1 files changed, 4 insertions, 1 deletions
diff --git a/libavcodec/nellymoserdec.c b/libavcodec/nellymoserdec.c
index 278b6b3..cd05482 100644
--- a/libavcodec/nellymoserdec.c
+++ b/libavcodec/nellymoserdec.c
@@ -151,17 +151,20 @@ static int decode_tag(AVCodecContext * avctx,
     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;
     NellyMoserDecodeContext *s = avctx->priv_data;
+    int data_max = *data_size;
     int blocks, i, block_size;
     int16_t *samples_s16 = data;
     float   *samples_flt = data;
+    *data_size = 0;
 
     block_size = NELLY_SAMPLES * av_get_bytes_per_sample(avctx->sample_fmt);
     blocks     = buf_size / NELLY_BLOCK_LEN;
+
     if (blocks <= 0) {
         av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
         return AVERROR_INVALIDDATA;
     }
-    if (*data_size < blocks * block_size) {
+    if (data_max < blocks * block_size) {
         av_log(avctx, AV_LOG_ERROR, "Output buffer is too small\n");
         return AVERROR(EINVAL);
     }