Re: [PATCH v2] power: supply: fix null pointer dereferencing in power_supply_get_battery_info

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 12/5/2022 3:51 PM, ruanjinjie wrote:
> when kmalloc() fail to allocate memory in kasprintf(), propname
> will be NULL, strcmp() called by of_get_property() will cause
> null pointer dereference.
> 
> So return ENOMEM if kasprintf() return NULL pointer.
> 
> Fixes: 3afb50d7125b ("power: supply: core: Add some helpers to use the battery OCV capacity table")
> Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>

LGTM.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>

> ---
> v2:
> - release resource instead of just returning error number
> ---
>   drivers/power/supply/power_supply_core.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
> index 4b5fb172fa99..afbe9eecfc30 100644
> --- a/drivers/power/supply/power_supply_core.c
> +++ b/drivers/power/supply/power_supply_core.c
> @@ -750,6 +750,11 @@ int power_supply_get_battery_info(struct power_supply *psy,
>   		int i, tab_len, size;
>   
>   		propname = kasprintf(GFP_KERNEL, "ocv-capacity-table-%d", index);
> +		if (!propname) {
> +			power_supply_put_battery_info(psy, info);
> +			err = -ENOMEM;
> +			goto out_put_node;
> +		}
>   		list = of_get_property(battery_np, propname, &size);
>   		if (!list || !size) {
>   			dev_err(&psy->dev, "failed to get %s\n", propname);