avcodec/pngdec: Fix off by 1 size in decode_zbuf()

Fixes out of array access
Fixes: 444/fuzz-2-ffmpeg_VIDEO_AV_CODEC_ID_PNG_fuzzer

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/targets/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2017-01-23 01:25:27 +01:00
parent a0341b4d74
commit e371f031b9
1 changed files with 3 additions and 3 deletions

View File

@ -437,13 +437,13 @@ static int decode_zbuf(AVBPrint *bp, const uint8_t *data,
av_bprint_init(bp, 0, -1);
while (zstream.avail_in > 0) {
av_bprint_get_buffer(bp, 1, &buf, &buf_size);
if (!buf_size) {
av_bprint_get_buffer(bp, 2, &buf, &buf_size);
if (buf_size < 2) {
ret = AVERROR(ENOMEM);
goto fail;
}
zstream.next_out = buf;
zstream.avail_out = buf_size;
zstream.avail_out = buf_size - 1;
ret = inflate(&zstream, Z_PARTIAL_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END) {
ret = AVERROR_EXTERNAL;