From fb3855342b9e4c577c63b38a7a5a574830a21934 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 28 Jan 2020 20:12:25 +0100 Subject: [PATCH] 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 --- libavcodec/lagarith.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c index 59169be5de..0a45812bc1 100644 --- a/libavcodec/lagarith.c +++ b/libavcodec/lagarith.c @@ -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. */ -- GitLab