From b08776e3ae9a5315c19e8619ca71921006c1abe1 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Mon, 19 Aug 2024 16:25:27 +0200 Subject: [PATCH] avcodec/magicyuvenc: better slice height Fixes: Use of uninitialized value Fixes: 71072/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MAGICYUV_fuzzer-4835252046987264 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/magicyuvenc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/libavcodec/magicyuvenc.c b/libavcodec/magicyuvenc.c index 93eabb9f9a..6e640d24cc 100644 --- a/libavcodec/magicyuvenc.c +++ b/libavcodec/magicyuvenc.c @@ -378,11 +378,14 @@ static int count_plane_slice(AVCodecContext *avctx, int n, int plane) Slice *sl = &s->slices[n * s->planes + plane]; const uint8_t *dst = sl->slice; PTable *counts = sl->counts; + const int slice_height = s->slice_height; + const int last_height = FFMIN(slice_height, avctx->height - n * slice_height); + const int height = (n < (s->nb_slices - 1)) ? slice_height : last_height; memset(counts, 0, sizeof(sl->counts)); count_usage(dst, AV_CEIL_RSHIFT(avctx->width, s->hshift[plane]), - AV_CEIL_RSHIFT(s->slice_height, s->vshift[plane]), counts); + AV_CEIL_RSHIFT(height, s->vshift[plane]), counts); return 0; }