From b0a8b40294ea212c1938348ff112ef1b9bf16bb3 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sun, 25 Oct 2020 00:23:12 +0200 Subject: [PATCH] avcodec/exr: skip bottom clearing loop when its outside the image Fixes: signed integer overflow: 1633771809 * 32960 cannot be represented in type 'int' Fixes: 26532/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EXR_fuzzer-5613925708857344 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- libavcodec/exr.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/libavcodec/exr.c b/libavcodec/exr.c index 8b701d1cd2..d233dd43fb 100644 --- a/libavcodec/exr.c +++ b/libavcodec/exr.c @@ -1842,13 +1842,14 @@ static int decode_frame(AVCodecContext *avctx, void *data, ymax = FFMAX(0, s->ymax + 1); // Zero out the end if ymax+1 is not h - for (i = 0; i < planes; i++) { - ptr = picture->data[i] + (ymax * picture->linesize[i]); - for (y = ymax; y < avctx->height; y++) { - memset(ptr, 0, out_line_size); - ptr += picture->linesize[i]; + if (ymax < avctx->height) + for (i = 0; i < planes; i++) { + ptr = picture->data[i] + (ymax * picture->linesize[i]); + for (y = ymax; y < avctx->height; y++) { + memset(ptr, 0, out_line_size); + ptr += picture->linesize[i]; + } } - } picture->pict_type = AV_PICTURE_TYPE_I; *got_frame = 1;