In the Linux kernel, the following vulnerability has been resolved: net: ethtool: fix NULL pointer dereference in phy_reply_size In… (CVE-2026-64120)
A NULL pointer dereference vulnerability in the Linux kernel's ethtool component was fixed. The issue occurs in the phy_prepare_data() function where memory allocation failures from kstrdup() were not checked, leading to a NULL pointer dereference and kernel panic in phy_reply_size(). This could cause a denial of service by crashing the kernel. The fix adds proper NULL checks and centralized error handling to prevent this condition.
AI Analysis
Technical Summary
The vulnerability (CVE-2026-64120) resides in the Linux kernel's ethtool code, specifically in the phy_prepare_data() function. Several strings are allocated using kstrdup() without verifying if the allocation succeeded. If kstrdup() returns NULL (allocation failure), subsequent code calls strlen() on the NULL pointer in phy_reply_size(), causing a kernel NULL pointer dereference and panic. The patch introduces NULL pointer checks for all kstrdup() calls and a centralized error handling path to free allocated resources on failure, preventing kernel crashes.
Potential Impact
This vulnerability can cause a denial of service by triggering a kernel panic due to a NULL pointer dereference. There is no indication of confidentiality or integrity impact. The CVSS score of 5.5 (medium severity) reflects the local attack vector requiring low privileges and no user interaction, with no confidentiality or integrity impact but high availability impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is applied, avoid conditions that could cause kstrdup() to fail in the affected code paths. Monitor for updates from the Linux kernel maintainers regarding an official fix.
In the Linux kernel, the following vulnerability has been resolved: net: ethtool: fix NULL pointer dereference in phy_reply_size In… (CVE-2026-64120)
Description
A NULL pointer dereference vulnerability in the Linux kernel's ethtool component was fixed. The issue occurs in the phy_prepare_data() function where memory allocation failures from kstrdup() were not checked, leading to a NULL pointer dereference and kernel panic in phy_reply_size(). This could cause a denial of service by crashing the kernel. The fix adds proper NULL checks and centralized error handling to prevent this condition.
CVSS v3.1
Score 5.5medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability (CVE-2026-64120) resides in the Linux kernel's ethtool code, specifically in the phy_prepare_data() function. Several strings are allocated using kstrdup() without verifying if the allocation succeeded. If kstrdup() returns NULL (allocation failure), subsequent code calls strlen() on the NULL pointer in phy_reply_size(), causing a kernel NULL pointer dereference and panic. The patch introduces NULL pointer checks for all kstrdup() calls and a centralized error handling path to free allocated resources on failure, preventing kernel crashes.
Potential Impact
This vulnerability can cause a denial of service by triggering a kernel panic due to a NULL pointer dereference. There is no indication of confidentiality or integrity impact. The CVSS score of 5.5 (medium severity) reflects the local attack vector requiring low privileges and no user interaction, with no confidentiality or integrity impact but high availability impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a patch is applied, avoid conditions that could cause kstrdup() to fail in the affected code paths. Monitor for updates from the Linux kernel maintainers regarding an official fix.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-4j8v-vv2j-8xpv
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-64120"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27a92a4a8d598912bbd0
Added to database: 07/19/2026, 19:38:17 UTC
Last enriched: 08/13/2026, 19:15:54 UTC
Last updated: 09/01/2026, 10:52:10 UTC
Views: 57
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