From 1e00bbb10cbde3da03a1e744265ce6def9ae4c56 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Mon, 13 May 2013 18:09:04 +0200
Subject: [PATCH] avcodec/lcldec: Check that dimensions are a multiple of the
subsample factors
Other dimensions would not work correctly currently,
also ask for a sample for files that fail this check.
This fixes an integer overflow leading to out of array
accesses.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/lcldec.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/libavcodec/lcldec.c b/libavcodec/lcldec.c
index 7948199802c..ad7ef91e8db 100644
--- a/libavcodec/lcldec.c
+++ b/libavcodec/lcldec.c
@@ -42,6 +42,7 @@
#include <stdlib.h>
#include "libavutil/mem.h"
+#include "libavutil/pixdesc.h"
#include "avcodec.h"
#include "bytestream.h"
#include "internal.h"
@@ -482,6 +483,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
unsigned int max_basesize = FFALIGN(avctx->width, 4) *
FFALIGN(avctx->height, 4);
unsigned int max_decomp_size;
+ int subsample_h, subsample_v;
if (avctx->extradata_size < 8) {
av_log(avctx, AV_LOG_ERROR, "Extradata size too small.\n");
@@ -507,6 +509,10 @@ static av_cold int decode_init(AVCodecContext *avctx)
max_decomp_size = max_basesize * 2;
avctx->pix_fmt = AV_PIX_FMT_YUV422P;
av_log(avctx, AV_LOG_DEBUG, "Image type is YUV 4:2:2.\n");
+ if (avctx->width % 4) {
+ avpriv_request_sample(avctx, "Unsupported dimensions\n");
+ return AVERROR_INVALIDDATA;
+ }
break;
case IMGTYPE_RGB24:
c->decomp_size = basesize * 3;
@@ -537,6 +543,12 @@ static av_cold int decode_init(AVCodecContext *avctx)
return AVERROR_INVALIDDATA;
}
+ av_pix_fmt_get_chroma_sub_sample(avctx->pix_fmt, &subsample_h, &subsample_v);
+ if (avctx->width % (1<<subsample_h) || avctx->height % (1<<subsample_v)) {
+ avpriv_request_sample(avctx, "Unsupported dimensions\n");
+ return AVERROR_INVALIDDATA;
+ }
+
/* Detect compression method */
c->compression = (int8_t)avctx->extradata[5];
switch (avctx->codec_id) {
--
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