From c4122406f6d2726aea833480a2a8e345833dd881 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 28 Jul 2024 22:08:23 +0200 Subject: [PATCH] avformat/matroskadec: Check desc_bytes so bits fit in 64bit Likely a tighter check can be done Fixes: signed integer overflow: 3305606804154370442 * 8 cannot be represented in type 'long' Fixes: 70449/clusterfuzz-testcase-minimized-ffmpeg_dem_WEBM_DASH_MANIFEST_fuzzer-4771166007918592 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavformat/matroskadec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c index c8741ff2af..a973b62756 100644 --- a/libavformat/matroskadec.c +++ b/libavformat/matroskadec.c @@ -4633,7 +4633,7 @@ static int64_t webm_dash_manifest_compute_bandwidth(AVFormatContext *s, int64_t int64_t desc_bytes = desc_end.end_offset - desc_beg.start_offset; int64_t desc_ns = desc_end.end_time_ns - desc_beg.start_time_ns; double desc_sec, calc_bits_per_second, percent, mod_bits_per_second; - if (desc_bytes <= 0) + if (desc_bytes <= 0 || desc_bytes > INT64_MAX/8) return -1; desc_sec = desc_ns / nano_seconds_per_second;