Patch attached
From 6e28dfde91443fba276fdd792dee9480c0b00558 Mon Sep 17 00:00:00 2001 From: Brian Kim <bk...@google.com> Date: Tue, 7 Jul 2020 11:42:04 -0700 Subject: [PATCH 2/3] libavcodec/decode: avoid UB when getting plane sizes
This uses av_image_fill_plane_sizes instead of av_image_fill_pointers when we are getting plane sizes to avoid UB from adding offsets to NULL. Signed-off-by: Brian Kim <bk...@google.com> --- libavcodec/decode.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/libavcodec/decode.c b/libavcodec/decode.c index de9c079f9d..c1753cfffb 100644 --- a/libavcodec/decode.c +++ b/libavcodec/decode.c @@ -1471,12 +1471,12 @@ static int update_frame_pool(AVCodecContext *avctx, AVFrame *frame) switch (avctx->codec_type) { case AVMEDIA_TYPE_VIDEO: { - uint8_t *data[4]; int linesize[4]; - int size[4] = { 0 }; int w = frame->width; int h = frame->height; - int tmpsize, unaligned; + int unaligned; + ptrdiff_t tmpsize, linesize1[4]; + size_t size[4]; avcodec_align_dimensions2(avctx, &w, &h, pool->stride_align); @@ -1494,20 +1494,22 @@ static int update_frame_pool(AVCodecContext *avctx, AVFrame *frame) unaligned |= linesize[i] % pool->stride_align[i]; } while (unaligned); - tmpsize = av_image_fill_pointers(data, avctx->pix_fmt, h, - NULL, linesize); + for (i = 0; i < 4; i++) + linesize1[i] = linesize[i]; + tmpsize = av_image_fill_plane_sizes(size, avctx->pix_fmt, h, + linesize1); if (tmpsize < 0) { ret = tmpsize; goto fail; } - for (i = 0; i < 3 && data[i + 1]; i++) - size[i] = data[i + 1] - data[i]; - size[i] = tmpsize - (data[i] - data[0]); - for (i = 0; i < 4; i++) { pool->linesize[i] = linesize[i]; if (size[i]) { + if (size[i] > INT_MAX - (16 + STRIDE_ALIGN - 1)) { + ret = AVERROR(EINVAL); + goto fail; + } pool->pools[i] = av_buffer_pool_init(size[i] + 16 + STRIDE_ALIGN - 1, CONFIG_MEMORY_POISONING ? NULL : -- 2.27.0.383.g050319c2ae-goog
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