[FFmpeg-cvslog] avcodec/pngdec: Only allow one IHDR chunk

Michael Niedermayer git at videolan.org
Thu Aug 20 14:53:44 CEST 2015


ffmpeg | branch: release/2.4 | Michael Niedermayer <michaelni at gmx.at> | Mon Jun 29 21:08:05 2015 +0200| [e35c5348900a371c467816a9189031192f08865a] | committer: Michael Niedermayer

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 at gmx.at>
(cherry picked from commit 47f4e2d8960ca756ca153ab8e3e93d80449b8c91)

Conflicts:

	libavcodec/pngdec.c

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e35c5348900a371c467816a9189031192f08865a
---

 libavcodec/pngdec.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index c2f417e..8c22da0 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -588,6 +588,11 @@ static int decode_frame(AVCodecContext *avctx,
                 goto fail;
             }
 
+            if (s->state & PNG_IHDR) {
+                av_log(avctx, AV_LOG_ERROR, "Multiple IHDR\n");
+                goto fail;
+            }
+
             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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