2022-03-02 10:13:42

by Hangyu Hua

Subject: [PATCH v2] powerpc: kernel: fix refcount leak in format_show()

Refcount leak will happen when format_show returns failure in multiple
cases. Unified management of of_node_put can fix this problem.

Signed-off-by: Hangyu Hua <[email protected]>
---

v2:
1. change the title and description information.
2. fix all possible refcount leak.

arch/powerpc/kernel/secvar-sysfs.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c
index a0a78aba2083..1ee4640a2641 100644
--- a/arch/powerpc/kernel/secvar-sysfs.c
+++ b/arch/powerpc/kernel/secvar-sysfs.c
@@ -26,15 +26,18 @@ static ssize_t format_show(struct kobject *kobj, struct kobj_attribute *attr,
const char *format;

node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend");
- if (!of_device_is_available(node))
- return -ENODEV;
+ if (!of_device_is_available(node)) {
+ rc = -ENODEV;
+ goto out;
+ }

rc = of_property_read_string(node, "format", &format);
if (rc)
- return rc;
+ goto out;

rc = sprintf(buf, "%s\n", format);

+out:
of_node_put(node);

return rc;
--
2.25.1

2022-03-07 05:59:10

by Hangyu Hua

Subject: Re: [PATCH v2] powerpc: kernel: fix refcount leak in format_show()

Any further suggestions for this patch? guys.

Thanks.

On 2022/3/2 10:19, Hangyu Hua wrote:
> Refcount leak will happen when format_show returns failure in multiple
> cases. Unified management of of_node_put can fix this problem.
>
> Signed-off-by: Hangyu Hua <[email protected]>
> ---
>
> v2:
> 1. change the title and description information.
> 2. fix all possible refcount leak.
>
> arch/powerpc/kernel/secvar-sysfs.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c
> index a0a78aba2083..1ee4640a2641 100644
> --- a/arch/powerpc/kernel/secvar-sysfs.c
> +++ b/arch/powerpc/kernel/secvar-sysfs.c
> @@ -26,15 +26,18 @@ static ssize_t format_show(struct kobject *kobj, struct kobj_attribute *attr,
> const char *format;
>
> node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend");
> - if (!of_device_is_available(node))
> - return -ENODEV;
> + if (!of_device_is_available(node)) {
> + rc = -ENODEV;
> + goto out;
> + }
>
> rc = of_property_read_string(node, "format", &format);
> if (rc)
> - return rc;
> + goto out;
>
> rc = sprintf(buf, "%s\n", format);
>
> +out:
> of_node_put(node);
>
> return rc;

2022-03-12 13:33:11

by Michael Ellerman

Subject: Re: [PATCH v2] powerpc: kernel: fix refcount leak in format_show()

On Wed, 2 Mar 2022 10:19:59 +0800, Hangyu Hua wrote:
> Refcount leak will happen when format_show returns failure in multiple
> cases. Unified management of of_node_put can fix this problem.
>
>

Applied to powerpc/next.

[1/1] powerpc: kernel: fix refcount leak in format_show()
https://git.kernel.org/powerpc/c/d601fd24e6964967f115f036a840f4f28488f63f

cheers