From e43a3d8d304dcafad023eb0327669fe94d6e2d9f Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Fri, 22 Dec 2023 21:49:48 +0100 Subject: [PATCH] avfilter/af_alimiter: Check nextpos before use Fixes: out of array read Fixes: tickets/10744/poc11ffmpeg Found-by: Li Zeyuan and Zeng Yunxiang. Signed-off-by: Michael Niedermayer (cherry picked from commit a88b06f9ee8c88f78bdd614fc25283225223e858) Signed-off-by: Michael Niedermayer --- libavfilter/af_alimiter.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/libavfilter/af_alimiter.c b/libavfilter/af_alimiter.c index f08893229d..9a86704764 100644 --- a/libavfilter/af_alimiter.c +++ b/libavfilter/af_alimiter.c @@ -195,9 +195,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in) int j = i % buffer_size; double ppeak = 0, pdelta; - for (c = 0; c < channels; c++) { - ppeak = FFMAX(ppeak, fabs(buffer[nextpos[j] + c])); - } + if (nextpos[j] >= 0) + for (c = 0; c < channels; c++) { + ppeak = FFMAX(ppeak, fabs(buffer[nextpos[j] + c])); + } pdelta = (limit / peak - limit / ppeak) / (((buffer_size - nextpos[j] + s->pos) % buffer_size) / channels); if (pdelta < nextdelta[j]) { nextdelta[j] = pdelta;