avcodec/brenderpix: Check input size before allocating image

An incomplete image is not supported prior to this and will
not produce any output. This commit moves the failure before
time consuming operations.

Fixes: Timeout (81sec -> 76ms)
Fixes: 15723/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BRENDER_PIX_fuzzer-5147265653538816

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 38b6c48c43)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer
2019-07-26 14:16:16 +02:00
parent debbbb5ba6
commit 1b8026a23b

View File

@@ -204,6 +204,10 @@ static int pix_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
avpriv_request_sample(avctx, "Format %d", hdr.format);
return AVERROR_PATCHWELCOME;
}
bytes_per_scanline = bytes_pp * hdr.width;
if (bytestream2_get_bytes_left(&gb) < hdr.height * bytes_per_scanline)
return AVERROR_INVALIDDATA;
if ((ret = ff_set_dimensions(avctx, hdr.width, hdr.height)) < 0)
return ret;
@@ -261,7 +265,6 @@ static int pix_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
bytestream2_skip(&gb, 8);
// read the image data to the buffer
bytes_per_scanline = bytes_pp * hdr.width;
bytes_left = bytestream2_get_bytes_left(&gb);
if (chunk_type != IMAGE_DATA_CHUNK || data_len != bytes_left ||