NULL pointer dereference in Linux

CVE-2025-21695

In the Linux kernel, the following vulnerability has been resolved: platform/x86: dell-uart-backlight: fix serdev race The dell_uart_bl_serdev_probe() function calls devm_serdev_device_open() before setting the client ops via serdev_device_set_client_ops(). This ordering can trigger a NULL pointer dereference in the serdev controller's receive_buf handler, as it assumes serdev->ops is valid when SERPORT_ACTIVE is set. This is similar to the issue fixed in commit 5e700b384ec1 ("platform/chrome: cros_ec_uart: properly fix race condition") where devm_serdev_device_open() was called before fully initializing the device. Fix the race by ensuring client ops are set before enabling the port via devm_serdev_device_open(). Note, serdev_device_set_baudrate() and serdev_device_set_flow_control() calls should be after the devm_serdev_device_open() call.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.7 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (6.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 6.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-21695: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000

Affected products

  • Linux — versions 484bae9e4d6acb5eec39e1ea47f9aa43f11b154d, 6.10, 0
  • Linux Kernel — versions 6.13

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-21695?
CVE-2025-21695 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 4.7/10. Published 2025-02-12.
How severe is CVE-2025-21695?
Medium severity. CVSS v3 base score is 4.7 out of 10.