[FFmpeg-devel] [PATCH] avcodec/rscc: Check that the to be uncompressed input is large enough

[Michael Niedermayer]

On Sun, Mar 31, 2019 at 05:35:33PM +0200, Paul B Mahol wrote:
> On 3/31/19, Michael Niedermayer <michael at niedermayer.cc> wrote:
> > Fixes: Out of array access
> > Fixes:
> > 13984/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RSCC_fuzzer-5734128093233152
> >
> > Found-by: continuous fuzzing process
> > https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavcodec/rscc.c | 7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/libavcodec/rscc.c b/libavcodec/rscc.c
> > index 7d4e842cd3..4adee9d7d4 100644
> > --- a/libavcodec/rscc.c
> > +++ b/libavcodec/rscc.c
> > @@ -199,6 +199,13 @@ static int rscc_decode_frame(AVCodecContext *avctx,
> > void *data,
> >          /* If necessary, uncompress tiles, and hijack the bytestream reader
> > */
> >          if (packed_tiles_size != tiles_nb * TILE_SIZE) {
> >              uLongf length = tiles_nb * TILE_SIZE;
> > +
> > +            if (bytestream2_get_bytes_left(gbc) < packed_tiles_size) {
> > +                av_log(avctx, AV_LOG_ERROR, "compressed input
> > truncated\n");
> > +                ret = AVERROR_INVALIDDATA;
> > +                goto end;
> > +            }
> > +
> >              inflated_tiles = av_malloc(length);
> >              if (!inflated_tiles) {
> >                  ret = AVERROR(ENOMEM);
> > --
> > 2.21.0
> >
> > _______________________________________________
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> > ffmpeg-devel at ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> > To unsubscribe, visit link above, or email
> > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> 
> Please commit without log message.

if you prefer that, sure, will do.
this will be the only AVERROR_INVALIDDATA case in that file without a log
message though.

Thanks

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

It is dangerous to be right in matters on which the established authorities
are wrong. -- Voltaire
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