From 47f4e2d8960ca756ca153ab8e3e93d80449b8c91 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Mon, 29 Jun 2015 21:08:05 +0200
Subject: [PATCH] avcodec/pngdec: Only allow one IHDR chunk
Multiple IHDR chunks are forbidden in PNG
Fixes inconsistency and out of array accesses
Fixes: asan_heap-oob_4d5c5a_1738_cov_2638287726_c-m2-8f2b481b7fd9bd745e620b7c01a18df2.png
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
libavcodec/pngdec.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index ceda383209a..f8b398ffde0 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -542,6 +542,11 @@ static int decode_ihdr_chunk(AVCodecContext *avctx, PNGDecContext *s,
return AVERROR_INVALIDDATA;
}
+ if (s->state & PNG_IHDR) {
+ av_log(avctx, AV_LOG_ERROR, "Multiple IHDR\n");
+ return AVERROR_INVALIDDATA;
+ }
+
s->width = bytestream2_get_be32(&s->gb);
s->height = bytestream2_get_be32(&s->gb);
if (av_image_check_size(s->width, s->height, 0, avctx)) {
--
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