[FFmpeg-cvslog] avformat/iamf_parse: add missing padding to AAC extradata

[James Almer]

ffmpeg | branch: release/7.0 | James Almer <jamrial at gmail.com> | Mon Jun 17 21:47:50 2024 -0300| [29d626ea854c90c692e73b9e0fd88c0eaa9c7aaa] | committer: James Almer

avformat/iamf_parse: add missing padding to AAC extradata

Fixes: out of array access
Fixes: 68863/clusterfuzz-testcase-minimized-ffmpeg_dem_IAMF_fuzzer-4833546039525376

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: James Almer <jamrial at gmail.com>
(cherry picked from commit 0ae157b3603f27d8057febd8f2680ac1030722ee)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=29d626ea854c90c692e73b9e0fd88c0eaa9c7aaa
---

 libavformat/iamf_parse.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavformat/iamf_parse.c b/libavformat/iamf_parse.c
index fc7b0c5362..d52dec792b 100644
--- a/libavformat/iamf_parse.c
+++ b/libavformat/iamf_parse.c
@@ -92,13 +92,16 @@ static int aac_decoder_config(IAMFCodecConfig *codec_config,
     if (left <= 0)
         return AVERROR_INVALIDDATA;
 
-    codec_config->extradata = av_malloc(left);
+    // We pad extradata here because avpriv_mpeg4audio_get_config2() needs it.
+    codec_config->extradata = av_malloc((size_t)left + AV_INPUT_BUFFER_PADDING_SIZE);
     if (!codec_config->extradata)
         return AVERROR(ENOMEM);
 
     codec_config->extradata_size = avio_read(pb, codec_config->extradata, left);
     if (codec_config->extradata_size < left)
         return AVERROR_INVALIDDATA;
+    memset(codec_config->extradata + codec_config->extradata_size, 0,
+           AV_INPUT_BUFFER_PADDING_SIZE);
 
     ret = avpriv_mpeg4audio_get_config2(&cfg, codec_config->extradata,
                                         codec_config->extradata_size, 1, logctx);