static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
				struct fuse_copy_state *cs, size_t nbytes)
{
	ssize_t err;
	struct fuse_conn *fc = fud->fc;
	struct fuse_iqueue *fiq = &fc->iq;
	struct fuse_pqueue *fpq = &fud->pq;
	struct fuse_req *req;
	struct fuse_in *in;
	unsigned reqsize;
	unsigned int hash;

 restart:
	spin_lock(&fiq->waitq.lock);
	err = -EAGAIN;
	if ((file->f_flags & O_NONBLOCK) && fiq->connected &&
	    !request_pending(fiq))
		goto err_unlock;

	err = wait_event_interruptible_exclusive_locked(fiq->waitq,
				!fiq->connected || request_pending(fiq));
	if (err)
		goto err_unlock;

	if (!fiq->connected) {
		err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV;
		goto err_unlock;
	}

	if (!list_empty(&fiq->interrupts)) {
		req = list_entry(fiq->interrupts.next, struct fuse_req,
				 intr_entry);
		return fuse_read_interrupt(fiq, cs, nbytes, req);
	}

	if (forget_pending(fiq)) {
		if (list_empty(&fiq->pending) || fiq->forget_batch-- > 0)
			return fuse_read_forget(fc, fiq, cs, nbytes);

		if (fiq->forget_batch <= -8)
			fiq->forget_batch = 16;
	}

	req = list_entry(fiq->pending.next, struct fuse_req, list);
	clear_bit(FR_PENDING, &req->flags);
	list_del_init(&req->list);
	spin_unlock(&fiq->waitq.lock);

	in = &req->in;
	reqsize = in->h.len;

	/* If request is too large, reply with an error and restart the read */
	if (nbytes < reqsize) {
		req->out.h.error = -EIO;
		/* SETXATTR is special, since it may contain too large data */
		if (in->h.opcode == FUSE_SETXATTR)
			req->out.h.error = -E2BIG;
		request_end(fc, req);
		goto restart;
	}
	spin_lock(&fpq->lock);
	list_add(&req->list, &fpq->io);
	spin_unlock(&fpq->lock);
	cs->req = req;
	err = fuse_copy_one(cs, &in->h, sizeof(in->h));
	if (!err)
		err = fuse_copy_args(cs, in->numargs, in->argpages,
				     (struct fuse_arg *) in->args, 0);
	fuse_copy_finish(cs);
	spin_lock(&fpq->lock);
	clear_bit(FR_LOCKED, &req->flags);
	if (!fpq->connected) {
		err = (fc->aborted && fc->abort_err) ? -ECONNABORTED : -ENODEV;
		goto out_end;
	}
	if (err) {
		req->out.h.error = -EIO;
		goto out_end;
	}
	if (!test_bit(FR_ISREPLY, &req->flags)) {
		err = reqsize;
		goto out_end;
	}
	hash = fuse_req_hash(req->in.h.unique);
	list_move_tail(&req->list, &fpq->processing[hash]);
	__fuse_get_request(req);
	set_bit(FR_SENT, &req->flags);
	spin_unlock(&fpq->lock);
	/* matches barrier in request_wait_answer() */
	smp_mb__after_atomic();
	if (test_bit(FR_INTERRUPTED, &req->flags))
		queue_interrupt(fiq, req);
	fuse_put_request(fc, req);

	return reqsize;

out_end:
	if (!test_bit(FR_PRIVATE, &req->flags))
		list_del_init(&req->list);
	spin_unlock(&fpq->lock);
	request_end(fc, req);
	return err;

 err_unlock:
	spin_unlock(&fiq->waitq.lock);
	return err;
}

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.