On 8/11/25 3:43 AM, Dan Carpenter wrote:
> The clean up in idxd_setup_wqs() has had a couple bugs because the error
> handling is a bit subtle. It's simpler to just re-write it in a cleaner
> way. The issues here are:
>
> 1) If "idxd->max_wqs" is <= 0 then we call put_device(conf_dev) when
> "conf_dev" hasn't been initialized.
> 2) If kzalloc_node() fails then again "conf_dev" is invalid. It's
> either uninitialized or it points to the "conf_dev" from the
> previous iteration so it leads to a double free.
>
> It's better to free partial loop iterations within the loop and then
> the unwinding at the end can handle whole loop iterations. I also
> renamed the labels to describe what the goto does and not where the goto
> was located.
>
> Fixes: 3fd2f4bc010c ("dmaengine: idxd: fix memory leak in error handling path of idxd_setup_wqs")
> Reported-by: Colin Ian King <colin.i.king@xxxxxxxxx>
> Closes: https://lore.kernel.org/all/20250811095836.1642093-1-colin.i.king@xxxxxxxxx/
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
> ---
> drivers/dma/idxd/init.c | 33 +++++++++++++++++----------------
> 1 file changed, 17 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
> index 35bdefd3728b..dda01a4398e1 100644
> --- a/drivers/dma/idxd/init.c
> +++ b/drivers/dma/idxd/init.c
> @@ -189,27 +189,30 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
> idxd->wq_enable_map = bitmap_zalloc_node(idxd->max_wqs, GFP_KERNEL, dev_to_node(dev));
> if (!idxd->wq_enable_map) {
> rc = -ENOMEM;
> - goto err_bitmap;
> + goto err_free_wqs;
> }
>
> for (i = 0; i < idxd->max_wqs; i++) {
> wq = kzalloc_node(sizeof(*wq), GFP_KERNEL, dev_to_node(dev));
> if (!wq) {
> rc = -ENOMEM;
> - goto err;
> + goto err_unwind;
> }
>
> idxd_dev_set_type(&wq->idxd_dev, IDXD_DEV_WQ);
> conf_dev = wq_confdev(wq);
> wq->id = i;
> wq->idxd = idxd;
> - device_initialize(wq_confdev(wq));
> + device_initialize(conf_dev);
> conf_dev->parent = idxd_confdev(idxd);
> conf_dev->bus = &dsa_bus_type;
> conf_dev->type = &idxd_wq_device_type;
> rc = dev_set_name(conf_dev, "wq%d.%d", idxd->id, wq->id);
> - if (rc < 0)
> - goto err;
> + if (rc < 0) {
> + put_device(conf_dev);
> + kfree(wq);
> + goto err_unwind;
> + }
>
> mutex_init(&wq->wq_lock);
> init_waitqueue_head(&wq->err_queue);
> @@ -220,15 +223,20 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
> wq->enqcmds_retries = IDXD_ENQCMDS_RETRIES;
> wq->wqcfg = kzalloc_node(idxd->wqcfg_size, GFP_KERNEL, dev_to_node(dev));
> if (!wq->wqcfg) {
> + put_device(conf_dev);
> + kfree(wq);
> rc = -ENOMEM;
> - goto err;
> + goto err_unwind;
> }
>
> if (idxd->hw.wq_cap.op_config) {
> wq->opcap_bmap = bitmap_zalloc(IDXD_MAX_OPCAP_BITS, GFP_KERNEL);
> if (!wq->opcap_bmap) {
> + kfree(wq->wqcfg);
> + put_device(conf_dev);
> + kfree(wq);
> rc = -ENOMEM;
> - goto err_opcap_bmap;
> + goto err_unwind;
> }
> bitmap_copy(wq->opcap_bmap, idxd->opcap_bmap, IDXD_MAX_OPCAP_BITS);
> }
> @@ -239,13 +247,7 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
>
> return 0;
>
> -err_opcap_bmap:
> - kfree(wq->wqcfg);
> -
> -err:
> - put_device(conf_dev);
> - kfree(wq);
> -
> +err_unwind:
> while (--i >= 0) {
> wq = idxd->wqs[i];
> if (idxd->hw.wq_cap.op_config)
> @@ -254,11 +256,10 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
> conf_dev = wq_confdev(wq);
> put_device(conf_dev);
> kfree(wq);
> -
> }
> bitmap_free(idxd->wq_enable_map);
>
> -err_bitmap:
> +err_free_wqs:
> kfree(idxd->wqs);
>
> return rc;
> --
> 2.47.2
