[FFmpeg-devel] [PATCH 4/4] avcodec/vqcdec: Check for end of input in decode_vectors()
Peter Ross
pross at xvid.org
Sat Nov 19 01:03:08 EET 2022
On Fri, Nov 18, 2022 at 10:09:18PM +0100, Michael Niedermayer wrote:
> Fixes: Timeout
> Fixes: 52695/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VQC_fuzzer-4882310386548736
>
> 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/vqcdec.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/libavcodec/vqcdec.c b/libavcodec/vqcdec.c
> index 5d1a03158c..18cd99462e 100644
> --- a/libavcodec/vqcdec.c
> +++ b/libavcodec/vqcdec.c
> @@ -137,7 +137,7 @@ static void seed_codebooks(VqcContext * s, const int * seed)
> }
> }
>
> -static void decode_vectors(VqcContext * s, const uint8_t * buf, int size, int width, int height)
> +static int decode_vectors(VqcContext * s, const uint8_t * buf, int size, int width, int height)
> {
> GetBitContext gb;
> uint8_t * vectors = s->vectors;
> @@ -155,9 +155,11 @@ static void decode_vectors(VqcContext * s, const uint8_t * buf, int size, int wi
> *dst++ = get_bits(&gb, 8);
>
> while (show_bits(&gb, 2) != 2) {
> -
> if (dst >= vectors_end - 1)
> - return;
> + return 0;
> +
> + if (get_bits_left(&gb) < 4)
> + return AVERROR_INVALIDDATA;
>
> if (!show_bits(&gb, 4)) {
> *dst++ = 0;
> @@ -182,6 +184,8 @@ static void decode_vectors(VqcContext * s, const uint8_t * buf, int size, int wi
> skip_bits(&gb, 2);
> vectors += 32;
> }
> +
> + return 0;
> }
>
> static void load_coeffs(VqcContext * s, const uint8_t * v, int width, int coeff_width)
> @@ -392,7 +396,9 @@ static int vqc_decode_frame(AVCodecContext *avctx, AVFrame * rframe,
> avpriv_request_sample(avctx, "gamma=0x%x, contrast=0x%x\n", gamma, contrast);
>
> seed_codebooks(s, seed);
> - decode_vectors(s, buf + 7, avpkt->size - 7, avctx->width, avctx->height);
> + ret = decode_vectors(s, buf + 7, avpkt->size - 7, avctx->width, avctx->height);
> + if (ret < 0)
> + return ret;
> decode_frame(s, avctx->width, avctx->height);
please apply
-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20221119/bfc82e06/attachment.sig>
More information about the ffmpeg-devel
mailing list