2023-01-03 13:13:37

by Yang Yingliang

Subject: [PATCH] powercap: fix possible name leak in powercap_register_zone()

In the error path after calling dev_set_name(), the device
name is leaked. To fix this, calling dev_set_name() before
device_register(), and call put_device() if it returns error.
All the resources is released in powercap_release(), so it
can return from powercap_register_zone() directly.

Fixes: 75d2364ea0ca ("PowerCap: Add class driver")
Signed-off-by: Yang Yingliang <[email protected]>
---
drivers/powercap/powercap_sys.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c
index 1f968353d479..e180dee0f83d 100644
--- a/drivers/powercap/powercap_sys.c
+++ b/drivers/powercap/powercap_sys.c
@@ -530,9 +530,6 @@ struct powercap_zone *powercap_register_zone(
power_zone->name = kstrdup(name, GFP_KERNEL);
if (!power_zone->name)
goto err_name_alloc;
- dev_set_name(&power_zone->dev, "%s:%x",
- dev_name(power_zone->dev.parent),
- power_zone->id);
power_zone->constraints = kcalloc(nr_constraints,
sizeof(*power_zone->constraints),
GFP_KERNEL);
@@ -555,9 +552,16 @@ struct powercap_zone *powercap_register_zone(
power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
power_zone->dev_attr_groups[1] = NULL;
power_zone->dev.groups = power_zone->dev_attr_groups;
+ dev_set_name(&power_zone->dev, "%s:%x",
+ dev_name(power_zone->dev.parent),
+ power_zone->id);
result = device_register(&power_zone->dev);
- if (result)
- goto err_dev_ret;
+ if (result) {
+ put_device(&power_zone->dev);
+ mutex_unlock(&control_type->lock);
+
+ return ERR_PTR(result);
+ }

control_type->nr_zones++;
mutex_unlock(&control_type->lock);
--
2.25.1

2023-01-20 14:23:35

by Rafael J. Wysocki

Subject: Re: [PATCH] powercap: fix possible name leak in powercap_register_zone()

On Tue, Jan 3, 2023 at 1:38 PM Yang Yingliang <[email protected]> wrote:
>
> In the error path after calling dev_set_name(), the device
> name is leaked. To fix this, calling dev_set_name() before
> device_register(), and call put_device() if it returns error.
> All the resources is released in powercap_release(), so it
> can return from powercap_register_zone() directly.
>
> Fixes: 75d2364ea0ca ("PowerCap: Add class driver")
> Signed-off-by: Yang Yingliang <[email protected]>
> ---
> drivers/powercap/powercap_sys.c | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/powercap/powercap_sys.c b/drivers/powercap/powercap_sys.c
> index 1f968353d479..e180dee0f83d 100644
> --- a/drivers/powercap/powercap_sys.c
> +++ b/drivers/powercap/powercap_sys.c
> @@ -530,9 +530,6 @@ struct powercap_zone *powercap_register_zone(
> power_zone->name = kstrdup(name, GFP_KERNEL);
> if (!power_zone->name)
> goto err_name_alloc;
> - dev_set_name(&power_zone->dev, "%s:%x",
> - dev_name(power_zone->dev.parent),
> - power_zone->id);
> power_zone->constraints = kcalloc(nr_constraints,
> sizeof(*power_zone->constraints),
> GFP_KERNEL);
> @@ -555,9 +552,16 @@ struct powercap_zone *powercap_register_zone(
> power_zone->dev_attr_groups[0] = &power_zone->dev_zone_attr_group;
> power_zone->dev_attr_groups[1] = NULL;
> power_zone->dev.groups = power_zone->dev_attr_groups;
> + dev_set_name(&power_zone->dev, "%s:%x",
> + dev_name(power_zone->dev.parent),
> + power_zone->id);
> result = device_register(&power_zone->dev);
> - if (result)
> - goto err_dev_ret;
> + if (result) {
> + put_device(&power_zone->dev);
> + mutex_unlock(&control_type->lock);
> +
> + return ERR_PTR(result);
> + }
>
> control_type->nr_zones++;
> mutex_unlock(&control_type->lock);
> --

Applied as 6.3 material, thanks!