From bd79a4e0ecb11a86e090316cd7a5724ebea1c658 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Wed, 21 Oct 2020 23:05:41 +0200 Subject: [PATCH] avformat/vividas: better check of current_sb_entry This is the simplest fix for the problem, it is possible to instead check this when the variables are set and propagate errors and then fail earlier Fixes: out of array access Fixes: 26490/clusterfuzz-testcase-minimized-ffmpeg_dem_VIVIDAS_fuzzer-5723367078100992 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer (cherry picked from commit b848baef0dc42d97a5c1ab975cc8994a265b88ae) Signed-off-by: Michael Niedermayer --- libavformat/vividas.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavformat/vividas.c b/libavformat/vividas.c index f5629f7eb4..d38bb8d84b 100644 --- a/libavformat/vividas.c +++ b/libavformat/vividas.c @@ -671,6 +671,10 @@ static int viv_read_packet(AVFormatContext *s, if (!pb) return AVERROR(EIO); off = avio_tell(pb); + + if (viv->current_sb_entry >= viv->n_sb_entries) + return AVERROR_INVALIDDATA; + off += viv->sb_entries[viv->current_sb_entry].size; if (viv->sb_entries[viv->current_sb_entry].flag == 0) {