|
Vulnerabilities
< Back

CVE-2025-39937

Updated on 04 Oct 2025

Severity

5.5 Medium severity

Details

CVSS score
5.5
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE ID
Links
NISTCIRCLRHELUbuntu

Overview

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

net: rfkill: gpio: Fix crash due to dereferencering uninitialized pointer

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

Details

Affected product:
AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
Affected packages:
linux-hwe @ 4.15.0 (+8 more)

In the Linux kernel, the following vulnerability has been resolved:

net: rfkill: gpio: Fix crash due to dereferencering uninitialized pointer

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