[PATCH v2] mmc: mmc_spi: fix error handling in mmc_spi_probe()

[PATCH v2] mmc: mmc_spi: fix error handling in mmc_spi_probe()

[Yang Yingliang]

If mmc_add_host() fails, it doesn't need to call mmc_remove_host(),
or it will cause null-ptr-deref, because of deleting a not added
device in mmc_remove_host().

To fix this, goto label 'fail_glue_init', if mmc_add_host() fails,
and change the label 'fail_add_host' to 'fail_gpiod_request'.

Fixes: 15a0580ced08 ("mmc_spi host driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
v1 -> v2:
  Fix a typo.
---
 drivers/mmc/host/mmc_spi.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 106dd204b1a7..cc333ad67cac 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -1437,7 +1437,7 @@ static int mmc_spi_probe(struct spi_device *spi)
 
 	status = mmc_add_host(mmc);
 	if (status != 0)
-		goto fail_add_host;
+		goto fail_glue_init;
 
 	/*
 	 * Index 0 is card detect
@@ -1445,7 +1445,7 @@ static int mmc_spi_probe(struct spi_device *spi)
 	 */
 	status = mmc_gpiod_request_cd(mmc, NULL, 0, false, 1000);
 	if (status == -EPROBE_DEFER)
-		goto fail_add_host;
+		goto fail_gpiod_request;
 	if (!status) {
 		/*
 		 * The platform has a CD GPIO signal that may support
@@ -1460,7 +1460,7 @@ static int mmc_spi_probe(struct spi_device *spi)
 	/* Index 1 is write protect/read only */
 	status = mmc_gpiod_request_ro(mmc, NULL, 1, 0);
 	if (status == -EPROBE_DEFER)
-		goto fail_add_host;
+		goto fail_gpiod_request;
 	if (!status)
 		has_ro = true;
 
@@ -1474,7 +1474,7 @@ static int mmc_spi_probe(struct spi_device *spi)
 				? ", cd polling" : "");
 	return 0;
 
-fail_add_host:
+fail_gpiod_request:
 	mmc_remove_host(mmc);
 fail_glue_init:
 	mmc_spi_dma_free(host);
-- 
2.25.1

Re: [PATCH v2] mmc: mmc_spi: fix error handling in mmc_spi_probe()

[Ulf Hansson]

On Tue, 31 Jan 2023 at 02:38, Yang Yingliang <yangyingliang@huawei.com> wrote:
>
> If mmc_add_host() fails, it doesn't need to call mmc_remove_host(),
> or it will cause null-ptr-deref, because of deleting a not added
> device in mmc_remove_host().
>
> To fix this, goto label 'fail_glue_init', if mmc_add_host() fails,
> and change the label 'fail_add_host' to 'fail_gpiod_request'.
>
> Fixes: 15a0580ced08 ("mmc_spi host driver")
> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>

Applied for fixes and by adding a stable tag, thanks!

Kind regards
Uffe


> ---
> v1 -> v2:
>   Fix a typo.
> ---
>  drivers/mmc/host/mmc_spi.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
> index 106dd204b1a7..cc333ad67cac 100644
> --- a/drivers/mmc/host/mmc_spi.c
> +++ b/drivers/mmc/host/mmc_spi.c
> @@ -1437,7 +1437,7 @@ static int mmc_spi_probe(struct spi_device *spi)
>
>         status = mmc_add_host(mmc);
>         if (status != 0)
> -               goto fail_add_host;
> +               goto fail_glue_init;
>
>         /*
>          * Index 0 is card detect
> @@ -1445,7 +1445,7 @@ static int mmc_spi_probe(struct spi_device *spi)
>          */
>         status = mmc_gpiod_request_cd(mmc, NULL, 0, false, 1000);
>         if (status == -EPROBE_DEFER)
> -               goto fail_add_host;
> +               goto fail_gpiod_request;
>         if (!status) {
>                 /*
>                  * The platform has a CD GPIO signal that may support
> @@ -1460,7 +1460,7 @@ static int mmc_spi_probe(struct spi_device *spi)
>         /* Index 1 is write protect/read only */
>         status = mmc_gpiod_request_ro(mmc, NULL, 1, 0);
>         if (status == -EPROBE_DEFER)
> -               goto fail_add_host;
> +               goto fail_gpiod_request;
>         if (!status)
>                 has_ro = true;
>
> @@ -1474,7 +1474,7 @@ static int mmc_spi_probe(struct spi_device *spi)
>                                 ? ", cd polling" : "");
>         return 0;
>
> -fail_add_host:
> +fail_gpiod_request:
>         mmc_remove_host(mmc);
>  fail_glue_init:
>         mmc_spi_dma_free(host);
> --
> 2.25.1
>