diff --git a/libavcodec/pnmdec.c b/libavcodec/pnmdec.c
index 68bb7a41ec..b99b26a390 100644
--- a/libavcodec/pnmdec.c
+++ b/libavcodec/pnmdec.c
@@ -63,6 +63,9 @@ static int pnm_decode_frame(AVCodecContext *avctx, AVFrame *p,
     if (avctx->skip_frame >= AVDISCARD_ALL)
         return avpkt->size;
 
+    if (avctx->width * avctx->height / 8 > s->bytestream_end - s->bytestream)
+        return AVERROR_INVALIDDATA;
+
     if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
         return ret;
     avctx->bits_per_raw_sample = av_log2(s->maxval) + 1;