avcodec/dnxhddec: Check dc vlc

Fixes: signed integer overflow: 1024 + 2147483640 cannot be represented in type 'int'
Fixes: 4671/clusterfuzz-testcase-minimized-6027464343027712

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>
This commit is contained in:
Michael Niedermayer 2018-01-03 23:42:00 +01:00
parent e425047a47
commit b2be76c0a4

View File

@ -383,6 +383,10 @@ static av_always_inline int dnxhd_decode_dct_block(const DNXHDContext *ctx,
UPDATE_CACHE(bs, &row->gb);
GET_VLC(len, bs, &row->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);
if (len < 0) {
ret = len;
goto error;
}
if (len) {
level = GET_CACHE(bs, &row->gb);
LAST_SKIP_BITS(bs, &row->gb, len);
@ -436,7 +440,7 @@ static av_always_inline int dnxhd_decode_dct_block(const DNXHDContext *ctx,
GET_VLC(index1, bs, &row->gb, ctx->ac_vlc.table,
DNXHD_VLC_BITS, 2);
}
error:
CLOSE_READER(bs, &row->gb);
return ret;
}