From 074c769de93bf12e9f44d77e58a8c7167f9dfb13 Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Fri, 15 Nov 2013 09:42:26 +0100 Subject: [PATCH] h264_cavlc: check the size of the intra PCM data. Fixes invalid reads. Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind CC:libav-stable@libav.org --- libavcodec/h264_cavlc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/libavcodec/h264_cavlc.c b/libavcodec/h264_cavlc.c index 5ed1d5d240..d3f6dcb068 100644 --- a/libavcodec/h264_cavlc.c +++ b/libavcodec/h264_cavlc.c @@ -765,6 +765,10 @@ decode_intra_mb: // We assume these blocks are very rare so we do not optimize it. h->intra_pcm_ptr = align_get_bits(&h->gb); + if (get_bits_left(&h->gb) < mb_size) { + av_log(h->avctx, AV_LOG_ERROR, "Not enough data for an intra PCM block.\n"); + return AVERROR_INVALIDDATA; + } skip_bits_long(&h->gb, mb_size); // In deblocking, the quantizer is 0