From 361d24e6d920e4f7e4e5fa1fd6fbb6922bff35f2 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 11 Dec 2024 21:36:11 +0100 Subject: [PATCH] avformat/matroskadec: Check pre_ns for overflow Fixes: signed integer overflow: -3483479120376300096 - 7442323944145700864 cannot be represented in type 'long' Fixes: 383187489/clusterfuzz-testcase-minimized-ffmpeg_dem_WEBM_DASH_MANIFEST_fuzzer-4561470580391936 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/matroskadec.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index 0e150f9138..efa3e44c85 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -4618,9 +4618,10 @@ static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t // The prebuffer ends in the last Cue. Estimate how much data was // 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) + if (desc_end.end_time_ns <= desc_end.start_time_ns || + desc_end.end_time_ns - (uint64_t)desc_end.start_time_ns > INT64_MAX) return -1; + pre_ns = desc_end.end_time_ns - desc_end.start_time_ns; pre_sec = pre_ns / nano_seconds_per_second; prebuffer_bytes += pre_bytes * ((temp_prebuffer_ns / nano_seconds_per_second) / pre_sec);