Hi, On Sat, May 02, 2020 at 04:10:56PM -0500, wu000...@umn.edu wrote: > From: Qiushi Wu <wu000...@umn.edu> > > In function power_supply_add_hwmon_sysfs(), psyhw->props is > allocated by bitmap_zalloc(). But this pointer is not deallocated > in several error paths, which lead to memory leak bugs. To fix > this, we can call bitmap_free() to free this pointer. > > Signed-off-by: Qiushi Wu <wu000...@umn.edu> > ---
You are correct, that there is a problem in the first instance, but
the other changes are incorrect and introduce a new double free. Please
read documentation for devm_add_action(). The proper fix is to just
replace the call to devm_add_action() with devm_add_action_or_reset().
Please send a new version for this. Also please add the following
tag:
Fixes: e67d4dfc9ff19 ("power: supply: Add HWMON compatibility layer")
Thanks,
-- Sebastian
> drivers/power/supply/power_supply_hwmon.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/power/supply/power_supply_hwmon.c
> b/drivers/power/supply/power_supply_hwmon.c
> index 75cf861ba492..7453390ab7a4 100644
> --- a/drivers/power/supply/power_supply_hwmon.c
> +++ b/drivers/power/supply/power_supply_hwmon.c
> @@ -307,7 +307,7 @@ int power_supply_add_hwmon_sysfs(struct power_supply *psy)
> ret = devm_add_action(dev, power_supply_hwmon_bitmap_free,
> psyhw->props);
> if (ret)
> - goto error;
> + goto out_free;
>
> for (i = 0; i < desc->num_properties; i++) {
> const enum power_supply_property prop = desc->properties[i];
> @@ -342,7 +342,7 @@ int power_supply_add_hwmon_sysfs(struct power_supply *psy)
> new_name = devm_kstrdup(dev, name, GFP_KERNEL);
> if (!new_name) {
> ret = -ENOMEM;
> - goto error;
> + goto out_free;
> }
> strreplace(new_name, '-', '_');
> name = new_name;
> @@ -353,10 +353,12 @@ int power_supply_add_hwmon_sysfs(struct power_supply
> *psy)
> NULL);
> ret = PTR_ERR_OR_ZERO(hwmon);
> if (ret)
> - goto error;
> + goto out_free;
>
> devres_close_group(dev, power_supply_add_hwmon_sysfs);
> return 0;
> +out_free:
> + bitmap_free(psyhw->props);
> error:
> devres_release_group(dev, NULL);
> return ret;
> --
> 2.17.1
>
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