power: supply: ab8500: Fix memory leak in ab8500_chargalg_sysfs_init

[PATCH] power: supply: ab8500: Fix memory leak in ab8500_chargalg_sysfs_init

Posted by Miaoqian Lin 4 years, 5 months ago

kobject_init_and_add() takes reference even when it fails.
According to the doc of kobject_init_and_add()

   If this function returns an error, kobject_put() must be called to
   properly clean up the memory associated with the object.

Fix this issue by adding kobject_put().

Fixes: c5b64a990e7f ("power: supply: ab8500: Rename charging algorithm symbols")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
---
 drivers/power/supply/ab8500_chargalg.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/power/supply/ab8500_chargalg.c b/drivers/power/supply/ab8500_chargalg.c
index c4a2fe07126c..658139797509 100644
--- a/drivers/power/supply/ab8500_chargalg.c
+++ b/drivers/power/supply/ab8500_chargalg.c
@@ -1907,8 +1907,10 @@ static int ab8500_chargalg_sysfs_init(struct ab8500_chargalg *di)
 	ret = kobject_init_and_add(&di->chargalg_kobject,
 		&ab8500_chargalg_ktype,
 		NULL, "ab8500_chargalg");
-	if (ret < 0)
+	if (ret < 0) {
 		dev_err(di->dev, "failed to create sysfs entry\n");
+		kobject_put(&di->chargalg_kobject);
+	}
 
 	return ret;
 }
-- 
2.17.1

Re: [PATCH] power: supply: ab8500: Fix memory leak in ab8500_chargalg_sysfs_init

Posted by Linus Walleij 4 years, 5 months ago

On Fri, Jan 28, 2022 at 6:33 PM Miaoqian Lin <linmq006@gmail.com> wrote:

> kobject_init_and_add() takes reference even when it fails.
> According to the doc of kobject_init_and_add()
>
>    If this function returns an error, kobject_put() must be called to
>    properly clean up the memory associated with the object.
>
> Fix this issue by adding kobject_put().
>
> Fixes: c5b64a990e7f ("power: supply: ab8500: Rename charging algorithm symbols")

Really? I think this code is older.

> @@ -1907,8 +1907,10 @@ static int ab8500_chargalg_sysfs_init(struct ab8500_chargalg *di)
>         ret = kobject_init_and_add(&di->chargalg_kobject,
>                 &ab8500_chargalg_ktype,
>                 NULL, "ab8500_chargalg");
> -       if (ret < 0)
> +       if (ret < 0) {
>                 dev_err(di->dev, "failed to create sysfs entry\n");
> +               kobject_put(&di->chargalg_kobject);
> +       }

I wouldn't bother with this.

This code is getting deleted in this patch:
https://lore.kernel.org/linux-pm/20220129004925.639684-10-linus.walleij@linaro.org/T/#u

Yours,
Linus Walleij