avcodec/pngdec: Check IHDR/IDAT order
authorMichael Niedermayer <michaelni@gmx.at>
Wed, 26 Nov 2014 14:45:47 +0000 (15:45 +0100)
committerMichael Niedermayer <michaelni@gmx.at>
Wed, 26 Nov 2014 15:00:01 +0000 (16:00 +0100)
Fixes out of array access
Fixes: asan_heap-oob_20a6c26_2690_cov_3434532168_mail.png
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
libavcodec/pngdec.c

index ee6a2ba..f80a3fe 100644 (file)
@@ -524,6 +524,12 @@ static int decode_ihdr_chunk(AVCodecContext *avctx, PNGDecContext *s,
 {
     if (length != 13)
         return AVERROR_INVALIDDATA;
+
+    if (s->state & PNG_IDAT) {
+        av_log(avctx, AV_LOG_ERROR, "IHDR after IDAT\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)) {