On Sat, 23 Sep 2023, Armin Wolf wrote:
> If a duplicate attribute is found using kset_find_obj(), a reference
> to that attribute is returned which needs to be disposed accordingly
> using kobject_put(). Move the setting name validation into a separate
> function to allow for this change without having to duplicate the
> cleanup code for this setting.
> As a side note, a very similar bug was fixed in
> commit 7295a996fdab ("platform/x86: dell-sysman: Fix reference leak"),
> so it seems that the bug was copied from that driver.
>
> Compile-tested only.
>
> Fixes: 1bcad8e510b2 ("platform/x86: think-lmi: Fix issues with duplicate attributes")
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
> drivers/platform/x86/think-lmi.c | 24 ++++++++++++++++++++----
> 1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
> index 4be6f28d4600..3a396b763c49 100644
> --- a/drivers/platform/x86/think-lmi.c
> +++ b/drivers/platform/x86/think-lmi.c
> @@ -1344,6 +1344,24 @@ static void tlmi_release_attr(void)
> kset_unregister(tlmi_priv.authentication_kset);
> }
>
> +static int tlmi_validate_setting_name(struct kset *attribute_kset, char *name)
> +{
> + struct kobject *duplicate;
> +
> + if (!strcmp(name, "Reserved"))
> + return -EINVAL;
> +
> + duplicate = kset_find_obj(attribute_kset, name);
> + if (duplicate) {
> + pr_debug("Duplicate attribute name found - %s\n", name);
> + /* kset_find_obj() returns a reference */
> + kobject_put(duplicate);
> + return -EBUSY;
> + }
> +
> + return 0;
> +}
> +
> static int tlmi_sysfs_init(void)
> {
> int i, ret;
> @@ -1372,10 +1390,8 @@ static int tlmi_sysfs_init(void)
> continue;
>
> /* check for duplicate or reserved values */
> - if (kset_find_obj(tlmi_priv.attribute_kset, tlmi_priv.setting[i]->display_name) ||
> - !strcmp(tlmi_priv.setting[i]->display_name, "Reserved")) {
> - pr_debug("duplicate or reserved attribute name found - %s\n",
> - tlmi_priv.setting[i]->display_name);
> + if (tlmi_validate_setting_name(tlmi_priv.attribute_kset,
> + tlmi_priv.setting[i]->display_name) < 0) {
> kfree(tlmi_priv.setting[i]->possible_values);
> kfree(tlmi_priv.setting[i]);
> tlmi_priv.setting[i] = NULL;
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
There seem to be two more of these in hp-bioscfg.
--
i.
