[FFmpeg-cvslog] avcodec/jpeg2000dec: clear pointer which become stale in get_ppt()

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun May 31 12:49:50 2020 +0200| [4b2248594c7faf1530c43e662c4b80655240b269] | committer: Michael Niedermayer

avcodec/jpeg2000dec: clear pointer which become stale in get_ppt()

Fixes: use after free
Fixes: 22484/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_fuzzer-5671488765296640

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Gautam Ramakrishnan <gautamramk at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4b2248594c7faf1530c43e662c4b80655240b269
---

 libavcodec/jpeg2000dec.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 65555424ed..b7766459c4 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -928,6 +928,7 @@ static int get_ppt(Jpeg2000DecoderContext *s, int n)
         tile->packed_headers = new;
     } else
         return AVERROR(ENOMEM);
+    memset(&tile->packed_headers_stream, 0, sizeof(tile->packed_headers_stream));
     memcpy(tile->packed_headers + tile->packed_headers_size,
            s->g.buffer, n - 3);
     tile->packed_headers_size += n - 3;