SB20260917164 - Improper control of a resource through its lifetime in Linux kernel s390 PCI hotplug slot handling

Description

This security bulletin contains information about 1 vulnerability.

1) Improper control of a resource through its lifetime (CVE-ID: CVE-2026-89795)

CWE-ID: CWE-664 - Improper control of a resource through its lifetime

CVSSv4: 6.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to reset an unintended PCI function and leak memory.

The vulnerability exists due to improper PCI slot assignment in the s390 PCI hotplug slot handling when requesting a function reset through the hotplug driver's slot_reset interface. A local user can request a reset for a PCI function to reset an unintended function and leak memory.

This occurs on s390 systems that expose the topology of multifunction PCI devices in a shared PCI domain.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/2050d900f9adbd6d6f38d30e182bcd9ad3108467
• https://git.kernel.org/stable/c/dcc5bec09e23bbc4f9de055a11fce9937244f2c8
• https://git.kernel.org/stable/c/ecdcceed4d377b02d4ea036b65f83f962c38ede7