CVE-2025-40255
net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()
Description
In the Linux kernel, the following vulnerability has been resolved: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower() The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL.
INFO
Published Date :
Dec. 4, 2025, 4:16 p.m.
Last Modified :
Dec. 4, 2025, 5:15 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2025-40255
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Add a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower().
- Return -EINVAL if ifr is NULL.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-40255.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/8817f816ae41908e9625c0770c4af0dcdcc01238 | |
| https://git.kernel.org/stable/c/f796a8dec9beafcc0f6f0d3478ed685a15c5e062 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-40255 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-40255
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-40255 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-40255 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Dec. 04, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower() The ethtool tsconfig Netlink path can trigger a null pointer dereference. A call chain such as: tsconfig_prepare_data() -> dev_get_hwtstamp_phylib() -> vlan_hwtstamp_get() -> generic_hwtstamp_get_lower() -> generic_hwtstamp_ioctl_lower() results in generic_hwtstamp_ioctl_lower() being called with kernel_cfg->ifr as NULL. The generic_hwtstamp_ioctl_lower() function does not expect a NULL ifr and dereferences it, leading to a system crash. Fix this by adding a NULL check for kernel_cfg->ifr in generic_hwtstamp_ioctl_lower(). If ifr is NULL, return -EINVAL. Added Reference https://git.kernel.org/stable/c/8817f816ae41908e9625c0770c4af0dcdcc01238 Added Reference https://git.kernel.org/stable/c/f796a8dec9beafcc0f6f0d3478ed685a15c5e062