SB2026081596 - Improper control of a resource through its lifetime in Linux kernel vhost driver

Description

This security bulletin contains information about 1 vulnerability.

1) Improper control of a resource through its lifetime (CVE-ID: CVE-2026-74356)

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

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 improper state management in vhost_get_avail_idx in the vhost subsystem when handling available ring entries with mergeable buffers enabled. A local user can trigger repeated processing of available entries to cause a denial of service.

The issue can lead to a host livelock when the guest is not making progress and notifications are re-enabled while entries remain in the ring.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/09861858a68342f851f71c669ac0f69865c32151
• https://git.kernel.org/stable/c/7f229d27bf27c7e589eca690d8612763a7a4801f
• https://git.kernel.org/stable/c/a9326b652bc7acd748d7a1143573845c7924d847
• https://git.kernel.org/stable/c/e115471008111f894c6528d9ab2ce7d0ce306f35