In the Linux kernel, the following vulnerability has been resolved:

net: ethtool: fix NULL pointer dereference in phy_reply_size

In phy_prepare_data(), several strings such as 'name', 'drvname',
'upstream_sfp_name', and 'downstream_sfp_name' are allocated using
kstrdup(). However, these allocations were not checked for failure.

If kstrdup() fails for 'name', it returns NULL while the function
continues. This leads to a kernel NULL pointer dereference and panic
later in phy_reply_size() when it unconditionally calls strlen() on
the NULL pointer.

While other strings like 'upstream_sfp_name' might be checked before
access in certain code paths, failing to handle these allocations
consistently can lead to incomplete data reporting or hidden bugs.

Fix this by adding proper NULL checks for all kstrdup() calls in
phy_prepare_data() and implement a centralized error handling path
using goto labels to ensure all previously allocated resources are
freed on failure.

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Sun, 19 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: net: ethtool: fix NULL pointer dereference in phy_reply_size In phy_prepare_data(), several strings such as 'name', 'drvname', 'upstream_sfp_name', and 'downstream_sfp_name' are allocated using kstrdup(). However, these allocations were not checked for failure. If kstrdup() fails for 'name', it returns NULL while the function continues. This leads to a kernel NULL pointer dereference and panic later in phy_reply_size() when it unconditionally calls strlen() on the NULL pointer. While other strings like 'upstream_sfp_name' might be checked before access in certain code paths, failing to handle these allocations consistently can lead to incomplete data reporting or hidden bugs. Fix this by adding proper NULL checks for all kstrdup() calls in phy_prepare_data() and implement a centralized error handling path using goto labels to ensure all previously allocated resources are freed on failure.
Title net: ethtool: fix NULL pointer dereference in phy_reply_size
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-07-19T15:40:19.044Z

Reserved: 2026-07-19T07:54:57.036Z

Link: CVE-2026-64120

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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