[FFmpeg-cvslog] avcodec/mjpegdec: Only allow 0x11110000 pix_fmt_id for bayer mode

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Sep 12 21:02:17 2019 +0200| [2006e5ccb6db3d4fd97096d8a1d0ba18f708f5fe] | committer: Michael Niedermayer

avcodec/mjpegdec: Only allow 0x11110000 pix_fmt_id for bayer mode

Fixes: NULL pointer dereference
Fixes: assertion failure
Fixes: 17003/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MJPEG_fuzzer-5696929253556224
Fixes: 17039/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MJPEG_fuzzer-5651008134316032

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2006e5ccb6db3d4fd97096d8a1d0ba18f708f5fe
---

 libavcodec/mjpegdec.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 1f2fabe2df..5a80b7d289 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -501,6 +501,8 @@ int ff_mjpeg_decode_sof(MJpegDecodeContext *s)
 
         switch (pix_fmt_id) {
         case 0x11110000: /* for bayer-encoded huffman lossless JPEGs embedded in DNGs */
+            if (!s->bayer)
+                goto unk_pixfmt;
             s->avctx->pix_fmt = AV_PIX_FMT_GRAY16LE;
             break;
         case 0x11111100: