On Sat, Sep 13, 2025 at 01:35:15PM +0200, Hans de Goede wrote:

Since commit 7d5e9737efda ("net: rfkill: gpio: get the name and type from device property") rfkill_find_type() gets called with the possibly uninitialized "const char *type_name;" local variable.

On x86 systems when rfkill-gpio binds to a "BCM4752" or "LNV4752" acpi_device, the rfkill->type is set based on the ACPI acpi_device_id:

    rfkill->type = (unsigned)id->driver_data;

and there is no "type" property so device_property_read_string() will fail and leave type_name uninitialized, leading to a potential crash.

rfkill_find_type() does accept a NULL pointer, fix the potential crash by initializing type_name to NULL.

Note likely sofar this has not been caught because:

1. Not many x86 machines actually have a "BCM4752"/"LNV4752" acpi_device
2. The stack happened to contain NULL where type_name is stored

Fixes: 7d5e9737efda ("net: rfkill: gpio: get the name and type from device property") Cc: stable@vger.kernel.org Cc: Heikki Krogerus heikki.krogerus@linux.intel.com Signed-off-by: Hans de Goede hansg@kernel.org

FWIW:

Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com

---

Changes in v2:

• Fix typo in stable email address

---

net/rfkill/rfkill-gpio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/rfkill/rfkill-gpio.c b/net/rfkill/rfkill-gpio.c index 41e657e97761..cf2dcec6ce5a 100644 --- a/net/rfkill/rfkill-gpio.c +++ b/net/rfkill/rfkill-gpio.c @@ -94,10 +94,10 @@ static const struct dmi_system_id rfkill_gpio_deny_table[] = { static int rfkill_gpio_probe(struct platform_device *pdev) { struct rfkill_gpio_data *rfkill;

• struct gpio_desc *gpio;

• const char *type_name = NULL; const char *name_property; const char *type_property;

• const char *type_name;

• struct gpio_desc *gpio; int ret;

if (dmi_check_system(rfkill_gpio_deny_table)) -- 2.51.0