[PATCH] gpio: omap: fix reference leak on platform_device_register() failure

Guangshuo Li posted 1 patch 2 months ago
drivers/gpio/gpio-omap.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
[PATCH] gpio: omap: fix reference leak on platform_device_register() failure
Posted by Guangshuo Li 2 months ago
omap_mpuio_init() ignores the return value of
platform_device_register(&omap_mpuio_device).

The call flow is:

  omap_mpuio_init()
    -> platform_device_register(&omap_mpuio_device)
         -> device_initialize(&omap_mpuio_device.dev)
         -> platform_device_add(&omap_mpuio_device)

If platform_device_add() fails, omap_mpuio_init() continues without
dropping the device reference acquired by device_initialize(), leading
to a reference leak.

The issue was identified by a static analysis tool I developed and
confirmed by manual review. Fix this by calling platform_device_put()
when platform_device_register() fails.

Fixes: 730e5ebff40c8 ("gpio: omap: do not register driver in probe()")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/gpio/gpio-omap.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index e39723b5901b..841bef431c22 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -800,11 +800,15 @@ static struct platform_device omap_mpuio_device = {
 static inline void omap_mpuio_init(struct gpio_bank *bank)
 {
 	static bool registered;
+	int ret;
 
 	platform_set_drvdata(&omap_mpuio_device, bank);
 	if (!registered) {
-		(void)platform_device_register(&omap_mpuio_device);
-		registered = true;
+		ret = platform_device_register(&omap_mpuio_device);
+		if (ret)
+			platform_device_put(&omap_mpuio_device);
+		else
+			registered = true;
 	}
 }
 
-- 
2.43.0
Re: [PATCH] gpio: omap: fix reference leak on platform_device_register() failure
Posted by Guangshuo Li 1 month, 3 weeks ago
Hi,

Please disregard this patch.

On Tue, 14 Apr 2026 at 00:08, Guangshuo Li <lgs201920130244@gmail.com> wrote:
>
> omap_mpuio_init() ignores the return value of
> platform_device_register(&omap_mpuio_device).
>
> The call flow is:
>
>   omap_mpuio_init()
>     -> platform_device_register(&omap_mpuio_device)
>          -> device_initialize(&omap_mpuio_device.dev)
>          -> platform_device_add(&omap_mpuio_device)
>
> If platform_device_add() fails, omap_mpuio_init() continues without
> dropping the device reference acquired by device_initialize(), leading
> to a reference leak.
>
> The issue was identified by a static analysis tool I developed and
> confirmed by manual review. Fix this by calling platform_device_put()
> when platform_device_register() fails.
>
> Fixes: 730e5ebff40c8 ("gpio: omap: do not register driver in probe()")
> Cc: stable@vger.kernel.org
> Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
> ---
>  drivers/gpio/gpio-omap.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> index e39723b5901b..841bef431c22 100644
> --- a/drivers/gpio/gpio-omap.c
> +++ b/drivers/gpio/gpio-omap.c
> @@ -800,11 +800,15 @@ static struct platform_device omap_mpuio_device = {
>  static inline void omap_mpuio_init(struct gpio_bank *bank)
>  {
>         static bool registered;
> +       int ret;
>
>         platform_set_drvdata(&omap_mpuio_device, bank);
>         if (!registered) {
> -               (void)platform_device_register(&omap_mpuio_device);
> -               registered = true;
> +               ret = platform_device_register(&omap_mpuio_device);
> +               if (ret)
> +                       platform_device_put(&omap_mpuio_device);
> +               else
> +                       registered = true;
>         }
>  }
>
> --
> 2.43.0
>

After re-checking it, omap_mpuio_device is a static platform_device and
it does not provide a dev.release callback. Therefore calling
platform_device_put() on the platform_device_register() failure path is
not appropriate here and can trigger the missing release callback warning.

This falls into the same static platform_device pattern pointed out in
the other reviews, so I will drop this patch.

Sorry for the noise.

Best regards,
Guangshuo Li