avcodec/dxv: Check op_offset in both directions

Fixes: signed integer overflow: 61 + 2147483647 cannot be represented in type 'int'
Fixes: 15311/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DXV_fuzzer-5742552826773504

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-06-27 00:29:06 +02:00
parent c7c0229beb
commit 8c7d5fcfc3

View File

@ -745,7 +745,7 @@ static int dxv_decompress_cocg(DXVContext *ctx, GetByteContext *gb,
int skip0, skip1, oi0 = 0, oi1 = 0;
int ret, state0 = 0, state1 = 0;
if (op_offset < 12)
if (op_offset < 12 || op_offset - 12 > bytestream2_get_bytes_left(gb))
return AVERROR_INVALIDDATA;
dst = tex_data;