CVE-2025-40255: net: core: prevent NULL deref in generic_hwtstamp_ioctl_lower()

Deferred
AliasesUBUNTU-CVE-2025-40255DEBIAN-CVE-2025-40255
Published 04-12-2025Last modified 11-05-2026

Vulnerability summary

CVE-2025-40255 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.2% of scored vulnerabilities.

Priority
Insufficient evidence

No CVSS vector published; no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
Not scored
010
No CVSS score recorded
EPSS score
0.19%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 11 · Related 11
OPENSUSE-SU-2026:20145-1SUSE-SU-2026:20207-1SUSE-SU-2026:20220-1SUSE-SU-2026:20228-1SUSE-SU-2026:20564-1USN-8094-1

Timeline

  1. 04-12-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

Risk metrics not yet published.

EPSS trend

Probability

0.19%

Chance of exploitation in the next 30 days

Percentile

8%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.19% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: not stated in public data.

Ubuntu107 products
  • linux< 6.17.0-19.19
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.17.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.17.10-1
Linux1 product
  • linux≥ 6e9e2eed4f39d52edf5fd006409d211facf49f6b, < 8817f816ae41908e9625c0770c4af0dcdcc01238 | ≥ 6e9e2eed4f39d52edf5fd006409d211facf49f6b, < f796a8dec9beafcc0f6f0d3478ed685a15c5e062 | 6.14

3 vendors · 109 products

References

12 links
Show all 12 references