NULL pointer dereference in Linux

CVE-2025-39937

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

EPSS: 0.001 (3.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-39937?
CVE-2025-39937 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2025-10-04.
How severe is CVE-2025-39937?
Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2025-39937 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.