static int pcm_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
			     unsigned int size, unsigned int __user *tlv)
{
	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
	const struct snd_pcm_chmap_elem *map;
	unsigned int __user *dst;
	int c, count = 0;

	if (snd_BUG_ON(!info->chmap))
		return -EINVAL;
	if (size < 8)
		return -ENOMEM;
	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
		return -EFAULT;
	size -= 8;
	dst = tlv + 2;
	for (map = info->chmap; map->channels; map++) {
		int chs_bytes = map->channels * 4;
		if (!valid_chmap_channels(info, map->channels))
			continue;
		if (size < 8)
			return -ENOMEM;
		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
		    put_user(chs_bytes, dst + 1))
			return -EFAULT;
		dst += 2;
		size -= 8;
		count += 8;
		if (size < chs_bytes)
			return -ENOMEM;
		size -= chs_bytes;
		count += chs_bytes;
		for (c = 0; c < map->channels; c++) {
			if (put_user(map->map[c], dst))
				return -EFAULT;
			dst++;
		}
	}
	if (put_user(count, tlv + 1))
		return -EFAULT;
	return 0;
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.