From 2201c91fbf672447aa2063bd752d821466b8f11b Mon Sep 17 00:00:00 2001 From: Yiyuan GUO Date: Sat, 15 May 2021 13:54:35 +0800 Subject: [PATCH] avfilter/vf_palettegen: add protection against potential divide by zero In libavfilter/vf_palettegen.c, the function get_avg_color requires that box->len greater than zero to avoid dividing by zero. However, the call sequence filter_frame -> get_palette_frame -> get_avg_color may not satisfy this precondition. Fixes #9222. Signed-off-by: Yiyuan GUO --- libavfilter/vf_palettegen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavfilter/vf_palettegen.c b/libavfilter/vf_palettegen.c index 4f53aa1aad..27f74fd147 100644 --- a/libavfilter/vf_palettegen.c +++ b/libavfilter/vf_palettegen.c @@ -528,7 +528,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in) if (s->stats_mode == STATS_MODE_DIFF_FRAMES) { av_frame_free(&s->prev_frame); s->prev_frame = in; - } else if (s->stats_mode == STATS_MODE_SINGLE_FRAMES) { + } else if (s->stats_mode == STATS_MODE_SINGLE_FRAMES && s->nb_refs > 0) { AVFrame *out; int i;