -51,9 +51,11 @@ 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;
+-- 
+2.31.1
+

meta/recipes-multimedia/ffmpeg/ffmpeg_4.4.bb

@@ -31,7 +31,8 @@ SRC_URI = "https://www.ffmpeg.org/releases/${BP}.tar.xz \
            file://fix-CVE-2020-22021.patch \
            file://fix-CVE-2020-22033-CVE-2020-22019.patch \
            file://fix-CVE-2021-33815.patch \
-           "
+           file://fix-CVE-2021-38171.patch \ 
+          "
 SRC_URI[sha256sum] = "06b10a183ce5371f915c6bb15b7b1fffbe046e8275099c96affc29e17645d909"
 
 # Build fails when thumb is enabled: https://bugzilla.yoctoproject.org/show_bug.cgi?id=7717