avcodec/dxv: Check op_offset in dxv_decompress_yo()

Fixes: signed integer overflow: -2147483648 - 8 cannot be represented in type 'int'
Fixes: 17745/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DXV_fuzzer-5734628463214592

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 97450d2b6a)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2019-09-30 08:02:11 +02:00
parent 6f2723e54b
commit 3a40d5ab2f
1 changed files with 3 additions and 0 deletions

View File

@ -799,6 +799,9 @@ static int dxv_decompress_yo(DXVContext *ctx, GetByteContext *gb,
uint8_t *dst, *table0[256] = { 0 }, *table1[256] = { 0 };
int ret, state = 0, skip, oi = 0, v, vv;
if (op_offset < 8 || op_offset - 8 > bytestream2_get_bytes_left(gb))
return AVERROR_INVALIDDATA;
dst = tex_data;
bytestream2_skip(gb, op_offset - 8);
if (op_size > max_op_size)