On Tue, Dec 01, 2020 at 10:02:54AM +0300, Dan Carpenter wrote:
> There are a few problems with the error handling in this function. They
> mostly center around the alloc_ordered_workqueue() allocation.
> 1) If that allocation fails or if the kcalloc() prior to it fails then
> it leads to a NULL dereference when we call
> destroy_workqueue(mhi_cntrl->hiprio_wq).
> 2) The error code is not set.
> 3) The "mhi_cntrl->mhi_cmd" allocation is not freed.
>
> The error handling was slightly confusing and I re-ordered it to be in
> the exact mirror/reverse order of how things were allocated. I changed
> the label names to say what the goto does instead of describing where
> the goto comes from.
>
> Fixes: 8f7039787687 ("bus: mhi: core: Move to using high priority workqueue")
> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Good find... Thanks for the patch, Dan!
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Thanks,
Mani
> ---
> drivers/bus/mhi/core/init.c | 29 ++++++++++++++---------------
> 1 file changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index 96cde9c0034c..f0697f433c2f 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -871,7 +871,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
> sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL);
> if (!mhi_cntrl->mhi_cmd) {
> ret = -ENOMEM;
> - goto error_alloc_cmd;
> + goto err_free_event;
> }
>
> INIT_LIST_HEAD(&mhi_cntrl->transition_list);
> @@ -886,7 +886,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
> ("mhi_hiprio_wq", WQ_MEM_RECLAIM | WQ_HIGHPRI);
> if (!mhi_cntrl->hiprio_wq) {
> dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n");
> - goto error_alloc_cmd;
> + ret = -ENOMEM;
> + goto err_free_cmd;
> }
>
> mhi_cmd = mhi_cntrl->mhi_cmd;
> @@ -932,7 +933,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
> ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
> SOC_HW_VERSION_OFFS, &soc_info);
> if (ret)
> - goto error_alloc_dev;
> + goto err_destroy_wq;
>
> mhi_cntrl->family_number = (soc_info & SOC_HW_VERSION_FAM_NUM_BMSK) >>
> SOC_HW_VERSION_FAM_NUM_SHFT;
> @@ -946,7 +947,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
> mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL);
> if (mhi_cntrl->index < 0) {
> ret = mhi_cntrl->index;
> - goto error_ida_alloc;
> + goto err_destroy_wq;
> }
>
> /* Register controller with MHI bus */
> @@ -954,7 +955,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
> if (IS_ERR(mhi_dev)) {
> dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n");
> ret = PTR_ERR(mhi_dev);
> - goto error_alloc_dev;
> + goto err_ida_free;
> }
>
> mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
> @@ -967,7 +968,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
>
> ret = device_add(&mhi_dev->dev);
> if (ret)
> - goto error_add_dev;
> + goto err_release_dev;
>
> mhi_cntrl->mhi_dev = mhi_dev;
>
> @@ -975,19 +976,17 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
>
> return 0;
>
> -error_add_dev:
> +err_release_dev:
> put_device(&mhi_dev->dev);
> -
> -error_alloc_dev:
> +err_ida_free:
> ida_free(&mhi_controller_ida, mhi_cntrl->index);
> -
> -error_ida_alloc:
> +err_destroy_wq:
> + destroy_workqueue(mhi_cntrl->hiprio_wq);
> +err_free_cmd:
> kfree(mhi_cntrl->mhi_cmd);
> -
> -error_alloc_cmd:
> - vfree(mhi_cntrl->mhi_chan);
> +err_free_event:
> kfree(mhi_cntrl->mhi_event);
> - destroy_workqueue(mhi_cntrl->hiprio_wq);
> + vfree(mhi_cntrl->mhi_chan);
>
> return ret;
> }
> --
> 2.29.2
>
