Missing Release of Resource after Effective Lifetime in Linux kernel - CVE-2026-98473

Vulnerability details

The vulnerability allows a local user to potentially cause a denial of service through leaked host resources.

The vulnerability exists due to missing resource release in the Linux kernel s390 vfio-ap reset-completion path when apq_status_check() encounters AP_RESPONSE_Q_NOT_AVAIL while checking a queue removed from the host's AP configuration. A local user can use a guest with interrupt handling enabled for the assigned queue under these removal conditions to leave KVM GISC registrations and pinned guest notification pages unreleased because apq_reset_check() does not perform the required cleanup, potentially exhausting host resources.

Affected software

How to mitigate CVE-2026-98473

External References

• https://git.kernel.org/stable/c/3c3433657c82f200dae36c29e2b80681c81b85be
• https://git.kernel.org/stable/c/65e05ec252a9b79e75930d3c4dd42d8877db04c5
• https://git.kernel.org/stable/c/cf441a0db681dfad5e89b015d6be11365159d7a9
• https://git.kernel.org/stable/c/da69d3ac53490724eba0ade9deb4e539a6ae9034

Related Security Bulletins

• Missing Release of Resource after Effective Lifetime in Linux kernel s390 crypto driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more