2023-06-22 09:32:41

by Wei Chen

Subject: [PATCH] mmc: sunplus: fix return value check of mmc_add_host()

mmc_add_host() may return error, if we ignore its return value,
1. the memory allocated in mmc_alloc_host() will be leaked
2. null-ptr-deref will happen when calling mmc_remove_host()
in remove function spmmc_drv_remove() because deleting not
added device.

Fix this by checking the return value of mmc_add_host(). Moreover,
I fixed the error handling path of spmmc_drv_probe() to clean up.

Signed-off-by: Wei Chen <[email protected]>
---
drivers/mmc/host/sunplus-mmc.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/sunplus-mmc.c b/drivers/mmc/host/sunplus-mmc.c
index db5e0dcdfa7f..a96e90ea6541 100644
--- a/drivers/mmc/host/sunplus-mmc.c
+++ b/drivers/mmc/host/sunplus-mmc.c
@@ -902,7 +902,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)

ret = mmc_of_parse(mmc);
if (ret)
- goto probe_free_host;
+ goto clk_disable;

mmc->ops = &spmmc_ops;
mmc->f_min = SPMMC_MIN_CLK;
@@ -911,7 +911,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)

ret = mmc_regulator_get_supply(mmc);
if (ret)
- goto probe_free_host;
+ goto clk_disable;

if (!mmc->ocr_avail)
mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
@@ -927,9 +927,17 @@ static int spmmc_drv_probe(struct platform_device *pdev)
host->tuning_info.enable_tuning = 1;
pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
- mmc_add_host(mmc);
+ ret = mmc_add_host(mmc);
+ if (ret)
+ goto pm_disable;

- return ret;
+ return 0;
+
+pm_disable:
+ pm_runtime_disable(&pdev->dev);
+
+clk_disable:
+ clk_disable_unprepare(host->clk);

probe_free_host:
if (mmc)
--
2.25.1

2023-07-13 11:16:52

by Ulf Hansson

Subject: Re: [PATCH] mmc: sunplus: fix return value check of mmc_add_host()

On Thu, 22 Jun 2023 at 11:02, Wei Chen <[email protected]> wrote:
>
> mmc_add_host() may return error, if we ignore its return value,
> 1. the memory allocated in mmc_alloc_host() will be leaked
> 2. null-ptr-deref will happen when calling mmc_remove_host()
> in remove function spmmc_drv_remove() because deleting not
> added device.
>
> Fix this by checking the return value of mmc_add_host(). Moreover,
> I fixed the error handling path of spmmc_drv_probe() to clean up.
>
> Signed-off-by: Wei Chen <[email protected]>

Applied for next, thanks!

Kind regards
Uffe


> ---
> drivers/mmc/host/sunplus-mmc.c | 16 ++++++++++++----
> 1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sunplus-mmc.c b/drivers/mmc/host/sunplus-mmc.c
> index db5e0dcdfa7f..a96e90ea6541 100644
> --- a/drivers/mmc/host/sunplus-mmc.c
> +++ b/drivers/mmc/host/sunplus-mmc.c
> @@ -902,7 +902,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)
>
> ret = mmc_of_parse(mmc);
> if (ret)
> - goto probe_free_host;
> + goto clk_disable;
>
> mmc->ops = &spmmc_ops;
> mmc->f_min = SPMMC_MIN_CLK;
> @@ -911,7 +911,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)
>
> ret = mmc_regulator_get_supply(mmc);
> if (ret)
> - goto probe_free_host;
> + goto clk_disable;
>
> if (!mmc->ocr_avail)
> mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
> @@ -927,9 +927,17 @@ static int spmmc_drv_probe(struct platform_device *pdev)
> host->tuning_info.enable_tuning = 1;
> pm_runtime_set_active(&pdev->dev);
> pm_runtime_enable(&pdev->dev);
> - mmc_add_host(mmc);
> + ret = mmc_add_host(mmc);
> + if (ret)
> + goto pm_disable;
>
> - return ret;
> + return 0;
> +
> +pm_disable:
> + pm_runtime_disable(&pdev->dev);
> +
> +clk_disable:
> + clk_disable_unprepare(host->clk);
>
> probe_free_host:
> if (mmc)
> --
> 2.25.1
>