SB2026081693 - Use-after-free in Linux kernel x86 kvm

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-72283)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use-after-free in the KVM x86 irqfd bypass handling in arch/x86/kvm/irq.c when updating the interrupt remapping table entry for bypass fails. A local user can trigger the affected irqfd routing state to cause a denial of service.

The issue can occur when the irqfd remains reachable through KVM routing while the associated producer is freed separately, such as when a VFIO PCI vector is disabled independently of routing updates.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/d1379888cc4230bac647ec24ab83306afbd03e88
• https://git.kernel.org/stable/c/d5560b6569cd05ba72c6b33427fbabc6ec46b8cf
• https://git.kernel.org/stable/c/ed446e8aa894883c08892cfee69782fdf8f6c3ca