2023-08-05 06:44:23

by Armin Wolf

Subject: [PATCH] platform/x86: dell-sysman: Fix reference leak

If a duplicate attribute is found using kset_find_obj(),
a reference to that attribute is returned. This means
that we need to dispose it accordingly. Use kobject_put()
to dispose the duplicate attribute in such a case.

Compile-tested only.

Fixes: e8a60aa7404b ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems")
Signed-off-by: Armin Wolf <[email protected]>
---
drivers/platform/x86/dell/dell-wmi-sysman/sysman.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
index b68dd11cb892..b929b4f82420 100644
--- a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
+++ b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
@@ -393,6 +393,7 @@ static int init_bios_attributes(int attr_type, const char *guid)
struct kobject *attr_name_kobj; //individual attribute names
union acpi_object *obj = NULL;
union acpi_object *elements;
+ struct kobject *duplicate;
struct kset *tmp_set;
int min_elements;

@@ -451,9 +452,11 @@ static int init_bios_attributes(int attr_type, const char *guid)
else
tmp_set = wmi_priv.main_dir_kset;

- if (kset_find_obj(tmp_set, elements[ATTR_NAME].string.pointer)) {
- pr_debug("duplicate attribute name found - %s\n",
- elements[ATTR_NAME].string.pointer);
+ duplicate = kset_find_obj(tmp_set, elements[ATTR_NAME].string.pointer);
+ if (duplicate) {
+ pr_debug("Duplicate attribute name found - %s\n",
+ elements[ATTR_NAME].string.pointer);
+ kobject_put(duplicate);
goto nextobj;
}

--
2.39.2

2023-08-09 20:24:33

by Hans de Goede

Subject: Re: [PATCH] platform/x86: dell-sysman: Fix reference leak

Hi,

On 8/5/23 07:36, Armin Wolf wrote:
> If a duplicate attribute is found using kset_find_obj(),
> a reference to that attribute is returned. This means
> that we need to dispose it accordingly. Use kobject_put()
> to dispose the duplicate attribute in such a case.
>
> Compile-tested only.
>
> Fixes: e8a60aa7404b ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems")
> Signed-off-by: Armin Wolf <[email protected]>

Thank you for your patch, I've applied this patch to my review-hans
branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once I've run some tests on this branch the patches there will be
added to the platform-drivers-x86/for-next branch and eventually
will be included in the pdx86 pull-request to Linus for the next
merge-window.

Regards,

Hans



> ---
> drivers/platform/x86/dell/dell-wmi-sysman/sysman.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
> index b68dd11cb892..b929b4f82420 100644
> --- a/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
> +++ b/drivers/platform/x86/dell/dell-wmi-sysman/sysman.c
> @@ -393,6 +393,7 @@ static int init_bios_attributes(int attr_type, const char *guid)
> struct kobject *attr_name_kobj; //individual attribute names
> union acpi_object *obj = NULL;
> union acpi_object *elements;
> + struct kobject *duplicate;
> struct kset *tmp_set;
> int min_elements;
>
> @@ -451,9 +452,11 @@ static int init_bios_attributes(int attr_type, const char *guid)
> else
> tmp_set = wmi_priv.main_dir_kset;
>
> - if (kset_find_obj(tmp_set, elements[ATTR_NAME].string.pointer)) {
> - pr_debug("duplicate attribute name found - %s\n",
> - elements[ATTR_NAME].string.pointer);
> + duplicate = kset_find_obj(tmp_set, elements[ATTR_NAME].string.pointer);
> + if (duplicate) {
> + pr_debug("Duplicate attribute name found - %s\n",
> + elements[ATTR_NAME].string.pointer);
> + kobject_put(duplicate);
> goto nextobj;
> }
>
> --
> 2.39.2
>