SB2026091260 - Out-of-bounds read in Linux kernel pci driver

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds read (CVE-ID: CVE-2026-89722)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause an out-of-bounds memory read and write unintended values to PCI I/O ports.

The vulnerability exists due to an unconditional 32-bit load in pci_write_legacy_io() when processing one- or two-byte writes to the legacy_io sysfs file. A local privileged user can submit a one- or two-byte write to the legacy_io sysfs file to cause an out-of-bounds memory read and write unintended values to PCI I/O ports.

The legacy_io sysfs file is available only on Alpha and PowerPC systems that define HAVE_PCI_LEGACY.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/7a99e9c7011905734cc2739038f2a224b6be0d1f
• https://git.kernel.org/stable/c/dc76258d0132df1d831a5a29758bd448ca9c566e
• https://git.kernel.org/stable/c/e892f05f1f790d5721cd8e3c561ed76da7e08bae