[FFmpeg-devel] [PATCH 2/2] avcodec/tiff: Check bpp/bppcount for 0

[Andreas Rheinhardt]

Michael Niedermayer:
> Fixes: division by zero
> Fixes: 24253/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-6250318007107584
> 
> 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/tiff.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/tiff.c b/libavcodec/tiff.c
> index 18b327e800..5c748e9650 100644
> --- a/libavcodec/tiff.c
> +++ b/libavcodec/tiff.c
> @@ -1290,7 +1290,7 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
>          s->height = value;
>          break;
>      case TIFF_BPP:
> -        if (count > 5U) {
> +        if (count > 5 || count <= 0) {
>              av_log(s->avctx, AV_LOG_ERROR,
>                     "This format is not supported (bpp=%d, %d components)\n",
>                     value, count);
> @@ -1321,7 +1321,7 @@ static int tiff_decode_tag(TiffContext *s, AVFrame *frame)
>                     "Samples per pixel requires a single value, many provided\n");
>              return AVERROR_INVALIDDATA;
>          }
> -        if (value > 5U) {
> +        if (value > 5 || value <= 0) {
>              av_log(s->avctx, AV_LOG_ERROR,
>                     "Samples per pixel %d is too large\n", value);

How about changing this to "Invalid samples per pixel %d\n"?

>              return AVERROR_INVALIDDATA;
>