diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 8a75a2e1dc..8263eee8e3 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -632,6 +632,8 @@ static int decode_idat_chunk(AVCodecContext *avctx, PNGDecContext *s,
     int ret;
     size_t byte_depth = s->bit_depth > 8 ? 2 : 1;
 
+    if (!p)
+        return AVERROR_INVALIDDATA;
     if (!(s->hdr_state & PNG_IHDR)) {
         av_log(avctx, AV_LOG_ERROR, "IDAT without IHDR\n");
         return AVERROR_INVALIDDATA;
@@ -1382,6 +1384,9 @@ skip_tag:
     }
 exit_loop:
 
+    if (!p)
+        return AVERROR_INVALIDDATA;
+
     if (avctx->codec_id == AV_CODEC_ID_PNG &&
         avctx->skip_frame == AVDISCARD_ALL) {
         return 0;
@@ -1551,7 +1556,7 @@ static int decode_frame_apng(AVCodecContext *avctx,
         s->zstream.zfree  = ff_png_zfree;
 
         bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
-        if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
+        if ((ret = decode_frame_common(avctx, s, NULL, avpkt)) < 0)
             goto end;
     }