create_durable_v2_buf(struct cifs_open_parms *oparms)
{
	struct cifs_fid *pfid = oparms->fid;
	struct create_durable_v2 *buf;

	buf = kzalloc(sizeof(struct create_durable_v2), GFP_KERNEL);
	if (!buf)
		return NULL;

	buf->ccontext.DataOffset = cpu_to_le16(offsetof
					(struct create_durable_v2, dcontext));
	buf->ccontext.DataLength = cpu_to_le32(sizeof(struct durable_context_v2));
	buf->ccontext.NameOffset = cpu_to_le16(offsetof
				(struct create_durable_v2, Name));
	buf->ccontext.NameLength = cpu_to_le16(4);

	/*
	 * NB: Handle timeout defaults to 0, which allows server to choose
	 * (most servers default to 120 seconds) and most clients default to 0.
	 * This can be overridden at mount ("handletimeout=") if the user wants
	 * a different persistent (or resilient) handle timeout for all opens
	 * opens on a particular SMB3 mount.
	 */
	buf->dcontext.Timeout = cpu_to_le32(oparms->tcon->handle_timeout);
	buf->dcontext.Flags = cpu_to_le32(SMB2_DHANDLE_FLAG_PERSISTENT);
	generate_random_uuid(buf->dcontext.CreateGuid);
	memcpy(pfid->create_guid, buf->dcontext.CreateGuid, 16);

	/* SMB2_CREATE_DURABLE_HANDLE_REQUEST is "DH2Q" */
	buf->Name[0] = 'D';
	buf->Name[1] = 'H';
	buf->Name[2] = '2';
	buf->Name[3] = 'Q';
	return buf;
}

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 Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.