avcodec/lagarith: Sanity check scale

A value of 24 and above can collaps the range to 0 which would not work.

Fixes: Timeout (75sec -> 21sec)
Fixes: 18707/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_LAGARITH_fuzzer-5708950892969984

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit fb3855342b)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2020-01-28 20:12:25 +01:00
parent d75d754b84
commit c4dccb509d
1 changed files with 3 additions and 0 deletions

View File

@ -226,6 +226,9 @@ static int lag_read_prob_header(lag_rac *rac, GetBitContext *gb)
}
}
if (scale_factor > 23)
return AVERROR_INVALIDDATA;
rac->scale = scale_factor;
/* Fill probability array with cumulative probability for each symbol. */