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@xxxxxxxxxxxxxxx
Cc: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Signed-off-by: Hans de Goede <hansg@xxxxxxxxxx>
---
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
