Medium [CVE-2026-68440] fix heap overflow when reading module EEPROM

In the Linux kernel, the following vulnerability has been resolved: net: txgbe: fix heap overflow when reading module EEPROM txgbe_read_eeprom_hostif() always copies round_up(length, 4) bytes into the caller buffer, which ethtool allocates with exactly 'length' bytes. A non-4-aligned length therefore causes an out-of-bounds write.

Copy only the remaining bytes on the final dword instead. A flaw was found in the Linux kernel's txgbe network driver.

When reading module EEPROM (Electrically Erasable Programmable Read-Only Memory), the txgbe_read_eeprom_hostif() function can attempt to copy more data than the allocated buffer size if the data length is not a multiple of four. This out-of-bounds write can lead to memory corruption, potentially causing system instability or a denial of service.

This issue affects Wangxun txgbe network adapters. ethtool EEPROM reads with non-4-byte-aligned lengths cause txgbe_read_eeprom_hostif() to write past the caller buffer. Systems without txgbe hardware are not affected.

Red Hat severity: Moderate — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-787.

Red Hat lists Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat Enterprise Linux for NVIDIA 26; Red Hat OpenShift Container Platform 4 as not affected.