avcodec/pngdec: Only allow one IHDR chunk
authorMichael Niedermayer <michaelni@gmx.at>
Mon, 29 Jun 2015 19:08:05 +0000 (21:08 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Tue, 28 Jul 2015 00:42:15 +0000 (02:42 +0200)
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>
(cherry picked from commit 47f4e2d8960ca756ca153ab8e3e93d80449b8c91)

Conflicts:

libavcodec/pngdec.c

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
libavcodec/pngdec.c

index 75feb04..092528e 100644 (file)
@@ -538,6 +538,11 @@ 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  = s->cur_w = bytestream2_get_be32(&s->gb);
     s->height = s->cur_h = bytestream2_get_be32(&s->gb);
     if (av_image_check_size(s->width, s->height, 0, avctx)) {