[FFmpeg-cvslog] avcodec/speexdec: Consider mode in frame size check

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Dec 26 11:18:51 2021 +0100| [d6b2357eddca392ee137cb2a92ff178a0a7d0cce] | committer: Michael Niedermayer

avcodec/speexdec: Consider mode in frame size check

No speex samples with non default frame sizes are known (to me)
the official speexenc seems to only generate the 3 default ones.
Thus it may be that the fuzzer samples where the first non default
values encountered by the decoder.
Possibly the "<" should be "!="

Fixes: out of array access
Fixes: 42821/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SPEEX_fuzzer-5640695772217344

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d6b2357eddca392ee137cb2a92ff178a0a7d0cce
---

 libavcodec/speexdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/speexdec.c b/libavcodec/speexdec.c
index 1c33607db2..dcbdf5e010 100644
--- a/libavcodec/speexdec.c
+++ b/libavcodec/speexdec.c
@@ -1419,7 +1419,7 @@ static int parse_speex_extradata(AVCodecContext *avctx,
         return AVERROR_INVALIDDATA;
     s->bitrate = bytestream_get_le32(&buf);
     s->frame_size = bytestream_get_le32(&buf);
-    if (s->frame_size < NB_FRAME_SIZE)
+    if (s->frame_size < NB_FRAME_SIZE << s->mode)
         return AVERROR_INVALIDDATA;
     s->vbr = bytestream_get_le32(&buf);
     s->frames_per_packet = bytestream_get_le32(&buf);