Re: [PATCH v2] acpi: battery: Sanitise model_number by dropping unprintable characters

[Rafael J. Wysocki (Intel)]

On Fri, Jul 10, 2026 at 5:36 PM Mark Pearson <mpearson-lenovo@xxxxxxxxx> wrote:
>
> On Fri, Jul 10, 2026, at 8:51 AM, Kate Hsuan wrote:
> > The battery Embedded Controller (EC) may return the model name with
> > trailing unprintable or non-ASCII characters. For example, on some systems:
> >
> > $ cat /sys/class/power_supply/BAT0/model_name
> > LNV-5B10W51864��
> >
> > If a non-ASCII or an unprintable character is found, it will be replaced
> > with '\0' to ensure the model_number is a valid string. If left intact,
> > the malformed string prevents udev rules and hwdb working correctly.
> >
> > Link: https://gitlab.freedesktop.org/upower/upower/-/work_items/345
> >
> > Signed-off-by: Kate Hsuan <hpa@xxxxxxxxxx>
> > ---
> >  drivers/acpi/battery.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> >
> > diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
> > index f5e0eb299610..4409fb95b988 100644
> > --- a/drivers/acpi/battery.c
> > +++ b/drivers/acpi/battery.c
> > @@ -10,6 +10,7 @@
> >
> >  #define pr_fmt(fmt) "ACPI: battery: " fmt
> >
> > +#include <linux/ctype.h>
> >  #include <linux/delay.h>
> >  #include <linux/dmi.h>
> >  #include <linux/jiffies.h>
> > @@ -483,6 +484,15 @@ static int acpi_battery_get_status(struct
> > acpi_battery *battery)
> >       return 0;
> >  }
> >
> > +static void acpi_battery_clean_unprintable_chars(char *str, size_t length)
> > +{
> > +     for (unsigned int i = 0; i < length; i++) {
> > +             if (!isascii(str[i]) || !isprint(str[i])) {
> > +                     str[i] = '\0';
> > +                     break;
> > +             }
> > +     }
> > +}
> >
> >  static int extract_battery_info(const int use_bix,
> >                        struct acpi_battery *battery,
> > @@ -524,6 +534,10 @@ static int extract_battery_info(const int use_bix,
> >           battery->capacity_now > battery->full_charge_capacity)
> >               battery->capacity_now = battery->full_charge_capacity;
> >
> > +     if (!result)
> > +             acpi_battery_clean_unprintable_chars(battery->model_number,
> > +                                     ARRAY_SIZE(battery->model_number));
> > +
> >       return result;
> >  }
> >
> > --
> > 2.55.0
>
> Thanks Kate - I know this impacts a few of our platforms and it will be great to have this fix.
>
> Implementation looks good to me.
> Reviewed-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>

Applied as 7.3 material, thanks!