From f79f5a97bdc563c629c1a9a64e5ac00cf53f0ca9 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 13 Feb 2022 15:20:02 +0100 Subject: [PATCH] avformat/matroskadec: Check pre_ns Fixes: division by 0 Fixes: 44615/clusterfuzz-testcase-minimized-ffmpeg_dem_WEBM_DASH_MANIFEST_fuzzer-6681108677263360 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit 710e51677a6f3a5c2b37dc31a597957a22a5e531) Signed-off-by: Michael Niedermayer --- libavformat/matroskadec.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index a6c22b0483..cd168faa29 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -4064,6 +4064,8 @@ static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t // prebuffered. pre_bytes = desc_end.end_offset - desc_end.start_offset; pre_ns = desc_end.end_time_ns - desc_end.start_time_ns; + if (pre_ns <= 0) + return -1; pre_sec = pre_ns / nano_seconds_per_second; prebuffer_bytes += pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second) / pre_sec);