avformat/jacosubdec: Use 64bit intermediate for start/end timestamp shift

Fixes: signed integer overflow: -1957694447 + -1620425806 cannot be represented in type 'int'
Fixes: 30207/clusterfuzz-testcase-minimized-ffmpeg_dem_JACOSUB_fuzzer-5050791771635712

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 2021-02-11 22:44:36 +01:00
parent b5d8fe1c87
commit 2c477be08a

View File

@ -125,8 +125,8 @@ static const char *read_ts(JACOsubContext *jacosub, const char *buf,
return NULL;
shift_and_ret:
ts_start64 = (ts_start + jacosub->shift) * 100LL / jacosub->timeres;
ts_end64 = (ts_end + jacosub->shift) * 100LL / jacosub->timeres;
ts_start64 = (ts_start + (int64_t)jacosub->shift) * 100LL / jacosub->timeres;
ts_end64 = (ts_end + (int64_t)jacosub->shift) * 100LL / jacosub->timeres;
*start = ts_start64;
*duration = ts_end64 - ts_start64;
return buf + len;