🛡️ CVE-2025-40255 on Debian — linux

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Distribution advisory

This page covers CVE-2025-40255 as tracked by Debian, for the package linux. The fix is available in version 6.17.10-1; earlier versions remain affected.

Affected software

DEBIAN-CVE-2025-40255 is recorded against 1 package.

  • linux (fixed in 6.17.10-1)

Timeline and source

Published on 4 December 2025 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2025-40255 on other distributions

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Details

Severity Unknown
CVSS Score N/A
CVSS Vector N/A
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2025-12-04
Updated 2026-08-11
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
linux — 6.17.10-1

Similar Threats

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