CVE-2023-54065: net: dsa: realtek: fix out-of-bounds access

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-12-24 · updated 2026-08-04

Description

In the Linux kernel, the following vulnerability has been resolved: net: dsa: realtek: fix out-of-bounds access The probe function sets priv->chip_data to (void *)priv + sizeof(*priv) with the expectation that priv has enough trailing space. However, only realtek-smi actually allocated this chip_data space. Do likewise in realtek-mdio to fix out-of-bounds accesses. These accesses likely went unnoticed so far, because of an (unused) buf[4096] member in struct realtek_priv, which caused kmalloc to round up the allocated buffer to a big enough size, so nothing of value was overwritten. With a different allocator (like in the barebox bootloader port of the driver) or with KASAN, the memory corruption becomes quickly apparent.

Affected products

Linux kernel: 5.18 — fixed in 6.3

How to fix

Upgrade to a fixed version: Linux kernel 6.3. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2023-54065 or the next vulnerability affects your stack